The influence of microwave cooking on the nutritional composition and antioxidant activity of the underutilized perah seed

Abstract

Perah (Elateriospermum tapos) seed is a type of seed that can be easily grown and is found in abundance, especially on the east coast of Malaysia and in southern Thailand. The perah fruits are about 2-2.5 in long, oblong, buff in colour and suffused pink on the exposed side, hanging singly on a stalk 1-6 in long. ABSTRACTBackground. Perah seed is one of the most underutilized oilseeds, containing high nutritional values and high percentage of α-linoleneic acid, which may have a high potential in food and pharmaceutical applications. The main objective of this study was to evaluate the influence of microwave (MW) cooking on the proximate composition and antioxidant activity of perah seeds. Material and methods. In this study, the proximate composition and amygdalin concentration of MW irradiated perah seeds were determined. The total phenolic content (TPC), Maillard reaction products (MRPs) and antioxidant activity of methanol (PME), 70% methanol in water (PMW), ethanol (PEE), 70% ethanol in water (PEW) extracts and methanol extract of oil (PMO) were evaluated during MW cooking. The antioxidant activity was evaluated using multiple assays, namely DPPH radical scavenging activity, β-Carotene bleaching assay, and reducing power. Results. Microwave cooking did not significantly increase crude lipid and carbohydrate content, and the amounts of other nutrients such as ash, crude protein and fibre remained almost unchanged. As evaluated by HPLC, the amygdalin concentration in the seeds was reduced by MW cooking. The TPC, MRP and antioxidant activity of the solvent extracts of perah seeds increased significantly with increasing roasting time.Of all the extracts, PMW at all MW cooking times displayed the highest antioxidant effectiveness. However, thermal treatment significantly reduced the antioxidant properties of PMO. The values for TPC, MRP and antioxidant effectiveness of the samples were ranked in the following order: PMW > PEW > PME > PEE > PMO, in both control and microwaved samples. Conclusions. In determining the overall quality of the products, MW cooking time was found to be a critical factor. Solubilization of phenolic compounds and formation of MRPs during MW cooking could have caused the increase in antioxidant activity of the perah seeds.

Nutritional and Phytochemical Composition of Mediterranean Wild Vegetables after Culinary Treatment

“…Moreover, variations in the cooking conditions, such as maximum temperature reached, cooking time, pH, surface/volume relation, water used, oxygen and light presence, matrix and/or food type, as well as compounds sensitivity to these factors can influence the final composition [26,27]. Some research works have been conducted on the analysis of nutritional and phytochemical composition, as well as antioxidant activity of traditionally consumed wild edible plants all over the world [28][29][30][31][32][33][34][35][36][37][38]. For example, Trichopoulou et al [28] reported data of the nutritional composition of Cretan pies elaborated with cultivated and wild vegetables (such as Rumex spp.…”