Search Results (22)

Plants are sources of compounds with important effects on health, but plant-based food industry generates substantial waste amounts, especially in oil production. This study aimed to characterize flours derived from oilseed by-products, pumpkin, sunflower, and apricot seed residues, and compare them with conventional grain flours (white and whole wheat). Nutritional composition was analyzed with emphasis on amino acid profiles performed by ion chromatography. Mineral profiles were determined by ICP-MS. Total phenolics and antioxidant activity were assessed using in vitro colorimetric microassays. Oil press cake flours showed significantly higher levels of protein and fiber compared to wheat flours (p < 0.05), while the latter contained more carbohydrates. Among the examined flours, pumpkin and apricot seed flours stood out with the highest potassium, while sunflower seed flour led in calcium content. Despite higher polyphenol content in wheat flours, apricot seed flour exhibited the greatest antioxidant activity, likely due to its diverse profile of hydrophilic and lipophilic bioactive compounds. These findings highlight oil press cakes as nutritionally valuable ingredients for protein-enriched and other innovative food products, aligning with circular economy principles and promoting resource efficiency in the agri-food sector. Full article

Cold pressing is a sustainable oil extraction method that operates without chemical solvents, requires relatively low energy input, and preserves bioactive compounds, making it a recognized green technology in line with circular economy principles. By enabling full utilization of raw materials and valorization of by-products, it supports resource efficiency, waste reduction, and the development of bio-based products. This study provides the first comprehensive mapping of Serbia’s small-scale cold-pressed oil producers, based on data from the Central Register of Food Business Operators, local inspectorates, agricultural fairs, and social media, classified according to NUTS 2024 statistical regions. A total of 55 producers were identified, with over 60% operating as artisanal units (≤15 t/year), typically using screw presses of 20–50 kg/h capacity. Pumpkin seed was the most common raw material (30 producers), followed by sesame (21), hazelnut (20), sunflower (19), and flaxseed (19), while niche oils such as jojoba, argan, and rosehip were produced on a smaller scale. Medium and large facilities (>15 t/year) were concentrated in Vojvodina and central Serbia, focusing on high-volume seeds like sunflower and soybean. Integration of green screw press technologies, zero-kilometer supply chains, and press cake valorization positions this sector as a driver of rural development, biodiversity preservation, and environmental sustainability, providing a strong basis for targeted policy support and process optimization. Full article

This study investigates the digestibility, fecal characteristics, and palatability of plant-based protein sources in canine diets. With an increasing number of pet owners adopting vegan lifestyles for ethical, health, and environmental reasons, the demand for plant-based dog diets has risen. Using plant by-products can also be a practical and sustainable option for feeding pets. This study included eight healthy female dogs fed four different plant-based diets using a Latin square (4 × 4) crossover design, with linseed press cake, sunflower press cake, pumpkin press cake, and soy press cake as protein sources. To measure the acceptance of the protein sources, a five-bowl test was used. The apparent total tract digestibility of the different diets and the fecal quality were compared as well as the acceptability of the individual protein sources. The results showed significantly (p < 0.0001) better acceptance for the pumpkin press cake compared to the other three tested press cakes, whereas the addition of potato flakes changed the acceptance and showed no significant (p = 0.1105) differences between the press cakes. Among the tested diets, the highest protein digestibility was observed for the pumpkin diet (85.11% ± 1.77%), followed by the sunflower (84.23% ± 2.20%) and soy diets (82.35% ± 3.37%), while the linseed diet showed the lowest protein digestibility (77.52% ± 6.04%). Full article

The aim of the study was to evaluate the use of sunflower and sesame oilseed press cakes, which are by-products of oil extraction, as functional ingredients in cookie production. The quality characteristics of these by-products were assessed, including water activity, pH, total phenolic content, and antioxidant activity, and HPLC analysis of the phenolic compounds was performed. Subsequently, cookies were prepared by replacing wheat flour with 30% or 50% press cake. The addition of sunflower press cake significantly increased the total phenolic content (up to 8.6 mg GAE/g dm) and antioxidant activity (up to 75.9%) in the cookies, whereas adding sesame press cake showed a less pronounced effect, reaching 0.91 g GAE/g dm and 8.9% for total phenolic content and antioxidant activity, respectively. HPLC analysis indicated that chlorogenic acid and its derivatives dominated in sunflower-enriched cookies, while sesame samples contained lignans such as sesamol and sesamin. Our study shows that 50% substitution improves the health-promoting properties of cookies and does not differ significantly from the 30% level in consumer sensory evaluations. These findings support the use of sunflower and sesame press cakes as valuable ingredients in food applications. This represents an important step toward developing healthier and more nutritious food products while supporting the principles of the circular economy through the upcycling of valuable raw materials. Full article

