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Article

The Effect of Nut Oil Cakes on Selected Properties of Enriched Wheat Bread and Their Changes During Storage

by
Karolina Pycia
1,* and
Lesław Juszczak
2
1
Department of Food Technology and Human Nutrition, Institute of Food Technology and Nutrition, Faculty of Technology and Life Sciences, University of Rzeszów, Zelwerowicza 4, 35-601 Rzeszów, Poland
2
Department of Food Analysis and Evaluation of Food Quality, University of Agriculture in Krakow, Balicka Street 122, 30-149 Krakow, Poland
*
Author to whom correspondence should be addressed.
Appl. Sci. 2025, 15(23), 12591; https://doi.org/10.3390/app152312591
Submission received: 14 October 2025 / Revised: 19 November 2025 / Accepted: 25 November 2025 / Published: 27 November 2025
(This article belongs to the Special Issue Advances in Food Processing Technology: Enhancing Quality, Safety, and Sustainability)
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Abstract

The aim of this study was to evaluate selected parameters during storage of wheat bread enriched with hazelnut oil cake (HOC) or walnut oil cake (WOC) at levels of 5%, 10%, and 15%. Bread volume and specific volume, chemical composition, crumb moisture, crumb color in the CIE L*a*b* space, crumb texture, total phenolic content (TPC), and antioxidant activity were determined. Tests were conducted on days 1, 3, and 7 of storage. It was found that the HOC/WOC-enriched breads had lower volume and specific volume compared to the control bread. The addition of HOC or WOC improved the nutritional value of the bread, as they had higher protein, mineral, and dietary fiber contents and lower carbohydrate levels. Crumb moisture decreased during storage. The addition of HOC or WOC to the recipe increased crumb hardness while reducing elasticity and cohesiveness. During storage, an increase in hardness, a decrease in elasticity and cohesiveness, and a darker crumb were observed. The enriched breads were characterized by significantly higher TPC and AA contents, and the values of these parameters increased with the addition of nut oil cake. However, the TPC decreased significantly during storage.

1. Introduction

Bread is a leading cereal product, still a staple in the daily diet of most societies. Estimates suggest that daily bread consumption averages 250 g per person [1]. Most breads are made with refined flour, which is very low in vitamins, minerals, dietary fiber, and bioactive substances with proven antioxidant potential. These valuable health-promoting substances are found in bran and germ, which are by-products of grain milling [2]. Although bread made from refined wheat flour has a high nutritional density and high caloric value, it also has a low content of biologically active compounds, which are important in preventing a number of diet-related diseases with which modern society struggles [3].
In the daily diet, wheat bread is primarily a source of carbohydrates, protein, and minerals, while providing only 2–3% dietary fiber. Therefore, from a functional and health-promoting perspective, it is advisable to improve the nutritional value of bread using various plant ingredients rich in phytochemicals. Common technological practice involving replacing part of the flour with other plant ingredients, leading to increased nutritional value or specific functional properties. Moreover, contemporary research trends are focused on the development of enriched products that can be labeled as “clean label” [1,4]. In the food industry, this term refers to products made from natural ingredients without additives but including natural preservatives [4]. Bread with this label should contain only natural ingredients. Artificial enhancers, colors, flavors, and preservatives are excluded.
Functional bakery products such as enriched wheat bread are a good response to contemporary global challenges related to food waste and the need to manage by-products from the food industry, such as bran, pomace, or oil cake [5]. The effective use of by-products valuable in terms of nutritional value and health-promoting properties, and the development of integrated food products, are consistent with the concept of a circular economy, promoting the effective management of by-products [1,6]. Nut oil cakes are an interesting by-product from the agri-food industry.
Nut oil cakes are a by-product of cold-pressing fat from oilseeds [7]. Hazelnut and walnut-based oil cakes are also interesting in terms of nutritional value and sensory characteristics. The literature provides examples of innovative food products such as bread [8], cookies, and pasta [7], in which some of the flour has been replaced with oil cakes, primarily from walnuts.
Walnuts have a number of health-promoting properties, primarily resulting from their high content of essential unsaturated fatty acids from the n-3 and n-6 groups. They contain tocopherols and other phytochemicals that lower LDL cholesterol and increase HDL cholesterol [7,9]. Nutritive value-wise, walnuts are a good source of protein, carbohydrates, minerals, and, importantly, bioactive substances, crucial in the prevention of many diseases. In the case of walnuts, a large portion of the biologically active substances is found in the fat-free portion of the kernel. Therefore, after oil extraction, they are concentrated in the walnuts oil cakes (WOCs). According to many researchers [10,11,12], these substances exhibit antioxidant, antiatherosclerotic, anticancer, antibacterial, and antireplicative potential against HIV.
Hazelnut oil cake (HOC), a by-product of the oil pressing process from hazelnut kernels, is characterized by very high protein (average 47%) with very good digestibility (average 85%) and carbohydrate contents (average 42%) [13,14]. HOCs exhibit strong antioxidant properties due to the bioactive substances they contain. According to researchers, the polyphenol content in HOC ranges widely from 0.53 to 15.96 mg GAE/g of the extract. In the phenolic compound profile, compounds with very strong antioxidant potential were identified, such as quinic acid, quercetin-3-O-rhamnoside, (+)-catechin, catechol, glansreginin A, glansreginin B, syringic acid hexoside esters, procyanidin dimer, trimer, and tetramers [14,15]. The antioxidant activity of HOCs results from the chemical composition of hazelnut seed kernels. It has been shown that hazelnut seeds are characterized by a high content of polyphenols, and their profile includes, among others, gallic and chlorogenic acids, catechins, quercetin hexoside, kaempferol hexoside, and the ellagic acid pentoside [16]. Hazelnut or walnut oil cakes are a valuable, cheap, and readily available source of nutrients such as protein, as well as dietary fiber, minerals, and bioactive substances with documented health-promoting properties [7,13,14]. The addition of HOC or WOC to bread recipes can have a measurable impact on their nutritional value and functional properties.
Changing consumer preferences and growing market demands are driving changes in bread recipes and production technologies. Bread quality encompasses, among others, nutritional value, sensory characteristics, including palatability, shelf life, and various consumer perceptions of attractiveness [17]. However, bread is a perishable food product, and quality declines after baking. This is primarily due to water loss, the development of unfavorable microflora, and the complex staling process [17,18]. In the case of enriched breads, in which health-promoting ingredients have been intentionally added, it is important to understand their impact on changes in product quality during storage, including crumb quality. Lipids present in bread, due to the addition of oilseeds, have been shown to delay the process of amylopectin retrogradation and, consequently, crumb hardening [19]. Therefore, the inclusion of nut oil cakes changes the nutritional value of bread and increases its health-promoting properties through bioactive substances, which may also affect crumb quality. Pycia et al. [8] studied the effect of walnut oil and laboratory oil cakes remaining after pressing walnut kernel oil on the quality of wheat bread. However, there is no data on changes in the quality of wheat bread enriched with hazelnut or walnut oil cakes during storage.
The aim of the study was to assess the effect of enriching wheat bread with walnut and hazelnut oil cakes at different levels on its quality (i) and to assess the direction of quality changes occurring during storage (ii).

2. Materials and Methods

2.1. Research Material

The test material consisted of breads (B) made from wheat flour (type 650, Złote Pola, Gromadka, Poland), which were replaced with hazelnut (HOC) or walnut (WOC) oil cakes (Warmińska Manufaktura, Radostowo, Poland) at levels of 5%, 10%, and 15% (BHOC5%/BWOC5%, BHOC10%/BWOC10%, BHOC15%/BWOC15%) [13,20]. HOC and WOC are the ground residue left after cold-pressing oil from hazelnuts or walnuts, respectively [13,20]. The nutrition value of HOC (36.4 g/100 g d.m. protein content, 22.8 g/100 g d.m. fat content, 5.3 g/100 g d.m. ash content, 7.5% moisture content) and WOC (42.7 g/100 g d.m. protein content, 22.1 g/100 g d.m. fat content, 5.6 g/100 g d.m. ash content, 5.6% moisture content) was described in previous work [13]. The control sample was unfortified bread (control). In previous studies, the rheological properties of flour [20] and dough [13] based on these systems were characterized.

