36E-27 |
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E. FLORES-AVILA, Dept. de Ingeniería Química y Alimentos, Univ. de las Américas, Puebla, Sta. Catarina Martir, Cholula, Puebla, 72820, Mexico, A. Argaiz, Dept. de Ing. Química y Alimentos, Univ. de las Américas, Puebla, Sta. Catarina Martir, Cholula, Puebla, 72820, Mexico, E. Palou, Center for Engineering Education, Univ. de las Americas, Puebla, Cholula, Puebla, 72820, Mexico, and A. Lopez-Malo, Dept. de Ingeniería Química y Alimentos, Univ. de las Américas-Puebla, Santa Catarina Mártir, Cholula, Puebla, 72820, Mexico. Passion fruit (Passiflora edulis f. flavicarpa) is marketed chiefly because of its poor stability during transportation and storage. Processed products of tropical fruits, including passion fruit, are becoming increasingly popular in developed countries. Pasteurized nectars and juices offer definite advantages, however, they tend to lose their flavor and develop a cooked taste during thermal processing. Kinetics of First Change on Flavor (FCF), ascorbic acid degradation, and pectinesterase (PE) inactivation were evaluated in passion fruit beverage puree subjected to several thermal treatments in a temperature range of 70 to 90° C. Passion fruit beverage (25% pulp and 14.5°Brix using fructose syrup) was subjected to selected pasteurization treatments. A sensory trained panel and the R-index test were used to determine FCF dependence on temperature. PE activity was determined after each treatment with the sensitized jelly test procedure. Ascorbic acid concentration was determined by titration with 2,6-dichloro-fenol-indophenol. For FCF and PE the logarithm of maximum and minimum heating time that gave a positive and negative result for every treatment temperature were plotted to obtain z values. Z value for the FCF was 48.9° C, for PE inactivation was 42.2° C, and for ascorbic acid degradation of 61.6° C. Different F=1 minute temperatures were obtained being lower for PE inactivation. This result allows designing pasteurization treatments at temperatures higher than 90° C that assure PE inactivation without detectable changes in flavor and low loses in ascorbic acid. Flavor and vitamin degradation as well as enzyme inactivation kinetics demonstrate that processes designed on PE inactivation could be optimized to obtain sound and high quality tropical fruit products.
Session 36E, Fruit & Vegetable Products: General
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |