Impact of germination alone or in combination with solid-state fermentation on the physicochemical, antioxidant, in vitro digestibility, functional and thermal properties of brown finger millet flours

Mechanism of the release and transformation of polyphenols during germination and fermentation in millets: profile and metabolomics based analysis

Germination and fermentation are effective ways to improve polyphenol contents in whole grains; however, their mechanisms await clear explanation. This study aimed to elucidate the mechanisms underlying the release and transformation of polyphenols during germination and fermentation with L. plantarum. Results showed that the phenolic content significantly increased after germination and fermentation. Dynamic changes of carbohydrate-hydrolyzing enzymes and structural characteristics detected by FTIR, X-ray diffraction, and CLSM indicated that the destruction of hemicellulose and the secretion of xylanase were crucial for releasing polyphenols. Targeted metabolomics revealed that a total of 73 polyphenols and their catabolites were identified. Differential metabolites between millets (M) and germinated millets (GM), as well as between GM and germinated-fermented millets (FGM), were revealed. Quantitative analysis of differential metabolites combined with KEGG pathways showed that the contents of cinnamic acid, caffeic acid, ferulic acid, and sinapic acid significantly increased after germination, likely associated with phenylpropanoid biosynthesis. However, these polyphenols markedly decreased after fermentation. The contents of 3,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, and 4-hydroxyphenylethanol significantly increased after fermentation, suggesting associations with phenylalanine, tyrosine, and tryptophan biosynthesis and tyrosine metabolism. Our results demonstrated the enhancement of polyphenol contents via the combination of germination and fermentation and the related mechanisms during these processes, which provides valuable insights for the utilization of cereals in the food industry.

Microwave-assisted protein extraction from foxtail millet: Optimization, structural characterization, techno-functional properties, and bioactivity of peptides

This research investigates the impact of microwave power, processing time, and solid-to-solvent ratio on protein recovery from foxtail millet (Setaria italica), using an artificial neural network (ANN) and genetic algorithm (GA). The extracted protein and subsequent hydrolysates were also evaluated for their techno-functional, structural, and digestibility properties. The ANN model, trained with the Levenberg-Marquardt algorithm and optimized by a GA, identified optimal extraction conditions (960 W, 66.14 s, 0.1264 g/mL), achieving a protein recovery yield of 30.02 ± 0.97 %. Protein recovery increased 1.15-fold for raw microwave-treated protein and 1.52-fold for germinated microwave-treated protein. The functional properties, including foaming, emulsifying, and digestibility were improved. Germinated microwave-treated protein hydrolysates (GMPH) exhibited the highest soluble protein content (17.79 ± 0.33 mg/mL) and degree of hydrolysis (7.63 ± 0.25 %) at 2.5 % (v/w) enzyme concentration, while raw microwave-treated protein hydrolysates (RMPH) showed 16.59 ± 0.36 mg/mL and 5.57 ± 0.14 %, respectively. Partially purified peptides from GMPH and RMPH showed strong antioxidant and angiotensin-converting enzyme (ACE) inhibitory activities, with GMPH showing the highest bioactivity. These findings highlight the potential of germination and microwave-assisted processing to produce high-quality protein and bioactive peptides, supporting the development of protein-rich foods and nutraceuticals to address global protein demand.

Recent advances in germinated cereal and pseudo-cereal starch: Properties and challenges in its modulation on quality of starchy foods

Germination is an environmentally friendly process with no use of additives, during which only water spraying is done to activate endogenous enzymes for modification. Furthermore, it could induce bioactive phenolics accumulation. Controlling endogenous enzymes' activity is essential to alleviate granular disruption, crystallinity loss, double helices' dissociation, and molecular degradation of cereal and pseudo-cereal starch. Post-treatments (e.g. thermal and high-pressure technology) make it possible for damaged starch to reassemble towards well-packed structure. These contribute to alleviated loss of solubility and pasting viscosity, improved swelling power, or enhanced resistant starch formation. Cereal or pseudo-cereal flour (except that with robust structure) modified by early germination is more applicable to produce products with desirable texture and taste. Besides shortening duration, germination under abiotic stress is promising to mitigate starch damage for better utilization in staple foods.