Bread Making and Storage Conditions

The dough was obtained via the direct method using yeast [21]. Baking was carried out at 230 °C. After baking, the breads were cooled for 24 h at 23 ± 1 °C. After this time, the loaves were analyzed, and those intended for storage testing were packed in plastic bags with controlled air access and stored at 23 ± 1 °C for 7 days. Analyses were performed on days 1, 3, and 7 of storage.

2.2. Research Methods

2.2.1. Chemical Composition Analysis of the Bread

The basic chemical composition of the control and enriched breads was determined according to the requirements of AACC standard methods [22]. During the analyses, the following components were determined: moisture (Method 44-15.02), protein by the Kjeldahl method (Nx6.25) (Method No. 46-12.01), fat (Method No. 30-25.01), and ash (Method 08-01.01). In addition, total dietary fiber was determined using the Megazyme Total Dietary Fiber Kit (Megazyme International Ireland Co., Ltd., Wicklow, Ireland) according to the AOAC Approved Method No. 991.43 [23]. Available carbohydrate content was calculated as the difference between 100% and the contents of moisture, protein, fat, ash, and dietary fiber. Energy value was estimated using conversion factors: 9 kcal/g for fat, 4 kcal/g for protein and carbohydrates, and 2 kcal/g for fiber [24]. The determinations were performed in triplicate, and the results are provided in (% d.m.).

2.2.2. Analysis of the Volume and Specific Volume of the Loaves

Twenty-four hours after baking, the mass and volume of the obtained bread loaves (cm3) were determined using a laboratory method based on the displacement of millet seeds [21,22,25]. The specific volume (cm3/g) was calculated based on the volume and mass of the bread loaves [21,26]. Photos of loaves and bread crumbs were also taken using a 6 MPix camera (Samsung, Suwon, Republic of Korea).

2.2.3. Analysis of Bread Crumb Color

Bread crumb color was evaluated using the UltraScan Vis spectrophotometer, illuminant D65 (HunterLab, Reston, VA, USA), using the reflectance method, and the results were expressed in the CIEL*a*b* color system. During the analysis, color coordinates were determined: L*, indicating lightness; a*, indicating red and green color saturation; and b*, indicating yellow–blue color saturation. Furthermore, the total color difference (∆E) between the control bread and the breads enriched with nut oil cakes was calculated. Color parameters were measured 24 h after baking and on days 3 and 7 of storage.

2.2.4. Analysis of Bread Crumb Texture

Texture analysis of the resulting breads was performed using the EZ-LX texturometer (Shimadzu, Kyoto, Japan) operated by Trapezium X Texture PL software v1.5.6 (Shimadzu, Kyoto, Japan). The analysis was performed using a 37 mm-diameter disk-shaped probe. Cubic crumb samples with 30 mm sides were used for measurements. The prepared crumb sample was compressed twice with a steel probe moving at a speed of 50 mm s−1 to half the initial sample height. The following parameters were determined: hardness (N), springiness (-), cohesiveness (-), and chewiness (N). Texturometric measurements were performed in four replicates on days 1, 3, and 7 of storage.

2.2.5. Analysis of Total Phenolic Content and Antioxidant Activity

The extract based on freeze-dried bread was used to determine the total phenolic content and antioxidant activity using the ABTS●+, DPPH●, and FRAP methods. To prepare the extract, 1 g of powdered freeze-dried bread was submerged in 10 mL of an 80% MeOH solution. The ultrasound-assisted extraction process was carried out in an ultrasonic bath for 30 min at 25–30 °C. The sample was then centrifuged for 10 min at 7000× g. The clear extract was used for analysis. The total polyphenol content in the methanol extracts was determined using the Folin–Ciocalteu reagent method [21,27]. The total polyphenol content was expressed in mg GAE (gallic acid equivalent)/100 g d.m.
The antioxidant activity of the obtained extrudates was analyzed via the ABTS●+ cation radical method [21,28] and the DPPH● [29] and FRAP methods [21,30]. Spectrophotometric measurements were performed using the Nicolet Evolution 300 Type U-2900 UV-VIS spectrophotometer (HitachiThermo, Waltham, MA, USA). The antioxidant activity of the tested control and enriched breads was expressed in mmol TE (Trolox Equivalent)/100 g d.m. Analyses were performed in triplicate on days 1, 3, and 7 of storage.

2.2.6. Statistical Analysis

All statistical analyses were carried out using the Statistica 13.3 program (TIBCO Software Inc., Santa Clara, CA, USA). Experimental data are shown in tables as means ± SD. All test results were subjected to two-way and three-way MANOVA. The significance of differences between mean values was assessed at the significance level of 0.05. Moreover, Pearson’s linear correlation coefficients were determined between the parameters of bread after 1 day.

3. Results and Discussions

3.1. Basic Chemical Composition

Table 1 summarizes the content of selected substances determining the nutritional and energy value of the resulting breads. It was found that the addition of HOC or WOC statistically significantly (p < 0.05) increased the average protein content in bread by 24.34% and 33.90%, respectively. This is probably due to the presence of significant amounts of protein in HOC/WOC at the level of 36.4% and 42.7%, respectively [13]. Kowalczewski et al. [31] also observed a protein content increase in bread enriched with strawberry oil cakes (by 12.33%) or raspberry oil cakes (by 3.77%) compared to the control sample. Wójcik et al. [25] similarly demonstrated an increase in protein levels regarding low-carbohydrate bread with the addition of defatted walnut flour. Pop et al. [7], however, did not observe an increase in protein content in pasta containing up to 50% walnut oil cake. Small changes were observed in fat content, which was low in enriched breads, averaging 2.68%. Statistical analysis showed that the percentage of HOC or WOC in the bread and interactions between factors significantly affected the content of this nutrient. The presence of HOC or WOC increased fat content by an average of 30% and 43% compared to the control sample. In the previous work [13], it was shown that the fat content in HOC and WOC was 22.8 g/100 g d.m. and 22.1 g/100 g d.m., which probably influenced the fat content in the tested breads. Furthermore, an increase in ash content and, importantly, dietary fiber content was also observed (Table 1). This is consistent with the observations of other authors examining the nutritional value of bread enriched with various fruit oil cakes [31]. Pop et al. [7] found no effect of walnut cake addition on the ash content in pasta. However, walnut oil cake is a rich source of various minerals, especially potassium, phosphorus, calcium, and magnesium [7,32,33]. Pop et al. [7] reported that the average content of K, P, Ca, and Mg in WOC was 506.88 mg/100 g, 267.37 mg/100 g, and 128.24 mg/100 g, respectively. However, according to Bernardes et al. [33], WOC contains minerals such as potassium (7276 mg/kg), phosphorus (5157 mg/kg), iron (89 mg/kg), or zinc (38 mg/kg) and copper (38 mg/kg). Pop et al. [7] claim that the content of minerals in nut oil cakes is influenced by numerous factors, the most important of which are genetic factors, varieties, degree of maturity, agro-technical conditions, but also analytical methods used for their detection. Dietary fiber is an extremely important ingredient in functional products. Consuming fiber-rich foods contributes to improved digestive and cardiovascular health and protects against cancer. Recommendations for fiber intake vary, but for adults, the average is 25–30 g/day. For residents of Europe and North America, excellent sources of dietary fiber include vegetables, whole grains, and nuts [34]. The results of two-way analysis of variance indicate that the level of flour substitution with HOC/WOC oil cakes had a significant (p < 0.001) effect on the total dietary fiber (TDF) content of bread. The type of oil cake and interactions between factors did not significantly affect the content of this component. However, it was found that the addition of oil cake to the bread recipe at the 15% level more than doubled the fiber content compared to the control sample. The addition of HOC or WOC significantly (p < 0.05) increased the TDF content by an average of 60% and 66%, respectively, compared to the control sample. This is consistent with the observations of other authors examining the nutritional value of food products enriched with oil cakes from various oilseeds. Pop et al. [7] demonstrated a 55% increase in crude fiber in pasta after a 50% addition of WOC. Wójcik et al. [25] determined the dietary fiber content in low-carbohydrate bread enriched with defatted walnut flour at a relatively high level of 45.28% DM (20% share). According to the cited authors, the control sample had a 46.41% DM content of this ingredient. Nut oil cakes positively impacted the health-promoting properties of the resulting breads. It should be noted that, in accordance with Regulation (EC) No. 1924/2006 of the European Parliament and of the Council of 20 December 2006 [35] on nutrition and health claims made on foods, all manufactured breads could be labeled with a nutrition claim indicating that the food is high in dietary fiber. Breads enriched with HOC/WOC are even more deserving of this type of nutritional claim. Therefore, the resulting bakery products can be an example of a functional food with a high dietary fiber content, intended for individuals suffering from overweight or obesity or other diet-related diseases for which high-fiber products are recommended in prevention or treatment. The obtained research results indicate that hazelnut or walnut oil cake is a recipe ingredient that increases the level of dietary fiber. This is a valuable property from the perspective of the possibility of developing functional foods with increased dietary fiber content, containing both insoluble and soluble fractions [7].
The carbohydrate content in the breads ranged from 60.65% (BWOC15%) to 75.13% (control). Enriched breads had a lower content of these components. Two-factor analysis of variance showed that the share of HOC or WOC statistically significantly (p < 0.001) affected the carbohydrate level. Their content decreased as the HOC/WOC ratio increased. This is due primarily to the increased levels of protein and dietary fiber in the enriched breads. This is consistent with the observations of other authors. Pop et al. [7] showed that the average carbohydrate content in WOC-enriched pastas was 67.35%, and their content decreased with increasing the share of oil cake. A similar tendency was observed by Kowalczewski et al. [31] and Wójcik et al. [25] when examining the nutritional value of bread enriched with strawberry or raspberry oil cakes and defatted walnut flour, respectively.
The energy value of the resulting breads was also calculated based on the content of individual ingredients. Two-factor analysis of variance revealed no significant (p > 0.05) effect of either the type of nut oil cake or its percentage on the energy value of the tested bread. The average energy value of the resulting breads was 379.24 kcal/100 g, resulting primarily from the high protein and carbohydrate content, and low fat content. Cereal products such as bread and pasta are characterized by a high energy value. However, in the case of the resulting breads, their increased protein and dietary fiber content is a significant advantage. Information on the energy value of food is important for planning a healthy diet but also for people struggling with overweight or obesity. Pop et al. [7] found that adding hazelnut oil cake to pasta reduced the energy value by 8%. According to the cited authors, this is an important observation from the perspective of overweightness and obesity and the related need to consume foods with a reduced energy value. A diet based on high-energy foods generally promotes the development of overweight and obesity in the long term [36].
The results were subjected to Pearson correlation analysis. A strong, significant (p < 0.05) correlation was found between protein content and fat, dietary fiber, and carbohydrate content (r = 0.97, r = 0.94, r = −0.98, respectively). Furthermore, fat content correlated significantly (p < 0.05) with carbohydrate content and TDF (r = −0.95, r = 0.89, respectively), and the correlation coefficient between TDF and carbohydrate content was r = −0.98 (p < 0.05). Furthermore, a significant (p < 0.05) linear correlation was found between bread loaf volume and ash content, TDF, and carbohydrate content (r = −0.92, r = −0.89, r = 0.86, respectively).

