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Legumes are rich sources of protein in human diet and their consumption has been associated with the prevention of chronic diseases attributable to their bioactive components. Pigeon pea (Cajanus cajan) is an underutilized legume with relatively high protein content (~24%). Protein hydrolysates were prepared from pea isolate by enzymatic hydrolysis using pepsin and pancreatin. Hydrolysates were evaluated for their amino acid composition, antioxidant properties, in vitro and in vivo antihypertensive properties. The hydrolysates had high hydrophobic amino acids, especially isoleucine, phenylalanine, and leucine. Pepsin‐pancreatin‐hydrolyzed pea protein (PPHPp) showed significantly higher ability to scavenge DPPH˙ while pancreatin‐hydrolyzed pea protein (PPHPa) had higher ˙OH, ABTS˙+ scavenging, Fe3+ reducing and linoleic acid peroxidation inhibition. PPHPp exhibited superior angiotensin‐converting enzyme inhibition (61.82%) while PPHPa showed higher renin inhibition (14.28%). PPHPp exhibited strong antihypertensive effect, showing an instantaneous systolic blood pressure lowering effect (−26.12 mmHg) within 2‐h post‐oral administration. Pigeon pea protein hydrolysate (especially from pancreatin digest) could therefore, be a promising source of bioactive peptides and potential ingredient for formulation of functional foods against oxidative stress and hypertension.

Pigeon pea was treated by blanching and used to supplement acha flour for the development of functional cracker biscuits. The flour ratios for acha and pigeon pea were 100:0 (ACC), 80:20 (APC1), and 70:30 (APC2), respectively. The developed cracker biscuits were evaluated for chemical acid compositions, antioxidant, as well as antidiabetic properties. Protein contents of the formulated crackers increased with increase in supplementation with pigeon pea flour. The antinutrient content of the formulated snack was low hence may not adversely affect nutrient bioavailability. Glutamic and aspartic acids were the predominant amino acids while methionine and lysine significantly increased as a result of supplementation with pigeon pea flour. The biscuit exhibited good antioxidant properties indicated by its strong ability to scavenge hydroxyl, superoxide, DPPH radicals, and reduced Fe3+ to Fe2+. The formulated snack especially APC2 possessed low glycemic index (47.95%) and significantly inhibited the key digestive enzymes (α‐amylase and α‐glucosidase). All parameters evaluated indicated that APC2 could serve as a functional snack in the management of hyperglycemia (diabetes) and prevention of associated degenerative diseases.

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Phenolic compounds of unripe and ripe sweet orange peels were determined using a high-performance liquid chromatography separation method with diode array detector (HPLC-DAD). The in vitro antioxidant properties and the EC50 (concentration required to obtain a 50% antioxidant effect) values were also determined. The predominant phenolic compounds were quercitrin, rutin, and quercetin with values of 18.77 ± 0.01 mg/mL, 18.65 ± 0.03 mg/mL, and 10.39 ± 0.01 mg/mL respectively in unripe orange peel and 22.61 ± 0.01 mg/mL, 17.93 ± 0.03 mg/mL, and 14.03 ± 0.02 mg/mL respectively in ripe orange peel. The antioxidant properties revealed 2,2′-azino-bis(3-ethyl benzothiazoline-6-sulfonic acid) diammonium salt (ABTS) scavenging ability of both unripe and ripe orange peels respectively as 14.68 ± 0.01 and 16.89 ± 0.02 mmol TEAC/g, the Ferric Reducing Antioxidant Properties (FRAP) as 70.69 ± 0.01 and 91.38 ± 0.01 mg gallic acid equivalents/100g, total phenol content as 5.27 ± 0.03 and 9.40 ± 0.01 mg gallic acid equivalents/g and total flavonoid content as 3.30 ± 0.30 and 4.20 ± 0.02 mg quercetin equivalent/g. The antioxidant assays showed enhanced potency of extract from ripe orange peel with EC50 values of 2.71 ± 0.03 mg/mL for 2,2-diphenyl-1-picrylhydrazyl (DPPH), 0.67 ± 0.03 mg/mL for hydroxyl radicals (OH*), 0.57 ± 0.02 mg/mL for Fe2+ chelation, and 0.63 ± 0.06 mg/mL for malondialdehyde (MDA), and was more potent than unripe orange peel.