Revealing Antioxidant and Antidiabetic Potency of Melinjo (Gnetum Gnemon) Seed Protein Hydrolysate at Different Stages of Seed Maturation

Abstract

roteins hydrolyzed from melinjo seeds (Gnetum gnemon) at green (GM), yellow (YM) and red (RM) stages of maturity were studied for their effectiveness in antioxidant and antidiabetic activities. The seed protein extract was hydrolyzed using alcalase 2.4L, and the resulting hydrolysates with the highest degree of hydrolysis, protein profile, and the most potent contributors to antioxidant and invitro antidiabetic activities were identified. The degree of hydrolysis value of hydrolysates ranged from 52-84%, and the SDS-PAGE protein profile showed two distinct bands in which the band with molecular weight of 30 kDa degraded more intensively. Antioxidant capacity was measured using different standard methods, including radical cation 2,2-azinobis-(3-ethylbenzothizoline-6-sulphonate) (ABTS•+) assay, hydroxyl radical (OH•), and superoxide anion (O2•-) scavenging. The green hydrolysate (GMH) had significantly higher (p<0.05) free radical scavenging (ABTS•+, OH•, and O2•-) activities than that of the yellow hydrolysate (YMH) and red hydrolysate (RMH). However, invitro antidiabetic testing was performed based on the inhibitory activity of α-amylase and α-glucosidase. GMH was found to be more effective than YMH and RMH. These results showed that the antioxidant and antidiabetic activity in hydrolyzed GM protein has high potential to be utilized as natural nutraceuticals.

Use of Alcalase in the production of bioactive peptides: A review

“…One interesting work reports that the Alcalase hydrolysis of melinjo seeds (Gnetum gnemon) at different stages of maturity (green, yellow and red) generated hydrolysates with different antioxidant activities [215]. Another study shows that the Alcalase hydrolysis of J o u r n a l P r e -p r o o f defatted garden cress (Lepidium sativum) seed meal protein improved their antioxidant activity [216].…”

The ethnobotony and local knowledge of sayur asem by the vegetable traders

“…The G. gnemon has invitro antidiabetic and showed α-amylase and α-glucosidase inhibitory activity. The hydrolyzate of green seeds was found to be more effective than yellow seeds and red of old seeds with red color (Supriyadi, Arum, Nugraha, Ratnadewi & Siswoyo, 2019 Nurhartadi., 2015), so it is the potential to be used as a natural preservative. Parhusip & Sitanggang (2011) reported that seed extract G. genimon inhibits bacterial growth of Aspergillus flavus, Bacillus careus, Staphylococcus aureus, and Enterobacter aerogenes.…”

Assessing the conservation value of medicinal plant collections in Bogor Botanic Gardens, Indonesia

“…Gnetum gnemon known as melinjo tree is a very popular vegetable ingredient and can be found in various regions in Indonesia. The indigenous people of Indonesia use melinjo as vegetables or processed delicacies (Supriyadi et al 2019). Beside its seed can be processed as chip, almost all parts can be consumed.…”