30G-30 |
Effect of polysaccharide and polysaccharide-fatty acid based edible films on coated pear wedges during refrigeration storage |
G. I. OLIVAS1, J. J. Rodríguez, and G. V. Barbosa-Cánovas. (1) Biological Systems Engineering, Washington State University, P.O. Box 646120, Pullman, WA 99164-6120 Cutting of fresh pears results in a product highly perishable due to the susceptibility of the wounded tissue to enzymatic degradation, microbial growth and a high increment in respiration rate. Edible coatings could be used to extend the shelf life and enhance the quality of fruits by carrying additives and preventing gas and water vapor permeation. The objective of this work was to evaluate the ability of methylcellulose (MC) and methylcellulose-stearic acid (MC-SA) based edible films along with calcium chloride, potassium sorbate and ascorbic acid to prolong the shelf life of pear wedges. Anjou pears were cut into wedges and subjected to 4 different treatments: (1) water immersion (control), (2) ascorbic acid, calcium chloride and potassium sorbate solution immersion (additives solution), (3) coating with MC based film plus the additives solution, and (4) coating with MC-SA based film plus the additives solution. Treated pear wedges were stored at 4ºC and 78% (±2) relative humidity and analyzed periodically for changes in weight loss, color, texture, acidity, soluble solids, and microbial load for 12 days. Results show that pears treated with additives and pears treated with additives plus edible coatings prolonged the shelf life of pear wedges compared to pears immersed in water. MC-SA coating showed to have the best properties for retaining humidity and texture. This film allowed 12.55% less water loss and kept pears 9% firmer than the rest of the treatments. Additives retarded browning regardless of the coating considered (all treatments retarded browning 13% compared to the control). No difference in acidity and soluble solids was found among treatments. These results demonstrated that a proper combination of lipids, carbohydrates, and additives coating fresh-cut pears increase the shelf life and quality of these high moisture commodities. The use of these edible films could increase the market for minimally processed pears.
Session 30G, Fruit & Vegetable Product: Processed Fruits and Vegetables
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