Study of the proteins in the defatted flour and protein concentrate of baru nuts (Dipteryx alata Vog)

Baru (Dipteryx alata Vog.) is an abundant legume in the Brazilian Savanna. Its nuts can be exploited sustainably using its protein and lipid fractions. This study aimed to analyze the proteins of the nuts present in the defatted flour and protein concentrate in terms of their functional properties, the profile of their fractions, and the in vitro digestibility. The flour was defatted with hexane and extracted at the pH of higher protein solubility to obtain the protein concentrate. The electrophoretic profile of the protein fractions was evaluated in SDS-PAGE gel. The functional properties of the proteins indicate the possibility of their use in various foods, like soybeans providing water absorption capacity, oil absorption capacity, emulsifying properties, and foamability. Globulins, followed by the albumins, are the major fractions of the flour and protein concentrate, respectively. Digestibility was greater for the concentrate than for the defatted flour.

Proteins of Bacuri almonds: nutritional value and in vivo digestibility

Bacuri (Scheelea phalerata Mart.) is a type of palm fruit tree widely distributed in the Brazilian Cerrado. The objective of this paper was to study the almonds of bacuri, in their form in natura and processed, focusing on their nutritional value through the profile of amino acids, anti-nutritional factors and in vivo digestibility. Raw and toasted samples of the almond presented a high level of proteins and fiber. Proteins of raw bacuri almond showed no limiting amino acid when compared to the ones recommended by FAO/WHO, and histidine was the most limiting essential amino acid in the toasted almonds. The almond of bacuri does not present anti- nutritional factors. In an assay with rats fed with control (casein), tests (bacuri almond flours) and aproteic diets, we verified the quantity of ration ingested and body weight gain, determining the urinary and metabolic nitrogen. Rats treated with the test diets presented inferior values of True Digestibility (DV), (82.9 and 72.3%, respectively for the raw and toasted almonds) when compared to the control group (92.3%). The raw bacuri almond presented a superior nutritional value to the one found in the toasted almond.

ACE-I inhibitory properties of hydrolysates from germinated and ungerminated Phaseolus lunatus proteins

Phaseolus lunatus protein concentrates and the proteases Alcalase(R) and Pepsin-Pancreatin were used for the production of protein hydrolysates that inhibit angiotensin-I converting enzyme (ACE). Protein concentrate obtained from germinated and ungerminated seeds flour was hydrolyzed with Alcalase(R) at enzyme/substrate ratio (E/S) 1/10 and during 0.5 and 2.0 h, respectively. On the other hand, protein concentrate obtained from ungerminated (E/S: 1/10) and germinated (E/S: 1/50) seeds flour was sequentially hydrolyzed with Pepsin-Pancreatin during 1.0 and 3.0 h, respectively. Peptide fractions with ACE inhibitory activity in a range of 0.9 to 3.8 µg/mL were obtained by G-50 gel filtration chromatography and high- performance liquid chromatography C18 reverse phase chromatography. The observed amino acid composition suggests a substantial contribution of hydrophobic residues to the peptides’ inhibitory potency, which potentially acts via blocking of angiotensin II production. These results show that P. lunatus seed proteins are a potential source of ACE inhibitory peptides when hydrolyzed with Alcalase(R) and Pepsin-Pancreatin.