Effects of different microwave power on the drying kinetics and physicochemical quality of brown shrimp (Metapenaeus dobsoni)

Abstract

Microwave processing is used in industry for drying food commodities as it improves the quality of products and reduces the drying period. In the present study, the effects of microwave power of 600 W (105 and 100 min), 800 W (95 and 90 min), and 1000 W (80 and 65 min) and temperature (60 and 70 °C) on the drying kinetics and quality of microwave-dried shrimp were investigated. The results revealed that increasing the microwave power and temperature increase the drying rate. During the drying process, protein, fat, and ash content increased, whereas the moisture content decreased. The energy value of the dried shrimp increased from 54.41 to 287 kcal g−1. The yield of dried shrimp was in the range of 24–25%. The pH, trimethylamine nitrogen (TMA-N), total volatile base nitrogen (TVB-N), free fatty acids (FFA), thiobarbituric acid-reactive substances (TBARS), and non-protein nitrogen (NPN) values increased slightly in the dried shrimp. Moreover, the hardness of the fried shrimp decreased, while its springiness, gumminess, cohesiveness, and chewiness increased slightly. The lightness (L*), redness (a*), yellowness (b*), chroma, browning index, whiteness index, and ΔE increased in the dried shrimp. The results indicated that the quality of the dried shrimp and drying time decreased when the microwave power was increased.