Effect of temperature on initial bacteria of prawn

Abstract

This study was carried out to evaluate the effect of heat and cold on the microorganisms existing in prawn. Roasting for 5 min, boiling for 10 min and storage at -18 degrees C for 10, 20 and 30 days were applied on raw prawn to study the effect of each treatment on the bacterial load. The average counts of APC (aerobic plate count) at 25 degrees C and 0 degree C, Enterobacteriaceae, Coliforms and Staphylococci were 1.3 x 10(7), 6 x 10(4), 2 x 10(2) and 3 x 10(3) organisms per gram raw prawn sample, respectively, then reduced to 10(4), 8 x 10(2), 3 x 10(3), less than 3 and 3 x 10(2) organisms per gram roasted prawn in shell, respectively. Such counts were more reduced in roasted peeled samples. Boiling reduced the average counts of APC at 25 degrees C and 0 degrees C, Enterobacteriaceae, Coliforms and Staphylococci from 8 x 10(8), 2 x 10(5) 2 x 10(7), 3 x 10 and 3 x 10(4) organisms per gram raw prawn sample to 2 x 10(5), 3 x 10(3), 2 x 10(2), less than 3 and 4 x 10(2) organisms, respectively. Concerning freezing storage, it could be observed that the average counts of APC at 25 degrees C and 0 degree C, Enterobacteriaceae, Coliforms and Staphylococci were reduced from 4 x 10(7), 5 x 10(5), 3 x 10(5), 10(3) and 3 x 10(2) organisms per gram raw sample to 5 x 10(4), 10(3), 3 x 10(2), 10 and less than 2 x 10(2) organisms per gram after freezing storage for 30 days.

The effect of several cooking treatments on subsequent chilled storage of thawed deepwater pink shrimp (Parapenaeus longirostris) treated with different melanosis-inhibiting formulas

“…Sedik et al (1991) showed that cooking decreased the total bacteria count and that of Enterobacteriaceae in 3 and 5 logs cycles, respectively. For total viable bacteria, two different plating methods were chosen thereby facilitating the identification of psychrotropic microbiota and those mesophilic species developing during the chilled storage of the shrimp.…”

“…Swartzentruber, Schwab, Duran, Wentz, and Read (1980) obtained counts of 4.9 and 5.5 log cfu/g in plate count agar incubated at 30 and 35 C, respectively in frozen in-shell shrimp. Frozen storage of prawn frequently causes a reduction in bacterial population, the reduction being higher the longer the storage time (Sedik, Roushdy, Khalafalla, & Awad, 1991) and as lower the temperature of storage (Riaz & Qadri, 1990). These authors reported a reduction of 3 log units in total counts (PCA at 25 C) in prawns stored for 30 days and frozen at À18 C. Table 1 Analyses of variance of TVB-N in boiled shrimp during 23 days of chilled storage.…”

EFFECTIVITY OF COLD CHAIN SYSTEM IN PEELED DEVEINED TAIL ON (PDTO) COOKED PEEL VANNAMEI SHRIMP (Litopenaeus vannamei) AT PT. XYZ, EAST JAVA

“…Shrimp frozen storage has an impact on reducing the number of bacterial populations. The decrease is getting bigger along with the lower the frozen storage temperature and the longer the storage time (Sedik et al, 1991).…”