The Impact of Germination on Sorghum Nutraceutical Properties

Optimization of the germination time of proso and foxtail millets to enhance the bioactive properties, antioxidant activity, and enzymatic power and reduce antinutritional factor

The germination of millets is a traditional yet underutilized method to enhance their nutritional and functional attributes. This study investigates the impact of germination time on the bioactive, enzymatic, and antinutritional properties of proso millet (Chino Dude) and foxtail millet (Kaguno Red and Kaguno White) varieties. Germination was conducted over five days (0-5 days), and changes in total phenolic and flavonoid content, tannin content, antioxidant activity, diastatic power, α-amylase activity, reducing sugars, and trypsin inhibition activity were measured. A two-way ANOVA revealed significant effects (p < 0.05) of varietal differences and germination time on these properties. Total phenolic and flavonoid content and antioxidant activity increased significantly (p < 0.05) unit day 3 of germination after which it decreased until day 5. Tannin content and trypsin inhibitor decreased significantly (p < 0.05) from day 1 to day 5 of germination, whereas diastatic power and α-amylase increased (p < 0.05) with an increase in germination time. The optimal germination time was determined to be 3.46 days using multiple regression models to maximize bioactive compounds and enzymatic activity while minimizing antinutritional factors. Moreover, Kaguno Red exhibited the highest bioactive levels, while Kaguno White had the lowest trypsin inhibition activity, indicating varietal-specific differences in analyzed parameters. This study highlights the potential of tailored germination strategies to enhance the nutritional and functional profiles of millets, providing actionable insights for functional food development in regions reliant on millet as a staple crop.

Exploring the potential of sorghum with reference to its bioactivities, physicochemical properties and potential health benefits

Sorghum, belonging to the Poaceae family, is a widely consumed grain, particularly in Africa. Sorghum grains have been used in traditional African diets for centuries. These grains, along with their products, are known for their high nutritional value and possess various bioactive properties, including antioxidant, anti-obesity, anti-diabetic, anti-cardiovascular, anti-inflammatory, antimicrobial, and anticancer activities. Despite these benefits, sorghum grains face challenges due to the presence of certain anti-nutritional components such as tannins, phytates, trypsin inhibitors, and protein crosslinkers. Processing techniques such as soaking, germination, fermentation, thermal processing, and irradiation can improve the nutritional quality of sorghum by reducing anti-nutritional factors. Among these, fermentation, particularly when combined with other methods like soaking and germination, is considered most effective in enhancing the grain's nutritional value. This review addresses the current knowledge gaps regarding sorghum's nutritional and phytochemical composition and its potential health benefits. It also emphasizes the importance of further research to enhance sorghum's inherent nutritional attributes and promote its use as a sustainable crop to address global food security challenges. The findings highlight sorghum's potential in improving dietary quality and contributing to better health outcomes worldwide.

Effect of fermentation, malting and ultrasonication on sorghum, mopane worm and Moringa oleifera: improvement in their nutritional, techno-functional and health promoting properties

Background

Food processing offers various benefits that contribute to food nutrition, food security and convenience. This study investigated the effect of three different processes (fermentation, malting and ultrasonication) on the nutritional, techno-functional and health-promoting properties of sorghum, mopane worm and Moringa oleifera.

Methods

The fermented and malted flours were prepared at 35°C for 48 h, and for ultrasonication, samples were subjected to 10 min at 4°C with amplitudes of 40-70 Hz. The biochemical, nutritional quality and techno-functional properties of the obtained flours were analysed using standard procedures.

Results

Fermentation resulted in significantly lower pH and higher titratable acidity in sorghum and mopane worm (4.32 and 4.76; 0.24 and 0.69% lactic acid, respectively), and malting resulted in higher total phenolic content and total flavonoid content in sorghum (3.23 mg GAE/g and 3.05 mg QE/g). Ultrasonication resulted in higher protein and fibre in raw sorghum flour (13.38 and 4.53%) and mopane worm (56.24 and 11.74%) while raw moringa had the highest protein (30.68%). Biomodification by fermentation in sorghum led to higher water and oil holding capacity and increased dispersibility in the ultrasonicated samples. Ultrasonication of mopane worms led to higher water holding capacity, oil holding capacity and dispersibility. Lightness was found to be significantly higher in the fermented samples in sorghum and mopane worm. Raw moringa had the greatest lightness compared to the ultrasonicated moringa. Moringa had the most redness and browning index among all samples.

