ISHS Acta Horticulturae 505: VII International Symposium on Rubus and Ribes
RESPONSE OF THREE RASPBERRY CULTIVARS TO DIFFERENT MODIFIED ATMOSPHERE CONDITIONS |
| Authors: | P. M.A. Toivonen, C. Kempler, S. Escobar, J. Emond |
| Keywords: | postharvest, quality, packaging, volatiles |
| DOI: | 10.17660/ActaHortic.1999.505.2 |
| Abstract:
The response of three raspberry cultivars (‘Meeker’, ‘Chilliwack’ and ‘Qualicum’) to modified atmosphere (MA) conditions was studied. Three levels of atmospheric modification were attained in polyethylene packages; 1. high - 10% CO2, 5% O2, 2. moderate - 6% CO2, 10% O2 and, 3, slight - 3% CO2, 15% O2. The highly modified atmosphere is in the range currently recommended for raspberries. A control of air-stored raspberries was used as a comparison. The three cultivars all showed a similar response for soluble solids and titratable acidity retention. Retention of soluble solids or titratable acidity was not affected by modified atmospheres over 7 days of storage at 1 °C. Ripening, as measured by fruit color, was delayed with increasing levels of atmospheric modification. There was no difference between cultivars for delay of ripening with MA. Initial firmness values for ‘Chilliwack’ and ‘Qualicum’ were much higher than for ‘Meeker’ and as a result final firmness values after 7 days of storage were also higher for these two cultivars. High levels of MA enhanced loss of firmness in ‘Qualicum’ and ‘Chilliwack’. Volatile analysis of the juice from ‘Qualicum’ and ‘Meeker’ after 7 days storage showed that ‘Qualicum’ was prone to greater accumulation of acetaldehyde and ethyl acetate than was ‘Meeker’. Ethyl acetate accumulations have been linked to off-flavors in MA packaged strawberries. These results show that both ‘Chilliwack’ and ‘Qualicum’ have superior storage characteristics. However susceptibility to off-flavor development in these two cultivars suggests that atmospheres much less modified than currently recommended for raspberries should be considered if MA shipping is a desired marketing strategy. | |
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