Effect of blanching and frying on textural profile and appearance of yam (Dioscorea rotundata) french fries

Abstract

Response surface methodology was employed to characterize the effects of blanching temperature, blanching time and final frying time on texture and appearance of fried yam chips produced from two cultivars of white yam (Dioscorea rotundata). Fifteen treatment combinations were derived from Box–Behnken design (k = 3) and run. Analysis of variance and multiple linear regression analyses were conducted to determine the effects of factors on the texture and color indices and to fit models for predicting the response variables. There were differences in the effects of the same set of factor combinations on textural attributes (hardness, fracturability, cohesiveness, gumminess and chewiness) and color (L, a, b) indices of the two cultivars used. Blanching temperature and frying time had a greater impact on texture and appearance of fried chips than blanching time. Adequately fitted models were derived for predicting the effects of blanching and frying on the textural profile and color of yam chips. Millions of tonnes of yam (Dioscorea rotundata) are cultivated annually; however, very few commercial products have been produced from yam. French fries are hugely popular all over the world, and frozen potato chips have evolved into a multibillion dollar business. Yam shares many characteristics with potatoes (Solanum tuberosum) and can equally be conveniently processed and packed for distribution as frozen chips for French fries production. This study provides information on the effects of processing factors on the quality characteristics of fried yam chips similar to potato French fries to facilitate the process of transforming yam into a convenient food product to meet urban demand