Identification and Quantification of Phenolic Compounds and Bioactive Properties of Sorghum-cowpea-based Food Subjected to an In vitro Digestion Model

This work identified and quantified some phenolics compound in sorghum-cowpea porridge after subjection to in vitro digestion. Flours, porridge and digested porridge were analysed for total phenolics, total flavonoids, ABTS-radical scavenging capacity and specific phenolic acids and flavonoids. Total phenolics and flavonoid content of the gastric (346.1 µg CE/g; 35.2 µg CE/g) and intestinal phase digest (1389.8 µg CE/g; 142.6 µg CE/g) were lower than the composite flour (2720.1 µg CE/g; 220.9 µg CE/g) and while its porridge were (1218.4 µg CE/g; 173.8 µg CE/g). The ABTS-radical scavenging capacity of all samples ranged from 21.0 – 507.3 µg TE/g. The gastric phase and intestinal phase digests maintained 4.7% and 58.3% of the radical scavenging capacity of the porridge. Catechin and gallic acid were lower in the intestinal digest (2760.0 µg/g; 226.7 µg/g) than the undigested porridge (4188.3 µg/g; 193.9 µg/g). Sorghum-cowpea composite porridge contains phenolic antioxidants even after gastric and intestinal digestion with potential to significantly impact human health

Role of grain organisational structure in sorghum protein digestibility

Please read the abstract in the section 00front of this documentThesis (PhD (Food Science))--University of Pretoria, 2006.Food Scienceunrestricte

Antioxidant effect of a crude phenolic extract from sorghum bran in sunflower oil in the presence of ferric ions

Whole grain condensed tannin sorghum, its bran and a crude phenolic extract (CPE) prepared from the bran were evaluated for total phenols (TP), condensed tannins (CT) and antioxidant activity (AA). Antioxidant effect of the CPE from the sorghum bran was evaluated in sunflower oil in the presence of ferric ions by measuring peroxide values (PVs) and anisidine values (AVs) during storage at 65 °C, in comparison with tertiary butyl hydroquinone (TBHQ). Sorghum bran contained three times more TP and AA, and seven times more CT than the whole grain. The CPE had highest levels of TP, CT and AA. Sunflower oil with CPE had lower PVs and AVs compared to control samples. Oil samples with TBHQ had PVs lower than, but AVs similar to samples containing CPE. In the presence of ferric ions, the CPE was less effective in reducing PVs, but was more effective than TBHQ in reducing AVs.The authors greatly acknowledge financial support from the German Academic Exchange Service (DAAD)

Production, health-promoting properties and characterization of bioactive peptides from cereal and legume grains

DATA AVAILABILITY STATEMENT : Data sharing not applicable - no new data generated, or the article describes entirely theoretical research.The search for bioactive components for the development of functional foods and nutraceuticals has received tremendous attention. This is due to the increasing awareness of their therapeutic potentials, such as antioxidant, antiinflammatory, antihypertensive, anti-cancer properties, etc. Food proteins, well known for their nutritional importance and their roles in growth and development, are also sources of peptide sequences with bioactive properties and physiological implications. Cereal and legume grains are important staples that are processed and consumed in various forms worldwide. However, they have received little attention compared to other foods. This review therefore is geared towards surveying the literature for an appraisal of research conducted on bioactive peptides in cereal and legume grains in order to identify what the knowledge gaps are. Studies on bioactive peptides from cereal and legume grains are still quite limited when compared to other food items and most of the research already carried out have been done without identifying the sequence of the bioactive peptides. However, the reports on the antioxidative, anticancer/inflammatory, antihypertensive, antidiabetic properties show there is much prospect of obtaining potent bioactive peptides from cereal and legume grains which could be utilized in the development of functional foods and nutraceuticals.http://wileyonlinelibrary.com/journal/biofam2023Consumer ScienceFood Scienc

Phenolic composition and bioactive properties of cell wall preparations and whole grains of selected cereals and legumes

Phenolic compounds are associated with cell walls in cereals and legumes. Phenolic composition and bioactive properties of cell walls and whole grain of sorghum, teff and cowpea were determined.Whole grain extracts had higher total phenolic content (630–2,782 mg CE/g) and total flavonoid content (0.033– 0.17 mg CE/g) than cell wall extracts (261–1,005 and 0.011–0.047 mg CE/g, respectively). Similar trends were observed for 2,2’-azinobis (3-ethylbenzothiazoline- 6 sulfonic acid) radical scavenging (whole grain: 30–87; cell wall: 22 mM TE/g), oxygen radical absorbance capacity (whole grain: 47–964; cell wall: 40–183 mM TE/g) and ferric reducing power (whole grain: 85–279; cell wall: 41–95 mg vitamin C equivalent/g). Whole grains contained both phenolic acids and flavonoids. Ferulic acid was a major component of cell walls.Whole grain and cell wall extracts inhibited low-density lipoprotein oxidation and protected against oxidative DNA damage. Cereal and legume cell walls may be considered important potential contributors to human health because of their phenolic composition.South African National Research Foundation including the award of a post-doctoral fellowship for S.O. Salawu.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1745-45142015-02-28hb201

Effects of processing sorghum and millets on their phenolic phytochemicals and the implications of this to the health-enhancing properties of sorghum and millet food and beverage products

