Unripe mango kernel starch: Partial characterization

Abstract

Although a rich source of polyphenols, starch and dietary fibre, unripe mango has been identified as a functional ingredient. The kernel of unripe mango is rich in starch and certain compounds such as non-starch polysaccharides (components of dietary fibre), polyphenols and lipids. The isolation of starch from unripe mango kernel can be an alternative to obtain non-conventional ingredients to diverse end-uses. The aim of this study was the isolation of starch from unripe mango kernel and its partial characterization. The isolated starch was studied in morphology with microscopic methods, X-ray diffraction, thermal properties, pasting profile, and in vitro digestibility. The starch granules were distinguished as oval and round-with a mean size of 50 μm and some debris of lipids in the surface. The amylose content of the starch granule was 23 g/100 g and A-type diffraction pattern was observed. The temperature and enthalpy of gelatinization are similar to conventional starch as maize with a low tendency to retrogradation. The pasting profile of mango kernel starch was identified as typical of native starch with gel formation upon cooling. The in vitro enzymatic hydrolysis of mango kernel starch was different from that of conventional starches with slow digestion rate in the cooked sample. The starch from unripe mango kernel can be an alternative to starchy raw materials like as cereals or pulses in food and non-food applications.