Production of chips from potato cultivars (Solanum tuberosum L.) with high sugar content using lactic acid fermentation

Summary Tubers of twelve cultivars ofSolanum tuberosum L., with a varying content of reducing sugars (0.49–2.30 g/100 g fresh weight), were sliced and fermented for up to 48 h by lactic acid bacteria in a brine of 1.5% NaCl, prior to frying. The content of reducing sugars decreased by 80 to 100%, depending on the initial sugar level. Colour of chips was measured using the CIE (1976) L^*a^*b^* colour system, where L^* is lightness, a^* is redness and b^* is yellowness of the material and by IBVL colour cards, photographs used for grading the colour of potato chips. L^*-values were the best measurement of chip colour. The scale of the IBVL colour cards was too narrow (scale 1–9) for this study, as chips from eight of the cultivars were scored lighter than IBVL 9 after 48 h of fermentation. Lighter coloured chips significantly correlated with lower contents of reducing sugars. The sugar content decreased as fermentation time increased. Fermentation time can thus be used to control potato chip colour, and all the cultivars tested can be used for production of chips with regard to colour.