Sunflower press cake (SPC), a by-product of the edible oil industry, represents a promising source of plant-based protein. This study aimed to investigate and optimize protein recovery from SPC using conventional (CE) and advanced extraction techniques, including Ultrasound and Microwave-Assisted Extraction (UMAE), Pressurized Liquid Extraction (PLE) and Enzyme-Assisted Extraction (EAE). The protein content both in extracts and in the precipitated mass was measured through Lowry assay, while the amino acid profile of the extracted proteins under optimal conditions was analyzed via High-Performance Liquid Chromatography (HPLC). Extraction parameters were optimized using response surface methodology (RSM) for each method. Among the novel methods studied, UMAE and PLE demonstrated superior efficiency over CE, yielding higher protein recovery in significantly shorter extraction times. Optimal UMAE conditions (10 min, 0.03 g/mL, 450 W microwave power, and 500 W ultrasound power) yielded a precipitation yield (PY) of 21.2%, protein recovery in extract (PR_E) of 79.9%, and protein recovery in precipitated mass (PR_P) of 66.3%, with a protein content (PC_P) of 902.60 mg albumin eq./g. Similarly, optimal PLE conditions (6 min, 0.03 g/mL, and 50 °C) resulted in PY, PR_E, and PR_P of 17.7, 68.9, and 47.4%, respectively, with a PC_P of 932.45 mg albumin eq./g. EAE using Aspergillus saitoi protease was comparatively less effective. The amino acid profiling confirmed SPC as a valuable protein source, with glutamic acid, arginine, and aspartic acid being the most abundant. These results highlight the potential of UMAE and PLE as efficient strategies for valorizing edible oil industry by-products into high-quality protein ingredients for food and biotechnological applications. Full article

Sustainability in the food chain and the prevention of food losses is an issue of increasing importance. There is a large number of processing by-products where innovative strategies are helpful for transferring these losses into a consumable state. In a step-by-step approach, this current study focused on the sensory properties of blends of sunflower press cake and whey, fermented with different consortia of microorganisms and intended for being used as a basis for a savory spread. In the first part of the work, blends fermented with six co-cultures from lactic acid bacteria and yeasts were characterized by free choice profiling and quantitative descriptive analysis. The respective results were used to modify the formulation and to select the fermentation cultures that were promising from a sensory point of view. Subsequent investigations allowed reducing sample dimensionality further, and the study was concluded by affective hedonic tests and a check-all-that-apply set-up performed by consumers. The final experiment also comprised a just-about-right approach performed for specifically evaluating spreadability. The outcome of the entire study indicates that it is possible to tailor attractive foods from by-products, provided that the need for final optimizations regarding palatability is considered. Full article

This study investigates the effects of hull and impurity content on the efficiency of cold-pressing high-oleic sunflower seeds using a screw press. High-oleic sunflower oil is valued for its oxidative stability and health benefits, and optimizing pressing conditions is crucial for maximizing yield and maintaining oil quality. The identification of high-oleic sunflower oil was performed by analyzing its fatty acid composition, iodine value, and refractive index. Eleven seed samples with varying hull and impurity contents were processed to assess their impact on cake composition, pressing efficiency, and pressing oil yield. Oil yield ranged from 39.24% to 76.52%, with higher hull content contributing to increased yield due to its role in facilitating oil drainage. Multiple linear regression models were developed to predict moisture and oil content in the cake, as well as pressing efficiency, based on hull and impurity content, demonstrating strong predictive accuracy. These parameters were selected as they represent economically significant indicators, given that moisture and oil content indirectly reflect the protein content in the cake, while sunflower cake is primarily used as animal feed. Additionally, pressing efficiency indicates oil yield during pressing, which is the most critical economic parameter of the cold-pressing process. Cluster analysis identified three sample groups with distinct characteristics, revealing interactions between seed composition and pressing performance. The results highlight the significance of seed preparation in optimizing cold-pressing efficiency and provide insights for improving oil extraction processes. These findings support the industrial application of high-oleic sunflower seed pressing and contribute to the development of sustainable, high-quality oil production methods. Full article