Enhancing the nutritional value and antioxidant properties of foxtail millet by solid-state fermentation with edible fungi

Foxtail millet is typically dehulled before consumption or processing. However, foxtail millet bran also contains abundant phenolic compounds and other nutrients. Edible fungi have rich extracellular enzyme systems; are environmentally friendly and safe for consumption; and have been shown to effectively degrade lignin and cellulose. This study aimed to screen edible fungi that can effectively ferment undehusked foxtail millet, improving its nutritional value and antioxidant properties through solid-state fermentation (SSF). The results demonstrated that fermentation utilizing Pleurotus geesteranus exhibited significant improvements in both the phenolic compound content and antioxidant properties of foxtail millet, with the optimal fermentation period determined to be 30 days. The physical and functional properties of fermented undehusked foxtail millet (FFM) flour were effectively improved, increasing crude protein, vitamin C, and crude polysaccharide contents by 11.46%, 27.78%, and 54.17%, respectively. In vitro scavenging activities of FFM were 73.19%, 93.86%, and 63.75% for 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS·+), and superoxide anion radicals (O2 -), respectively. The total antioxidant capability (T-AOC) and superoxide dismutase (SOD) activity of FFM were 1.01 mM Trolox equivalents (TE)/g and 89.05 U/g, respectively. Additionally, T-AOC, SOD, and glutathione peroxidase (GSH-Px) activities increased, whereas malondialdehyde (MDA) levels decreased in the heart, liver, and kidneys of mice treated with FFM flour, indicating enhanced antioxidant capacity. Therefore, fermentation with edible fungi is suitable for improving the nutritional composition and antioxidant properties of foxtail millet.

Effect of fermentation on nutrient composition, antinutrients, and mineral bioaccessibility of finger millet based Injera: A traditional Ethiopian food

Finger millet, like other cereals, contains high amounts of antinutrients that bind minerals, making them unavailable for absorption. This study explores the effect of traditional fermentation on nutritional, antinutritional, and subsequent mineral bioaccessibility (specifically iron, zinc, and calcium) of finger millet based Injera. Samples of fermented dough and Injera prepared from light brown and white finger millet varieties were analyzed for nutritional composition, antinutritional content, and mineral bioaccessibility following standard procedures. With some exceptions, the proximate composition of fermented dough was significantly affected by fermentation time. Compared to unfermented flour, the phytate and condensed tannin content significantly (p < 0.05) decreased for fermented dough and Injera samples. A strong decline in phytate and condensed tannin content was observed in white finger millet Injera as fermentation time increased, compared to light brown finger millet based Injera. The mineral bioaccessibility of Injera prepared from finger millet and maize composite flour increased with fermentation time, leading to a significant increase in bioaccessible iron, zinc, and calcium, ranging from 15.4-40.0 %, 26.8-50.8 %, and 60.9-88.5 %, respectively. The results suggest that traditional fermentation can be an effective method to reduce phytate and condensed tannin content, simultaneously increasing the bioaccessibility of minerals in the preparation of finger millet based Injera.

Effects of germination time on the structure, functionality, flavour attributes, and in vitro digestibility of green Altamura lentils (Lens culinaris Medik.) flour

