Low-volume procedure to determine phytate and ascorbic acid in potatoes: standardization and analysis of Indian cultivars

Abstract

Phytate and ascorbic acid are the two major compounds present in potatoes that affect mineral absorption process in human body. Potato cultivars having high ascorbic acid to phytate ratio may be considered appropriate for mineral fortification for targeted mineral delivery since phytate inhibit mineral absorption while ascorbic acid promote their absorption. Rapid chemical methods have been standardized for phytate and ascorbic acid estimation in Indian potato cultivars using ELISA plate reader. Pooled analytical data of two years’ harvest of 48 potato cultivars was used for this study. The phytic acid content in potato cultivars ranged from 3.39 mg/100 g (Kufri Giriraj) to 61.34 mg/100 g (Kufri Red); whereas, the ascorbic acid content ranged between 19.40 mg/100 g (Kufri Lauvkar) to 58.39 mg/100 g on fresh wt. basis; (Kufri Chipsona-1). Among the various processing cultivars, Kufri Chipsona-4 showed the highest ascorbic acid to phytate ratio (1.942) followed by Kufri Chipsona-3(1.567), Kufri Frysona (1.549), Kufri Chipsona-1(1.296) and Kufri Chipsona-2 (0.991). Based on the results, the cultivars were classified into three groups of ‘Low (0.43–3.9)’, ‘Medium (4.0−7.4)’, and ‘High (7.5−10.0)’ for ascorbic acid to phytate ratio which comprising 46, 1 and 1 potato cultivars, respectively. Results showed Kufri Chipsona-4 to be highly suitable for fortification of potato chips, while, for French fries’ fortification, Kufri Frysona would be effective. Multivariate non-hierarchical cluster analysis optimized three clusters using average silhouette method and showed that table purpose cultivars are more promising carrier than processing cultivars for fortification.