3.2. Volume and Appearance of the Loaves

Loaf volume is one of the most important parameters determining bread quality. It indirectly indicates the degree of retention and retention of gases produced during dough fermentation but also influences consumer acceptance of bread. Consumers generally prefer bread with a large volume and a soft and elastic crumb. Smaller loaves, on the other hand, tend to have a firmer crumb but also a lower glycemic index [3]. Two-factor analysis of variance showed that the volume and specific volume of the resulting loaves depended significantly (p < 0.001) on the type of oil cake and the level of flour substitution. The volume of the loaves was found to range from 373 cm3 (BHOC15%) to 560 cm3 (control) (Figure 1A). The specific volume associated with this parameter also ranged from 1.7 cm3/g (BHOC15%) to 2.7 cm3/g (control) (Figure 1B). Therefore, the HOC/WOC-enriched breads were characterized by significantly lower volume compared to the control bread. Both the volume and the specific volume decreased with increasing the share of nut oil cake in the bread recipe. This is likely due to the introduction of higher amounts of protein and fiber into the bread through nut oil cake, which can potentially cause defects in the gluten network, limiting the ability to retain fermentation gases. de Lamo and Gomez [19] argue that fiber, especially cellulose, and plant proteins generally reduce the specific volume of bread, which becomes more compact. The observations described in this paper are consistent with the conclusions of other authors. A reduction in the volume of bread loaves following the addition of laboratory walnut oil cakes and walnut flour was observed by Pycia et al. [8] and Chochkov et al. [37], respectively. Wójcik et al. [25] argue that the addition of defatted walnut flour (WF) to bread caused a significant increase in loaf volume. The cited authors claim that WF strengthened the dough structure but also the crumb hardness. The fiber and protein present in WF are characterized by high water absorption, which strengthens the dough structure, gas retention capacity, and water retention [25]. However, according to Hamdane et al. [38] and Nawrocka et al. [39], fiber competes with gluten and starch for water and can thus disrupt and hinder the hydration of these substances. As a result, it adversely affects the structure of the dough and the quality of the finished product. The gluten matrix formed in dough is crucial for the rheological properties of the dough and the quality of the finished product. Enriching ingredients can adversely affect the dough’s microstructure and texture. Therefore, breads enriched with plant additives are typically characterized by a smaller volume and increased crumb hardness [1]. The appearance of the control and HOC/WOC-enriched loaves is shown in Figure 2. The images clearly show a decrease in the volume of the loaves of bread due to the HOC/WOC addition. Furthermore, increasing the degree of flour substitution resulted in a significant darkening of the crumb color. The numerical data demonstrating these changes are provided in Table 2.