There has been an increase in the use of adoptable bioprocessing methods for the development of high-quality leguminous ingredients. The potential use of germinated green Altamura lentils as a food ingredient is closely related to the resulting properties. The objective of this study was to evaluate the impact of three germination times - 0 (C), 24 (G) and 48 (H) hours - on the physicochemical, microstructural, flavour, functional, and nutritional features of lentil flour samples (CF, GF and HF). Lentil flour samples were obtained by grinding both whole green seeds (C) and germinated seeds (G and H), and then sifting them to obtain a particle size < 300 μm. The germinated samples - GF (24 h) and HF (48 h) - exhibited differences (P < 0.05) in the physicochemical and bioactive properties of CF (control). Similarly, compared with those in the control sample, the total starch, amylose and total phenolic contents in the GF and HF samples decreased, while the protein content increased (p < 0.05). A decrease in the presence of intact starch granules was observed via SEM in the germinated samples. The germination time had a significant (P < 0.05) effect on the colour indices, L*, a*, and b* of the samples. Flavour attributes were significantly influenced by the germination time. Overall, a total of 14 (CF) and 17 (GF and HF) aromatic compounds were identified. The technological characteristics of the CF, GF and HF dough samples were studied using a Brabender farinograph. Germination time affects the flour properties, leading to a significant decrease in farinographic parameters such as water absorption (WA), dough development time (DT), and dough stability (DS) and an increase in the degree of dough weakening (DOS). Differential scanning calorimetry was employed to examine the gelatinization transition of the samples. Germination strongly influenced all the thermal properties of the samples. It also had a significant impact on the in vitro starch digestibility, starch fraction and glycaemic index (eGI) of the samples. In particular, the eGI of germinated lentils was lower than that of the CF. In conclusion, the germination time could be a key factor modulating some crucial lentil flour properties.

Physicochemical properties, anti-nutritional and bioactive constituents, in vitro digestibility, and techno-functional properties of bioprocessed whole wheat flour

This study investigated the impact of bioprocessing techniques (germination, solid-state fermentation, the combination of germination, and solid-state fermentation) on the physicochemical properties, anti-nutritional and bioactive constituents, in vitro digestibility, and techno-functional properties of whole wheat grains were investigated. Bioprocessed whole wheat flour (WWF) samples and the raw flour (control) were prepared using standard procedures. Proximate, anti-nutritional, mineral and amino acid (AA) compositions, protein digestibility, antioxidant activities, starch characteristics, and techno-functional properties were studied using standard methods. The bioprocessing methods increased (p ≤ 0.05) the protein (13.37-16.84 g/100 g), total dietary fiber, mineral constituents, resistant starch (7.19-9.87 g/100 g), slowly digestible starch, phenolic content, antioxidant activities (ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity), most AAs, and protein digestibility. Also observed were decreases (p ≤ 0.05) in rapidly digestible starch, phytic acid, tannin, and trypsin inhibitor activity. The adopted bioprocessing techniques modified the thermal, functional, color, and pasting properties of the WWF and resulted in molecular interactions in some functional groups, as revealed by Fourier transform infrared spectroscopy, compared to the raw flour. The combination of germination and fermentation improved the physicochemical (titratable acidity = 4.93%), protein (16.84/100 g) and starch digestibility (resistant starch = 9.87%), antioxidant (FRAP = 78.90 mg/GAE/100 g), and mineral contents (calcium = 195.28 mg/100 g), modified the pasting (peak viscosity = 90.34 RVU), thermal (peak temperature = 64.82°C), and color properties of WWF with reduced anti-nutritional factors. The combination of these processing techniques could serve as a natural and low-cost technique for the modification of whole wheat functionality and subsequently as an improved functional ingredient during food product development.

A review of the effects of fermentation on the structure, properties, and application of cereal starch in foods

Fermentation is one of the oldest food processing techniques known to humans and cereal fermentation is still widely used to create many types of foods and beverages. Starch is a major component of cereals and the changes in its structure and function during fermentation are of great importance for scientific research and industrial applications. This review summarizes the preparation of fermented cereals and the effects of fermentation on the structure, properties, and application of cereal starch in foods. The most important factors influencing cereal fermentation are pretreatment, starter culture, and fermentation conditions. Fermentation preferentially hydrolyzes the amorphous regions of starch and fermented starches have a coarser appearance and a smaller molecular weight. In addition, fermentation increases the starch gelatinization temperature and enthalpy and reduces the setback viscosity. This means that fermentation leads to a more stable and retrogradation-resistant structure, which could expand its application in products prone to staling during storage. Furthermore, fermented cereals have potential health benefits. This review may have important implications for the modulation of the quality and nutritional value of starch-based foods through fermentation.

