30G-2 |
Fruit puree preservation by hurdle technology |
J. WELTI-CHANES1, M. Pacheco-Pensado, A. López-Malo, E. Palou, and F. T. Vergara-Balderas. (1) Departamento de Ingenieria Quimica y Alimentos, Universidad de las Americas-Puebla, Sta. Catarina Martir, Cholula, Puebla, 72820, Mexico Most of the industries that manufacture nectars and other fruit beverages use as base concentrated purees that are maintained under refrigeration or freezing. These processes represent high costs and reduction of the quality . An alternative to substitute this type of purees is the use of the hurdle technology to obtain minimally processed products. Purees of apple and peach were obtained and stabilized through slight reduction of aw (0.96 and 0.98), pH (3.0 and 3.5) and incoporation of potassium sorbate. Glucose syrup and citric acid solutions were incorporated to the purees obtained. In some cases, potassium sorbate was also added to obtain 1000 ppm. The purees were placed in plastic bags to store them at 15 and 25C, and stored up to 90 days evaluating on regular intervals the total counts of microorganisms, molds and yeast. Changes in aw, pH and color were also evaluated, and duo-trio and 9 point hedonic scale sensory tests were applied to such products . The nectars were formulated with the purees studied here, and with thermally treated purees that are employed by the industry.The pulps of both fruits stored without potassium sorbate presented microbiological problems after 30 days of storage, independently of the levels of the other parameters under study. In contrast, those purees containing the antimicrobial did not presented microbial problems (CFU lower than 100). The nectars formulated with these last purees were always more accepted in function of their flavor and color compared to the reference products. The changes in composition of the studied purees were not statistically significant. The results obtained showed that it is feasible to apply the minimal processing concepts and hurdles technology to obtain fruit purees that can be used in the formulation of high quality nectars, and with lower costs compared to the traditional processes actually employed in industry.
Session 30G, Fruit & Vegetable Product: Processed Fruits and Vegetables
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