ROLE OF CALCIUM ON INTERNAL BROWNING OF PINEAPPLES
Internal browning (IB) of pineapples limits the storage life and transportation potential at low temperature. Queen and Smooth Cayenne pineapples were harvested from various planting locations in Thailand. The total calcium content in nine sample fruits was determined and the remainder stored at 10°C for 21 days. It was found that Queen pineapple developed more internal browning after storage than Smooth Cayenne pineapple. A relationship was found between the calcium content and IB in one experiment but not in the other. The effect of preharvest and postharvest calcium applications on IB of Queen pineapple was also studied. Pineapples sprayed with 1,000 mg L-1 calcium-boron solution combined with 150 kg ha-1 of calcium oxide exhibited a 47.6% internal browning reduction. In a second experiment, the calcium application was not effective in reducing IB. In a postharvest study, calcium application by the immersion of pineapple fruit stems in 0, 1, 2 and 4% calcium chloride solutions at 25°C (80-85% RH) for 18 hours reduced IB by 35, 77 and 79%, respectively. The 2 and 4% calcium chloride solutions caused a dark brown area in the fruit stem, which extended 2.5 cm into the core. Repeated experiments could not confirm the effect of postharvest calcium application on IB reduction. This suggests that calcium content is only one of the factors influencing internal browning in pineapples.
Pusittigul , I., Siriphanich, J. and Juntee, C. (2014). ROLE OF CALCIUM ON INTERNAL BROWNING OF PINEAPPLES. Acta Hortic. 1024, 329-338
storage life, 'Smooth Cayenne', calcium chloride, black heart