Screening and characterization of lactic acid bacteria and fermentation of gamma-aminobutyric acid-enriched bamboo shoots

In order to produce fermented bamboo shoots with functional properties, two strains of lactic acid bacteria were selected for inoculation and fermentation. One strain, Lactiplantibacillus plantarum R1, exhibited prominent potential probiotic properties (including gastrointestinal condition tolerance, adhesion ability, antimicrobial ability, and antibiotic resistance), while the other, Levilactobacillus brevis R2, demonstrated the capability of high γ-aminobutyric acid (GABA) production (913.99 ± 14.2 mg/L). The synergistic inoculation of both strains during bamboo shoot fermentation led to a remarkable increase in GABA content (382.31 ± 12.17 mg/kg), surpassing that of naturally fermented bamboo shoots by more than 4.5 times and outperforming mono-inoculated fermentation. Simultaneously, the nitrite content was maintained at a safe level (5.96 ± 1.81 mg/kg). Besides, inoculated fermented bamboo shoots exhibited an increased crude fiber content (16.58 ± 0.04 g/100 g) and reduced fat content (0.39 ± 0.02 g/100 g). Sensory evaluation results indicated a high overall acceptability for the synergistically inoculated fermented bamboo shoots. This study may provide a strategy for the safe and rapid fermentation of bamboo shoots and lay the groundwork for the development of functional vegetable products enriched with GABA.

Germination and probiotic fermentation: a way to enhance nutritional and biochemical properties of cereals and millets

Probiotics have become increasingly popular as consumers demand balanced nutrition and health benefits from their diet. However, lactose intolerance and allergies to milk proteins may make dairy-based probiotics unsuitable for some individuals. Thus, probiotics derived from cereals and millets have shown promise as an alternative to dairy probiotics. Soaking, germination, and fermentation can reduce the anti-nutritional factors present in cereal grains and improve nutrient quality and bioactive compounds. Biochemical properties of probiotics are positively influenced by fermentation and germination. Thus, the current review provides an overview of the effect of fermentation and germination on the biochemical properties of probiotics. Further, probiotics made from non-dairy sources may prevent intestinal infections, improve lactose metabolism, reduce cholesterol, enhance immunity, improve calcium absorption, protein digestion, and synthesize vitamins. Finally, health-conscious consumers seeking non-dairy probiotic options can now choose from a wider variety of low-cost, phytochemically rich probiotics derived from germinated and fermented cereal grains.

Complementary nutritional and health promoting constituents in germinated and probiotic fermented flours from cowpea, sorghum and orange fleshed sweet potato

Germination and fermentation are age-long food processes that beneficially improve food composition. Biological modulation by germination and probiotic fermentation of cowpea, sorghum, and orange-fleshed sweet potato (OFSP) and subsequent effects on the physicochemical (pH and total titratable acidity), nutritional, antinutritional factors and health-promoting constituents/properties (insoluble dietary fibres, total flavonoid and phenolic contents (TFC and TPC) and antioxidant capacity) of the derived flours were investigated in this study. The quantification of targeted compounds (organic acids and phenolic compounds) on an ultra-high performance liquid chromatography (UHPLC) system was also done. The whole cowpea and sorghum were germinated at 35 °C for 48 h. On the other hand, the milled whole grains and beans and OFSP were fermented using probiotic mesophilic culture at 35 °C for 48 h. Among the resultant bioprocessed flours, fermented sorghum and sweet potato (FSF and FSP) showed mild acidity, increased TPC, and improved ferric ion-reducing antioxidant power. While FSF had better slowly digestible and resistant starches and the lowest oxalate content, FSP indicated better hemicellulose, lowest fat, highest luteolin, caffeic and vanillic acids. Germinated cowpea flour exhibited reduced tannin, better lactic acid, the highest crude fibre, cellulose, lignin, protein, fumaric, L-ascorbic, trans-ferulic and sinapic acids. The comparable and complementary variations suggest the considerable influence of the substrate types, followed by the specific processing-based hydrolysis and biochemical transitions. Thus, compositing the bioprocessed flours based on the unique constituent features for developing functional products from climate-smart edibles may partly be the driver to ameliorating linked risk factors of cardiometabolic diseases.