3.3. Color and Moisture of Bread Crumb During Storage

Qualitative changes during the 7-day storage of bread include, among others, changes in the color of the crumb and the moisture content of the bread. In Table 2, a summary is provided regarding the determinants of fresh bread crumb color and changes in the values of these parameters during storage. It was observed (Figure 2) and demonstrated, based on the measured parameters L*, a*, and b*, that replacing part of the wheat flour with hazelnut (HOC) or walnut (WOC) oil cakes resulted in a clear, statistically significant change in bread crumb color. Bread enriched with HOC or WOC changed the color to a darker one, as evidenced by significantly lower values of the L* parameter, which reflects the degree of lightness. It was also shown that the mean values of the L* parameter decreased with increasing HOC or WOC content in the bread. Therefore, the BHOC15% and BWOC15% breads had the darkest crumb. Furthermore three-factor analysis of variance revealed a statistically significant effect concerning the type of nut oil cake, the amount of nut oil cake in the bread recipe, i.e., the degree of wheat flour substitution, storage duration, and the majority of factor interactions on the L* parameter values of the bread crumb (p < 0.001) (Table 2). Crumb color depends to a greater extent on the recipe ingredients.
Table 2. Results for the color parameters for crumbs of breads supplemented with nut oil cakes.
Table 2. Results for the color parameters for crumbs of breads supplemented with nut oil cakes.
SamplesL*a*b*∆E
1 day
control69.97 ± 0.78 k1.83 ± 0.32 b20.61 ± 0.75 i-
BHOC5%60.98 ± 1.54 jk2.87 ± 0.13 c13.77 ± 0.16 c11.43 ± 1.79 a
BHOC10%57.82 ± 1.28 fgh4.10 ± 0.16 d13.14 ± 0.05 b14.44 ± 1.08 bc
BHOC15%56.50 ± 0.33 f4.81 ± 0.11 e13.23 ± 0.23 b15.67 ± 0.44 cd
BWOC5%52.75 ± 0.60 d6.83 ± 0.07 i15.67 ± 0.16 e18.52 ± 0.38 g
BWOC10%48.64 ± 1.16 c6.60 ± 0.06 hi16.51 ± 0.35 f21.82 ± 1.27 a
BWOC15%47.16 ± 0.35 b6.67 ± 0.12 i17.37 ± 0.24 g23.56 ± 0.57 j
3 day
control71.84 ± 0.23 l1.60 ± 0.08 a19.59 ± 0.40 h-
BHOC5%59.86 ± 0.42 ij2.84 ± 0.04 c13.43 ± 0.32 bc13.52 ± 0.65 b
BHOC10%58.48 ± 1.19 gh3.92 ± 0.08 d12.44 ± 0.18 a15.33 ± 1.44 cd
BHOC15%57.17 ± 0.69 fg4.67 ± 0.30 e12.57 ± 0.32 a16.55 ± 0.60 de
BWOC5%55.00 ± 0.49 e6.25 ± 0.15 g14.47 ± 0.34 d18.21 ± 0.51 fg
BWOC10%49.04 ± 0.71 c6.36 ± 0.23 g15.53 ± 0.33 e23.64 ± 0.61 j
BWOC15%49.84 ± 0.71 c6.23 ± 0.21 g16.99 ± 0.49 g22.64 ± 0.57 ij
7 day
control71.91 ± 0.76 l1.86 ± 0.20 b19.53 ± 0.95 h-
BHOC5%61.74 ± 0.46 k3.02 ± 0.06 c13.56 ± 0.06 bc11.88 ± 0.54 a
BHOC10%58.74 ± 0.20 hi3.92 ± 0.07 d12.37 ± 0.10 a15.17 ± 0.23 c
BHOC15%56.72 ± 0.51 f4.70 ± 0.05 e12.33 ± 0.12 a17.08 ± 0.56 fg
BWOC5%51.49 ± 0.30 d6.62 ± 0.05 hi14.33 ± 0.22 d21.62 ± 0.31 hi
BWOC10%52.23 ± 0.70 d5.96 ± 0.11 f15.70 ± 0.05 e20.49 ± 0.74 h
BWOC15%45.81 ± 0.48 a6.41 ± 0.19 gh16.33 ± 0.08 f26.70 ± 0.48 k
three-way MANOVA p-values
Factor 1p < 0.001p < 0.001p < 0.001p < 0.001
Factor 2p < 0.001p < 0.001p < 0.001p < 0.001
Factor 3p < 0.001p < 0.001p < 0.001p < 0.001
Factor 1 × factor 2p = 0.030p < 0.001p < 0.001p < 0.001
Factor 1 × factor 3p < 0.001p < 0.001p = 0.034p < 0.001
Factor 2 × factor 3p < 0.001p < 0.001p = 0.127p < 0.001
Factor 1 × factor 2 × factor 3p < 0.001p = 0.070p = 0.017p < 0.001
Data presented as means ± standard deviations from triplicate analyses. Values of each parameter with different superscript letters in the columns are significantly different (p < 0.05) (Duncan’s test). Factor 1: type of nut oil cake; Factor 2: share of nut oil cake; Factor 3: storage time. Mean values marked with different letters differ statistically significantly (p < 0.05).
In the case of the a* parameter, which reflects the proportion of red (a* > 0) and green (a* < 0), and the b* parameter, which is related to the balance of blue (b* < 0) and yellow (b* > 0) colors, changes were also observed due to the presence of nut oil cakes in the bread recipe. It was found that the red color was higher in the crumb of BHOC and BWOC breads compared to the bread without additives. Furthermore, the b* parameter values indicate that the crumb color was less yellow compared to the control sample. It was shown that during storage, the values of the color determinants L*, a*, and b* underwent small but statistically significant (p < 0.001) changes. After 7 days of storage, the values of the L*, a*, and b* parameters generally decreased compared to those determined 24 h after baking (Table 2). The total color difference (∆E) for the bread crumbs ranged from 11.43 (BHOC5%) to 23.56 (BWOC15%). This parameter increased with increasing HOC or WOC content in the bread recipe and assumed statistically significantly (p < 0.05) higher values for breads containing WOC. During storage, changes in the value of this parameter were observed, resulting from changes in the L*, a*, and b* color determinants. The ∆E parameter indicates the ability to visually perceive differences in the product’s color compared to the control sample. ∆E values in the range of 0–2 prevent the recognition of differences between samples. On the other hand, values of this parameter in the range of 2 to 3.5, and, according to some authors [40], even up to 3, enable the identification of differences even by an inexperienced observer [25,41]. On the other hand, ∆E greater than 3.5 indicates that color differences are significant [25,41]. Therefore, in the analyzed case, all enriched breads had ∆E values much greater than 3.5, which points to a very distinct color difference noticeable by consumers compared to unenriched bread. Therefore, enriching wheat bread with nut oil cakes clearly changed the color of both the crust and the bread crumb. These observations are consistent with the results of previous studies [8,42] and with the results of other authors [12,25]. Pycia et al. [8] and Pycia and Ivanisova [42] observed a darkening of the crumb color of wheat bread enriched with laboratory walnut oil cakes at the level of 3%, 6%, and 9%, as well as with ground hazelnuts or walnuts, respectively. Furthermore, Bakalbbasi et al. [12] and Wójcik et al. [25] also noted a reduction in brightness and an increase in red and yellow color in the dough and crumb of low-carbohydrate bread, respectively, due to the addition of walnut oil cake and walnut flour. Furthermore, Kowalczewski et al. [31], examining the effect of strawberry and raspberry oil cake on the crumb color of wheat bread, found a reduction in the L* and b* parameters and an increase in the a* and ∆E parameters in the enriched bread compared to the control. According to the cited researchers, this results from the presence of anthocyanin pigments in the fruit oil cake. Color changes in products exposed to walnut oil cake or defatted nut flour are caused by the presence of carotenoids and flavonoids, naturally occurring in nuts, as well as the presence of their transformation/degradation products under the influence of temperature during baking. The color of wheat bread is indirectly due to the color of wheat flour, which is determined by the content of carotenoids, fiber, and protein [43] but also by changes during baking. The color changes observed during storage are associated with changes in the biochemical and physicochemical nature of the bread crumb. Water loss due to evaporation and water redistribution, as well as complex changes related to bread staling, likely contribute to the darkening of the crumb color. Furthermore, a darker color may not necessarily be perceived as unfavorable, as informed consumers associate darker bread color with higher nutritional value and biologically active substance content.
Bread crumb moisture is a determinant of its quality, and its value depends on storage time and conditions. It was found that crumb moisture significantly (p < 0.05) depend on bread storage time (Figure 3). The HOC or WOC content and other factor interactions did not affect the values of these parameters (p > 0.05). The average moisture content of fresh bread was 40.28%, and during storage it decreased by 12% (3 days) and 22% (7 days). Novotni et al. [44] also observed a decrease in crumb moisture during bread storage, but the cited authors did not find a significant effect of packaging type.
The decrease in bread moisture content during storage is a natural, yet complex, process. It involves water evaporation from the bread surface, its migration from deeper layers of the crumb towards the crust, and, importantly, the entire bread staling process. Water migration and starch retrogradation are the main processes associated with bread staling. During retrogradation, amylose retrogrades first, followed by amylopectin. This results in the formation of a crystalline amylopectin structure, accompanied by a decrease in water binding capacity [17]. Furthermore, the formation of complexes between starch, proteins, and fats can slow the rate of bread aging. Dough components such as protein and fiber can play a significant role in retaining water in the dough. Consequently, if water in the dough is retained by these components, its redistribution during storage does not occur or occurs more slowly and to a lesser extent, preventing the crumb from losing moisture as quickly. In the presented studies, a decrease in crumb moisture was observed during storage, which may be due, among other things, to the insufficient presence of components capable of retaining water. Furthermore, during starch retogradation and recrystallization, water is forced out of its structure due to the strengthening of the structure by hydrogen bonds and the formation of new crystalline structures.

