Effect of genotype, raw-material storage time and cut type on native potato suitability for fresh-cut elaboration

The suitability for fresh-cut processing of three native colored-fleshed potatoes (i.e., Bruja, Michuñe roja and Michuñe azul) and one commercial non-colored-fleshed potato (i.e., Asterix) was investigated. The impact of the storage time of the raw material and the type of cut (i.e., cube and chip) was also examined. Fresh-cut potato from raw material stored 2 months at 12 °C and 90% relative humidity (RH) displayed 1 to 2.5 times higher respiration activity than potatoes stored 4 months under the same conditions. Lower CO2 emission was only observed when potatoes stored 4 months were used. Fresh-cut potato shelf life decreased (less than 23 d at 5 °C) due to microbial growth. Approximately 7 log cfu g−1 for mesophilic and psycrophilic bacteria and Enterobactericeae when potatoes stored 4 months were used. Microbial growth was higher in chips than cube. The native colored-fleshed potatoes were rich in polyphenols, and total antioxidant capacity is 1 to 2 times higher than that of commercial potato. Total polyphenol content was not affected by the storage time of the raw material and remained stable under storage at 5 °C. However, fresh-cut potato processed from raw material stored 2 months had 1.5 to 3 times more total antioxidant capacity than that processed from raw material stored 4 months. For both parameters, Bruja exhibited values approximately 60% higher. Although all the analyzed varieties were suitable for fresh-cut elaboration, Bruja and Michuñe roja displayed higher metabolic activity and susceptibility to microbial deterioration and browning. To guarantee fresh-cut potato quality, raw material should be maintained no longer than 4 months in storage. From this moment some quality parameters alterations, that limited the fresh-cut shelf life, begin to be observed.