Effect of malting on physicochemical, antioxidant, and microstructural properties of finger millet (Eleusine coracana) flours

Finger millet (Eleusine coracana L. Gaertn.) is a gluten-free crop with a high amount of fiber, calcium and iron, outstanding malting qualities and a low glycemic index. The study aimed to determine the physicochemical, functional, antioxidant and microstructural properties of malted finger millet (light and dark brown) flours. The two varieties of finger millet grains were germinated for 0, 24, 48 and 72 h and kilned for 8 h. The lightness (L*) values of malted finger millet flours significantly increased, with light brown having the highest L* value of 76.62. The hue angle and total color differences (ΔE) of the malted finger millet flours increased significantly (p ≤ .05.), and values ranged from 63.43° to 71.20° (light brown) and 2.12° to 4.32° (dark brown), respectively. The moisture, ash, fiber, protein, total phenolic, total flavonoids contents and DPPH activity of both malted finger millet flours significantly increased. On the contrary, the fat, carbohydrate, energy contents and FRAP activity significantly decreased with each malting period of both finger millet flours. Both malted finger millet flours' solubility index, water and oil absorption capacity increased significantly while the packed and loose bulk density decreased. Malting had no significant effect on the viscosity of the cold paste; however, a significant decrease in the viscosity of the cooked paste in both finger millet flours was observed, with values ranging from 285 to 424.00 cP (light brown) and 271.33 to 418.00 cP (dark brown), respectively. Malting resulted in changes in the thermal properties of finger millet flours with an increase in the onset, peak and conclusion temperatures. Fourier-Transform Infrared Spectra showed that malting slightly changed the peaks of both finger millet flours. Scanning electron microscopy showed that malting altered the microstructural characteristics of finger millet flours. The results showed that malted finger millet flours are promising raw materials for gluten-free bakery products.

The Effect of Germination and Fermentation on the Physicochemical, Nutritional, and Functional Quality Attributes of Samh Seeds

This study investigated the effects of fermentation and germination on the physicochemical, nutritional, functional, and bioactive quality attributes of samh seeds. Regardless of the processing treatment, samh seeds were found to be a rich source of phenolic compounds, namely gallic acid (79.6-96.36 mg/100 g DW), catechol (56.34-77.34 mg/100 g DW), and catechin (49.15-84.93 mg/100 g DW), and they possessed high DPPH antiradical activity (65.27-78.39%). They also contained high protein content (19.29-20.41%), essential amino acids content (39.07-44.16% of total amino acids), and unsaturated fatty acid content (81.95-83.46% of total fatty acids) and a low glycemic index (39.61-41.43). Fermentation and germination increased L*, b*, foaming capacity, oil absorption capacity (OAC), water absorption capacity (WAC), swelling power, microbial counts, antioxidant activity, total flavonoid content (TFC), total phenolic content (TPC), in vitro protein digestibility, protein efficiency ratio, and total essential amino acids and reduced water solubility, emulsion stability, tannin, and phytate contents compared to raw samh seeds (p < 0.05). The highest levels of pH, ash, carbohydrate, fiber, and glycemic index were observed in raw samh seeds, and both germination and fermentation processes reduced these attributes to various degrees (p < 0.05). Germination increased the redness (a*), moisture content, essential and non-essential amino acids, potassium, zinc, phosphorous, stearic acid, and oleic and unsaturated fatty acids and reduced total solids, fat content, iron, zinc, calcium, magnesium, sodium, palmitic acid, and total saturated fatty acids of the samh seeds compared to the raw ones. Fermentation increased the total solid, acidity, fat, protein, calcium, magnesium, sodium, phosphorous, iron, zinc, palmitic acid, and total saturated fatty acids and reduced the a* value, moisture, non-essential amino acids, and total unsaturated fatty acids of the samh seeds compared to the raw ones. In conclusion, samh seeds are a rich source of nutrients that could generally be enhanced by germination and fermentation processes. The reported information facilitates strategies towards the application of these underutilized seeds in foods.

