Search Results (18)

In this study, the effects of pregelatinization on the physicochemical properties of corn grits and the quality of cooked waxy corn wrapped in plant leaves were investigated. This investigation was conducted to address the issues of partial gelatinization and poor texture in corn grits when applied to food processing such as cooked waxy corn wrapped in plant leaves. After the corn grits were soaked at 55 °C, they were steamed for 30 min and dried at 45 °C (steam temperature maintained at 100 °C), reaching a gelatinization degree of 48.28%. The modified grits were characterized using Rapid Visco Analyzer (RVA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) to analyze pasting properties, retrogradation behavior, crystallinity, molecular structure, and morphology. The results showed that pregelatinization significantly reduced setback viscosity (from 274.83 to 154.52 mPa·s), crystallinity (from 11.12% to 3.62%), and retrogradation tendency while improving solubility, swelling power, and water-holding capacity. When used in cooked waxy corn wrapped in plant leaves, pregelatinized grits enhanced the gelatinization degree (96.11%), texture (reduced hardness by 19.49%, increased chewiness and cohesiveness), and moisture retention during storage. The findings demonstrate that pregelatinization optimizes starch functionality, mitigates retrogradation, and improves the overall quality of traditional corn-based foods, providing a practical approach for industrial applications. Full article

This paper analyzed the influence of the addition of Zn- and Se-fortified wheat flour to corn extrudates on viscosity, total starch content, starch damage, and bioavailability of zinc and selenium. Fortified wheat flour was added to corn grits in 90:10, 80:20, 70:30, and 60:40 ratios at three extrusion temperature profiles: 140/170/170 °C, 150/180/180 °C, and 160/190/190 °C. Viscosity values decreased significantly at different extrusion temperature profiles and at different proportions of wheat. The extrusion process increased the starch content, regardless of the extrusion temperature, and decreased it by adding different proportions of flour enriched with zinc and selenium. The starch damage increased with extrusion, without significant changes with extrusion temperature increment. The addition of different proportions of Zn- and Se-fortified wheat flour reduced starch damage values proportionally to the added content of enriched wheat. Increasing the temperature and the proportions, the total zinc content in the extrudates increased. Zinc bioavailability increased with increasing extrusion temperature. As for selenium, the total content increased by proportion increment but decreased with an increase in the extrusion temperature, though there were no significant differences in selenium bioavailability regardless of changes in extrusion temperature or the proportion of enriched wheat. Full article

Apple pomace is a by-product of the apple processing industry and can be used for various uses such as animal feed, for composting, or to extract valuable compounds such as pectin or antioxidants. In recent years, it has also gained attention as a potential food ingredient due to its fibre content and antioxidant properties. The aim of this study was to examine the effect of three parameters: the percentage of wheat flour replaced by extrudate (5%, 10%, and 15%), the percentage of apple pomace in the extrudate (15%, 30%, and 45% based on the mass of corn grits), and the particle size of the extrudate (<250 µm; 250–1000 µm; 1000–2000 µm) on the properties of cookies, using the Box–Behnken experimental design. The addition of extrudates enriched with apple pomace significantly increased the total fibre and ash content of the cookies. The hydroxymethylfurfural content also increased, but not above the permitted limits (25 mg/kg). The sensory quality was strongly influenced by the particle size, especially the hardness, graininess, and appearance of the cookies. The addition of extrudate led to a darker colour of the cookies and a significant increase in the proportion of red tones, but generally had no negative influence on the acceptability of the cookies and their microbiological stability during the 6-month storage period. Full article

This research studies the influence of the addition of defatted press cakes (from the production of hazelnut, camelina, pumpkin, and hemp seed oil) on nutritionally important components: fibre, resistant starch, polyphenols, hydroxymethylfurfural (HMF), and acrylamide in directly and indirectly expanded snacks. The amounts of press cakes added to corn grits were 3, 6, and 9%. Extrusion was carried out in a laboratory single-screw extruder. For indirectly expanded products (SCFX), supercritical CO₂ was injected during extrusion, and secondary expansion was completed in the microwave oven. The type and content of press cake, as well as the type of product, significantly influenced total polyphenol content and antioxidant activity. Press cakes increased the contents of both soluble and insoluble fibre (from 1.94% d. m. and 1.28% d. m. for extrudates without press cakes up to 3.17% d. m. and 6.94% d. m. for SCFX extrudates with press cakes, respectively), and resistant starch was not markedly influenced by their addition. The influence of the content of press cake on HMF was not significant, whereas the type of cake and the type of extrusion influenced HMF significantly. In a raw mixture of corn grits with 3% of pumpkin press cake, HMF was below the limit of detection, and the highest content was found in the classically extruded sample with the addition of 9% of camelina press cake (580 ppb). In all samples, the acrylamide content was below the limit of detection, indicating that safe products were obtained. This research shows potential for the implementation of supercritical CO₂ extrusion in the production of safe, nutritionally improved snack products. Future research might bring about the design of cost-effective processes applicable in the industry. Full article

