Physicochemical, Functional, and In Vitro Digestibility of Protein Isolates from Thai and Peru Sacha Inchi (Plukenetia volubilis L.) Oil Press-Cakes

Abstract

Proteins from Sacha inchi (SI) have been widely known for their health-benefiting properties. This study aimed to investigate the different protein isolates obtained from oil press-cakes of Thai and Peru SI. The protein content and protein recovery of Thai and Peru SI were estimated to be 93.27, 90.67%, and 49.15, 59.32%, respectively. The protein patterns of the Thai and Peru SI samples analyzed by SDS-PAGE showed glycoprotein as a major protein, with a molecular weight of 35 kDa. Both protein isolates (PI) showed water and oil holding capacities in the range of 2.97–3.09 g/g sample and 2.75–2.88 g/g sample, respectively. The emulsifying properties of the PI from Thai SI were higher than those of Peru (p < 0.05), while the foaming properties were not analogous to the emulsion properties. The Thai SI sample showed lower digestibility up to 120 min of in vitro digestion time than that of the Peru SI sample (p < 0.05). However, simulated in vitro pepsin digestion of Thai and Peru Si samples displayed hydrolyzed protein bands compared to trypsin digestion, which showed no protein patterns in both SI samples on a 4–20% gradient gel. These results suggest that the protein isolates from Thai and Peru SI exhibit marked variations in physical and techno-functional properties and have a high potential to be employed as plant-based protein additives for future non-animal-based protein-rich foods.

Isolation and Characterization of Protein Fractions for Valorization of Sacha Inchi Oil Press-Cake

“…The extraction conditions were chosen for their effects on protein solubility and extraction efficiency [9,14,15]. The pH 7 was chosen as a neutral condition to extract soluble proteins at a physiological pH, and it was previously reported for Inca Peanut Albumin extraction [7,10].…”

“…Moreover, SI proteins are considered of high biological value. They contain essential amino acids, including lysine, leucine, histidine, and phenylalanine [9]. However, SI proteins have scarcely been investigated.…”

“…Additionally, crude papain (pH 7.0 at 40 • C) and Calotropis proteases (pH 8.0 at 60 • C) have been employed for protein extraction from SIPC, recovering peptides with molecular weights ranging between <8 and 57 kDa [12]. In a recent study, the physicochemical, functional, and in vitro digestibility of SI protein isolates from Thailand and Peru were investigated, concluding that these isolates have potential applications as plant-based protein additives [9]. Taking into account that SI proteins could be used as ingredients in the food industry, and that protein demand is increasing [7], there is a need to investigate how the extraction procedures affect the properties of the protein fractions.…”

Antioxidant and Hypoglycemic Activity of Sacha Inchi Meal Protein Hydrolysate

“…The protein content of kernel is 24.2-27.0%, similar to those of soybeans (28%), cottonseed (33%), sunflower seeds (24%) and peanuts (23%) [2]. As a by-product after oil extraction, the protein content of sacha inchi meal (SIM) was up to 55%, which was not effectively used except for the aquatic animal feed [3].…”