Impacts of Solid-State Fermented Barley with Fibrolytic Exogenous Enzymes on Feed Utilization, and Antioxidant Status of Broiler Chickens

The present and future high demand of common cereals as corn and wheat encourage the development of feed processing technology that allows for the dietary inclusion of other cereals of low nutritional value in poultry feeding. Barley grains contain anti-nutritional factors that limit their dietary inclusion in the poultry industry. The treatment of barley with solid-state fermentation and exogenous enzymes (FBEs) provides a good alternative to common cereals. In this study, barley grains were subjected to solid-state microbial fermentation using Lactobacillus plantarum, Bacillus subtilis and exogenous fibrolytic enzymes. This study aimed to assess the impact of FBEs on growth, feed utilization efficiency, immune modulation, antioxidant status and the expression of intestinal barrier and nutrient transporter-related genes. One-day-old broiler chicks (Ross 308, n = 400) comprised four representative groups with ten replicates (10 chicks/replicate) and were fed corn-soybean meal basal diets with inclusions of FBEs at 0, 5, 10 and 15% for 38 days. Solid-state fermentation of barley grains with fibrolytic enzymes increased protein content, lowered crude fiber and reduced sugars compared to non-fermented barley gains. In consequence, the group fed FBEs10% had the superior feed utilization efficiency and body weight gain (increased by 4.7%) with higher levels of nutrient metabolizability, pancreatic digestive enzyme activities and low digesta viscosity. Notably, the group fed FBEs10% showed an increased villi height and a decreased crypt depth with a remarkable hyperactivity of duodenal glands. In addition, higher inclusion levels of FBEs boosted serum immune-related parameters and intestinal and breast muscle antioxidants status. Intestinal nutrient transporters encoding genes (GLUT-1, CAAT-1, LAT1 and PepT-1) and intestinal barriers encoding genes (MUC-2, JAM-2, occludin, claudins-1 and β-defensin 1) were upregulated with higher dietary FBEs levels. In conclusion, feeding on FBEs10% positively enhanced broiler chickens' performance, feed efficiency and antioxidant status, and boosted intestinal barrier nutrient transporters encoding genes.

Nutritional and physicochemical changes in two varieties of fonio (Digitaria exilis and Digitaria iburua) during germination

Germination is a cheap and effective bioprocessing technique used for improvement of the nutritional, physicochemical and health-promoting properties of seeds. The benefits of germination on two fonio varieties (Digitaria exilis and Digitaria iburua) have not been studied. This study investigated the nutritional and physicochemical changes in two varieties of fonio germinated for 24, 48 and 72 h at 28 °C. The antioxidant, protein and starch digestibility, functional, pasting, and thermal properties were also determined. Germination over time (24, 48, 72 h) significantly (p ≤ 0.05) increased the protein, ash, total dietary fiber, majority of the amino acids, minerals, protein digestibility, resistant starch, total phenolics and antioxidant activities while phytic acid, tannin, saponin and digestible starch contents decreased in both varieties. Germination significantly increased water and oil absorption capacity, and slightly modified pasting and thermal characteristics while bulk density decreased in both varieties. The principal component analysis revealed germination time to be the key determinant in the physicochemical, nutritional, and techno-functional characteristics of fonio rather than variety, with raw and 24 h germinated grains having similar attributes. The study established that germination improved the nutritional, antioxidant, and techno-functional properties of Digitaria exilis and Digitaria iburua, which can serve as novel food ingredients for product development.

