Estudio de las condiciones de modificación por acetilación del almidón de banano y sus efectos en las propiedades funcionales

Abstract

The present research work aims to study the effect of modification conditions on the physicochemical properties of banana starch (Musa spp. AAA subgroup Cavendish). In the starch extraction process, the wet milling method was used, yielding a recovery rate of 9.671±1.545 %. Subsequently, a chemical modification was carried out through acetylation, using acetic anhydride as the modifying agent at different reaction temperatures (30, 40, and 50°C). The degree of modification was evaluated based on the percentage of acetyl groups and the degree of substitution. Additionally, the chemical composition (percentages of carbohydrates, protein, fats, moisture, ash, and crude fiber) and physical properties (swelling power, water solubility index, oil retention capacity, water absorption index, bulk density, and syneresis) of the acetylated starches were analyzed at different temperatures and compared to their native counterparts. The increasing of the reaction temperature led to a significant increase in the percentage of acetyl groups (% AC) and the degree of substitution (p ≤ 0.05), reaching values of %AC of 3.3104±0.3826% and degree of substitution of 0.1289± 0.0154, respectively. A similar trend was observed for ash, lipids, proteins, fiber, and moisture content (p ≤ 0.05). In contrast, carbohydrate content decreased, indicating that reaction conditions and varieties affect the chemical composition of acetylated starches. Regarding functional properties, such as swelling power, water solubility index, and water absorption index, it was observed that native starches subjected to maximum reaction temperatures (50°C) achieved the highest modification values when exposed to temperatures of 90°C. Meanwhile, their oil retention capacity increased significantly (p≤0.05). Conversely, bulk density decreased as the maximum reaction temperature (50°C) was reached (p ≤ 0.05). During refrigeration, acetylated starches exhibited reduced retrogradation over time, demonstrating greater stability under refrigeration for starches acetylated at a reaction temperature of 50°C