Estudio del almidón modificado de banano (m. sapientum l.)variedad cavendish obtenido por acetilación.

Abstract

Starch is composed by two molecules, amylose and amylopectin, which, depending on compositional and structural arrangement, confer a unique physical and chemical properties and provide benefits to food products at first hand; this, however, can be easily affected by stress under shear and thermal decomposition. Detrimental factors such as high retrogradation and syneresis can be overcome through starch modification. Modified starch improves gelatinization temperature reduction, retrogradation retardation, thermal stability improvement, these allow modified starch to be applied in the food industry. Some common applications can be as an agent of clouding, film conformer, foam stabilizer, bread anti-aging, gelling agent, glazing, humectant, texturizer, and thickener in both, pharmaceutical and chemical industry. The main objective of the present research work was to evaluate banana (M. sapientum L.) modified starch obtained by acetylation characteristics. Acetylation processes consist on a chemical reaction in which hydroxyl groups of the native starch molecule are replaced by Acetyl groups; this is also called esterification. This produces changes in starch at both, chemical structure and functional characteristics. Modification processes depend on certain factors such as starch source, reagent concentration, reaction time, amylose/amylopectin ratio, pH, among others (Figueroa et al., 2016). In this research, the effect of chemical modification by acetylation is evaluated by a factorial design of 32; factors on said design were acetic anhydride volume (5 mL, 12 mL, and 17 mL) at different reaction times (30 min, 60 min, and 90 min) to look for independent variables incidence over the dependent ones (Acetyl groups percentage, substitution degree, swelling power, solubility, water adsorption index. Statistical analyzes were carried out by Statgraphic Centurion Version 17. 1. 12. The ANOVA analysis was performed; significant differences were found in acetyl groups percentage and substitution degree (DS) related to acetic anhydride volume (p <0.05). Water absorption and solubility index were affected by acetic anhydride volume (p <0.05), whereas swelling power was not affected by any of the 2 factors (p <0.05). Adjusted model equation in response variables (%Acetyl, substitution degree) determines the present research work reliability. It can be said that the model adjustment is good since R2 value ranges from 0.80 to 0.95. Swelling power, solubility, and water absorption index properties model equation R2 was not close to 1, -1; it showed an uncommon behavior. Substitution degree and acetyl percentage in treatments were low showing their application to be viable in different food products declared by FAO. According to Vargas et al. 2016, acetylation modification is the most suitable for frozen foods.