Effect of Sprouting on Biomolecular and Antioxidant Features of Common Buckwheat (Fagopyrum esculentum)

Buckwheat is a pseudo-cereal widely grown and consumed throughout the world. Buckwheat is recognized as a good source of nutrients and, in combination with other health-promoting components, is receiving increasing attention as a potential functional food. Despite the high nutritional value of buckwheat, a variety of anti-nutritional features makes it difficult to exploit its full potential. In this framework, sprouting (or germination) may represent a process capable of improving the macromolecular profile, including reducing anti-nutritional factors and/or synthesizing or releasing bioactives. This study addressed changes in the biomolecular profile and composition of buckwheat that was sprouted for 48 and 72 h. Sprouting increased the content of peptides and free-phenolic compounds and the antioxidant activity, caused a marked decline in the concentration of several anti-nutritional components, and affected the metabolomic profile with an overall improvement in the nutritional characteristics. These results further confirm sprouting as a process suitable for improving the compositional traits of cereals and pseudo-cereals, and are further steps towards the exploitation of sprouted buckwheat as a high-quality ingredient in innovative products of industrial interest.

Millet Fermented by Different Combinations of Yeasts and Lactobacilli: Effects on Phenolic Composition, Starch, Mineral Content and Prebiotic Activity

Millet is the sixth-highest yielding grain in the world and a staple crop for millions of people. Fermentation was applied in this study to improve the nutritional properties of pearl millet. Three microorganism combinations were tested: Saccharomyces boulardii (FPM1), Saccharomyces cerevisiae plus Campanilactobacillus paralimentarius (FPM2) and Hanseniaspora uvarum plus Fructilactobacillus sanfranciscensis (FPM3). All the fermentation processes led to an increase in minerals. An increase was observed for calcium: 254 ppm in FPM1, 282 ppm in FPM2 and 156 ppm in the unfermented sample. Iron increased in FPM2 and FPM3 (approx. 100 ppm) with respect the unfermented sample (71 ppm). FPM2 and FPM3 resulted in richer total phenols (up to 2.74 mg/g) compared to the unfermented sample (2.24 mg/g). Depending on the microorganisms, it was possible to obtain different oligopeptides with a mass cut off ≤10 kDalton that was not detected in the unfermented sample. FPM2 showed the highest resistant starch content (9.83 g/100 g) and a prebiotic activity on Bifidobacterium breve B632, showing a significant growth at 48 h and 72 h compared to glucose (p < 0.05). Millet fermented with Saccharomyces cerevisiae plus Campanilactobacillus paralimentarius can be proposed as a new food with improved nutritional properties to increase the quality of the diet of people who already use millet as a staple food.

Sustainable plant-based ingredients as wheat flour substitutes in bread making

Bread as a staple food has been predominantly prepared from refined wheat flour. The world's demand for food is rising with increased bread consumption in developing countries where climate conditions are unsuitable for wheat cultivation. This reliance on wheat increases the vulnerability to wheat supply shocks caused by force majeure or man-made events, in addition to negative environmental and health consequences. In this review, we discuss the contribution to the sustainability of food systems by partially replacing wheat flour with various types of plant ingredients in bread making, also known as composite bread. The sustainable sources of non-wheat flours, their example use in bread making and potential health and nutritional benefits are summarized. Non-wheat flours pose techno-functional challenges due to significantly different properties of their proteins compared to wheat gluten, and they often contain off-favor compounds that altogether limit the consumer acceptability of final bread products. Therefore, we detail recent advances in processing strategies to improve the sensory and nutritional profiles of composite bread. A special focus is laid on fermentation, for its accessibility and versatility to apply to different ingredients and scenarios. Finally, we outline research needs that require the synergism between sustainability science, human nutrition, microbiomics and food science.

The Influence of Different Pretreatment Methods of Highland Barley by Solid-State Fermentation with Agaricus sinodeliciosus var. Chaidam ZJU-TP-08 on Its Nutrient Content, Functional Properties and Physicochemical Characteristics

To enhance the nutritional value of highland barley (HB), this work investigated the effects of solid-state fermentation (SSF) by Agaricus sinodeliciosus var. Chaidam ZJU-TP-08 on nutrient content, phenolic components, antioxidant activities, and physicochemical characteristics of HB upon different pretreatments (germination, ultrasound and soaking). The results showed that germinated highland barley (GHB) exhibited higher levels of ergosterol (0.19 ± 0.01 mg/g) in all fermentation groups. The content of β-glucan was higher in the SSF-GHB, with an increase of 24.21% compared to the control. The content of total amino acids, dietary fiber, total phenols and flavonoids were higher in the fermentation HB pretreated by ultrasound, increasing respectively by 5.60%, 61.50%, 25.10% and 65.32% compared to the control group. In addition, the colonized HB exhibited excellent physicochemical characteristics, including increased water solubility index and decreased pasting characteristics. Herein, the nutritional value and the biological activities were enriched in the pretreated HB through SSF, indicating its potential application for nutrition-enriched functional foods.

