Nutritional composition, anti‐nutritional properties, and sensory attributes of fried white yam (Dioscorea rotundata) slice as influenced by different pre‐treatment methods
Authors: Omoniyi Saheed Adewale , Ibrahim Maimuna , Oke Emmanuel Kehinde , Okolie Pius Ifeanyi 
Published: June 2022

The study evaluated the effect of different pre‐treatments on nutritional composition, anti‐nutritional, and sensory attributes of fried white yam slices. Different four samples (fried boiled yam slice, fried boiled yam slice with wheat flour, fried soaked yam slice, and fried boiled yam slice with eggs) of fried yam slices were purchased from sellers in Gashua, Yobe state Nigeria and laboratory prepared fried yam slice sample which served as a control sample was used for the study. Proximate composition, mineral content, and anti‐nutritional properties of fried yam slices were analyzed using standard methods. The values obtained for proximate composition and mineral content were significantly different (p < .05). The values obtained for proximate composition ranged from 32.45–38.94%, 1.95–2.48%, 5.32–17.15%, 7.06–13.26%, 3.08–3.86%, and 30.82–47.70% for moisture, ash, crude protein, crude fat, crude fiber, and carbohydrate content, respectively, while the values of mineral content ranged from 257.48–829.98 mg/100 g, 20.22–65.17 mg/100 g, 55.51–178.94 mg/100 g, 8.25–26.58 mg/100 g, 0.64–2.06 mg/100 g, and 0.50–1.15 mg/100 g for potassium, calcium, phosphorus, magnesium, iron, and zinc content, respectively. Also, the values obtained for the anti‐nutritional properties ranged from 0.02–0.06 mg/100 g, 0.01–0.05 mg/100 g, 0.01–0.03 mg/100 g, and 0.02–0.05 mg/100 g for oxalate, phytate, tannin, and saponin content, respectively, while the mean sensory scores ranged from 6.60–8.40, 6.60–8.20, 6.80–8.20, 7.00–8.60, 6.40–8.00, and 6.80–8.40 for appearance, color, texture, aroma, taste, and overall acceptability, respectively. The study showed that the pre‐treatments increased the nutritional composition, drastically reduced the anti‐nutritional properties and sensory attributes of fried yam slice were accepted panelists.

Novel impact statement

In Nigeria, yam tuber usually fried after peeling, slicing, and washing with clean water. However, recently in Gashua, yam slices undergo some pre‐treatments before frying and such pre‐treatments include boiling, salting, dipping into egg, and wheat flour solutions.

These pre‐treatments led to different processing of yam slices before frying. That is, peeled and washed yam slices usually soaked in salted water, boiled, boiled and dipped in egg emulsion, and boiled and dipped in wheat flour solution before frying.

These pre‐treatments give four different fried yam slices which resulted in choice to the consumers and led to the increase in consumption of fried yam slices.

Also, consumers only patronize the fried yam slice of their choice. In addition, fried yam slices which normally consumed as a snack now consumes as a meal especially as breakfast and lunch by consumers.

The highest value for ash, protein potassium, calcium, phosphorus, magnesium, iron and zinc content was observed in fried yam slice with eggs.

All the anti‐nutritional contents of fried yam slice were lower especially samples pre‐treated with boiled water before frying.

Boiling and frying are more efficient in reducing the anti‐nutritional contents of yam.

Fried boiled yam with egg had the highest mean sensory scores in terms appearance, color, aroma, taste, and overall acceptability.

All the sensory attributes of four pre‐treatment fried yam slices were accepted by the panelists.

The pre‐treatments increased the nutritional composition and drastically reduced the anti‐nutritional properties of fried yam slice.