Protein Digestibility of Selected Legumes Treated with Ultrasound and High Hydrostatic Pressure During Soaking

Abstract

In vitro protein digestibility (IVPD) of lentils, chickpeas, peas, and soybeans treated with ultrasound or high hydrostatic pressure (HHP) during soaking and then heated for 30 min at 98°C was determined using the three‐enzyme method (trypsin, chymotrypsin, and peptidase). The IVPD of raw legumes ranged from 72% for soybeans to 83% for dry green peas. The increase in the IVPD after soaking was observed in lentils but not in other legumes. Heating increased the IVPD of the tested legumes by 2–13%. While the effects of applying ultrasound or HHP on IVPD of legumes were mostly inconsistent or insignificant, soaking under HHP for 1 hr and subsequent heating at 98°C for 30 min increased IVPD of legumes. Compared with raw legumes, the soluble protein concentrates exhibited 2–4% higher IVPD, while insoluble proteins exhibited 0.2–1.5% lower IVPD. SDS‐PAGE of legume proteins before enzyme digestion exhibited 8–18 protein bands from 20 kDa to 100 kDa representing isolated soluble proteins and from 20 kDa to 100 kDa representing insoluble proteins. After enzyme digestion, soluble proteins exhibited 2–6 minor protein bands with molecular weights <30 kDa, while insoluble proteins of lentils, chickpeas, and peas exhibited one major protein band at ≈52 kDa and two or three minor protein bands with molecular weights <30 kDa. The major insoluble proteins observed as electrophoresis bands after enzyme digestion may be responsible for the reduced protein digestibility of legume proteins.

Impact of ultrasound on egg white proteins as a pretreatment for functional hydrolysates production

“…However, our results are in conflict with several previous studies which shown that the ultrasound treatment of various proteins did not significantly alter the overall DH or the effects were minimal [43,44]. In this light, Lei et al [27] showed that the sonication of ovotransferrin before thermolysin hydrolysis had insignificant effect on its digestibility.…”

Nutritional and protein quality of dry Brazilian beans (Phaseolus vulgaris L.)

“…Dther studies on Brazilian and Italian beans cvs. also observed high TPC and antioxidant capacities (Estrada-Girón et al, 2005;Han et al, 2007).…”

Pulse proteins: Processing, characterization, functional properties and applications in food and feed

“…In other studies, Carbanaro, Cappelloni, Nicoli, Lucarini, & Carnovale, 1997 reported that while cooking improved in vitro digestibility of chickpea and common bean flour/concentrates, it did not increase the digestibility of faba bean and lentil flour. Differences clearly exist in the digestibility and nutritional quality of different pulses and the factors influencing digestibility can vary (Han, Swanson, & Baik, 2007;Yasmin, Zeb, Khalil, Paracha, & Khattak, 2008). Further studies on the digestibility of pulse flours, protein concentrates and protein isolates as a function of different processes and processing conditions would, therefore, be very useful.…”