Morphological, Functional, and Physico-Chemical Properties of Non-Conventional Starch Derived from Discarded Immature Apples

The starch yield of 23-28% (db) with 35-43% amylose content is recovered from different immature apple varieties. Scanning electron microscopy reveals the presence of the dome to spherical shaped granules of 3.1-11.62 & mu;m size. The transition temperatures, onset temperature, peak temperature, conclusion temperature, and enthalpy of gelatinization are calculated using differential scanning calorimetry (DSC) ranges between 61.62 and 64.48 & DEG;C, between 64.61 and 68.07 & DEG;C, between 68.64 and 72.37 & DEG;C, and between 4.35 and 17.49 J g(-1), respectively. The water absorption capacity and oil absorption capacity of starches range between 1.036 and 1.372 mL g(-1) and between 0.876 and 1.125 mL g(-1), respectively. The peak viscosity of 638-1942 cP is achieved in 3.8-6.10 min at a pasting temperature of 65-71 & DEG;C. A yield stress of 10-39 Pa is sufficient to instigate the Herschel Bulkley flow. The paste of Mollie's Delicious starch is more structured and elastic; its gel has a hardness of 3.5 N and maximum recovery strength.