INFLUENCE OF INTERMITTENT WARMING ON REDUCING CHILLING INJURY AND KEEPING QUALITY OF ‘VALENCIA” . EXPORT ORANGES | ||||
| Journal of Plant Production | ||||
| Article 12, Volume 31, Issue 12, December 2006, Page 7885-7901 PDF (242.43 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/jpp.2006.236428 | ||||
 View on SCiNiTO | ||||
| Author | ||||
| Amira A. E. El-Helaly, | ||||
| Hort. Res. Station, Sabahia, Alex., Hort. Res. INS., A.R.C. Giza, Egypt. | ||||
| Abstract | ||||
| Dunng 2004 and 2005 seasons, consignment of ValenciaN oranges was obtained from citrus packinghouse before shipping to overseas markets. The fruits were stored for up to 15 weeks at the following temperature regimes (a) Continuous temperature at 5 oc (control), the remained fruits were subjected to intermittent warming (1W) cycles of (b) 18 days[d] at 5°C + 36 hours[h] at 20°C; (c) 18 d at 5°C + 48h at 20°C; (d) 18d at 5°C + 60h at 20°C; (e) 18d at 5°C + 72h at 20°C; (f) 13d at 5°C + 24h at 20°C; (g) 6d at 5°C + 12h at 20°C and (h) 6d at 5°C + 24h at 20°C, with RH 85-90%. AIl fruits then were held at 20°C with RH 80-90% for one week to simulate re(ial marketing. The results indicated that, in both experimental seasons, as the storage penod advanced, the percentages of unmarketable fruits, weight loss, total soluble solids (TSS) and TSS: acid ratio were significantly increased. Meanwhile, the percentages of titratable acidity (TA), fruit juice (%) and values of ascorbic acid (V.C) significantly decreased, as an average for ail treatments. The highest significant unmarketable (%) existed ¡n fruits stored continuously at 5°C (control) (37.22 and 33.33% in first and second season, respectively), compared with those in oranges treated with 1W treatments (9.44- 24.44% in first season and 10.55 — 27.22% in the second), as an average for all storage penods. In addition, dunng the following shelf life period, those percentages were significantly decreased from 90% in both seasons in fruits stored continuously at 5°C to 46.66 -73.33% and 40.00- 73.33% in first and second seasons, respectively ¡n ones treated with intermittent warming treatments. Moreover, 1W had a great effect on decreasing fruit weight loss percentages. The effectiveness of 1W treatments on improving physical properties, was not clea1y noticed on chemical ones such as TSS, TA, fruit juice (%), TSS: TA and V.C content. In spite of the efficiency of 1W on TA was not clearly obvious, it was found that fruits treated with long cycle 1W treatments (b),(c), (d) and (e) showed highest percentages followed by medium one (f) then those of short cycles (g) and (h). The best 1W treatment was (g) (6d at 5°C + 12h at 20°C) as the most clear reduction in unmarketable fruits (%)associated with that treatment especiaIy during storage period, while the worst one was (f) (13 d at 5°C + 24h at 20°C) whereas the rest of 1W treatments showed medium effects. Generally, there were no significant differences among long cycles intermittent warming treatments (b), (C), (d) and (e) on reducing the percentages of unmarketabe fruits and weight loss. Also between short cycles 1W treatments (g) and (h) on reducing weight loss. | ||||
| Keywords | ||||
| Va1encia” orange fruits; storage; intermittent warming and chilling injury | ||||
|
Statistics Article View: 55 PDF Download: 131 |
||||