Palm and palm kernel oils are preferred ingredients in industrial food processing for baked goods and chocolate-based desserts due to their unique properties, such as their distinctive melting behaviors. However, ongoing concerns about the social and environmental sustainability of palm oil production, coupled with consumer demands for palm oil-free products, have prompted the industry to seek alternatives which avoid the use of other tropical or hydrogenated fats. This project investigated replacing palm oils with chemically unhardened Swiss sunflower or rapeseed oils. Target applications were cookies and chocolate fillings. These oils were physically modified through emulsification, stabilized with finely ground oil press cake particles and crystallized waxes. Findings indicated that the emulsification of the oils increased viscosity and that the addition of wax was beneficial for long-term stability; however, the extent of this effect depended on the combination of oil and wax types. Furthermore, wax pre-crystallization and low shear during crystallization significantly improved emulsion stability. Despite these improvements, the resulting emulsions did not achieve sufficient stability and exhibited lower viscosity than palm oil. Future experiments should explore higher wax concentrations (1% or more) and develop analytical methods to better understand the wax composition and its role in oleogel formation. Full article

Seed cakes, by-products from the cold press extraction of vegetable oils, are valuable animal feed supplements due to their high content of proteins, carbohydrates, and minerals. However, the presence of anti-nutrients, as well as the rancidification and development of aflatoxins, can impede their intended use, requiring alternative treatment and valorisation methods. Thermal treatment as a procedure for the conversion of seed cakes from walnuts, hemp, pumpkin, flax, and sunflower into valuable products or energy has been investigated in this paper. Thermogravimetry shows the particular behaviour of seed cakes, with several degradation stages at around 230–280 and 340–390 °C, before and after the typical degradation of cellulose. These are related to the volatilisation of fatty acids, which are either free or bonded as triglycerides, and with the thermal degradation of proteins. Torrefaction at 250 °C produced ~75–82 wt% solids, with high calorific values of 24–26 kJ/g and an energy yield above 90%. The liquid products have a complex composition, with most parts of the compounds partitioning between the aqueous phase (strongly dominant) and the oily one (present in traces). The structural components of seed cakes (hemicelluloses, cellulose, and lignin) produce acetic acid, hydroxy ketones, furans, and phenols. In addition to these, most compounds are nitrogen-containing aromatic compounds from the degradation of protein components, which are highly present in seed cakes. Full article

Palm fat has uniquely optimal melting characteristics that are difficult to replace in products such as baked goods and chocolate-based items. This study investigates the efficacy of using Pickering emulsions derived from Swiss plant oils and their micromilled press cakes. Emulsification was carried out at both the lab and pilot scales using sunflower- and rapeseed-based recipes, with and without additional surfactants, for both oil-in-water and water-in-oil emulsions. The resulting emulsions were measured for viscosity and short- and long-term stability and linked to the properties of the raw materials. The results indicated that the contact angle, size, and macronutrient composition of the particles significantly impact emulsion quality, though differences in oil pressing methods might predominate these effects. The combination of particles and surfactants demonstrated a clear advantage with respect to interface stabilisation, with a suggested link between the wax content of the oil and particles and the resulting emulsion quality and stability. Full article

The current food system suffers from the inefficient use of resources, including the generation of side streams of low economic value that still contain nutritional components. One potential approach to reach a more sustainable food system is to reintroduce such side streams into a circular value chain and valorise them in novel food products, preferably in an unrefined or minimally refined manner. Blending side streams from different industries might be a suitable way to improve the nutritional value of the final matrix. In this study, sunflower seed press cake and cheese whey were combined to obtain matrices containing valuable proteins, structuring polysaccharides, as well as lactose and minerals facilitating fermentation with three different co-cultures of lactic acid bacteria and yeasts. Fermentation for 48 h at 26 °C decreased the pH from ~6.3 to ~4.7 and enhanced the storage stability of the blends with no effect on their rheological properties and microstructure. This research demonstrates the potential of fermentation as a mean to stabilise side stream blends while only minimally affecting their physical appearance. Full article

