Storage of markies cultivar potatoes for prossessing

ABSTRACT The refrigerated induce the sweetening of the potato, which results in the dark color. The objective of this study was to determine the temperature and shelf life of Markies potato tubers under refrigerated storage for the processing of French fries. The levels of total soluble sugar (TSS), reducing sugars (RS), peroxidase (POD) and polyphenoloxidase (PPO) activity, color after frying and start of sprout were determined. The accumulation of TSS started at 30 days in the tubers at 4 and 5 °C and in the tubers at 6 and 8 °C, at 150 days. The activity of POD and PPO were not influenced by temperature or storage time. Tubers at 4 e 5 °C showed higher TSS and RS contents and darker color after frying than tubers stored at 6 and 8 °C which had their color maintained within the industry-acceptable standard up to 240 days of storage. Temperatures of 4 and 5 °C delayed the onset of sprouting, starting at 150 days, and at temperatures of 6 and 8 °C, the onset of sprouting occurred from 90 and 60 days of storage, respectively. It is concluded that the cultivar Markies should be stored at 6 °C for 240 days.摘要 冷藏环境会诱导马铃薯发生糖化反应，进而导致其油炸后色泽加深。本研究旨在探究用于炸薯条加工的Markies马铃薯块茎在冷藏储存条件下的适宜温度与货架期。实验测定了总可溶性糖（total soluble sugar, TSS）、还原糖（reducing sugars, RS）、过氧化物酶（peroxidase, POD）与多酚氧化酶（polyphenoloxidase, PPO）的活性，以及块茎油炸后的色泽与发芽起始时间。结果表明，4℃与5℃储存组的块茎，其总可溶性糖积累于储存30天时启动；而6℃与8℃组块茎的糖积累则始于150天。过氧化物酶与多酚氧化酶的活性不受储存温度与时长的影响。4℃与5℃组块茎的总可溶性糖与还原糖含量更高，油炸后色泽更深；而6℃与8℃组块茎的色泽在储存240天内均可维持在行业可接受标准范围内。4℃与5℃的储存温度可延缓发芽起始时间，该组块茎于储存150天时开始发芽；而6℃与8℃组块茎的发芽起始时间分别为储存90天与60天。综上，Markies马铃薯品种的适宜储存条件为6℃，储存时长可达240天。