FUNCTIONAL PROPERTIES AND POTENTIAL UTILIZATION OF STARCH ISOLATED FROM CHAYOTE FRUIT

Abstract

Chayote, Sechium edule (Jacq.) Sw., is anoverlooked food‎ plant despite its various ‎potentialities. This study investigated the characteristics of starch isolated from ‎chayote fruit cultivated in Algiers which is known for its Mediterranean ‎climate. The granules morphology, functional properties and amylose content of Algerian chayote fruit starch were examined. Spherical, oval and polygonal shapes and smooth surface were observed using three imaging techniques: a normal and polarized light microscopy with Lucia ‎software and Scanning Electron Microscopy (SEM).‎ Starch granules size was in the rang 3.56-‎‎37.24 μm, and for the chayote tubers, it‎ was 7-50 μm. The amylose content (‎20.36%‎) ‎‎is different from that of the chayote tubers (12.81%), but ‎close‎‎‎ to those of ‎conventional sources. The Algerian chayote fruit starch showed higher swelling strength and lower ‎melting ‎index.‎ The Rapid Visco Analyzer pasting profile revealed a lower peak ‎viscosity (2158.3 cP) than that from chayote tubers (14746 cP).‎ However, Differential Scanning Calorimetry analysis showed higher gelatinisation temperatures (66.89 °‎C) and ‎transition enthalpy (‎15.79‎ J/g)‎. X-ray diffraction profile showed B-type.‎ The digestibility (D∞), hydrolysis index, HI, and average glycemic index, (GI), were estimated at 50.66 %, 52.16% and 70.16 ‎%‎ respectively.‎ The results showed that starch has an ‎acceptable nutritional value with significant in vitro digestion properties and it is suitable for human health and nutrition.‎ The starch of Algerian chayote fruit showed interesting ‎functional characteristics which makes it suitable for relevant applications in both the field food and cosmetics industries. It can, also, be a raw material for starch processing.