Effect of the delay between harvest and the start of cooling on the quality of pineapple fruit

Abstract

Introduction. Frequently, harvested pineapple fruit experience cooling delays due to the distance from the field to the packing plant. The industry reports 6 hours as the maximum convenient time however, there is no published information about it. Objetive. To determine the effect of the time between harvest and cooling on quality of pineapple (Ananas comosus) var. Golden Extra Sweet, with transport simulation. Materials and methods. Four trials were conducted in different regions and seasons (dry and rainy season). Freshly harvested fruits were exposed to ambient conditions for 6, 12, 24 and 48 hours before cooling, after these periods fruits were disinfected with chlorine at 150 mg.l^-1. Prochloraz fungicide at 300 mg.l^-1 was applied, fruits were waxed (vegetable oil based wax), packed, and forced air cooled for 4-5 hours until they reached 12-13°C. They were them subject to transport simulation and stored for 21 days at 7,5°C and 85-90% R.H. Treatment effects were evaluated on quality variables: weight loss, external and internal color, mold on peduncle, partial fruit dehydration, flesh translucency, flesh firmness, acidity and total soluble solids. Results. After 12 hours of cooling delay, fruit quality declined, with more evident impact on dehydration and mold development, and reduction o pulp firmness. External and internal color, translucency, titratable acidity and total soluble solids were not affected. Conclusions. Cooling delay had a negative impact on pineapple fruit quality, especially on mold development and partial fruit dehydration and a minor impact on flesh firmness. Under the conditions of this study, maximum allowable delay in cooling the fruit was 12 hours.