Alleviation of internal browning in pineapple fruit by peduncle infiltration with solutions of calcium chloride or strontium chloride under mild chilling storage

The development and control of internal browning (IB, a form of chilling injury) were studied in fruit of two commercial cultivars of pineapples. The symptoms develop in tissues surrounding the core when the fruit are stored at <15 °C for several weeks. It was found that core and the fruitlets of fruit of 'Smooth Cayenne' and 'Trad-Srithong' could be effectively infiltrated with water soluble carmoisine dye or salt solutions by transpiration via the peduncle over three days at storage temperatures of 8, 13, and 20 °C. IB was more severe in 'Trad-Srithong' than in 'Smooth Cayenne' fruit particularly at 8 °C. Infiltration via the peduncle increased calcium or strontium concentrations in the core and adjacent flesh tissue and reduced IB in 'Trad-Srithong' stored at 13 °C. There were no differences in severity of IB between green and quarter ripe fruit. Infiltration with calcium or strontium through the peduncle was more effective when the treatment was applied to freshly harvested fruit under mild chilling conditions

Response of internal browning in pineapple fruit vacuum infiltrated with solutions of calcium chloride or strontium chloride

The development of internal browning (IB) was studied in pineapple fruits treated with CaCl2 and SrCl2. ‘Smooth Cayenne’, ‘73-50’ and ‘Gold’ grown in Queensland, Australia were vacuum infiltrated at 30 kPa for 2 min in aqueous solutions of 0.18 M CaCl2 or 0.18 M SrCl2, stored at 13 or 20°C (80-90% RH) for 14 days, and assessed for IB after 3 days at 20°C. In Australian grown ‘Smooth Cayenne’, black heart (BH), a form of IB is a common disorder found in the fruit maturing during the winter months. Storage at 13°C increased IB in ‘Smooth Cayenne’ fruit harvested in March, September and December 2007 and in February 2008 but there was a low incidence of IB only in ‘Gold’ harvested in September 2007. Fruit of ‘73-50’ harvested in September 2007 had a high incidence of IB but no IB developed in fruit of this cultivar harvested in December 2007. Vacuum infiltration did not significantly increase the calcium content in the core or adjacent flesh tissue and treatment with calcium or strontium had no effect on the incidence or severity of IB

Effect of harvest seasonal and gamma irradiation on the physicochemical changes in pineapple fruit cv. Pattavia during stimulated sea shipment

Gamma irradiation is used as a phytosanitary treatment for tropical fresh fruit from some producing countries. An experiment was carried out to study the effect of gamma irradiation and season of harvest on the quality ‘Pattavia’ pineapple fruit. Fruit harvested in the summer and the rainy cool (winter) seasons were exposed to gamma radiation at dose levels of 0 and 400–600 Gy from a 60 Cobalt source and the fruit stored at 13°C and 90% RH for up to 21 days. Gamma irradiation did not affect the ratio of TSS/TA, antioxidant content, or ascorbic acid concentration. However, gamma irradiation did delay color development and also induced internal browning over 50% of flesh discolored in fruit stored for 14 days, especially harvested winter fruit. Moreover, harvesting fruit in different seasons had a significant effect on fruit quality after harvest and during stimulated sea shipment storage. The result showed that gamma irradiation can be used as a phytosanitary treatment with minor changes in eating quality. However, the internal browning was greater if fruit were stored longer than 1 week at 13°C