Radiation Pasteurization of Fresh and Blanched Tropical Shrimps

Abstract

SUMMARY— The storage life of fresh, peeled and deveined tropical shrimps at 10—12°C is extended to 10—14 and 18—21 days with 0.15 and 0.25 Mrad, respectively, as against spoilage of unirradiated samples within 4 days. Blanching treatment (steaming for 4 min) with or without brine (3.0% NaCl) extends the storage life up to 30 days at lo—12°C. the former retaining the shell‐fish flavor. However, the blanched products develop musty odor and slimy texture during storage; subjected to irradiation (0.15 Mrad) these are devoid of undesirable attributes and are acceptable for 60 and 130 days, respectively, at 10—1°C and 2—4°C. Bacterial counts exceeding 108/g and high levels of TMAN and TVBN concur with spoilage of unirradiated shrimps. In contrast, low levels of TMAN and TVBN, despite high TBC, corroborate with high acceptability of radiation processed shrimps. In blanched as well as in blanched and irradiated shrimps TBC, TMAN and TVBN are low. Samples subjected to blanching only have low acceptability as against the improvement in quality by irradiation. These alterations in storage property have been discussed in the light of shifts in microflora.

Alternative Seafood Preservation Technologies: Ionizing Radiation and High Pressure Processing

“…The shelf life of Bombay duck (Harpodon nehereus), under refrigeration was shown to be about 5-7 days. Radiation doses of 1.5-2.5 kGy extended the shelf life to about 15-20 days (Kumta et al, 1970). According to Chuaqui-Offermanns et al (1988), whitefish (Coregonus clupeaformis) were gamma irradiated at 0.82 and 1.22 kGy, and stored at 3°C for 17-21 days.…”

The application of ESR spectroscopy for the identification of irradiated Crustacea

“…As with all forms of seafood, Crustacea are partieularly susceptible to bad handling and poor quality control, the major problem being associated with microbial contamination, espeeially by pathogens such as species of Salmonella and Vibrio [1][2][3]. If not inhibited or destroyed, these microorganisms may presenta public health hazard and, in addition, growth of spoilage flora will also result in a decrease in the shetf-life of the product.…”