Evaluation of yam (Dioscorea rotundata) chips pre-treatment conditions (salting, sulphiting, and blanching) combined with dehydrofrozen storage for fries production

Abstract

Yam is a highly perishable commodity lacking commercial utilization, like potato for French fries production. Frozen yam chips could be a panacea for its increased utilization as fries and export commodity for Nigeria. Hence, Yam (Dioscorea rotundata) Chips pre-treatment conditions (Salting, sulphiting, blanching) combined with dehydrofrozen storage for fries production was studied. Yam chips were pre-treated (Salting, sulphiting, and blanching), dehydrated (60°C for 10 min), and stored for five months at frozen temperature. Standard methods were used to determine the proximate composition, textural and sensory properties of yam fry samples. Yam fries proximate composition ranged as 5.19-11.33% (moisture), 14-36.92% (Fat), 0.74-2.34% (Protein), 0.67-2.01% (Crude fibre), 0.97-1.06% (ash), and 51.7-75.93% (carbohydrate). The range of the textural properties of the yam fries were hardness (27.38-442.13 N), energy to peak (0.07-0.87 N•m), gumminess (8.55-271.98 N), chewiness (3.57-238.48 N), springiness (0.23-0.91 mm), stringiness (0.52-3.67 mm) and cohesion (0.1-0.75). Salted and blanched fried yam chips showed lesser variation in textural properties throughout storage. Sensory scores for appearance, aroma, taste, palatability, texture, and overall acceptability of the yam fries decreased as the storage duration of the yam chips increased, except for yam fries pre-treated by blanching and salting. The blanched and salted dehydrofrozen yam chips were acceptable by panelists until the fourth month of storage. High-quality and acceptable yam fries could be produced by combining salting and blanching of yam chips before dehydrofrozen storage. The commercial success of this product will reduce the huge post-harvest losses of yams and provide income to the farmers.

Keywords

• yam fries
• dehydrofrozen
• salting
• blanching
• sulphiting