INFLUENCE OF TEMPERATURE ON QUALITY OF BROCCOLI UNDER MODIFIED ATMOSPHERE PACKAGING

The influence of temperature on the quality of broccoli (Brassica oleracea L. italica group) under modified atmosphere packaging was studied. Samples were prepared as follows; 1 broccoli was packed with a perforated low density polyethylene film pouch of 0.03 mm thickness at 10 degrees C and stored at 10 degrees C, 2 broccoli was packed with a non-perforated polyethylene film pouch of 0.03mm of thickness (PE30) at 10 degrees C and stored at 10 degrees C, 3 broccoli was packed with PE 30 at 10 degrees C and stored at 10 degrees C for 2 days, and then transferred to 30 degrees C for 1 day, and stored at 10 degrees C again, 4 broccoli was packed with PE 30 after precooling (5 degrees C) and stored at 10 degrees C, 5 broccoli was kept at 30 degrees C for 4 hours before packaging with PE 30, and stored at 10 degrees C. The O-2/CO2 concentration in the pouches of samples 1, 2, 3, 4 and 5 after 8 days of storage were 18.4/0.5, 1.2/5.3, 0.4/10.8, 1.8/6.6, 0.3/9.0%, respectively. These results reflect the influence of the temperature on the respiration rate of broccoli. The sample O deteriorated visually in 4 days, and its chlorophyll and ascorbic acid contents decreased rapidly. No apparent changes in color had occurred in other samples. However, an unpleasant odor was detected in the samples 3 and 5. The development of undesirable odors was mainly due to ethanol emanation under anaerobic condition. The sugar and ascorbic acid contents in the sample 3 decreased drastically after transferring of broccoli to 30 degrees C. Among the sample conditions tested, marked effects on retaining sensory quality and on the delay of losses of chlorophyll, ascorbic acid and sugar were observed in the samples 2 and 4.