Sunflower is a major agricultural oilseed crop, and the Republic of Kazakhstan has been steadily strengthening its position as a producer of oilseeds. In this study, an oil pressing machine with two processes, including grinding sunflower seeds and pressing the obtained cake to separate the oil, is constructed. The experiment investigated the impact of different grinding degrees (hole diameters of plates of 5 mm, 4 mm, 3 mm, and 2 mm) and screw rotation speeds (ranging from 30 rpm to 250 rpm) on oil pressing efficiency. The study used sunflower seeds with an oil content of 45–47% and moisture of 7–9%. The results showed that increasing the grinding degree and screw rotation speed led to higher oil yield. The optimal condition was a grinding degree of 4 mm and a screw rotation speed of 60 rpm, resulting in the highest oil yield of 15.6 g/s. Additionally, the residual oil content of the seed cake decreased significantly as pressure increased during pressing, particularly with 4 mm grinding. Power consumption increased with higher screw rotation speeds and finer grinding degrees, indicating the influence of grinding components on energy demand. The cake density increased with higher screw rotation speeds and finer grinding degrees, highlighting the impact of grinding mechanisms on cake compactness. Moreover, the temperature of the cake rose with increased screw rotation speed and the presence of grinding sieves. These findings provide valuable insights into optimizing the sunflower oil pressing process, highlighting the importance of selecting appropriate grinding degrees and screw rotation speeds to maximize oil yield and pressing efficiency. Full article

Due to the increasing demand for alternative protein feed ingredients, the utilization of oilseed by-products in animal nutrition has been sought as a promising solution to ensure cheap and environmentally sustainable feedstuffs. This review aimed to summarize the nutritional value of six cold-pressed cakes (rapeseed, hempseed, linseed, sunflower seed, camelina seed, and pumpkin seed) and the effects of their inclusion in diet for ruminant, pig, and poultry on nutrient digestibility, growth and productive performance, and quality of the products. The presented results indicated that these unconventional feed ingredients are a good protein and lipid source and have a balanced amino acid and fatty acid profile. However, contradictory results of animal production performances can be found in the literature depending on the cake type and chemical composition, dietary inclusion level, animal category, and trial duration. Due to the substantial amount of essential fatty acid, these cakes can be efficiently used in the production of animal products rich in n-3 and n-6 polyunsaturated fatty acids. However, the utilization of cakes in pig and poultry nutrition is limited because of the presence of antinutritive factors that can deteriorate feed intake and nutrient utilization. Full article

Polyurethane (PUR) foams are some of the most promising thermal insulating materials because of their high flammability, but further applications are limited. Therefore, the development of flame-retardant materials with sufficient strength characteristics, water resistance, and low thermal insulating properties is of great importance to the modern building industry. This study evaluates the possibility of a vacuum-based liquid glass (LG) infusion into bio-based fillers, in this case, sunflower press cake (SFP) particles, to improve the mechanical performance, water absorption, thermal insulation, ignitability, thermal stability, and flame retardancy of the resulting polyurethane (PUR) foam composites. The main findings show that LG slightly improves the thermal stability and highly contributes to the ignitability and flame retardancy of the resulting products. Most importantly, from 10 wt.% to 30 wt.%, the SFP/LG filler reduces the thermal conductivity and water absorption values by up to 20% and 50%, respectively, and increases the compressive strength by up to 110%. The results obtained indicate that the proposed SFP/LG filler-modified PUR foam composites are suitable for applications as thermal insulation materials in building structures. Full article

The current environmental challenge is pushing food systems towards more sustainable models of production that require reorganizing of processes by re-using side products still containing nutrients. This work aimed at valorising a mix of bovine sweet whey and sunflower press cake, through targeted fermentation. After preliminary screening based on growth rate, final pH, lactose/galactose assimilation, phytase activity, six Lactic Acid Bacteria strains (Lacticaseibacillus casei, L. paracasei (2), Lactococcus lactis, Lentilactobacillus parakefiri and Leuconostoc pseudomesenteroides) and three yeasts (Kluyveromyces lactis, K. marxianus and Torulaspora delbrueckii) were co-cultivated in pairs in microcosms (1-part ground press cake: 4-parts whey). All tested microorganisms were able to grow and acidify the blend: the LAB counts increased during the incubation (26 °C for 48 h) of +2.80 log CFU/g, whereas yeasts counts were of +1.98 log CFU/g, with significant differences among the different associations (p < 0.01). Mould counts were always <3 log CFU/g. Interestingly, the bacterial contaminants count significantly varied in samples with different pairs of strains (p < 0.001). Acidification level, acetic acid and ethanol contents were the limiting factors affecting the growth of spoilage micro-organisms. Best performances were attained in microcosms inoculated with L. lactis or L. paracasei and K. lactis or K. marxianus. Full article