The impact of multiple pre-treatment combinations and storage on some quality parameters of apple chips fried by vacuum combined infrared radiation

The effects of citric acid, ethanol, and ultrasound pre-treatments and storage on the quality characteristics of semi-dried and subsequently fried apple chips by using vacuum combined infrared technique were investigated. While increasing ethanol concentration resulted in better color values and lower 5-hydroxymethylfurfural (HMF) content, the fat content in the sample increased with increasing ultrasound amplitude. The most effective pre-treatment for the production of apple chips with lower fat content and higher general acceptability was the combination of 50% ultrasonic amplitude/100% ethanol/%0.75 citric acid. During storage, while peroxide and p-anisidine values remained almost constant at 20 °C, these parameters showed an increasing trend at 30 and 40 °C. P-anisidine values of samples kept at 30 and 40 °C showed a remarkable increase after the 4th and 2nd months, respectively. The results showed that the 50% ultrasonic/100% ethanol/0.75% citric acid combination, could be successfully applied as a pre-treatment to produce fried apple chips with higher quality and greater oxidative stability.