Changes of allergenecity of salted and fermented shrimp

Bae, Sang Woon; Choi, Soo Young; Jin, Hyun Sun; Kim, Cheol Woo; Lee, Kwang Eun; Kang, Eun Seok; Park, Jun Yong; Hong, Sung Pil; Choi, Hoon Young; Jung, Jae Hun; Kim, Yong Soo; Hong, Chein Soo

Abstract

BACKGROUND AND OBJECTIVE
Shrimp is one of the most common food allergens. The salted and fermented shrimp (S/F shrimp) is a traditional food and ingested frequently in the daily life of many Korean people. But few studies have been investigated on the allergenicity of S/F shrimp. The aim of our study is to observe the allergenicity of S/F shrimp and to compare it with the allergenicity of shrimp. MATERIAL AND METHODS: Crude extracts were made from three kinds of S/F shrimps and four kinds of shrimps after boiling. The extracts were used for SDS-PAGE, ELISA, ELISA inhibition test, immunoblotting, and immunoblotting inhibition test with sera from 10 subjects who have shrimp specific IgE by radioallergosorbent (RAST) (3+ or 4+). RESULTS: The protein concentrations of S/F shrimp extracts were less than half of the extracts of shrimps (1.9 mg/ml, 1.2 mg/ml, 1.1 mg/ml vs 4mg/ml, 3.83 mg/ml, 6.8 mg/ml, 6.6 mg/ml). The extracts of S/F shrimp showed weaker and more diffusely distributed protein bands in SDS-PAGE and showed less than half of the O.D. value in IgE-ELISA compared to those of shrimp extracts. The specific IgE immunoblotting of S/F shrimp extracts showed 9 bands (36, 33, 30, 29, 28, 26, 23, 20, 19 kDa). Dose dependent inhibition was observed between shrimps and S/F shrimp in ELISA-inhibition and immnunoblotting inhibition test. The allergen concentration of S/F shrimp needed to inhibit 50% of shrimp-lgE ELISA was five times higher than that of shrimp. CONCLUSION: The crude extracts of S/F shrimps showed less than half the amount of protein compared to crude extracts of shrimps have and also showed reduced allergenicity by salting and fermentation.