3.4. Bread Texture Results

Texture is a comprehensive concept combining mechanical, geometric, and surface characteristics of the product. It is expressed using parameters reflecting the structure of the food and its changes under the influence of applied mechanical forces [45,46]. During bread storage, a number of unfavorable changes occur, such as water migration from the crumb to the crust, aroma loss, textural changes associated with increased hardness, and generally loss of crumb cohesion. As a result of retrogradation and water loss, bread becomes hard, dry, and crumbly, which is negatively perceived by consumers and generates economic losses. The scale and rate of bread staling is a function of the production process, including recipe ingredients, packaging methods, and storage conditions [44,47]. A summary regarding the values of texture parameters for the control and enriched breads after baking is given in Table 3, while in Figure 4 trends are shown concerning changes in texture parameters during storage. The basic parameter of TPA analysis used to assess bread quality and its changes during storage is hardness. It was found that the crumb hardness of the bread enriched with nut oil cakes was higher than that of the control sample, and the value of this parameter increased with increasing flour substitution with increasing storage time. This is consistent with the observations of other authors examining the texture of bread enriched with fruit oil cakes [31], laboratory WOC [8], and defatted nut flour [25]. Three-factor analysis of variance (MANOVA) indicated a statistically significant effect of all tested factors (p < 0.001) and most of their interactions on crumb hardness (Table 3). Crumb hardness depends on the type and amount of recipe ingredients, crumb porosity, as well as storage time and conditions. Typically, recipe ingredients that are water-absorbing increase crumb moisture. In this system, water, acting as a plasticizer, hydrates the crumb, which becomes softer [3]. The increase in crumb hardness during storage is likely related to water migration into the crust. Crumb moisture was found to decrease significantly (p < 0.05) during subsequent days of storage (Table 3). Another reason for the increasing crumb hardness is starch retrogradation and moisture loss during staling [48]. Moreover, the increase in bread crumb hardness during the staling process results from the formation of weak cross-links, which are hydrogen bonds between swollen starch granules and denatured gluten [17]. Moisture loss occurs during storage, which is associated with an increase in the bread’s cohesive strength and hardness. This increase in hardness is primarily due to the retrogradation of amylopectin and the redistribution or loss of water. After baking, amylopectin occurs in a plasticized, amorphous form. However, during bread storage, the reverse process occurs: amylopectin recrystallization. Reorganization of the side chains of this starch fraction causes the formation of double helices, creating an ordered structure, which is manifested by increased hardness, stiffness, and loss of crumb elasticity. Furthermore, due to the retrogradation process, an increased formation of type B crystalline polymorphs is observed, which are capable of immobilizing more water molecules compared to type A crystals, further increasing the hardness of the bread crumb [49]. According to Wójcik et al. [25], the introduction of plant additives to bread recipes usually reduces the volume of loaves, which is associated with increased crumb hardness. Furthermore, Kowalczewski et al. [31] found that enriching bread with plant additives rich in protein and dietary fiber promotes increased hardness and decreased crumb elasticity. This is reflected in the presented research results. The increased hardness of breads containing nut oil cakes may result from competition for water between gluten and the oil cake’s components, such as protein and fiber. This leads to a weakening of the gluten network, reduced bread volume, and increased crumb hardness. In the case of fresh bread (1 day), all types containing HOC/WOC were characterized by a statistically significantly (p < 0.05) lower crumb elasticity compared to the control sample. During storage, the crumb elasticity of all bread types decreased. A similar situation occurred with crumb cohesion. The values of this parameter were statistically significantly (p < 0.001) influenced by all analyzed factors. Wójcik et al. [25] generally observed an increase in cohesion, elasticity, and chewiness of the crumbs from low-carbohydrate bread with an increasing percentage of defatted walnut flour. Crumb chewiness did not depend on the percentage of oil cake in the bread (p = 0.875). The highest chewiness was observed in the control and the 15% BHOC sample. However, the presence of HOC/WOC in the bread reduced the value of this parameter. A decrease in crumb chewiness was generally observed during storage, similar to cohesiveness and elasticity (Figure 3). Meanwhile, according to other authors, crumb chewiness of low-carbohydrate bread increased with the addition of walnut flour [25] and strawberry or raspberry oil cake [31]. According to Kowalczewski et al. [31] chewiness reflects the energy required to chew food in the mouth and depends on the cohesiveness and elasticity of the product.
Statistical analysis indicated significant linear correlations between parameters illustrating bread crumb texture and other parameters determined in the study. A correlation was found between hardness and ash content as well as loaf volume (r = 0.97, r = −0.84, p < 0.01). Crumb elasticity correlated with TDF, carbohydrate content, loaf volume, specific volume, and the L* parameter of the crust (r = −0.88, r = 0.85, r = 0.81, r = 0.83, r = 0.85, p < 0.05, respectively). Cohesiveness, in turn, correlated with protein, fat, TDF, and carbohydrate content (r = −0.97, r = −0.92, r = −0.89, r = 0.94, p < 0.05, respectively).

3.5. Total Phenolic Content and Antioxidant Activity

In Figure 5, the parameters illustrating the total phenolic content (TPC) and antioxidant potential (AA) of the control and enriched breads, as well as changes in these parameters during storage, are presented. Three-way analysis of variance demonstrated a statistically significant (p < 0.001) effect of all tested factors and their interactions on the TPC and AA of the breads. Ozdemir et al. [14] reported that HOCs are a very valuable ingredient in terms of their antioxidant properties as a by-product. This is due to the phenolic compound content ranging from 0.53 to 15.96 mg GAE/g of extract. The most common phenolic compound profile includes quinic acid, quercetin-3-O-rhamnoside, catechins and their derivatives (+)-catechin, catechol, glansreginin A, glansreginin B, hexose esters of syringic acid, procyanidin dimers, trimers, and tetramers [14,50]. Furthermore, Bakkalbasi et al. [12] also emphasize the high antioxidant potential of WOC, resulting mainly from the presence of ellagitannins and other phenolic compounds in the residue after pressing walnut fat. Polyphenol content in the walnut cakes (WOC) used were characterized by a significantly higher content of total polyphenols compared to the hazelnut cakes (HOC)–1685 mg GAE/100 g d.m. and 170 mg GAE/100 g d.m., respectively [51]. Therefore, valorization of food products with HOC/WOC should promote increased TPC and AA. With respect to fresh breads (1 day) differing in the level of HOC/WOC substitution, TPC ranged widely from 40.77 mg GAE/100 g d.m. (control) to 224.92 mg GAE/100 g d.m. (BWOC15%). In turn, AA determined by the ABTS•+, DPPH•, and FRAP methods ranged from 0.42 mmol TE/100 g d.m. (control) to 2.68 mmol TE/100 g d.m. (BWOC15%); from 0.42 mmol TE/100 g d.m. (control) to 5.87 mmol TE/100 g d.m. (BWOC10%); and from 0.05 mmol TE/100 g d.m. (control) to 0.71 mmol TE/100 g d.m. (BWOC15%), respectively. TPC and AA increased statistically significantly (p < 0.05) with increasing HOC/WOC content in bread. The control sample was characterized by a low content of total polyphenols and the associated AA. This is due to the presence of ferulic acid in wheat flour-based bread [8,12] and small amounts of caffeic, coumaric, and sinapic acids [8]. Moreover, during bread baking, Maillard reaction products are formed, especially those with low molecular weight characterized by high AA [12]. Pop et al. [7] also found a significant increase from TPC and AA in pasta enriched with walnut oil cakes. According to the cited authors, TPC in walnut oil cakes depends on the conditions prevailing during the nut vegetation (temperature, precipitation) but also on the degree of ripeness and storage conditions. Furthermore, there are other known examples indicating that the TPC of bread increased when wheat flour was substituted with defatted walnut flour [25]. It was shown that during storage, especially after 7 days of storage, the TPC and AA of all tested breads decreased statistically significantly (p < 0.001) by an average of 53% and 64% (ABTS•+ method). This is consistent with the observations of Novotni et al. [44] and Yalcin [52] who examined changes in TPC and AA of stored bread. Phenolic compounds have strong antioxidant potential and inhibit lipid oxidation, which is accelerated by food exposure to light. As a result, the content of phenolic compounds decreases [44]. According to Yalcin [52], the instability of phenolic compounds under the influence of light and oxygen in the air decreases with regard to the series ferulic acid ˃ p-coumaric acid ˃ chlorogenic acid ˃ cinnamic acid ˃ gallic acid ˃ syringic acid ˃ vanillic acid. TPC in bread affects its oxidative stability. As the content of polyphenols in bread decreases, fat oxidation processes intensify, and their volatile products adversely affect the aroma of bread [44].
A significant correlation was found between TPC and crumb moisture, parameters illustrating the antioxidant potential of ABTS•+, DPPH•, and FRAP, as well as crumb color parameters L*, b*, and ∆E (r = −0.95, r = 0.98, r = 0.93, r = 0.98, r = −0.94, r = 0.93, r = 0.95, p < 0.05, respectively). Furthermore, the ABTS•+ parameter correlated with crumb moisture (r = −0.94, p < 0.05), with the DPPH•, FRAP parameter, and crumb color parameters L*, b*, and ∆E (r = 0.97, r = 0.99, r = −0.96, r = 0.94, r = 0.95, p < 0.05, respectively), whereas the DPPH• parameter correlated with crumb moisture (r = −0.91, p < 0.05), with the ABTS•+, FRAP parameters, and crumb color parameters L*, b*, ∆E and (r = 0.97, r = 0.97, r = −0.94, r = 0.93, r = 0.93, p < 0.05, respectively). It was also shown that the FRAP parameter correlated with crumb moisture (r = −0.96, p < 0.05), with the ABTS•+, DPPH• parameter, and crumb color parameters L*, a*, b*, and ∆E (r = 0.99, r = 0.97, r = −0.97, r = −0.81, r = 0.96, r = 0.96, p < 0.05, respectively).