Andean roots, such as zanahoria blanca, achira, papa China, camote, oca, and mashua, contain high amounts of dietary fiber, vitamins, minerals, and fructo-oligosaccharides. This study aimed to demonstrate the possibility of obtaining healthy second-generation (2G) snacks (products obtained from the immediate expansion of the mixture at the exit of the extruder die) using these roots as raw materials. Corn grits were mixed with Andean root flour in a proportion of 80:20, and a Brabender laboratory extruder was used to obtain the 2G snacks. The addition of root flour increased the water content, water activity, sectional expansion index, hygroscopicity, bulk density, and water absorption index but decreased the porosity. However, all 2G snacks manufactured with Andean root flour showed better characteristics than did the control (made with corn grits) in texture (softer in the first bite and pleasant crispness) and optical properties (more intense and saturated colors). The developed snacks could be considered functional foods due to the high amount of carotenoids and phenolic compounds they exhibit after the addition of Andean root flours. The composition of raw roots, specifically the starch, fiber, and protein content, had the most impact on snack properties due to their gelatinization or denaturalization. Full article

This research was undertaken to evaluate the influence of the extrusion process on the sorption behavior of deproteinized sunflower meal (DSM). A patterned food extrudate (PFE), prepared from a mixture of DSM and corn grits (1:1), was obtained, and the equilibrium isotherms of both products (DSM and PFE) were determined at three temperatures (20 °C, 30 °C, and 40 °C) by the static gravimetric method. The comparison of the sorption behavior of the products showed that extrusion decreased the equilibrium moisture content and the monolayer moisture, while the hysteresis effect was significantly raised in size and span. The experimental sorption isotherms were fitted by five modified models including the temperature effect: Chung–Pfost, Halsey, Oswin, Henderson, and GAB. The modified models of Oswin were established to be suitable to describe the equilibrium sorption isotherms in the temperature range from 20 °C to 40 °C. The net isosteric heat of sorption of DSM and PFE decreases consistently with the increase in moisture content. Extrusion reduces the bond energy between the solid matrix and the water molecules. The ranges of moisture content and relative humidities in the temperature interval studied, appropriate for long-term storage of DSM and PFE, were predicted. Full article

Andean tubers and tuberous roots have nutritional and medicinal properties transferred through ancestral generations. In this study, we aim to promote cultivation and consumption by developing a snack based on these crops. Corn grits were thoroughly mixed with sweet potato, mashua, and three varieties of oca flour (white, yellow, and red) in an 80:20 ratio, and a single-screw laboratory extruder was utilized to produce third-generation (3G) dried pellets. Microwave expansion was studied, and the dried 3G pellets and expanded snacks were characterized. The microwave expansion curves of the dried 3G pellets were adjusted to the Page, logarithmic, and Midilli–Kucuk models. During the characterization, the influence of the raw material composition was observed in sectional expansion, water content, water activity, water absorption, water solubility, swelling, optical and textural properties, and bioactive compounds. According to global color variation (mixture vs. expanded and dried vs. expanded) and bioactive compound analysis, the mashua suffered little chemical change or nutritional loss during the process. The extrusion process was shown to be an ideal method for manufacturing snacks from Andean tuber flours. Full article

Food waste is becoming a growing and important concern at both local and global levels. One-third of all food production is lost or wasted globally. It is necessary to look for alternatives that allow the use of agri-food waste or byproducts and that can provide value to other foodstuffs. The utilization of beetroot byproducts for producing value-added third generation (3G) snacks was the main aim of this work. These snacks are obtained by indirect expansion by extrusion and later heat expansion. In order to achieve this aim, a corn grits base was used and the influence of water content and beetroot byproduct content effect was studied on expansion kinetics by microwave energy and on texture, colour, extrusion parameters and bioactive compounds of expanded 3G snacks. The microwave expansion kinetics study determined the appropriate time to expand the formulations studied. Samples with higher water content in the mixtures needed more expansion time. In terms of expansion, all samples presented acceptable values; however, samples with 25% water in the mixtures showed better results. Furthermore, these snacks showed more crunchiness and less hardness. Beetroot byproduct incorporation provided additional functional value to the snacks. The betalains and phenols contained in the beetroot byproduct were presented in the expanded snacks and increased the antioxidant capacity of the snacks. With this study, it can be recommended to use 25% water content and 10% beetroot byproduct in corn mixture to obtain a third-generation snack with added value. Full article

