Sensory, chemical and bacteriological changes during storage of iced squid (Todaropsis eblanae)

Abstract

Aims: To relate sensory shelf-life of iced whole and gutted squid to bacterial growth and chemical changes. Methods and Results: Cooked mantles from whole and gutted individuals were rejected after 10 and 12 days of storage, respectively, due to ammoniacal off-odours. Rate of production of both ammonia and trimethylamine was highest in the whole lot. Agmatine, which was only present in trace amounts in freshly-caught squid, increased rapidly in both lots. The main microflora at the time of sensory rejection of iced whole squid included Gram-negative, motile and non-fermentative rods, which were psychrophilic and had a requirement for NaCl. 16S rDNA sequence analyses identified the strains as belonging to the genus Pseudoalteromonas. Shewanella putrefaciens, Pseudoalteromonas sp. and Pseudomonas sp. dominated in spoiled gutted squid. Identification of strains from the stomach and digestive gland of recently-captured squid showed that the main flora consisted of Photobacterium phosphoreum. Conclusions: Spoilage of iced squid is likely to result from a combination of autolytic and bacterial changes. Agmatine seems to be an excellent freshness indicator. Photobacterium phosphoreum may contribute to spoilage through activity in the digestive gland, followed by diffusion of volatile compounds and amines to the mantle. Significance and Impact of the Study: Due to the psychrophilic nature of P. phosphoreum and Pseudoalteromonas sp., spread-plating and low temperature incubation are recommended for bacteriological evaluation of iced squid.

Sensory, biochemical and bacteriological properties of octopus (Cistopus indicus) stored in ice

“…The increase was attributed to the production of ammonia due to the bacterial deamination of proteins, amino acids and other basic nitrogenous compounds in the flesh of cephalopods (Lougovois et al 2008). Paarup et al (2002) reported an increase in ammoniacal nitrogen of squids stored in ice similar to this finding.…”

“…There are few reports that there was a steady increase in the TVB-N levels in octopus stored in ice until the day of rejection (Atrea et al 2009). Paarup et al (2002) proposed the limit of acceptability for TVB-N as 45-60 mg/100 g for pressurised vacuum packed squid. However, Ohashi et al (1991) found that TVB-N values were not suitable as freshness indicators for the quality of octopus, as some of the pathways are different.…”

Determination of Biogenic Amines and Endotoxin in Squid, Musky Octopus, Norway Lobster, and Mussel Stored at Room Temperature

“…Putrescine is the major amine produced in a squid decomposing at a relatively high temperature, which is in agreement with Yamanaka et al (21), who found putrescine at the early stage of decomposition of common squid (Todarodes pacifi cus) stored at 0 °C and 15 °C. Paarup et al (5) suggest that rapid putrescine formation in decomposed squid is owed to early bacterial conversion of agmatine, a biogenic amine that otherwise indicates freshness. Although putrescine has no adverse health effects, high putrescine levels in decomposed squid could potentiate the toxic effects of histamine and tyramine (1,3).…”

“…Generally, histamine level in decomposed cephalopods and shellfi sh is low and poisoning by histamine is not usually related to their consumption (4). Putrescine, cadaverine, and agmatine have been proposed as freshness indicators in shrimp and squid, as they were the only amines detected before the initial decomposition (5,6).…”

Softening of Jumbo Squid Dosidicus gigas via Enzyme Injection

“…The jumbo squids are members of the flying squid family, and can attain 2 m in length and weigh up to 45 kg. Jumbo squid is commonly used in Korea to prepare dried shredded squid, spicy seafood noodle soup, salt-fermented squid, and fried "calamari" (Paarup et al, 2002;International Business Publications, 2007). Therefore, we explored the effects of proteases on squid protein and tenderness, to expand the consumption options (and ultimately health) of elderly Koreans.…”