Influence of storage temperature on ethanol content, microbial growth and other properties of queen pineapple fruit

Abstract

Temperature and relative humidity are the two main factors that affect a pineapple's properties after harvest. The post-harvest physico-chemical characteristics Queen pineapples cv. Ninh Binh planted in Vietnam were studied. The pineapple is crispy, very sweet, a little sour and has an excellent flavor. The effects of different storage temperature (9, 12, 15 and 20°C ± 1°C: 85 ± 2% RH) on ethanol content, microbial growth, chilling injury index (CI), weight loss, total soluble solids (TSS) content, titratable acidity (TA), firmness and color of Queen pineapples were studied over a 30 days storage period. An increase in storage temperature also increased the production of ethanol within the fruit. The effect of storage temperature on the total aerobic count (TAC) and the amount of yeast, mold and bacteria on the surface of the pineapples during the 30 days storage period was also studied. Fruit surface TACs were generally in the range of 105 to 106 colony forming units (CFU). There were chilling injury symptoms and a higher CI index for the fruit stored at 9°C, 85% RH by the 10th day of storage. The TSS and TA values of the pineapples increased over a 5 to 15 day storage period but had decreased slightly by the end of the storage for all treatments. The lowest value in terms of weight loss, the highest value in terms of firmness and a lighter flesh color were obtained for those fruit stored at 12°C. The results showed that 12°C: 85% RH were the optimal conditions needed to store the pineapples, while maintaining a good quality level up to 30 days. © 2013 Friends Science Publishers.