Conclusion

In this study, all the investigated processes were found to have caused variations in flours' biochemical, nutritional and techno-functional properties. Ultrasonication process was noteworthy to be the most efficient to preserve the nutritional value in sorghum, mopane worm and M. oleifera flours.

Functional, nutritional, and sensorial evaluation of sorghum-based beverages produced by single- and two-stage acid, α-amylase enzyme, and germination treatments

Nowadays, the consumption of functional foods, such as plant-based beverages, is increasing due to their health-promoting properties. The low extraction yield of nutritional and functional components is considered a major challenge during the production of sorghum-based beverages (SBB), as well as their sensorial properties. This investigation studied the effects of various treatments (acidic using phosphoric acid, enzymatic using α-amylase, germination, germination-acidic, germination-enzymatic, and acidic-enzymatic) on the functional, nutritional, and sensorial properties of SBB. The two-stage acidic-enzymatic treatment demonstrated the highest extraction yield, dry matter, ash, carbohydrates, and reducing sugar contents, as well as the lowest starch content (p < .05). Furthermore, the highest protein content (0.98%) was achieved by the germination treatments of sorghum grains. While the highest fat content was achieved by the acidic treatment (1.38%), the germination-acidic treatment exhibited the highest energy value (26.02 kcal/100 mL). Moreover, the total phenolic content of the acidic-enzymatic treatment (44.56 mg GAE/L) was significantly higher than that of other treatments. However, all treatments demonstrated lower antioxidant properties compared to the control treatment (142.85 mg BHT eq./L). Furthermore, the sensory evaluation of the germination and germination-enzymatic treatments showed acceptable scores (≥7) for consumers. In conclusion, the results indicated that the two-stage treatments of sorghum, especially the acidic-enzymatic treatment, were more effective than single treatments for the extraction of functional and nutritional components during the production of SBB.

Tracking the changes and bioaccessibility of phenolic compounds of sorghum grains (Sorghum bicolor (L.) Moench) upon germination and seedling growth by UHPLC-QTOF-MS/MS

In this study, phenolic profile/content was analyzed by high-resolution untargeted metabolomics after short germination (72 h) and seedling growth (144 h), using three sorghum genotypes varying in tannin content (IS 29569, Macia and IS 30400). In vitro antioxidant capacity and phenolic bioaccessibility were determined by microplate-based and INFOGEST methods, respectively. A total of 58 % annotated compounds were found in all genotypes; and phenolic acids and flavonoids represent more than 80 % of sorghum total abundance. PCA analysis showed higher phenolic variability in germination times (72 %) than genotypes (51 %). Germination reduced total ion abundance (-7 %) and free:bound phenolic compounds ratio (2.4-1.1), but antioxidant capacity remained constant. These results indicate the cell matrix-phenolic decomplexation, with the free compounds were quickly consumed after radicle emergence. Germination increased phenolic bioaccessibility (mainly in oral phase) but reduces flavonoids contents in gastric/intestinal digestion steps. This work can stimulate seed germination as a viable option for sorghum-based foods development, with improved nutritional and bioactive properties.

Utilization of Germinated Seeds as Functional Food Ingredients: Optimization of Nutrient Composition and Antioxidant Activity Evolution Based on the Germination Characteristics of Chinese Chestnut (Castanea mollissima)

The current study investigated the impact of germination duration on the functional components (vitamin C, γ-aminobutyric acid (GABA), polyphenols, flavonoids) and antioxidant activity of germs and cotyledons of the germinated Chinese chestnut (Castanea mollissima). We utilized seeds of the "Zaofeng" Chinese chestnut to germinate, and sowed the seeds in wet sand at 22 °C and 85% relative humidity. The germination rate, length, diameter, and fresh weight of the sprouts were investigated at 0, 2, 4, 6, 8, and 10 days after sowing, and the kinetic changes of amylose, amylopectin, sugar components, soluble protein, vitamin C, GABA, total phenols, flavonoids, and the DPPH and ABTS free radical scavenging activity in the germs and cotyledons were monitored, respectively. The findings revealed that the germination rate and germ biomass increased continuously during germination. The germination rate reached 90% on the 8th day after sowing. Germination reduced amylose in cotyledons from 42.3% to 34.2%, amylopectin from 42.9% to 25.8%, total sugar from 12.6% to 11.4%, and vitamin C from 1.45 mg/g to 0.77 mg/g. Meanwhile, soluble protein in the embryos rose from 0.31% to 0.60%, vitamin C from 21.1 to 29.4 mg/g, GABA from 0.49 to 1.68 mg/g, total flavonoids from 53.6 to 129.7 mg/g, and ABTS antioxidant activity from 1.52 to 3.27 μmol TE/g. The average contents of D-fructose, inositol, vitamin C, GABA, polyphenols, and flavonoids and the DPPH and ABTS antioxidant activity in germs were as high as 22.5, 6, 35, 7.5, 10, 20, and 10 and 20-fold those of cotyledons, respectively. Especially, the average content of glucose in germ was as high as 80-fold that of cotyledon. D-xylulose, D-galacturonic acid, and D-ribose were only found in germs, but not in cotyledons. Considering the germ biomass and functional components content, germs of Chinese chestnuts germinated at 22 °C for 8 days are considered the most suitable raw material for functional food products. In conclusion, controlled germination not only enhances the physicochemical and functional properties of Chinese chestnut germs but also reduces the caloric content and improves the nutritional composition of the cotyledons appropriately. Moreover, the comprehensive evaluation of compositional changes and functionality in the embryo and cotyledon of Chinese chestnuts will provide a solid foundation for subsequent functional food processing utilizing germinated Chinese chestnuts.

