Laboratory-scale production of low-fat potato chips by coating with hydrocolloids

Globally, potatoes are the fourth main food item after wheat, rice and corn. Potato chips are a very popular snack However, due to the high content of oil (40%), consumption of this product is not desirable from a nutritional point of view. The aim of this study was to produce low-fat potato chips by coating with hydrocolloids and investigate the effects of the hydrocolloid coating on chemical, sensory, and shelf-life of potato chips. Potatoes (Agria variety) were sliced, and the slices were then coated by immersion in 1%, 3%, and 5% pectin, 0.5%, 1.0%, and 1.5% sodium alginate, and 0.5%, 1.0%, and 1.5% carboxymethylcellulose (CMC) solutions. The coated samples, as well as an uncoated control sample, were fried in a frying oil. The moisture content, oil uptake, and the total acceptability of all the samples were determined, and then their acid and peroxide values were measured after zero, 2, 4, 6, and 8 weeks of storage. The results showed that hydrocolloid coating caused an increase in moisture content and a reduction in oil uptake in potato chips (p<0.05). Coating with 5% pectin brought about the highest reduction of oil uptake (28.6% oil and 34.4 % reduction), while treatment with 1.5% CMC resulted in the highest retention of moisture (6.06%). Based on the sensory evaluation of the total acceptability and the oil uptake reduction, concentrations of 5% pectin, 1% sodium alginate and 1% CMC for each type of hydrocolloids were selected. The results also showed that hydrocolloid coating causes significant reductions (p<0.05) in peroxide and acid values during 2 months of storage: the lowest peroxide value (61.32% reduction) and the lowest acid value (42.1% reduction) were due to treatment with 5% pectin and 1.5% CMC, respectively. The 5%-pectin coating was selected as the most suitable coating because it brought about the highest reduction in oil uptake, the highest total acceptability, the highest reduction in peroxide value, and a considerable increase in the shelf-life of potato chips.