The tailored formulation of raw materials and the combination of grain germination and extrusion processes could be a promising strategy to achieve the desired goal of developing healthier expanded extrudates without compromising sensory properties. In this study, modifications in the nutritional, bioactive profile and physicochemical properties of corn extrudates as influenced by the complete or partial replacement by sprouted quinoa (Chenopodium quinoa Willd) and cañihua (Chenopodium pallidicaule Aellen) were investigated. A simplex centroid mixture design was used to study the effects of formulation on nutritional and physicochemical properties of extrudates, and a desirability function was applied to identify the optimal ingredient ratio in flour blends to achieve desired nutritional, texture and color goals. Partial incorporation of sprouted quinoa flour (SQF) and cañihua flour (SCF) in corn grits (CG)-based extrudates increased phytic acid (PA), total soluble phenolic compounds (TSPC), γ-aminobutyric acid (GABA) and oxygen radical antioxidant activity (ORAC) of the extrudates. Sprouted grain flour usually results in an deleterious effect physicochemical properties of extrudates, but the partial mixture of CG with SQF and SCF circumvented the negative effect of germinated flours, improving technological properties, favoring the expansion index and bulk density and increasing water solubility. Two optimal formulations were identified: 0% CG, 14% SQF and 86% SCF (OPM1) and 24% CG, 17% SQF and 59% SCF (OPM2). The optimized extrudates showed a reduced amount of starch and remarkably higher content of total dietary fiber, protein, lipids, ash, PA, TSPC, GABA and ORAC as compared to those in 100% CG extrudates. During digestion, PA, TSPC, GABA and ORAC showed good stability in physiological conditions. Higher antioxidant activity and amounts of bioaccessible TSPC and GABA were found in OPM1 and OPM2 digestates as compared to those in 100% CG extrudates. Full article

The cereal grains, which represent the cultivated grasses fruits, supply almost half of the total caloric requirements for humans and provide more nourishment compared with any other class of the food. Out of many cereals used for food, maize, rice, and wheat are the most important food resources for humans, representing 94% of the total cereals consumption. According to the data of the Republic Institute of Statistics for the year 2018, the harvested areas of corn amount to 906,753 hectares. The production of about 7 million tons was achieved with an average yield of 7.7 t/ha according to the Ministry of Agriculture of the Republic of Serbia. Serbia is still among the ten largest exporters of wheat and corn in the world for the period of 2014/15–2017/18. More precisely, it ranks seventh in the export of corn. Utilization of maize products for food animal nutrition (1000 t) is 491,48, and for industrial processing (1000 t) 278,862 expressed as the total consumption (1000 t) is 769,910. Therefore, a total of 103 samples of maize products were analyzed for the presence of toxins, i.e., tropane alkaloids (TAs). The samples were collected from the retail stores in the Republic of Serbia in 2021 and analyzed for the presence of atropine and scopolamine (33 corn grits, 39 polenta, and 31 semolina samples). Therefore, the Recommendation 2015/976/EU on the monitoring of TAs in food was adopted by the EU Commission to obtain more occurrence data on TAs in food. The monitoring extent, however, is restricted because reliable analytical methods and appropriate sensitivity are limited. There was a limit of 1 g/kg for each atropine and scopolamine in cereals containing millet, sorghum, buckwheat, or their derivatives. All the samples were analyzed by the LC-MS/MS. The LOQ was set at 1.0 μg/kg. Out of the total 103 tested samples, 32 samples (31.1%) were contaminated with atropine and scopolamine in concentrations above the LOQ. The highest concentrations of the studied TAs were observed in a semolina sample-atropine: 58.80 μg/kg, scopolamine: 10.20 μg/kg. The obtained results indicate that the TAs concentrations are above the LOQ which can be considered potential human and animal health hazards. Full article

A trend related to adding legume seeds to various products has been observed. This work aimed to use fermented red bean/broad bean seeds and their hulls to produce extruded snacks with more beneficial nutritional properties and good sensory quality. Extruded snacks containing fermented ground seeds (50%) or hull (10%) of red bean/broad bean and corn grits with the addition of selected herbs/spices (0.5%) were prepared. The chemical composition, phenolic profile, antioxidant activity, and sensory quality were analysed. The results showed that the protein content ranged from 9 to 22.9 g 100 g⁻¹, phenolic compounds ranged from 3.97 to 12.80 mg 100 g⁻¹ (with the addition of herbs/spices, even up to 62.88 mg 100 g⁻¹), and antioxidant activities ranged from 4.32 to 10.23 Trolox g⁻¹ (ABTS assay), depending on the type of fermented materials. The addition of ground seeds/hull did not influence the consumer desirability, whereas the addition of selected herbs/spices, particularly lovage, increased it. The application of fermented red bean and broad bean seeds and their hulls, as part of the assumptions of the planetary diet, enabled enrichment of extruded corn products, which are often consumed by vegans and vegetarians, with nutritionally valuable ingredients. Full article