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.

Unlocking the Potential of Sprouted Cereals, Pseudocereals, and Pulses in Combating Malnutrition

Due to the global rise in food insecurity, micronutrient deficiency, and diet-related health issues, the United Nations (UN) has called for action to eradicate hunger and malnutrition. Grains are the staple food worldwide; hence, improving their nutritional quality can certainly be an appropriate approach to mitigate malnutrition. This review article aims to collect recent information on developing nutrient-dense grains using a sustainable and natural process known as "sprouting or germination" and to discuss novel applications of sprouted grains to tackle malnutrition (specifically undernutrition). This article discusses applicable interventions and strategies to encourage biochemical changes in sprouting grains further to boost their nutritional value and health benefits. It also explains opportunities to use spouted grains at home and in industrial food applications, especially focusing on domestic grains in regions with prevalent malnutrition. The common challenges for producing sprouted grains, their future trends, and research opportunities have been covered. This review article will benefit scientists and researchers in food, nutrition, and agriculture, as well as agrifood businesses and policymakers who aim to develop nutrient-enriched foods to enhance public health.

Modification on phenolic profiles and enhancement of antioxidant activity of proso millets during germination

Changes in phenolic profiles and antioxidant activity of three varieties of proso millet during germination were investigated. Total phenolic content (TPC) and total flavonoid content (TFC) increased significantly with prolongation in germination period. After germination for 6 days, TPC of the free and bound fractions increased 6.30-8.66-fold and 77.65-116.18%, respectively. The free and bound phenolic compounds identified by UPLC-MS/MS, displayed significant variations. Feruloylquinic acid and N,N'-bis-(p-coumaroyl)-putrescine biosynthesized during germination, are reported for the first time in proso millets. Other phenolics including trans- and cis-ferulic, trans-p-coumaric, vanillic acid and ferulic acid dimers (DFAs) were increased significantly along with a new DFA (8,5'-DFA) seemingly produced during germination. The germinated proso milllets displayed superior antioxidant activity than the corresponding ungerminated samples indicating that germination could be one applicable method for improving phenolic profiles and antioxidant capacity of proso millets. Thus germinated proso millet could be exploited as a functional ingredient in several products.

Genome-Wide Association Study of Seed Morphology Traits in Senegalese Sorghum Cultivars

Sorghum is considered the fifth most important crop in the world. Despite the potential value of Senegalese germplasm for various traits, such as resistance to fungal diseases, there is limited information on the study of sorghum seed morphology. In this study, 162 Senegalese germplasms were evaluated for seed area size, length, width, length-to-width ratio, perimeter, circularity, the distance between the intersection of length & width (IS) and center of gravity (CG), and seed darkness and brightness by scanning and analyzing morphology-related traits with SmartGrain software at the USDA-ARS Plant Science Research Unit. Correlations between seed morphology-related traits and traits associated with anthracnose and head smut resistance were analyzed. Lastly, genome-wide association studies were performed on phenotypic data collected from over 16,000 seeds and 193,727 publicly available single nucleotide polymorphisms (SNPs). Several significant SNPs were found and mapped to the reference sorghum genome to uncover multiple candidate genes potentially associated with seed morphology. The results indicate clear correlations among seed morphology-related traits and potential associations between seed morphology and the defense response of sorghum. GWAS analysis listed candidate genes associated with seed morphologies that can be used for sorghum breeding in the future.

