Chemical, physical and physicochemical properties of modified banana starch

Abstract

Unripe banana starch has shown a potential to film formation. However, its hydrophilic nature is caused a high water vapor permeability film. The objective was to determine the effect of modification methods and starch contents on chemical, physical and physicochemical properties of modified banana starch. Sodium trimetaphosphate (STMP) was used to produce cross-linked banana starch (CBS) at different starch contents (4, 6, and 8 g). Another modification method miniemulsion of CBS (MCBS) was obtained from CBS with a mixture of cyclohexane and surfactants. Cross-linked and miniemulsion cross-linked technique did not change in shape and particle size of banana starch granules. CBS and MCBS showed lower swelling power (SP) and solubility (S) values at room temperatures (29 degree Celsius) and gelatinization temperature (80 degree Celsius) compared to native banana starch (NBS) corresponding to an increase in degree of substitution (DS) of modified starch. Moreover, starch content was directly proportional to DS and inversely proportional to S of modified banana starches. MCBS with 8 g of NBS provided the highest DS and the lowest S values. This might improve film water barrier. Further study on the method of particle size reduction is needed to enhance film properties.