4. Conclusions

Bakery products enriched with plant-based additives of interest in terms of nutritional value and health-promoting properties are an important group of functional foods. The attempt to enrich bread with hazelnut or walnut oil cakes at various levels, undertaken in this study, demonstrated that these by-products improve the nutritional value of bread and its antioxidant potential. Nut oil cakes, a by-product of the fat extraction process, are a valuable source of protein, dietary fiber, and bioactive substances with documented antioxidant potential, essential for reducing free oxygen radicals. The introduction of HOC or WOC was shown to increase the levels of protein, fat, minerals, and, importantly, dietary fiber. This content allowed the bread to be labeled with the nutritional claim “high fiber.” However, the storage studies conducted confirmed expected quality changes, such as darkening of the crumb, loss of crumb moisture, increased crumb hardness, and decreased elasticity or cohesiveness. Total polyphenol content and antioxidant potential also decreased significantly. Therefore, the presence of cakes did not halt these unfavorable changes. In the case of fresh bread, the most beneficial level of HOC or WOC in terms of health-promoting properties is 15%, but these breads were also characterized by the smallest volume and the highest crumb hardness. The results of the conducted research indicate that wheat bread enriched with hazelnut or walnut oil cakes can be a functional bakery product that supports consumer health, the sustainable development of the food industry, and helps reduce the problem of by-products in the agri-food industry. Further research is warranted on the bioavailability of substances from this type of functional bakery product, as well as the oxidative stability of bread containing HOC/WOC due to the presence of unsaturated fatty acids in nut oil cakes.

Author Contributions

Conceptualization, K.P.; Methodology, K.P.; Formal Analysis, K.P.; Investigation, K.P.; Resources, K.P.; Data Curation, K.P.; Writing—Original Draft Preparation, K.P. and L.J.; Writing—Review and Editing, K.P. and L.J.; Visualization, K.P.; Supervision, K.P.; Funding Acquisition: K.P. All authors have read and agreed to the published version of the manuscript.

