Influence of Frozen Storage and Defrosting on the Chemical and Nutritional Quality of Sardine ((Clupea pilchardus)

Abstract

Studies were carried out on the changes in solubility in SDS+β‐mercaptoethanol, the –SH group content, the amino acid and the fatty acid compositions, and nutritional quality of the muscle protein following freezing, storage at −20°C and conventional defrosting of sardines (Clupea pilchardus). During the processes, 8% of the total SH– group content was lost and there was a slight drop in solubility in SDS+β‐mercaptoethanol. The amino acids which dropped to the greatest extent were the S‐amino acids, followed by histidine, tyrosine, leucine, lysine and phenylalanin. The C22:6/C16:0 ratio dropped and this was considered to be related to oxidation phenomena. The digestibility of protein, biological value and net protein utilization (NPU) also dropped as a result of the processes studied.

The influence of ante-mortem hypoxia on the physicochemical stability of myofibrillar proteins in the muscle tissue of white shrimp (Litopenaeus vannamei) exposed to multiple freeze–thaw cycles

“…It is likely that both factors contributed to the modification of the physicochemical qualities of the proteins, causing a reduction in the hydration capacity. In contrast, no differences were observed between the Similar to this study, a reduction in solubility was also reported for the muscle tissue of other species subjected to multiple freeze-thaw cycles, including the following: Clupea pilchardus [25], Machrobrachium rosenbergii [26], Gadus morhua [13], and Cherax quadricarinatus [15]. There is a relationship between the solubility and the WHC of shrimp muscle proteins; both are dependent on inter-and intra-molecular forces (hydrogen bonds, electrostatic interactions, hydrophobic interactions, and dipoledipole interactions) to maintain thermodynamic stability.…”

Effect of thermal processing on the biochemical constituents of green mussel (Perna viridis) in Tin-free-steel cans

“…Water content located within the narrow channels between the thick and thin filaments of myofibrils (Offer et al 1984;Bertola et al 1994) releases due to the heat denaturation and subsequent shrinkage of myofibrils (Ofstad et al 1993). The increased protein, fat and ash content in the canned samples may be due to the water loss from the muscle during sterilization (Castrillón et al 1996;García-Arias et al 1994). In the present study the pH of the raw mussel meat sample was around 6.59 suggesting the mussel used was of good quality (Riaz and Quadri 1985).…”

“…A similar result was also reported by Gallardo et al (1990); Ruiz-Roso et al (1998);Mai et al (1978); Puwastien et al (1998);Gall et al (1983); Gokoglu et al (2003) in thermal processed fish products. Water loss in mussel meat can be explained in terms of heat treatment and protein degradation of muscle, this leading to a decreasing water holding capacity of the myofibrillar protein fraction (Castrillón et al 1996;García-Arias et al 1994). From the present study it was observed that most of the cook loss was water.…”

Comparative evaluation of the quality changes in Squid (Ommastrephes bartrami) during flake and slurry ice storage

“…While in the sample stored in FI the water content decreased to 78.35% after 15 days. The losing in water content refers to disruption of the muscle structure and denaturation of myofibrillar proteins and sarcoplasmic, resulting in to a decreasing water holding capacity of the protein fraction (Castrillón et al, 1996;Rodríguez et al, 2008). The salinity content of the squid stored in SI increased from 0.52 to 2.81‰ at the end of the storage period (15 days), while the squid stored in FI changed slightly and the senility content was 0.58‰ after 15days (Fig.…”