Sourdough Fermentation Improves the Antioxidant, Antihypertensive, and Anti-Inflammatory Properties of Triticum dicoccum

The fermentation process has been widely used to improve plant-based foods’ nutritional and nutraceutical properties. This study aimed to investigate and compare the impact of sourdough fermentation on the bioactive content and profile, antioxidant and antihypertensive activities, as well as the anti-inflammatory properties of fermented (FS) and non-fermented (NFS) flour from Tuscan Triticum dicoccum wheat (spelt) on tumor necrosis factor-alpha (TNF-α)-inflamed human intestinal epithelial cells (HT-29). FS showed significantly higher total phenolic and flavonoid content, in vitro and ex vivo antioxidant activities, and ACE-inhibitory activities than NFS. Gallic acid was identified by HPLC-DAD as the most representative polyphenol, followed by rutin, trans-ferulic acid, iso-quercitrin, and quercetin, in the fermented spelt sample. Instead, rutin and gallic acid were identified as the predominant compounds in the non-fermented ones. Moreover, FS exhibited a better protective effect on inflamed HT-29 cells by significantly counteracting the TNFα-induced alterations, lowering the expression of IL-8, COX-2, and ICAM-1 inflammatory mediator while enhancing antioxidant enzyme HO-1 gene expression. In conclusion, sourdough fermentation positively affected the nutraceutical and functional properties of spelt, which may represent a valuable ingredient for the formulation of functional foods and a key product for managing hypertension and inflammatory intestinal diseases.

Bio-Functional Activities of Tuscan Bee Pollen

Bee pollen represents one of the most complete natural foods playing an important role in the diet for its health qualities and therapeutic properties. This work aimed to characterize a Tuscan bee pollen by evaluating its phytochemical profile and the in vitro and ex vivo antioxidant activities. The isolation and taxonomic and functional characterization of yeasts in the sample has been also conducted. Finally, the pollen anti-inflammatory potential has been assessed on a TNFα-inflamed human colorectal adenocarcinoma cell line (HT-29). Our results highlighted a good phytochemical composition in terms of polyphenols, flavonoids, flavonols, monomeric anthocyanins, and carotenoids. In addition, we detected good antioxidant activity and radical scavenging capacity by in vitro and ex vivo assays, as well as good antioxidant activity by isolated yeasts. Data showed no cytotoxic effects of bee pollen extracts, with average viability values >80% at each tested dose. Moreover, TNFα treatment did not affect HT-29 viability while upregulating IL-8, COX-2, and ICAM-1 gene expression, otherwise reduced by both doses of bee pollen. In conclusion, our sample represents an interesting functional food and a potential probiotic product, having high phytochemical compound levels and good antioxidant activities, as well as anti-inflammatory effects on the TNFα-inflamed HT-29 cell line.

Effects of Exogenous Caffeic Acid, L-Phenylalanine and NaCl Treatments on Main Active Components Content and In Vitro Digestion of Germinated Tartary Buckwheat

Germination is an effective method for improving the nutritional value of Tartary buckwheat (TB). The effects of exogenous additive treatments (caffeic acid (CA), L-phenylalanine (L-Phe), NaCl) on germination, main active component contents and antioxidant activities before and after in vitro digestion of germinated TB were investigated. Compared with the natural growth group, the T₄ group (CA 17 mg/L, L-Phe 2.7 mmol/L, NaCl 2.7 mmol/L) treatment increased the germination rate (67.50%), sprout length, reducing sugar (53.05%), total flavonoid (18.36%) and total phenolic (20.96%) content, and antioxidant capacity of TB. In addition, exogenous additives treatment induced the consumption of a lot of nutrients during seed germination, resulting in a decrease in the content of soluble protein and soluble sugar. The stress degree of natural germination on seeds was higher than that of low concentrations of exogenous additives, resulting in an increase in malondialdehyde content. In vitro digestion leads to a decrease in phenolics content and antioxidant capacity, which can be alleviated by exogenous treatment. The results showed that treatment with exogenous additives was a good method to increase the nutritional value of germinated TB, which provided a theoretical basis for screening suitable growth conditions for flavonoid enrichment.

