Effects of processing methods on nutrient and antinutrient composition of yellow yam (Dioscorea cayenensis) products

- Raw yellow yam was high in moisture and carbohydrate content compared with its other nutrients.
- Processing the yam to different products improved the macronutrient content of products.
- The low sodium, lipid and antinutrient content coupled with improved mineral and β-carotene values of the products qualify them for consumption by everyone.
- Pounding yam with the boiling water retained greater part of the nutrients.
- The energy content of yam products qualifies them as source of energy to consumers.

There is dearth of documented information on nutrient retention of Dioscorea cayenensis products. This study was carried out to evaluate effects of processing methods on nutrient and antinutrient retention of yellow yam products. Fresh Dioscorea cayenensis tubers were purchased from Bodija market in Ibadan, peeled, cut into small pieces, divided into nine portions. One portion was treated as raw sample, and others processed into local delicacies. All nine samples were analysed for proximate, mineral, vitamin and antinutrient composition using AOAC methods. Data were analysed using ANOVA at p = 0.05. Raw yam contained 66.79 g moisture, 2.62 g crude protein, 0.27 g lipid, 0.17 g fibre, 0.63 g ash, 29.69 g carbohydrates, 262.30 mg potassium, 61.53 mg magnesium, 0.79 mg iron, 0.39 mg zinc, and yielded 108.26 kcal energy with insignificant vitamin content/100 g edible portion. Processing significantly improved macronutrients and energy content with significant reduction in all antinutrients of products (p < 0.05). The yam products can serve as staple source of energy to consumers.