Effect of ultrasound on extraction of carotenoids of lycopene and beta-carotene from chili pepper fruit and response surface optimization of extraction conditions

Chili pepper (Capsicum annum L.) belongs to the family Solananceae and contains large amounts of secondary metabolites (phenol antioxidants and carotenoids). Considering pigments content of pepper having red color and strong antioxidant effects, it is widely used in the preparation of food grade dyes. The use of ultrasonic waves due to its promising effects on maintenance and processing of food is growing. The aim of this study was to evaluate the effectiveness of ultrasound in the extraction of carotenoid compounds extracted from red pepper and process optimization using response surface methodology (RSM). Variables in study were extraction temperatures at 3 levels (30, 40 and 50 °C), extraction times at 3 levels (10, 25 and 40 minutes) and power at 3 levels (30, 60 and 90 watt). The results based from optimization using RSM showed that with increasing time and temperature of extraction, carotenoid content decreased and increased, respectively. Carotenoid contents also increased in red pepper with increasing ultrasound power. The optimal conditions for extracting maximum carotenoid compounds out of pepper were treatment temperature of 49 °C for 10 minutes and 89.9 percent ultrasound power. Under these conditions, the values of extracted carotenes were 430.6 mg/kg for beta-carotene and 261.4 mg/kg for lycopene. The results showed that using ultrasound pretreatment before extraction of carotenoids increased the amount of extracted lycopene and beta-carotene.