Effect of wet milling and purification process on yield and color of jackfruit seed starch

Abstract

Jackfruit is a common fruit, which grows in Asian areas, including Thailand, India, China and Vietnam. Jackfruit seeds are a by-product of the food industry, and are typically ignored as a source of nutrients in the human diet given their possible application.. Starch production is a conventional ways to take advantage of this by-product source. The wet milling and purification process are the two main processes for extracting and improving the color of starch. Therefore, this research aims to determine the impact of wet milling and purification process on yield and color of starch as well as evaluate some parameters of physicochemical properties in jackfruit seed starch. In this study, the ratio of jackfruit seed:water (1:1, 1:2, 1:3, 1:4 and 1:5) and the time of wet milling (1, 2, 3, 4 and 5 min) are investigated. Three main factors observed in the purification process were the type of solvent (water and ethanol), solvent ratio (1:2, 1:4, 1:6 and 1:8) and the number of purification (1, 2, 3, 4 and 5 times). The result revealed that the ratio of jackfruit seed: water reached the highest starch yield was 1:3 (32.11±1.06%, db) and the time achieved 3 min (40.77±1.25%, db). The selected solvent for purification of starch was ethanol with the ratio of sample: water was 1:4 and the number of purification was two times for the best color. Some of characteristic nutrition values was evaluated, including %protein: 3.8, %ash: 0.08, %carbohydrate 86.99 and %lipid 0.20). The water solubility index and viscosity of starch were contradictory. When the temperature increased, the viscosity of starch decreased but the solubility index increased. Jackfruit seed starch was spherical or semi-oval which was presented by SEM (Scanning Electron Microscope) method.