Utilization of potato peel (domestic waste) in deep oil fried wheat chips

This study was conducted to test the usability of potato peels in deep oil fried wheat chips. For this purpose, potato belonging to the melody varieties (Solanum tuberosum L.) was taken from a local market and peeled by hand. The peels were then freeze dried, followed by grinding using a blender. The obtained potato peel flours were then passed through 500 µm sieve and stored in a refrigerator (4 °C) until the production of chips. Potato peel flour was incorporated at 2-4-6-8 and 10 g/100g into the formulation for the production of wheat chips, which were then evaluated for their physicochemical, bioactive, textural and sensory properties. Significant decreases in oil contents of wheat chips were identified when potato peel flour amount was increased in the formulation (p<0.05). Wheat chips oil contents varied from 45.57 to 27.46 g/100g. The oil contents of the chips were found to be decreased by % 40 when % 10 potato peel flour was included in the formula. Significant increases were also observed in the protein contents of chips samples when potato peel flour was added (p<0.05). Protein contents at the samples altered from 7.47 to 9.15 g/100g. The highest instrumental hardness value was measured (22.64 kg) in the chips containing 8 g/100g potato peel. However, the lowest instrumental hardness was detected (13.32 kg) in potato peel flour-free chips sample. Color values of samples (L*, a*and b*) showed significant changes with an addition of potato peel flour into formula (p<0.05). The sensory analyses revealed that potato peel flour addition did not impact the overall sensory acceptability of the samples (p>0.05), suggesting that 10 g/100g potato peel flour content can be used without impacting consumer acceptability of the chips. Phenolic contents of the samples were found to be linearly increased with potato peel flour incorporation (p<0.05). Total phenolic content of samples were detected to be between 364.7 and 1108.0 mg GAE/kg. The antioxidant capacities of the samples were measured to be: 842.5, 1165.0, 1283.8, 1978.8, 1757.5, and 2070.0 mg A.A Cin/kg for chips made using 0, 2, 4, 6, and 8 g/100g potato peel flour, respectively. Total dietary fiber content of the control sample (in potato peel without chips) was 4.8 g/100g, while the 6th sample (10 g/100g potato peel flour in the chips) was determined to be 6.9. This shows that the dietary fiber level of samples increased by 29 % when 10 g/100g potato peel flour was included. The estimated glycemic index content (eGI) ranged from 88.2 to 93.1 and the lowest value was found in the 6th sample containing 10 g/100 g of potato peel flour. The eGI of the samples significantly decreased with increasing the potato peel flour in the chips formulation (p<0.05). In conclusion, this study clearly shows that the potato peel flour can be used in deep fat fried wheat chips and other kinds of chips in order to increase the nutrition qualities.