Biochemical and functional attributes of raw and boiled potato flesh and peel powders for suitability in food applications

Four different potato cultivars, namely, Kufri Chipsona 1 and Kufri Frysona (processing purpose), Kufri Jyoti and Kufri Bahar (table purpose) were converted into flesh and peel powder (raw and after boiling) and studied for their respective biochemical and functional attributes to get an idea of possible dynamics of their utilization in different food formulation as bioadditives. The 16 variants of powder obtained retained less than 10% moisture content and demonstrated 'very good' to 'fair' flowability. Peel powders recorded a higher total mineral, fiber, phenolic contents and total antioxidant activity than the flesh powders which were significantly affected by boiling. Among raw and boiled flesh powders, highest reducing and total sugars were recorded for Kufri Bahar while least was observed in Kufri Chipsona 1. Colour coordinate showed that boiling imparts brightness to flesh powder while peel powder got darkened. Boiling of the tubers resulted in an increase in the resistant starch (~ 29% maximum) and flavour (~ 180% maximum) component. Peel exhibited a total glycoalkaloid content in the range of 0.75 (Kufri Frysona) to 1.7 mg/100 g (Kufri Bahar) that is well within the acceptable limits. Rheological study of the flesh powders revealed a reduction of about 11-18 °C in pasting temperature and about 87-90% in peak viscosity, setback, breakdown value and final viscosity upon boiling. This study revealed that the traditional processing method such as boiling can significantly modify the techno-functional characteristics of potato flesh and peel powders which can further govern their end use in various food formulations.