30G-28 |
Ascorbic acid incorporation in peach pieces throughout vacuum impregnation |
E. R. Astorga-Solari1, J. Welti-Chanes, E. Palou, and A. LÓPEZ-MALO1. (1) Departamento de Ingeniería Química y de Alimentos, Universidad de las Américas-Puebla, Sta. Catarina Mártir, Cholula, Puebla, 72820, Mexico
Consumer's demand for functional and fresh food products (fresh-like products) has generated an important change in the trends of application of food preservation techniques, ascorbic acid (Vitamin C) has been included as fortification in several fruit products, especially drinks. Fruit pieces can be fortified with ascorbic acid and used as minimally processed fruits. The application of vacuum impregnation processes at constant temperature (25°C) to incorporate ascorbic acid into the porous structure of peach pieces was evaluated. The fruit effective porosity was determined employing vacuum impregnation in isotonic sucrose solutions obtaining values around 3.0%. The fruit (cylinders, 1 cm diameter, 2 cm height) was submitted to vacuum osmotic impregnation (VOI) processes (50 mbar) in 13.5°Brix peach juices with 1, 4 or 7% added ascorbic acid. Fruit - juice ratio was varied from 1-3, 1-11.5 or 1-20, impregnation and relaxation (at atmospheric pressure) times were 10 min each. Ascorbic acid content after VOI was determined by dye titration. Sensory evaluation (hedonic scale, color, flavor, and overall acceptability) was performed between impregnated peaches. Statistical analysis demonstrated that fruit - juice ratio as well as initial ascorbic acid content and their interaction have a significant effect (p<0.05) on final ascorbic acid content on the fruit. The ascorbic acid content range from 4.0 (fresh fruit) to 1700.0 mg/100g (1-20, fruit -juice ratio; 7% initial ascorbic acid). For each fruit - juice ratio tested, an increase in ascorbic acid in the juice increased the final ascorbic acid content in the fruit. Fixing an optimum content of 500 mg of ascorbic acid/100g fruit, several combinations of the tested variables can be employed during the VOI process. With 1% initial ascorbic acid in the juice and 1-20 fruit-juice ratio this target concentration can be achieved during VOI, permitting the re-use of the impregnation juice at least three times. Ascorbic acid incorporation during VOI process improves color of the fruit and has acceptable sensory attributes.
Session 30G, Fruit & Vegetable Product: Processed Fruits and Vegetables
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