Development of lentil peptides with potent antioxidant, antihypertensive, and antidiabetic activities along with umami taste

Abstract

Lentil peptides have shown promising bioactive properties regarding the antioxidant activity and also inhibitory activity of angiotensin‐I‐converting enzyme (ACE). Sequential hydrolysis of proteins has shown a higher degree of hydrolysis with enhanced antioxidant and ACE‐inhibitory activities. The lentil protein concentrate (LPC) was sequentially hydrolyzed using Alcalase and Flavourzyme at 2% w/w. The hydrolysate (LPH) was cross‐linked (LPHC) or sonicated (LPHUS) and sequentially cross‐linked (LPHUSC). Amino acid profile, molecular weight (MW) distribution, DPPH and ABTS radical scavenging activities (RSA; 7 mg/mL), ACE (0.1–2 mg/mL), α‐glucosidase, and α‐amylase inhibitory activities (10–500 μg/mL), and umami taste were determined. The highest DPPH RSA was obtained for LPH (68.75%), followed by LPHUSC (67.60%), and LPHUS (67.49%) while the highest ABTS RSA values were obtained for LPHC (97.28%) and LPHUSC (97.20%). Cross‐linking and sonication led to the improvement of the ACE‐inhibitory activity so that LPHUSC and LPHC had IC50 values of 0.23 and 0.27 mg/mL, respectively. LPHC and LPHUSC also indicated higher α‐glucosidase inhibitory activity (IC50 of 1.2 and 1.23 mg/mL) compared to LPH (IC50 of 1.74 mg/mL) and LPHUS (IC50 of 1.75 mg/mL) while the IC50 value of acarbose indicated 0.51 mg/mL. Moreover, LPHC and LPHUSC exhibited higher α‐amylase inhibitory activities (IC50 of 1.35 and 1.16 mg/mL) than LPHUS (IC50 of 1.95 mg/mL), and LPH (IC50 of 2.51 mg/mL) while acarbose had an IC50 value of 0.43 mg/mL. Umami taste analysis revealed that LPH and LPHC due to MW of 1.7 and 2.3 kDa and also high umami amino acids could be well considered as representative of meaty and umami analog flavors while indicating stronger antioxidant, antihypertension, and antidiabetic attributes.

Conjugation of gum Arabic and lentil protein hydrolysates through Maillard reaction: Antioxidant activity, volatile compounds, functional and sensory properties

“…Initially, the LPI solution was provided at 3% (w/w), followed by the denaturation of protein at 90°C for 30 min. In the next stage, the protein sequentially underwent the hydrolysis process using Alcalase and Flavourzyme (Rezvankhah et al., 2023 ). The hydrolysis was carried out at the enzyme‐to‐substrate (E:S) ratio of 2:100, and the optimal activity of enzymes was carried out during which the temperatures were 60 and 50°C and the pH values were 8.0 and 7.0 for Alcalase and Flavourzyme, respectively (based on the suggestions rendered by the respective enzyme producers).…”

“…In our previous study, sequential hydrolysis and cross-linking of LPH led to the development of umami taste (Rezvankhah et al, 2023). In addition, development of umami taste in MLPH and MLPHC increased their chance to be used in meat products as a replacer of meat proteins and flavor enhancers such as MSG with high health risks (Rezvankhah et al, 2023;Zanfirescu et al, 2019).…”

“…Hydrolysis significantly increased the saltiness, bitterness, and umami tastes (p < .05). Hydrolysis could break down the peptide chains, liberating peptides with low MW, and exposing the amino acids contributing predominantly to umami taste (Rezvankhah et al, 2021a(Rezvankhah et al, , 2023. Cross-linking of LPH by MTGase led to reduction of saltiness and bitterness while umami taste was increased (p < .05).…”

“…For instance, Australians (2.5 million, 12.1%) are consuming diets that are composed of entirely or primarily plant origin. Therefore, a great research field has been formed to develop plant‐based products (Rezvankhah et al., 2023 ; Zhang et al., 2022 ).…”

“…Lentil protein (21%–31% of total seed) is primarily composed of storage proteins, mainly salt‐soluble globulins and water‐soluble albumins (Rezvankhah et al., 2021a , 2021b ). Lentil protein has been recognized to contain high amounts of essential amino acids such as lysine and leucine, compared to soy protein (Mirzaee et al., 2023 ; Rezvankhah et al., 2023 ). Several studies have shown that lentil protein has high nutritional and biological quality along with favorable functional properties (Avramenko et al., 2013 ; Chang et al., 2015 ; Joshi et al., 2012 ; Karaca et al., 2013 ; Rezvankhah et al., 2021b ; Rezvankhah, Yarmand, & Ghanbarzadeh, 2022 ).…”