Funding

The project is financed by the program of the Minister of Education and Science named “Regional Initiative of Excellence” in the years 2019–2023, project number 026/RID/2018/19, the amount of financing PLN 9,542,500.00.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Data sets generated during the current study are available from the corresponding author upon reasonable request.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Zarzycki, P.; Wirkijowska, A.; Pankiewicz, U. Functional Bakery Products: Technological, Chemical and Nutritional Modification. Appl. Sci. 2024, 14, 12023. [Google Scholar] [CrossRef]
  2. Kaim, U.; Goluch, Z.S. Health Benefits of Bread Fortification: A Systematic Review of Clinical Trials according to the PRISMA Statement. Nutrients 2023, 15, 4459. [Google Scholar] [CrossRef]
  3. Cacak-Pietrzak, G.; Dziki, D.; Gawlik-Dziki, U.; Sułek, A.; Wójcik, M.; Krajewska, A. Dandelion Flowers as an Additive to Wheat Bread: Physical Properties of Dough and Bread Quality. Appl. Sci. 2023, 13, 477. [Google Scholar] [CrossRef]
  4. Vargas, M.C.A.; Simsek, S. Clean label in bread. Foods 2021, 10, 2054. [Google Scholar] [CrossRef]
  5. Day, D.; Richter, J.; Ek, P.; Gu, B.-J.; Ganjyal, G.M. Utilization of Food Processing By-products in Extrusion Processing: A Review. Front. Sustain. Food Syst. 2021, 4, 603751. [Google Scholar] [CrossRef]
  6. Jung, J.-M.; Kim, J.Y.; Kim, J.-H.; Kim, S.M.; Jung, S.; Song, H.; Kwon, E.E.; Choi, Y.-E. Zero-waste strategy by means of valorization of bread waste. J. Clean. Prod. 2022, 365, 132795. [Google Scholar] [CrossRef]
  7. Pop, A.; Păucean, A.; Socaci, S.A.; Alexa, E.; Man, S.M.; Muresan, V.; Chi, S.M.S.; Salantă, L.; Popescu, I.; Berbecea, A.; et al. Quality Characteristics and Volatile Profile of Macarons Modified with Walnut Oilcake By-Product. Molecules 2020, 25, 2214. [Google Scholar] [CrossRef] [PubMed]
  8. Pycia, K.; Kapusta, I.; Jaworska, G. Walnut oil and oilcake affect selected the physicochemical and antioxidant properties of wheat bread enriched with them. J. Food Process. Preserv. 2020, 44, e14573. [Google Scholar] [CrossRef]
  9. Anderson, K.J.; Teuber, S.S.; Gobeille, A.; Cremin, P.; Waterhouse, A.L.; Steinberg, F.M. Walnut polyphenolics inhibit in vitro human plasma and LDL oxidation. J. Nutr. 2021, 131, 2837–2842. [Google Scholar] [CrossRef]
  10. Lin, C.C.; Hsu, Y.F.; Lin, T.C.; Hsu, H.Y. Antioxidant and hepatoprotective effects of punicalagin and punicalin on acetaminophen-induced liver damage in rats. Phytother. Res. 2021, 15, 206–212. [Google Scholar] [CrossRef]
  11. Martino, V.; Morales, J.; Martinez-Irujo, J.J.; Font, M.; Monge, A.; Coussio, J. Two ellagitannins from the leaves of Terminalia triflora with inhibitory activity on HIV-1 reverse transcriptase. Phytother. Res. 2004, 18, 667–669. [Google Scholar] [CrossRef] [PubMed]
  12. Bakkalbasi, E.; Meral, R.; Dogan, I.S. Bioactive compounds, physical and sensory properties of cake made with walnut press-cake. J. Food Qual. 2015, 38, 422–430. [Google Scholar] [CrossRef]
  13. Pycia, K.; Juszczak, L. Rheological Characteristics of Wheat Dough Containing Powdered Hazelnuts or Walnuts Oil Cakes. Foods 2024, 13, 140. [Google Scholar] [CrossRef]
  14. Ozdemir, M.B.; Kılıçarslan, E.; Demir, H.; Koca, E.; Salum, P.; Berkta¸s, S.; Çam, M.; Erbay, Z.; Aydemir, L.Y. Upgrading the Bioactive Potential of Hazelnut Oil Cake by Aspergillus oryzae under Solid-State Fermentation. Molecules 2024, 29, 4237. [Google Scholar] [CrossRef]
  15. Acan, B.G.; Toker, O.S.; Palabiyik, I.; Rasouli Pirouzian, H.; Bursa, K.; Kilicli, M.; Yaman, M.; Er, T.; Konar, N. Physicochemical Properties of Chocolate Spread with Hazelnut Cake: Comparative Study and Optimization. LWT-Food Sci. Technol. 2021, 147, 111548. [Google Scholar] [CrossRef]
  16. Pycia, K.; Kapusta, I.; Jaworska, G. Changes in antioxidant activity, profile, and content of polyphenols and tocopherols in common hazel seed (Corylus avellana L.) depending on variety and harvest date. Molecules 2020, 25, 43. [Google Scholar] [CrossRef]
  17. Fik, M. Bread staling and methods of prolonging its freshness. Food Sci. Technol. Qual. 2004, 2, 5–22. (In Polish) [Google Scholar]
  18. Erdogdu-Arnoczky, N.; Czuchajowska, Z.; Pomeranz, Y. Functionality of whey and casein in fermentation and in breadbaking by fixed and optimized procedures. Cereal Chem. 1996, 73, 309–316. [Google Scholar]
  19. De Lamo, B.; Gómez, M. Bread Enrichment with Oilseeds. A Review. Foods 2018, 7, 191. [Google Scholar] [CrossRef]
  20. Pycia, K.; Juszczak, L. Influence of hazelnut and walnut oil cakes powder on thermal and rheological properties of wheat flour. Foods 2023, 12, 4060. [Google Scholar] [CrossRef] [PubMed]
  21. Pycia, K.; Pawłowska, A.M.; Kaszuba, J. Assessment of the Application Possibilities of Dried Walnut Leaves (Juglans regia L.) in the Production of Wheat Bread. Appl. Sci. 2024, 14, 3468. [Google Scholar] [CrossRef]
  22. AACC. American Association of Cereal Chemistry Approved Methods, 10th ed.; American Association of Cereal Chemists: Saint Paul, MN, USA, 2010; Available online: http://methods.aaccnet.org/toc.aspx (accessed on 10 May 2025).
  23. AOAC International. Official Methods of Analysis of AOAC International, 20th ed.; Association of Official Analytical Chemists: Gaithersburg, MD, USA, 2016. [Google Scholar]
  24. Culețu, A.; Susman, I.E.; Mult, E.M.; Cucu, S.E.; Belc, N. Corn Extrudates Enriched with Health-Promoting Ingredients: Physicochemical, Nutritional, and Functional Characteristics. Processes 2023, 11, 1108. [Google Scholar] [CrossRef]
  25. Wójcik, M.; Dziki, D.; Matwijczuk, A.; Gawlik-Dziki, U. Walnut Flour as an Ingredient for Producing Low-Carbohydrate Bread: Physicochemical, Sensory, and Spectroscopic Characteristics. Foods 2023, 12, 3320. [Google Scholar] [CrossRef]
  26. Bourekoua, H.; Różyło, R.; Gawlik-Dziki, U.; Benatallah, L.; Zidoune, M.N.; Dziki, D. Evaluation of physical, sensorial, and antioxidant propertiesof gluten-free bread enriched with Moringa Oleifera leaf powder. Eur. Food Res. Technol. 2018, 244, 189–195. [Google Scholar] [CrossRef]
  27. Gao, X.; Ohlander, M.; Jeppsson, N.; Björk, L.; Trajkovski, V. Changes in antioxidant effects and their relationship to phytonutrients in fruits of sea buckthorn (Hippophae rhamnoides L.) during maturation. J. Agric. Food Chem. 2000, 48, 1485–1490. [Google Scholar] [CrossRef]
  28. Re, R.; Pellegrini, N.; Proteggente, A.; Pannala, A.; Yang, M.; Rice-Evans, C. Antioxidant activity applying an improved ABTS radical cation decolorization assay. Free Radic. Biol. Med. 1999, 26, 1231–1237. [Google Scholar] [CrossRef]
  29. Yen, G.C.; Chen, H. Antioxidant activity of various tea extracts in relation to 434 their antimutagenicity. J. Agr. Food Chem. 1995, 43, 27–32. [Google Scholar] [CrossRef]
  30. Benzie, I.F.F.; Strain, J.J. The ferric reducing ability of plasma (FRAP) as a measure of antioxidant power: The FRAP assay. Anal. Biochem. 1996, 239, 70–76. [Google Scholar] [CrossRef]
  31. Kowalczewski, P.Ł.; Walkowiak, K.; Masewicz, Ł.; Duda, A.; Poliszko, N.; Różańska, M.B.; Jeżowski, P.; Tomkowiak, A.; Mildner-Szkudlarz, S.; Baranowska, H.M. Wheat bread enriched with raspberry and strawberry oilcakes: Effects on proximate composition, texture and water properties. Eur. Food Res. Technol. 2019, 245, 2591–2600. [Google Scholar] [CrossRef]
  32. Grosu, C. Mineral Composition of Walnut Kernel and Walnut Oil Cake; Academia de Studii Economice a Moldovei: Iasi, Romania, 2017; pp. 225–226. Available online: https://ibn.idsi.md/sites/default/files/imag_file/225-226.pdf (accessed on 10 May 2025).
  33. Bernardes, E.N.; Flôres, S.H.; Thys, R.C.S. Are Psyllium Fiber and Flaxseed Flour An Exciting Combination of Ingredients in the Development of Gluten-free Vegan Bread? J. Culin. Sci. Technol. 2022, 22, 480–495. [Google Scholar] [CrossRef]
  34. McKeown, N.M.; Fahey, G.C.; Slavin, J.; Van der Kamp, J.-W. Fibre intake for optimal health: How can healthcare professionalssupport people to reach dietary recommendations? BMJ 2022, 378, e054370. [Google Scholar] [CrossRef] [PubMed]
  35. Regulation (EC) No 1924/2006 of the European Parliament and of the Council of 20 December 2006 on Nutrition and Health Claims Made on Foods. Available online: http://data.europa.eu/eli/reg/2006/1924/oj (accessed on 3 July 2024).
  36. Rolls, B.J.; Drewnowski, A.; Ledikwe, J.H. Changing the Energy Density of the Diet as a Strategy for Weight Management. J. Am. Diet. Assoc. 2005, 105, 98–103. [Google Scholar] [CrossRef] [PubMed]
  37. Chochkov, R.; Chonova, V.; Karadzhov, G.; Nedelcheva, R. The influence of WF quantity on the quality of wheat bread. Int. J. Eng. Res. 2016, 7, 1161–1164. [Google Scholar]
  38. Hemdane, S.; Jacobs, P.J.; Bosmans, G.M.; Verspreet, J.; Delcour, J.A.; Courtin, C.M. Study on the effects of wheat bran incorporation on water mobility and biopolimer behavior during bread making and storage using time-domain 1H NMR 749 relaxometry. Food Chem. 2017, 236, 76–750. [Google Scholar] [CrossRef]
  39. Nawrocka, A.; Szymańska-Chargot, M.; Miś, A.; Wilczewska, A.Z.; Markiewicz, K.H. Effect of dietary fibre polysaccharides on structure and thermal properties of 825 gluten proteins–A study on gluten dough with application of FT-Raman spectroscopy, TGA and DSC. Food Hydrocoll. 2017, 69, 410–827. [Google Scholar] [CrossRef]