Sorghum and millet grains are generally rich in phytochemicals, particularly various types of phenolics. However, the types and amounts vary greatly between and within species. The food processing operations applied to these grains: dehulling and decortication, malting, fermentation and thermal processing dramatically affect the quantity of phenolics present, most generally reducing them. Thus, the levels of phytochemicals in sorghum and millet foods and beverages are usually considerably lower than in the grains. Notwithstanding this, there is considerable evidence that sorghum and millet foods and beverages have important functional and health- promoting effects, specifically antidiabetic, cardiovascular disease and cancer prevention due to the actions of these phytochemicals. Also their lactic acid bacteria fermented products may have probiotic effects related to their unique microflora. However, direct proof of these health-enhancing effects is lacking as most studies have been carried out on the grains or grain extracts and not the food and beverage products themselves, and also most research work has been in vitro or ex vivo and not in vivo. To provide the required evidence, better designed studies are needed. The sorghum and millet products should be fully characterised, especially their phytochemical composition. Most importantly, well-controlled human clinical studies and intervention trials are required.http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1097-00102016-01-31hb201

Cooking quality, nutritional and antioxidant properties of gluten-free maize – orange-fleshed sweet potato pasta produced by extrusion

Maize and orange-fleshed sweet potato (OFSP) composite (100:0, 50:50, 70:30, 80:20) flours were extruded into pasta using a twin-screw extruder. The cooking quality, textural and nutritional properties of the pasta were assessed. An increase in the proportion of OFSP flour added increased the cooking loss but decreased cooking time and water absorption capacity of pasta. The dietary fibre in the OFSP flour caused a loosening of the compact structure of the pasta, disrupting the compact protein-starch matrix of maize, resulting in higher cooking loss and sticky pasta. Extruded pasta had low cooking time due to pre-gelatinized starch, which promotes greater water absorption and heat dissemination during cooking. Extruded pasta samples had lower betacarotene, probably due to cis-trans isomerization, fragmentation, and oxidative decomposition, but the pasta showed higher antioxidant properties, likely due to Maillard reaction and caramelization products with reducing properties. These results indicate that OFSP can be composited with maize flour and extruded to produce good quality and nutritious gluten-free pasta.The DSI-NRF Centre of Excellence in food security (South Africa).https://www.elsevier.com/locate/lwtam2023Consumer ScienceFood Scienc

Pigmented flower extracts of plant species from the Geraniaceae and Lamiaceae families as natural food colourants : anthocyanin composition, thermal and oxidative stability

This study determined the anthocyanin profile of pigmented flower extracts from some Geraniaceae and Lamiaceae plant species found in South Africa, and their thermal and oxidative stability to assess their potential food application. Anthocyanins in the Geraniaceae (Pelargonium grandiflorum Willd. and Pelargonium × hortorum L.H. Bailey, Pelargonium zonale hybrid) were 3,5-diglucosides of delphinidin, petunidin, pelargonidin, peonidin and malvidin and acetyl-acylated malvidin, delphinidin and petunidin. The Lamiaceae species (Salvia aurea × dolomitica Bae’s blue, Salvia dolomitica Codd and Plectranthus zuluensis T. Cooke) mainly contained rutinosides of pelargonidin, glucosides of petunidin, pelargonidin and p-coumaric acid- and malonyl-acylated delphinidin and malvidin. Lamiaceae pigments had higher thermal and oxidative stability. This could be due to aromatic malonyl-acylated anthocyanin self-association and strong intermolecular interactions with phenolic acids and derivatives. Flowers from Lamiaceae and Geraniaceae have potential application as natural food colourants, but temperature and oxidising conditions must be considered depending on the particular species being used.The University of Pretoria.https://onlinelibrary.wiley.com/journal/13652621hj2023Consumer ScienceFood SciencePlant Production and Soil Scienc

Effect of drying methods on chemical composition and antioxidant activity of underutilized stinging nettle leaves

Stinging nettles provide low-cost quality nutrition for alleviating malnutrition. Previous research on stinging nettles focused mainly on the nutritional quality of fresh leaves. In this study, the effect of drying method on macronutrients, mineral content, ascorbic acid, β-carotene content and total phenols content and antioxidant activity were investigated. The contribution of fresh, oven dried or freeze dried stinging nettle leaves to the required daily value for the nutrients were also determined. Oven drying of nettle leaves resulted in a higher loss of β-carotene and ascorbic acid content compared to freeze drying. In contrast, the total phenols content and total antioxidant activity were higher in oven dried stinging nettle leaves compared to freeze dried leaves. Overall, freeze dried and oven dried nettle leaves can be considered as a rich source of Ca, Mg and vitamin A; a good source of vitamin C, Fe, and Mn; and a source for Mg and K. Stinging nettle leaves could potentially be used as a cheap natural source of antioxidants and for addressing micronutrient malnutrition.The Organization for Women in Sciences for Developing Countries (OWSD), Trieste, Italy, which contributed towards a PhD Scholarship.http://www.cell.com/heliyonam2020Consumer ScienceFood Scienc

Nutritional quality and antioxidant activity of marama–sorghum composite flours and porridges

Marama bean, an underutilised legume in southern Africa, is a good source of protein, fat and phenolic compounds, the latter known to have potential health benefits. Marama flours, sorghum meal, marama– sorghum composite flours and porridges were analysed for proximate composition, amino acid composition, energy value, fatty acid composition, total phenolic content and antioxidant activity. Compositing sorghum meal (70%) with marama flours (30%) significantly increased the protein and fat contents in flours and porridges. Energy values of marama–sorghum composite porridges were 11– 24% higher than sorghum porridge. Lysine content was 3–4 times higher in marama–sorghum porridges than in sorghum porridge. There was an increase in oleic acid as sorghum meal was composited with marama flour. There was a positive correlation between the total phenolic content and antioxidant activity in all samples. Use of marama flour in sorghum composite flours and porridges improved the nutritional quality and antioxidant activity.This research was sponsored by the EU MARAMA II PROJECT.http://www.elsevier.com/locate/foodchemnf201