EFFECT OF OCTENYLSUCCINYLATION ON FUNCTIONAL PROPERTIES OF LIMA BEAN (PHASEOLUS LUNATUS) STARCH

Abstract

ABSTRACT The functional properties of lima bean (Phaseolus lunatus) starch modified with octenyl succinic anhydride (OSA) were evaluated and compared with native starch. The OSA starch was produced from a starch aqueous suspension at 40% (w/w) with 3% OSA at pH 7 for 30 min. The modified starch had 0.51% succinyl groups and a 0.008 degree of substitution. Succinylation increased emulsifying capacity from 0.47 mL oil/mL sample in the native starch to 0.53 mL oil/mL sample in the OSA starch. Starch gel clarity (transmittance percentage) increased from 23.8 to 37.3%. Viscosity increased from 700 to 1,000 BU. Gel firmness decreased from 0.3401 kgf for gel rupture in the native starch to 0.0314 kgf for rupture in the OSA starch. Gelatinization temperature decreased from 75.3 to 64.6C and gel enthalpy decreased from 10.7 to 9.7 J/g. Succinylation caused not significant changes in solubility, swelling power and water absorption capacity. OSA starch stability was lower under refrigeration conditions.PRACTICAL APPLICATIONSThe incorporation of octenylsuccinate groups into lima bean starch produce a derivative with more versatility as a food additive providing new and improved functional properties. The octenylsuccinylation allows the use of the lima bean starch in products such as beverages, salad dressings and soups where the use of this starch is limited because lack of diversity in their functional properties necessaries in the alimentary industry. Therefore, the improved properties of the Phaseolus lunatus octenyl succinic anhydride starch make it potentially useful in processes requiring a thickening agent that must gel at lower temperatures; it can also serve to reduce energy consumption during cooking processes or like thickening or emulsifying agent or make it potentially useful as an additive in jellies and candies to provide brightness. However, the election of this derived as additive in food, should take into account the functional properties that it presents, the ingredients and the process conditions.