Changes in Nitrogenous Compounds in Freshwater Crayfish (Procambarus Clarkii) Tail Meat Stored in Ice

Abstract

Changes in the protein and nonprotein nitrogen (NPN) fractions in the tail meat of freshwater crayfish (Procambarus clarkii) were monitored during ice storage. In addition, the accumulation of nonprotein nitrogenous compounds was estimated and compared with sensory evaluation. The myofibrillar fraction, expressed as a percentage of total nitrogen, did not vary during this study while the NPN, sarcoplasmic and stroma protein fractions changed during the first week of storage. SDS‐PAGE patterns of the sarcoplasmic fraction showed slight differences over storage time. Ammonia nitrogen (NH3‐N), trimethylamine nitrogen (TMA‐N) and pH rose at a slow rate during the first week but increased rapidly up to the end of storage. Amino nitrogen (A‐N) did not augment to a great extent over time. Sensory scores were significantly correlated (p < 0.05) with pH, A‐N, TMA‐N, and NH3‐N in descending order.

Freshness Loss in Sierra Fish (Scomberomorus Sierra) Muscle Stored in Ice as Affected by Postcapture Handling Practices

“…1998). A steep pH increment indicates accumulation of alkaline metabolites such as TMA and TVB because of increased bacterial activity (Flick et al. 1994; Huss 1996).…”

Postmortem Biochemical and Textural Changes in the Adductor Muscle of Catarina Scallop Stored at 0c

“…Riaz and Qadri (1985), evaluating quality changes in lobster muscle ( Panulirus poliphagus ) stored on ice, reported that increments during storage lower than or equal to 0.1 pH units represented a first‐quality muscle. Pronounced pH increase indicates the accumulation of alkaline metabolites from bacterial accumulation over time (Flick et al. 1994; Huss 1995).…”

Effect of previous chilling storage on quality loss in frozen (&#8211;20 &#176;C) sierra (Scomberomorus sierra) muscle packed with a low-density polyethylene film containing butylated hydroxytoluene

“…Endogenous proteolytic activity may be another factor related with alteration of pH in sea products. Final pH 7 in control samples at 15 days suggests a quality loss of fish muscles, according to several authors who reported that a significant increase in pH indicates a loss in the freshness of fish muscle (Flick et al, 1994;Huss, 1996;Castillo-Yáñez et al, 2007).…”