Cereals as a Source of Bioactive Compounds with Anti-Hypertensive Activity and Their Intake in Times of COVID-19

Cereals have phytochemical compounds that can diminish the incidence of chronic diseases such as hypertension. The angiotensin-converting enzyme 2 (ACE2) participates in the modulation of blood pressure and is the principal receptor of the virus SARS-CoV-2. The inhibitors of the angiotensin-converting enzyme (ACE) and the block receptors of angiotensin II regulate the expression of ACE2; thus, they could be useful in the treatment of patients infected with SARS-CoV-2. The inferior peptides from 1 to 3 kDa and the hydrophobic amino acids are the best candidates to inhibit ACE, and these compounds are present in rice, corn, wheat, oats, sorghum, and barley. In addition, the vitamins C and E, phenolic acids, and flavonoids present in cereals show a reduction in the oxidative stress involved in the pathogenesis of hypertension. The influence of ACE on hypertension and COVID-19 has turned into a primary point of control and treatment from the nutritional perspective. The objective of this work was to describe the inhibitory effect of the angiotensin-converting enzyme that the bioactive compounds present in cereals possess in order to lower blood pressure and how their consumption could be associated with reducing the virulence of COVID-19.

Effect of stress on germination of djulis (Chenopodium formosanum Koidz.) sprouts: a natural alternative to enhance the betacyanin and phenolic compounds

BACKGROUND

Germination is regarded as a natural method for improving the bioavailability of seed nutrients against stress, which enhances the accumulation of bioactive compounds. The present study aimed to determine the effect of stress (H₂ O₂ , catechin, gallic acid, tyrosine, and NaCl) during germination of djulis (Chenopodium formosanum Koidz.) sprouts on betacyanin, phytochemicals, and antioxidant capacities.

RESULTS

The betacyanin and antioxidant activities of the djulis sprouts increased significantly compared to seeds. The lowest betacyanin was found in NaCl-stressed sprouts. The djulis sprouts reported the presence of celosianins I and II (50.72%), which was absent in seeds. Hydroxycinnamic acids accounted for > 60% of the total phenolic compounds in sprouts, whereas rutin predominated in the seeds.

CONCLUSION

Germination under stress may represent an effective natural method for improving the bioactive potential of sprouts, an alternative to use seeds, in the development of bioactive compounds-enriched healthy foods that are good for public health. © 2022 Society of Chemical Industry.

Potential food applications of sorghum (Sorghum bicolor) and rapid screening methods of nutritional traits by spectroscopic platforms

Sorghum is a drought-resistant crop widely spread in tropical regions of the American, African, and Asian continents. Sorghum flour is considered the main alternative for wheat flour, and it exhibits gluten-free nature. Generally, conventional wet chemical methods are used to analyze the nutritional profile of sorghum. Since many sorghum plants are available in breeding grounds, the application of conventional methods has limitations due to high cost and time consumption. Therefore, rapid screening protocols have been introduced as nondestructive alternatives. The current review highlights novel and portable devices that can be used to analyze the nutritional composition, color parameters, and pest resistance. Sorghum is often a traditional food item with minimal processing, and the review elaborates on emerging food applications and feasible food product developments from sorghum. The demand for gluten-free products has been rapidly increasing in developed countries. In order to develop food products according to market requirements, it is necessary to screen high-quality sorghum plants. Rapid analysis techniques effectively select the best sorghum types, and the novel tools have outperformed existing conventional methods.

Germinated Buckwheat: Effects of Dehulling on Phenolics Profile and Antioxidant Activity of Buckwheat Seeds

The aim was to investigate the effects of the cold dehulling of buckwheat seeds on their germination, total phenolic content (TPC), antioxidant activity (AA) and phenolics composition. Cold dehulling had no negative effects on germination rate and resulted in faster rootlet growth compared to hulled seeds. Although the dehulling of the seeds significantly decreased TPC and AA, the germination of dehulled seeds resulted in 1.8-fold and 1.9-fold higher TPC and AA compared to hulled seeds. Liquid chromatography coupled to mass spectrometry identified several phenolic compounds in free and bound forms. Rutin was the major compound in hulled seeds (98 µg/g dry weight), orientin and vitexin in 96-h germinated dehulled seeds (2205, 1869 µg/g dry weight, respectively). During germination, the increases in the major phenolic compounds were around two orders of magnitude, which were greater than the increases for TPC and AA. As well as orientin and vitexin, high levels of other phenolic compounds were detected for dehulled germinated seeds (e.g., isoorientin, rutin; 1402, 967 µg/g dry weight, respectively). These data show that dehulled germinated seeds of buckwheat have great potential for use in functional foods as a dietary source of phenolic compounds with health benefits.