| Abstrakt: |
Egypt produces annually about 30 million tons of fruits and vegetables. High temperature is prevailing most of the year in Egypt's climate and this hastens maturity of fresh fruits and vegetables. Keeping fresh produce in lower temperature by cooling is very important to maintain quality of these products. For economic and practical reasons, fruits and vegetables are placed sometimes together in the same refrigerated trucks during transportation. Mixed loads should be subjected to an intermediate temperature to inhibit metabolic senescence of maturation and limit ethylene formation and its effects and to avoid chilling injury of susceptible products like summer squash. This study aimed to test the effect of jasmine oil vapors, containing methyl jasmonate among other volatiles, on preserving quality of mixed load of apricot and summer squash during cold storage as a simulation of the refrigerated transport. Apricots were brought from a farm located in Noubarya district, Behaira Governorate, Egypt, while summer squash was harvested from a farm in El Sharkia Governorate Egypt. Two concentrations of jasmine oil were applied (0.025% and 0.05%) as vapor, in separate treatments, over fruits in carton boxes comprising 2 kg of squash and 2 kg of apricot mixed together in the same carton. Jasmine oil was treated by an oxidizing' agent according to the method mentioned by Ben -- Yehoshua, (2008), (U.S patent No7645469- B2), and kept, 20 minutes in ambient temperature before transferring to cold .storage at 5°C for 9 days. Samples were taken after 3, 6, 9 days of the cold storage immediate quality parameters evaluation whereas half of. these samples were kept for additional 2days at 10°C as shelf life (supermarkets conditions), and their quality parameters tested afterwards. Results showed that summer squash and apricot placed together, were intact with acceptable quality for the first 6 days at 5°C, and the quality deterioration occurred after this period at 5°C and deterioration began also after transfer to 10°C. Weight loss averaged 3.5-4 % and about 5% for both jasmine oil treated apricot and squash, respectively, after 6 days at 5°C, while weight loss in control which showed more than 5% for apricot and less than 6% for squash. Firmness of treated apricots was acceptable (5.5-6lb/in²) after 6 days at 5°C and was about 6.6-7 lb/in² for treated squash under the same conditions but control fruits were softened. Jasmine oil vapors at 5°C caused very little changes in color for apricots at 5°C after 6 days, and squash color was not affected, while at 10°C squash color was more pale and dull. Total soluble solids T.S.S % of apricots increased normally to reach 13% after 6 days at 5°C, while T.S.S % for squash decreased slowly to attain 4.7 - 5% under the same conditions compared to 4.5% for the control. Summer squash had a good and acceptable appearance till 6 days with the rate of 7, compared to the control, but it declined afterwards, and also, when transferred to 10°C. Appearance of apricot was rated by the end of storage and found in good conditions, especially with the higher concentration of jasmine oil, compared to control which had the poor note of (4.5). Exposing squash fruits to high level of jasmine oil vapors at concentration of 0.05% delayed significantly the development of chilling injury (CI) symptoms for 6days of storage at 5°C comparing with the lower level 0.025% and control which displayed CI symptoms after 3 days of storage at 5°C. [ABSTRACT FROM AUTHOR] |
