RHEOLOGICAL AND MACROMOLECULAR QUALITY OF PECTIN EXTRACTED WITH NITRIC ACID FROM PASSION FRUIT RIND
Résumé
Yellow passion fruit processing in Brazil releases large amounts of waste (300,000 metric tons per year) that could be used as an alternative raw material for extracting potentially 2,000 metric tons of pectin. Valorization of pectin extracted from passion fruit rind demands the establishment of a proper protocol to maintain a high standard of product quality. In this work, a central composite experimental design of 23 was used to verify the influence of different conditions on the molecular characteristics and rheological behavior of extracted pectin. The extraction conditions were time (545 min), temperature (6397C) and nitric acid concentration (892 mM). The responses significantly influenced (P < 0.05) in the trials were yield extraction, the apparent viscosity and reduced viscosity. The ideal conditions for extracting pectin with the highest apparent viscosity and with a high molecular weight were obtained with short time (5 min), medium temperature (80C) and 50 mM nitric acid.