30G-22 |
Calcium incorporation in papaya by low temperature blanching |
I. Perez-López1, J. Welti-Chanes, A. LÓPEZ-MALO3, E. Palou, and A. Ibarz5. (1) Deptartamento de Ingeniería Química y Alimentos, Universidad de las Americas-Puebla, Sta. Catarina Martir, Cholula, Puebla, 72820, Mexico, (2) Departamento de Ingeniería Química y Alimentos, Universidad de las Americas-Puebla, Sta. Catarina Martir, Cholula, Puebla, 72820, Mexico, (3) Departament de Tecnologia d'Aliments, Universitat de Lleida, Rovira Roure, 177, Lleida, 25198, Spain
Low temperature blanching (LTB) treatments improved final firmness of several processed vegetables and fruits by activating native pectin methyl esterase (PME) in the tissue of those products. Addition of calcium to blanching water further improve the texture throughout calcium pectate formation. Calcium incorporation could have additional benefits as mineral enrichment in fruits subjected to LTB prior to processing by freezing, canning, or drying. The objective of this work was to evaluate the effects of LTB treatments applied to papaya pieces at selected temperatures (45, 55 or 65ºC), calcium chloride concentration solutions (0.2, 0.6 or 1.0%), and treatment times (20, 40 or 60 min) following a Box Behnken experimental design, on calcium concentration and texture retention of papaya. Papaya cylinders (2.5 cm diameter, 1 cm height) were subjected to LTB treatments following the experimental design, submerging 20 fruit pieces (100g) in the pre-heated calcium solution (1-10, fruit-solution ratio) for each time-temperature combination. After treatment, fruit was cooled with tap water. Texture and calcium concentration were determined by measuring the maximum force during compression and by atomic absorption spectrophotometry, respectively. Statistical analysis was performed to maximize calcium incorporation and texture retention. Statistical analysis demonstrated that calcium incorporation and texture retention in papaya were significantly affected (p<0.05) by temperature, time and calcium chloride levels as well as their interactions. At 55°C and low calcium concentration, LTB treatments reduce the initial fruit texture which was related with lower calcium concentrations. At 45 or 65ºC, fruit calcium concentration increased along with treatment time and calcium concentration in the blanching solution. Using 1.0% calcium chloride solutions during LTB resulted in a texture retention higher than 150% reaching calcium concentrations higher than 500 ppm in a short treatment time. LTB treatments significantly increase calcium content promoting fruit texture retention which can be a useful pre-treatment for papaya subjected to further processing.
Session 30G, Fruit & Vegetable Product: Processed Fruits and Vegetables
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