Effect of Freezing, Additives, and Packaging Techniques on the Quality of Processed Blue Crab Meat1,2

Abstract

Experiments were conducted to study the effect of freezing technique on quality of Blue crab meat. Freshly processed crabmeat was used as a control. The treatments were evaluated by a trained sensory panel and analyses for trimethyl amine (TMA), total volatile base (TVB), and pH. The first experiment involved comparisons of crabmeat pre-treated with malic acid vs. phosphate, can vs. vacuum packaging in plastic pouches and storage at −18 and −30 C for 8 months. The results indicated that freezing and storing of crabmeat in a conventional air-circulating freezer (−18 C) significantly reduced the quality (aroma, flavor, texture, appearance) when compared to fresh crabmeat. Even when stored at −30 C, the quality was substantially lower than that of fresh crabmeat after 1½ months of storage. The two packaging methods and application of malic acid or phosphates did not prevent quality deterioration. A second experiment included a similar design except that the effect of freezing crabmeat with dichlorodifluoromethane (“Freon” Food Freezant) was compared with conventional freezing. The same packaging method was used but the additives were omitted. Freezing with “Freon” for 1½ month caused no significant difference in meat quality when compared with fresh crabmeat (stored 0 days) but quality of the frozen crabmeat decreased significantly after 1½ months. Storage at −18 C was unsatisfactory for both freezing methods. TMA, TVB, and pH analyses were not of major value in assessing the quality of the fresh or frozen crabmeat.

Standardization of Pasteurization Process for Soft- and Hard-Shell Blue Swimming Crab (Portunus pelagicus)

“…Crabs are traditionally precooked at a temperature of 100 °C in boiling water for 8-10 min [16,31]. Alternatively, precooking of whole crabs is also done by using steam at 121 °C for 10 min, followed by air cooling in some instances [32]. In the generic HACCP plan developed by the National Sea Grant College Program of the National Oceanic and Atmospheric Administration (NOAA), the USA for blue crabs, precooking is done in a retort at 121 °C for 10 min under 15 psi pressure and cooled in an air cool room for 2 h [33].…”

“…Studies on the changes in TVB-N in crab meat are very minimal. The effect of freezing on the quality of blue crab meat (Callinectes sapidus) was studied by Webb et al [32], and later, they examined the effect of freezing, additive, and packaging methods on the quality of processed blue crab meat [32]. Gates et al [56] observed that TVB-N increased from 26.2 mg/100 g on day 1 to 117.2 mg/100 g on day 13 in cooked and refrigerated blue crabs (Callinectes sapidus).…”