Tailoring banana starch characteristics through combined preheating and branching enzyme approaches

Digestibility of starch, a notable raw bioresource, is affected by its granular form, structure, and processing conditions. This study aimed to investigate the effect of pre-heating temperatures (60-85 °C) and subsequent branching enzyme (BE) modification on green banana starch to modify its structural and functional properties. Pre-heating at 60-65 °C maintained granular integrity while enabling BE to increase α-1,6 linkages (5.2-8.4 %). At 70 °C, partial gelatinization facilitated greater BE access, resulting in amylose reduction (3.2 %) and maximum branch formation (10.4 %). Complete gelatinization at 75-85 °C eliminated Maltese crosses and maximized BE accessibility, producing amorphous structures with negligible amylose content (< 1.1 %). Both solubility and gel transmittance increased progressively with higher pre-heating temperatures, with completely gelatinized samples exhibiting the highest values. Chain-length distribution analysis revealed an increase in short chains (DP 6-12) with a concurrent decrease in longer chains across all the modified samples. In-vitro digestibility results demonstrated that BE-modified starches exhibited substantially increased slowly digestible and resistant starch content after cooking, particularly at higher temperatures. This approach offers a versatile strategy for producing banana starch ingredients with tailored structural, functional, and nutritional properties.