30B-21 |
Physiological response of chayote (Secchium edule) coated with a hydrophobic film to chill stress |
J. DE LA CRUZ1, L. E. Barahona, M. E. Quezada, R. Diaz-Sobac4, and H. S. Garcia. (1) UNIDA, Instituto Tecnologico de Veracruz, M.A. de Quevedo # 2779, Col. Formando Hogar, Veracruz, Ver., 91897, Mexico, (2) Instituto de Ciencias Basicas, Universidad Veracruzana, Xalapa, Ver., Mexico Chayote fruits suffer shrinkage when handled or stored at ambient temperature after a period of over 2 weeks. Post-harvest losses are estimated in 10-15 % of the crop when sent to the U.S. market, and 15-25 % when shipped to Europe. Low temperature storage (t<9°C) is known to cause chilling injury, and storage at t>15°C produces sprouting. Edible coatings may offer enough protection to chilling stress, sprouting and shrinking but have not been investigated for this particular purpose. Our objective was to evaluate the physiology of chayote under chill stress conditions when an edible coating is used. A single batch of chayotes were obtained from a grower and a coating was applied to half of the fruits by immersion. The coating consisted of 10DE maltodextrins, and non-ionic surfactants. Coated and control chayotes were stored at 6, 12 or 25 °C. Every third day, samples were withdrawn and analyzed for pH, °Bx, reducing sugars, respiration rate, textural firmness, weight loss and electrolyte leakage. Weight loss in control chayotes was higher (36%) than coated fruits (11%) Ripening parameters (pH values, °Bx and reducing sugars) increased in coated fruits at days 33, 42 and 36 days and 24, 33 and 24 days at storage temperatures of 25, 12 and 6 °C, respectively. Textural firmness was lost at a faster rate in control than in coated chayotes and such effect was more pronounced at 6 °C. Electrolyte leakage at 6 °C reached 81% in control mangoes at day 24, while in coated fruits such value was 77% at day 42. The maltodextrin-based hydrophobic coating reduced the severity of chilling injury symptoms in chayotes. Shelf life was extended at 12 °C from 27 days for control fruits to 42 days for coated fruits.
Session 30B, Fruit & Vegetable Products: Sensory, Product Development, Fresh-Cut, and Storage
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