Issoufou Amadou

Functionality and Antioxidant Properties of Tilapia (Oreochromis niloticus) as Influenced by the Degree of Hydrolysis

Freeze dried protein powders (Fresh minced meat, FMM and Hot water dip, HWD) from tilapia (Oreochromis niloticus) were hydrolyzed by Alcalase 2.4 L (Alc), Flavourzyme (Flav) and Neutrase (Neut), and investigated for antioxidant activity and their functional properties. FMM and HWD hydrolysed by Alc, exhibiting superior antioxidant activity, had estimated degrees of hydrolysis (DH) of 23.40% and 25.43%, respectively. The maximum values of the 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), 3-(2-pyridyl) 5,6-bis(4-phenyl-sulphonic acid)-1,2,4-triazine (ferrozine), radical scavenging activities and metal chelating properties were 86.67%, 91.27% and 82.57%, and 84.67%, 92.60% and 78.00% for FMM and HWD, respectively, with a significant difference (P < 0.05) between the samples. Essential amino acids were above the amounts recommended by the Food and Agricultural Organization/World Health Organization (FAO/WHO/UNU) for humans. Lower molecular weight sizes <3,000 Da were more predominant in FMM and HWD hydrolysed by Alc, while in hydrolysed by Flav and Neut they were >8,000 Da. At pH 2, FMM and HWD hydrolysates have varying solubilities above 85% (Alc FMM; 91.33%, Flav FMM; 79.5%, Neut FMM; 83.8% and Alc HWD; 90.45%, Flav HWD; 83.5%, and Neut HWD; 85.8%). They have ‘U’ shaped solubility curves, water holding capacity was in the range of 2.77 and 1.77 mL/g, while oil holding capacity ranged between 3.13 and 2.23 mL/g. FMM and HWD have the highest bulk density of 0.53 and 0.53 for Neutrase and Alcalase 2.4 L, respectively. Foam capacity and stability ranged from 125.5 to 61.4, 138.5 to 45.2, 130.0 to 62.5, and 124.5 to 55.0, 137.5 to 53.3, 129.6 to 62.7 for FMM and HWD hydrolyzed with Alcalase 2.4 L, Flavourzyme and Neutrase, respectively. Tilapia fish protein hydrolysates are thus potential functional food ingredients.

Reducing, Radical Scavenging, and Chelation Properties of Fermented Soy Protein Meal Hydrolysate by Lactobacillus plantarum LP6

Fermented soybean protein meal hydrolysate (FSPMH) was fractionated by gel filtration on Sephadex G-15. The fractions obtained were subjected to various antioxidant assays, amino acid and molecular weight determinations. Among the seven fractions, the highest antioxidant activity was found in fraction F2, with significant differences (P < 0.01) 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, hydroxyl radicals (.OH) scavenging and Cu2+ chelating activity. Fraction F2 exhibited scavenging of DPPH (59.43%), .OH (72.80%) and 44.47% Cu2+ chelating activity. All other fractions showed variable activities in different assays. Amino acid analyses of F2 fraction with the strongest antioxidant activity also had the highest percentage of related antioxidative amino acids content (Histidine 3.46, Serine 5.78, Valine 4.08 and Lysine 11.49 g/100 g protein) compared with other six fractions. The molecular weight distribution of F2 was found to vary from 170 to 1500 Da.

Evaluation of Antimicrobial, Antioxidant Activities, and Nutritional Values of Fermented Foxtail Millet Extracts by Lactobacillus paracasei Fn032

Solid-state bioprocessing of foxtail millet by Lactobacillus paracasei Fn032 is a biotechnological strategy to produce fermented foxtail millet meal with more beneficial components. The objective of this study was to evaluate the antioxidant, antimicrobial properties and nutritional values of water extracts from fermented foxtail millet flour and its bran with and without protease. Fermented foxtail millet flour with added protease extract showed higher scavenging ability on 1,1-diphenyl-2-picrylhydrazyl radicals as well as reducing power than fermented foxtail millet flour and fermented foxtail millet bran extracts. Both extracts, fermented foxtail millet flour and fermented foxtail millet flour with protease, showed significant (P < 0.05) effectiveness inhibition abilities on microbial growth when compared with fermented foxtail millet bran extracts. Amino acid profile revealed that fermented foxtail millet flour with protease, with relatively strongest antioxidant, antimicrobial activity, also had the highest total hydrophobic amino acids content (51.39%) and hydrophobic index (8.47 Kj/mol amino acid residue). Moreover, fermented foxtail millet flour with protease revealed the highest protein content, predicted protein efficiency ratio, and protein digestibility. Molecular weight of the whole extracts varied from 180–5000 Da. Based on the results obtained, fermented foxtail millet flour extracts were relatively effective in the antioxidant, antimicrobial properties assayed and might be potential biological values for application in food products.

Effect of boiling on the physicochemical properties of Roselle seeds ( Hibiscus sabdariffa L.) cultivated in Mali

Mali was shown. Proximate analysis indicated that boiled whole Roselle seeds (BWRS) are potential high protein source. Moreover, the results of lipid analysis indicated that the seeds were good source of unsaturated fatty acid (74.33%) with that of linoleic (35.55%), oleic (36.64%), palmitic (19.34%) and stearic acid (4.86%) being the major fatty acid constituents. The most predominant inorganic elements were found to be potassium, followed by magnesium and calcium. Aluminum and phosphorus were relatively low in both BWRS and un-boiled whole Roselle seeds (WRS). Roselle seeds exhibited various molecular weight distributions as revealed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis. Scanning electron microscopic (SEM) analysis revealed that boiling had little influence on the physical particles size. In addition, Roselle seed powder meals maintained excellent protein, lipid and minerals compositions, following boiling with protein quality of powders prepared from whole and boiled seeds being similar.