Effect of apple by-product as a supplement on antioxidant activity and quality parameters of pasta

In this study, pasta was prepared by replacement of durum semolina (DS) with 10% and 15% of apple peel powder (APP). The control sample was pasta made from 100% DS. Total phenolic content (TPC), antioxidant capacity (AOA) and quality parameters of pasta were determined before and after cooking. Extraction of phenolics with methanol and ethanol, assisted with ultrasound (15 min) and by stirring (with magnetic stirrer for 1 h) was also compared. Results showed that addition of APP increased cooking loss and the amount of absorbed water of the pasta samples. Hardness and adhesiveness of pasta samples was decreased with APP addition. Pasta with added APP had significant higher levels of TPC and AOA compared with pasta without addition of APP. The highest TPC (1.4 g of gallic acid equivalents/kg) was in raw pasta with addition of 15% APP from which phenolics were extracted with ultrasound assisted extraction and methanol. Regarding AOA, the highest antioxidant activity (0.8 mg gallic acid equivalents/100g) was also in raw pasta with 15% APP, from which phenolics were extracted by stirring and ethanol. In cooked pasta, the levels of TPC and AOA, were significantly lower compared to raw pasta (p≤0.05). Sensory evaluation showed that there was no significant difference between DS and DS + 10% APP. Apple peel powder (APP) could be a food by-product, conveniently used as additive, for delivering health-promoting bioactive compounds such as polyphenols