Preharvest Calcium Effects on Internal Breakdown and Quality of 'Pattavia' Pineapple during Low Temperature Storage

Thailand is one of the world's leading producers and exporters of processed pineapple products such as juice and canned products, but it lags behind in fresh fruit export. Main factor limiting exports of fresh pineapples is the development of internal browning. This physiological disorder could possibly be minimized by preharvest management of nutrients such as calcium, boron and silicon. This study was conducted to determine the effect of preharvest application calcium on internal breakdown and quality of pineapple fruit 'Pattavia' during storage at 10 degrees C. Three months before harvest, pineapple fruits were sprayed every two weeks with calcium chloride at concentrations of 1.5 and 3.0 g/fruit; unsprayed fruit served as the control. Calcium at 1.5 g/fruit was found to reduce internal browning and translucent symptoms when compared to the control. It also reduced disease severity during storage. Total soluble solid from all treatments did not show any significant change during storage while titratable acidity slightly increased. Combined application of 1.5 g calcium chloride, 0.4% boron or 40 mM silicon further reduced internal browning. This result suggests the great potential of calcium application alone or in combination with boron and silicon as a preharvest component in the total management of internal breakdown and quality of pineapples after harvest.