Determination of Nutrient Composition and Total Volatile Basic Nitrogen (TVB-N) Levels in Sea Snail (Rapana venosa Valenciennes, 1846) Process Steps

Abstract

It was aimed to determine the TVB-N (Total Volatile Basic Nitrogen) content as a nutrient content and chemical quality parameter for each processing step of sea snail (Rapana venosa) in a fishery processing plant. In the research, after the raw material (sea snail) entered the processing plant, samples were taken from six different stages, namely boiling, washing, shell removal, calibration, freezing (24 hours -35 degrees C to -40 degrees C), and storage (1 week at -18 degrees C), according to the process steps. According to the results of the analysis, the raw moisture contents during the processing stages were found to be 73.32 +/- 0.90% (scalding), 70.53 +/- 0.17% (washing), 72.67 +/- 0.27% (skin removal), 75.51 +/- 0.57 (calibration), 76.79 +/- 0.14% (shocking), and 76.01 +/- 0.10% (containment). Besides, the raw ash content contents were determined as2.49 +/- 0.03% (scalding), 2.31%+/- 0.27% (washing), 2.74 +/- 0.50% (skin removal), 1.25 +/- 0.14% (calibration), 1.08%+/- 0.16% (shock) and 1.09 +/- 0.14 (containment). Moreover, crude protein contents were calculated as 19.44 +/- 0.07% (scalding), 21.46 +/- 0.70% (washing), 20.07 +/- 0.08% (skin removal), 18.92 +/- 0.72% (calibration), 19.28 +/- 0.57% (shock) and 18.17%+/- 0.41 (containment).As for crude oil levels, of the steps, they were found to be 0.83 +/- 0.52% (scalding), 1.65%+/- 0.65% (washing), 0.53 +/- 0.0% (skin removal), 0.53 +/- 0.00% (calibration), 0.49 +/- 0.04% (shock) and 0.56%, respectively. It was determined to be +/- 0.04 (containment). TVBN-analysis results of sea snail (Rapana venosa) in the processing stages were 8.20 +/- 0.08 mg/100g for blanching, 9.61 +/- 0.09 mg/100g for washing, 12.26 +/- 0.14 mg/100g for shell removal, 8.23 +/- 0.16 mg/100g for calibration, 8.94 +/- 1.02 mg/100g for freezing and 6.87 +/- 0.15 mg/100g for preservation. Lastly, it was also revealed that the TVB-N limit for fresh and chilled snail meat samples was in the range of consumable standards during the processing stages.