Effects of thermal processing on the nutritional and functional properties of defatted conophor nut (Tetracarpidium conophorum) flour and protein isolates

Functional Bioactivities of Soluble Seed Proteins from Two Leguminous Seeds

Storage proteins from Sphenostylis stenocarpa and Phaseolus lunatus were fractionated, and their in vitro bioactivities were investigated. Albumin, globulin, prolamin, and glutelin constituents of the respective seeds were successively fractionated using the modified Osborne method. Phenylmethylsulfonyl fluoride (1 mM) was used as a protease inhibitor. The antioxidant, anti-inflammatory, and acetylcholinesterase-inhibitory activities of the protein fractions were evaluated using different appropriate techniques. Globulin was the predominant fraction, with a yield of 43.21±0.01% and 48.19±0.03% for S. stenocarpa and P. lunatus, respectively, whereas prolamin was not detected in both seeds. The protein fraction markedly scavenges hydroxyl radicals, nitric oxide radicals, and 2,2-diphenyl-1-picryldydrazyl radicals with concomitant high free radical-reducing power. Albumin and globulin fractions elicited the highest acetylcholinesterase-inhibitory potential of 48.75% and 49.75%, respectively, indicating their great application potential in managing neurodegenerative diseases. In this study, the albumin, globulin, and glutelin fractions of these underutilized legumes showed great analeptic bioactivities, which could be utilized as health-promoting dietary supplements/products.

Nutritional Characteristics Assessment of Sunflower Seeds, Oil and Cake. Perspective of Using Sunflower Oilcakes as a Functional Ingredient

Ample amounts of by-products are generated from the oil industry. Among them, sunflower oilcakes have the potential to be used for human consumption, thus achieving the concept of sustainability and circular economy. The study assessed the nutritional composition of sunflower seeds, cold-pressed oil and the remaining press-cakes with the aim of its valorization as a food ingredient. Sunflower oil contains principally oleic (19.81%) and linoleic (64.35%) acids, which cannot be synthetized by humans and need to be assimilated through a diet. Sunflower seeds are very nutritive (33.85% proteins and 65.42% lipids and 18 mineral elements). Due to the rich content of lipids, they are principally used as a source of vegetable oil. Compared to seeds, sunflower oilcakes are richer in fibers (31.88% and 12.64% for samples in form of pellets and cake, respectively) and proteins (20.15% and 21.60%), with a balanced amino acids profile. The remaining oil (15.77% and 14.16%) is abundant in unsaturated fatty acids (95.59% and 92.12%). The comparison between the three products showed the presence of valuable components that makes them suitable for healthy diets with an adequate intake of nutrients and other bioactive compounds with benefic effects.

Effect of germination, roasting, and variety on physicochemical, techno-functional, and antioxidant properties of chickpea (Cicer arietinum L.) protein isolate powder

Chickpeas are a very important part of the human diet due to their nutritional and bioactive composition. Ethiopia is one of the top chickpea producers and consumers of chickpea-based products daily. However, limited studies were conducted on the effect of common processing methods, roasting and germination, on techno-functional and nutritional properties of chickpea protein isolates. Two varieties of chickpea, Arerti (Kabuli type) and Natoli (Desi type), were selected and treated with different roasting temperature (150 and 180 °C) and germination time (24, 48, and 72 h). The protein was isolated with alkaline-solubilization followed by isoelectric precipitation. Freeze-dried isolates were investigated for proximate composition, techno-functional properties, antioxidant properties, and antinutritional content. Chickpea protein isolates (CPIs) mean protein content was between 79.72 and 87.43%, comparatively lower for those from roasted and higher for those from germinated chickpea. Mean values of CPIs’ water holding capacity (WHC), oil holding capacity (OHC), protein solubility (PS), foaming capacity (FC), and Emulsifying capacity (EC) for both varieties were in a range of 1.07–2.47 g/g, 1.40–2.21 g/g, 43.88–69.99%, 14.00–94.00%, and 56.44–84.16%, respectively. Roasting at 150 °C improved most of the techno-functional properties (WHC, OHC, PS, and FC) while roasting at 180 °C negatively affected almost all the techno-functional properties. Both heat treatments significantly increased the antioxidant properties of the isolates. Germination for 72 h was the best treatment in improving all antioxidant properties. CPIs from treated chickpea had lower antinutritional content than those from native chickpea except for phytate on Natoli variety where no statistical difference (p > 0.05) was observed. The finding showed that based on the intended use the different techno-functional properties of the isolates can be altered by applying those treatments. Proximate, techno-functional, antioxidant, and antinutritional characters indicated that CPIs can be a good ingredient for the food industry to formulate functional foods.

Effects of thermal processing on the nutritional and functional properties of defatted conophor nut (Tetracarpidium conophorum) flour and protein isolates

Conophor nut (Tetracarpidium conophorum) was processed using different heat treatments to explore its full potential as food ingredients. The raw, boiled, and toasted nuts were defatted and the proteins isolated by alkaline solubilization and isoelectric precipitation. The variously processed nuts were analyzed for the proximate and amino acid compositions, and functional properties. The protein contents of the isolate ranges between 86.86 g/100g and 87.74 g/100 g, about 1.5-fold higher than those of the defatted flour samples. The essential amino acids of the isolates ranged between 40.57%-41.55%. Glutamic acid, aspartic acid, and arginine were the most predominant amino acids, while methionine and lysine were the first and second limiting amino acids, respectively. The protein efficiency ratio, biological values as well as the functional properties of the proteins were improved with processing. These properties may enhance the potential use of conophor nut protein isolates as high-quality protein ingredient in food systems.