Mineral Content, Functional, Thermo-Pasting, and Microstructural Properties of Spontaneously Fermented Finger Millet Flours

Finger millet is a cereal grain which is superior to wheat and rice in terms of dietary fibre, minerals, and micronutrients. Fermentation is one of the oldest methods of food processing, and it has been used to ferment cereal grains such as finger millet (FM) for centuries. The aim of this study was to investigate the impact of spontaneous fermentation (SF) on mineral content, functional, thermo-pasting, and microstructural properties of light- and dark-brown FM flours. Spontaneous fermentation exhibited a significant increase in the macro-minerals and micro-minerals of FM flours. In terms of functional properties, SF decreased the packed bulk density and swelling capacity, and it increased the water/oil absorption capacity of both FM flours. Spontaneous fermentation had no effect on the cold paste viscosity of FM flours. However, significant decreases from 421.61 to 265.33 cP and 320.67 to 253.67 cP were observed in the cooked paste viscosity of light- and dark-brown FM flours, respectively. Moreover, SF induced alterations in the thermal properties of FM flours as increments in gelatinisation temperatures and gelatinisation enthalpy were observed. The results of pasting properties exhibited the low peak viscosities (1709.67 and 2695.67 cP), through viscosities (1349.67 and 2480.33 cP), and final viscosities (1616.33 and 2754.67 cP), along with high breakdown viscosities (360.00 and 215.33 cP) and setback viscosity (349.33 and 274.33 cP), of spontaneously fermented FM flours. Scanning electron microscopy showed that SF influenced changes in the microstructural properties of FM flours. The changes induced by SF in FM flours suggest that flours can be used in the food industry to produce weaning foods, jelly foods, and gluten-free products that are rich in minerals.

Nutritional Quality, Antioxidant, Microstructural and Sensory Properties of Spontaneously Fermented Gluten-Free Finger Millet Biscuits

Finger millet (FM) is a nutritious and gluten-free cereal grain which is rich in dietary fibre, minerals and antioxidant properties, thereby making it an ideal raw material for preparing gluten-free foods for people suffering from celiac disease. Spontaneous fermentation of FM grains has shown improved nutritional and functional properties of its flour and can be used as a functional ingredient for gluten free biscuits. The aim of this study was to determine the effect of spontaneous fermentation (SF) on the nutritional quality, antioxidant, microstructural, and sensory characteristics of gluten-free FM biscuits obtained from light and dark brown FM flours. Results showed that SF decreased ash, crude fibre, and crude fat contents as well as total phenolic and flavonoids contents. Protein content, carbohydrates content, energy values, antioxidant activity (DPPH and FRAP), and mineral content of FM biscuits increased due to SF. The colour properties such as lightness (L*), showed a significant increase as SF period increased in light brown FM biscuits, however dark brown FM biscuits showed no significant difference. The hue angle and colour differences (ΔE) of FM biscuits increased with the increasing period of SF, ranging from 43.20 to 53.76° and from 0.67 to 7.96, respectively. Spontaneous fermentation also decreased physical properties of biscuits such as diameter (4.76 to 4.54 cm), weight (12.77 to 11.99 g), and spread ratio (7.25 to 6.05), while an increase in thickness and hardness was noted. Spontaneous fermentation also induced changes on the microstructure of FM biscuits. Among the fermented biscuits, panelists preferred 24 h gluten-free fermented FM biscuits since they had better sensory properties. Overall, SF enhanced the nutritional value and health promoting compounds of gluten-free FM biscuits.