A quantitative method to analysis shrimp peelability and its application in the shrimp peeling process

Abstract

Shrimps are rich in protein, mineral elements, essential amino acids, polyunsaturated fatty acids, and other useful substances, making it a nutritionally balanced protein source (Zhang, Deng, & Wang, 2015). In recent years, shrimp processing industry has grown rapidly and accounted for over 45% of the processed seafood market (Mao, Guo, Sun, & Xue, 2017), and frozen peeled shrimps are one of the main commercial products (Yi et al., 2012). Thus, shelling is crucial for processing. For fresh caught shrimp, the shell is tightly attached to the epidermis by attachment fibers (intracuticular fibers), which is firmly attached to the muscle by extensive interdigitation (Talbot, Clark, & Lawrence, 1972). This tight shell-muscle adhesion makes it difficult to remove the shell (Dang et al., 2018b), which results in low peeling efficiency when shelling by manual or mechanical processing and damaging the integrity of the shrimp meat. Thus, incomplete shelling, low meat yield, decreased sensory quality, and color change are the key factors restricting the efficient industrial processing of shrimp (Dang et al., 2018a; Liu, Liu, Wang & Qin, 2014). Therefore, it is essential to loosen the shell-muscle attachment of shrimp before peeling, which is called pretreatment.