Physico-chemical properties and nutrition quality of potato flour: chuño vs modern processing technology

Abstract

Chuño production is a kind of ancient method of potato preservation that has been used to the present day. In this study, physicochemical property and nutrition quality of white chuño (WC), black chuño, and dehydrated potato flour prepared by hot air drying (AD) and freezing drying were analyzed and compared. The results revealed that the average particle size of the starch in WC is almost 10 times of the dehydrated potato flour by AD treatment according to the laser particle size meter. During the dehydration of WC, water-soluble minerals (K + , Mg 2+ ), proteins, ascorbic acid, etc. were partly lost while Ca 2+ content increased dramatically. In addition, WC showed the lowest antioxidant capacity among the four different kinds of dehydrated potato products. The polyphenol oxidase activity of WC, black chuño and AD were between 0.62–12.2 U/g fresh weight, which indicated that the color will be stable when chuño was used as staple food ingredient in the subsequent process. Therefore, as a potato processed food, chuño displayed great potential for promotion in the cold and poor rural areas of the northern China.