  40. Bellary, A.N.; Indiramma, A.R.; Prakash, M.; Baskaran, R.; Rastogi, N.K. Anthocyanin infused watermelon rind and its stability during storage. Innov. Food Sci. Emerg. Technol. 2016, 33, 554–562. [Google Scholar] [CrossRef]
  41. Romankiewicz, D.; Hassoon, W.H.; Cacak-Pietrzak, G.; Sobczyk, M.; Wirkowska-Wojdy, M.; Ceglińska, A.; Dziki, D. The Effect of Chia Seeds (Salvia hispanica L.) Addition of Quality and Nutritional Value of Wheat Bread. J. Food Qual. 2017, 7352631. [Google Scholar] [CrossRef]
  42. Pycia, K.; Ivanišová, E. Physicochemical and antioxidant properties of wheat bread enriched with hazelnuts and walnuts. Foods 2020, 9, 1081. [Google Scholar] [CrossRef]
  43. Nogueira, A.C.; Sehn, G.A.; Rebellato, A.P.; Coutinho, J.P.; Godoy, H.T.; Chang, Y.K.; Clerici, M.T.P. Yellow sweet potato flour: Use in sweet bread processing to increase β-carotene content and improve quality. An. Acad. Bras. Ciências 2018, 90, 283–293. [Google Scholar] [CrossRef]
  44. Novotni, D.; Ćurić, D.; Galić, K.; Škevin, D.; Neđeral, S.; Kraljić, K.; Gabrić, D.; Ježek, D. Influence of frozen storage and packaging on oxidative stability and texture of bread produced by different processes. LWT—Food Sci. Technol. 2011, 44, 643–649. [Google Scholar] [CrossRef]
  45. Abdul Aziz, N.A.; Wong, L.M.; Rajeev, B. Nutritional and sensory quality evaluation of sponge cake prepared by incorporation of high dietary fiber containing mango (Mangifera indica var. Chokanan) pulp and peel flours. Int. J. Food Sci. Nutr. 2011, 62, 559–567. [Google Scholar]
  46. Medina-Rendon, E.A.; Guatemala-Morales, G.M.; Padilla-Camberos, E.; Corona-González, R.I.; Arriola-Guevara, E.; García-Fajardo, J.A. Production of Extrudate Food with Mango By-Products (Mangifera indica): Analysis of Physical, Chemical, and Sensorial Properties. Processes 2021, 9, 1660. [Google Scholar] [CrossRef]
  47. Armero, E.; Collar, C. Crumb firming kinetics of wheat breads with antistaling additives. J. Cereal Sci. 1998, 28, 165–174. [Google Scholar] [CrossRef]
  48. Manonmani, D.; Bhol, S.; Bosco, S.J.D. Effect of Red Kidney Bean (Phaseolus vulgaris L.) Flour on Bread Quality. Open Access Libr. J. 2014, 1, 1–6. [Google Scholar] [CrossRef]
  49. Alpers, T.; Kerpes, R.; Frioli, M.; Nobis, A.; Hoi, K.I.; Bach, A.; Jekle, M.; Becker, T. Impact of Storing Condition on Staling and Microbial Spoilage Behavior of Bread and Their Contribution to Prevent Food Waste. Foods 2021, 10, 76. [Google Scholar] [CrossRef]
  50. Ceylan, F.D.; Adrar, N.; Bolling, B.W.; Capanoglu, E. Valorisation of Hazelnut By-Products: Current Applications and Future Potential. Biotechnol. Genet. Eng. Rev. 2022, 39, 586–621. [Google Scholar] [CrossRef]
  51. Gałkowska, D.; Pycia, K.; Krykhta, A. Fortification of Durum Wheat Pasta with Nut Oil Cake: Effects on Nutritional andTechnological Properties. Molecules 2025, 30, 3411. [Google Scholar] [CrossRef]
  52. Yalcin, S. Effect of Storage on the Antioxidant, Color and Sensory Properties of Local Bread. AKU J. Sci. Eng. 2024, 24, 341–349. [Google Scholar] [CrossRef]
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Figure 1. Volume (A) and specific volume of breads (B). Mean values marked with different letters differ statistically significantly (p < 0.05).
Figure 1. Volume (A) and specific volume of breads (B). Mean values marked with different letters differ statistically significantly (p < 0.05).
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Figure 2. Photographic documentation of wheat breads enriched with nut oil cakes ((A) breads enriched with HOC; (B) breads enriched with WOC).
Figure 2. Photographic documentation of wheat breads enriched with nut oil cakes ((A) breads enriched with HOC; (B) breads enriched with WOC).
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Applsci 15 12591 g003
Figure 3. Moisture content of breads. Data presented as means ± standard deviations from triplicate analyses. Values of each parameter with different superscript letters in the columns are significantly different (p < 0.05) (Duncan’s test).
Figure 3. Moisture content of breads. Data presented as means ± standard deviations from triplicate analyses. Values of each parameter with different superscript letters in the columns are significantly different (p < 0.05) (Duncan’s test).
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Figure 4. Changes in selected texture parameters of the tested breads during storage. Data presented as means ± standard deviations from triplicate analyses.
Figure 4. Changes in selected texture parameters of the tested breads during storage. Data presented as means ± standard deviations from triplicate analyses.
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Figure 5. Changes in the total polyphenol content (A) and antioxidant activity (B–D) of the tested breads during storage. Data presented as means ± standard deviations from triplicate analyses. Values of each parameter with different superscript letters in the columns are significantly different (p < 0.05) (Duncan’s test).
Figure 5. Changes in the total polyphenol content (A) and antioxidant activity (B–D) of the tested breads during storage. Data presented as means ± standard deviations from triplicate analyses. Values of each parameter with different superscript letters in the columns are significantly different (p < 0.05) (Duncan’s test).
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Table 1. Basic chemical composition of breads (% DM).
Table 1. Basic chemical composition of breads (% DM).
SamplesProtein
(%)		Fat
(%)		Ash
(%)		Total Dietary
Fiber (%)		Carbohydrates (%)Energy Value (Kcal/100 g)
control13.39 ± 0.03 a1.96 ± 0.11 ab3.35 ± 0.08 a6.14 ± 0.27 a75.13 ± 0.10 e384.10 ± 0.76 b
BHOC5%14.51 ± 0.30 b1.76 ± 0.02 ab3.49 ± 0.11 a6.97 ± 1.97 a73.44 ± 1.68 d380.88 ± 2.84 b
BHOC10%15.86 ± 0.32 c2.60 ± 0.70 bc3.79 ± 0.07 b9.91 ± 0.78 c67.81 ± 0.42 c378.03 ± 3.48 abc
BHOC15%16.65 ± 0.41 d3.32 ± 0.76 c4.19 ± 0.10 c12.71 ± 0.46 d63.28 ± 1.50 b374.40 ± 2.41 a
BWOC5%14.82 ± 0.16 b1.58 ± 0.81 a3.41 ± 0.03 a8.24 ± 0.05 b71.87 ± 0.66 d377.77 ± 2.80 ab
BWOC10%15.82 ± 0.28 c2.16 ± 0.03 ab3.68 ± 0.07 b9.68 ± 0.61 c68.70 ± 0.11 c376.74 ± 0.75 ab
BWOC15%17.93 ± 0.47 e4.69 ± 0.92 d3.74 ± 0.16 b12.85 ± 0.57 d60.65 ± 2.20 a382.82 ± 2.35 b
two-way MANOVA p-values
Factor 1p < 0.001p = 0.269p < 0.001p = 0.236p = 0.058p = 0.292
Factor 2p < 0.001p < 0.001p < 0.001p < 0.001p < 0.001p = 0.443
Factor 1 × factor 2p < 0.001p = 0.010p = 0.012p = 0.171p = 0.040p < 0.001
Data presented as means ± standard deviations from triplicate analyses. Values of each parameter with different superscript letters in the columns are significantly different (p < 0.05) (Duncan’s test). Factor 1: type of nut oil cake; Factor 2: share of nut oil cake; Factor 1 × factor 2: interaction between type of nut oil cake and share of nut oil cake.
Table 3. Texture parameters after 1 day of crumb storage with the addition of nut oil cakes.
Table 3. Texture parameters after 1 day of crumb storage with the addition of nut oil cakes.
SamplesHardness
(N)		Springiness
(-)		Cohesiveness
(-)		Chewiness
(N)
1 day
control12.68 ± 2.40 a0.74 ± 0.02 j0.57 ± 0.04 f5.38 ± 0.73 ghi
BHOC5%13.65 ± 1.95 b0.66 ± 0.04 i0.57 ± 0.03 f5.15 ± 0.51 ghi
BHOC10%16.94 ± 0.89 bcd0.54 ± 0.03 efg0.53 ± 0.02 e4.86 ± 0.29 defghi
BHOC15%20.87 ± 4.13 de0.50 ± 0.03 cde0.53 ± 0.04 e5.38 ± 0.33 ghi
BWOC5%13.74 ± 2.06 b0.59 ± 0.03 ghi0.56 ± 0.02 ef4.50 ± 0.61 cdefgh
BWOC10%15.22 ± 1.22 bc0.64 ± 0.02 i0.54 ± 0.03 e5.23 ± 0.74 ghi
BWOC15%15.08 ± 1.75 bc0.51 ± 0.02 cdef0.49 ± 0.02 d3.75 ± 0.37 bcd
three-way MANOVA p-values
Factor 1p < 0.001p = 0.640p < 0.001p < 0.001
Factor 2p < 0.001p < 0.001p < 0.001p = 0.875
Factor 3p < 0.001p < 0.001p < 0.001p = 0.020
Factor 1 × factor 2p < 0.001p = 0.169p = 0.112p = 0.028
Factor 1 × factor 3p = 0.024p = 0.520p = 0.028p = 0.025
Factor 2 × factor 3p < 0.001p = 0.014p = 0.046p = 0.013
Factor 1 × factor 2 × factor 3p = 0.447p < 0.001p = 0.087p < 0.001
Data presented as means ± standard deviations from four analyses. Values of each parameter with different superscript letters in the columns are significantly different (p < 0.05) (Duncan’s test). Factor 1: type of nut oil cake; Factor 2: share of nut oil cake; Factor 3: storage time. Factor 1 × factor 2: interaction between type of nut oil cake and share of nut oil cake.
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Pycia, K.; Juszczak, L. The Effect of Nut Oil Cakes on Selected Properties of Enriched Wheat Bread and Their Changes During Storage. Appl. Sci. 2025, 15, 12591. https://doi.org/10.3390/app152312591

AMA Style

Pycia K, Juszczak L. The Effect of Nut Oil Cakes on Selected Properties of Enriched Wheat Bread and Their Changes During Storage. Applied Sciences. 2025; 15(23):12591. https://doi.org/10.3390/app152312591

Chicago/Turabian Style

Pycia, Karolina, and Lesław Juszczak. 2025. "The Effect of Nut Oil Cakes on Selected Properties of Enriched Wheat Bread and Their Changes During Storage" Applied Sciences 15, no. 23: 12591. https://doi.org/10.3390/app152312591

APA Style

Pycia, K., & Juszczak, L. (2025). The Effect of Nut Oil Cakes on Selected Properties of Enriched Wheat Bread and Their Changes During Storage. Applied Sciences, 15(23), 12591. https://doi.org/10.3390/app152312591

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