Circular economy plays a key role in increasing the sustainability of the agricultural sector, given the countless possibilities of transforming crop residues and recycling precious resources. The maize cultivation process produces a significant amount of residual organic materials, commonly left on the field, as a soil conditioner and source of nutrients even if some parts, such as the cob, play a minor role in these actions. The solutions for the valorization of this remnant depend on economic and environmental factors and the evaluation of the environmental performances of the processes in a life-cycle perspective is important to compare the overall sustainability of the valorization alternatives, maximizing their environmental added value. This work reports the results of Life Cycle Analysis, from cradle-to-gate of corn cob valorized as a raw material in two scenarios: corn cob pellet and corn cob abrasive grits to use as blasting or finishing media. A comparative study has been performed with two products available on the market and with the same functions. The results show that cob-based products have lower impact than those currently used. The work provides indication for evaluating the benefits of turning agricultural wastes in natural-based materials and intends to promote circular economy processes in agriculture production. Full article

Sugar beet pulp (SBP) is a by-product of the sugar industry in which the dietary fiber content ranges from 73% to 80%. Compared to cereal fibers mainly used in biscuit production, sugar beet fibers are gluten free and have a perfect ratio of 2/3 insoluble fiber. In this work, sugar beet pulp was extruded with corn grits (ratios of corn grits to sugar beet pulp in extrudates were 85:15, 70:30, and 55:45), and the obtained sugar beet pulp extrudates (SBPEs) were used for improving the nutritional quality of cookies. The wheat flour in cookies was replaced with SBPEs in the amount of 5, 10, and 15%. The influence of three factors (the percentage of sugar beet pulp in the SBPEs, the size of the SBPE particles, and the percentage of wheat flour substituted with SBPEs) and their interactions on the nutritional quality of cookies, as well as their physical and sensory characteristics are examined using the Box–Behnken experimental design. The addition of extruded sugar beet pulp (SBPEs) significantly increased the amount of total dietary fiber and mineral matter of cookies. On the whole, the addition of SBPEs increased cookie hardness, but the hardness decreased with an increase in extrudate particle size. Sensory characteristics (except for the taste) were the most influenced by extrudate particle size. Full article

The addition of brewer’s spent grain (BSG), sugar beet pulp (SBP) and apple pomace (AP), on the nutritional properties of directly expanded snack products based on corn grits was investigated. Snack products were produced in a laboratory single screw extruder with the addition of 5, 10 and 15% d. m. of these by-products in corn grits. Chemical composition, total phenolic content, antioxidant activity, dietary fiber, resistant starch, starch damage and pasting properties of the mixtures and extruded samples were determined. Extrusion process and by-product additions had a significant effect on the proximate chemical composition. All three by-products increased contents of both soluble and insoluble dietary fiber, while the extrusion caused a reduction of insoluble fiber and increase of soluble fiber. After the extrusion process starch damage and antioxidant activity increased, while resistant starch content and total polyphenol content decreased. According to obtained results, it can be concluded that the investigated by-products can be used in the production of nutritionally more valuable corn snacks. Full article

Corn is one of the most cultivated cereals in Brazil. However, its grains are constantly exposed to contamination by mycotoxins. Corn grits are used by the food industry to produce a large variety of corn products such as canjiquinha, a cultural food easily purchased by the Brazilian consumer at low prices. Some studies have demonstrated high contamination of this product by aflatoxins (AFs), representing a potential risk of exposure due to such a contamination. In this study, the efficacy of gaseous ozonation was evaluated on the levels of aflatoxins and on the microbial contamination of corn grits. The application of gaseous ozone was tested in different combinations of exposure time, ozone concentration, and canjiquinha mass. After the ozonation treatment, samples were collected for aflatoxin and microbiological analyses. Aflatoxins were evaluated using a high-performance liquid chromatography with fluorescence detection (HPLC-FD) system using pre-column derivatization, and the microbiological analyses were carried out for toxin-producer fungi and mesophilic bacteria. After ozone detoxification, results showed reductions up to 57% in aflatoxin levels. Total fungal count was reduced around 3.0 cycles log CFU g⁻¹ and total mesophilic counts were reduced to non-detectable levels. These results demonstrated that ozonation is an effective alternative for reducing aflatoxin and microbial contamination in products like canjiquinha, thereby improving food safety. Full article