Spoilage potential of ice‐stored whole musky octopus (Eledone moschata)

Abstract

The spoilage potential of fresh musky octopus (Eledone moschata) was determined by evaluating the changes in biochemical and physical properties, microbial growth and sensory quality of the mantle and tentacles, over a period of 18 days. Whole musky octopus, stored in melting ice from the time of harvest, had a storage life of 10 days. Early deterioration in the sensory quality resulted primarily from autolytic reactions. Pseudomonas spp. dominated the spoilage flora, reaching an average count of 10 8 CFU g )1 at the end of the trial. The bacterial metabolic end products (trimethylamine, total volatile bases) were not useful as objective indicators of freshness, and measurements of pH would only provide an indicator of decomposition. Changes in the dielectric properties of the mantle were reflective of quality deterioration, but could not yield precise information on the storage history of the cephalopod. The common sulphide producer, Shewanella putrefaciens, was not a major spoiler of ice-stored musky octopus.

Biochemical and Bacteriological properties of fresh and frozen sold cephalopods in the Egyptian market.

“…Meanwhile, a significant increase (P < 0.05) was recorded in pH of frozen squids (8.0±0.01). This value was within the observed range in other studies by Albanese et al (2005) and Lougovois et al (2007) who noticed that freezing caused a significant increase of pH in different cephalopods. They attributed that to the rapid spoilage of the product and the formation of alkaline compounds of autolysis and bacterial metabolites in the muscles.…”

“…However, in general few studies on cephalopods quality were directed mostly to the squid (Ruíz-Capillas et al, 2002a&b;Albaneses et al, 2005) and Octopus (Lougovois et al, 2007;Atrea et al, 2009). Therefore, from the nutritional point of view, the objectives of this research are: 1-Comparison of the chemical (pH, trimethylamine and volatile base nitrogen) and biochemical composition of the most commonly consumed fresh chilled cephalopods in the Suez Canal area with the imported frozen squid in the market.…”

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

“…4). 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.…”

“…In support of our findings, Barbosa and Vaz-Pires (2003) perceived slightly unpleasant odour in ice stored octopus between days 4 and 5, which later became unacceptable on day 8. Lougovois et al (2008) observed sour and rotten odour but not ammoniacal odour during the spoilage of whole musky octopus stored in ice. As the octopus stored in ice was wrapped in polythene bags, the ammonia liberated due to autolytic degradation might have got trapped within the bags instead of getting dissolved in ice water and this had lead to the formation of ammoniacal odour.…”

“…Among the cephalopods, studies are mainly focused on squid and cuttlefish; and there are only a very few reports on the iced storage of octopus (Vaz Pires and Barbosa 2004;Lougovois et al 2008). Studies have been carried out on the chilled storage of pressurized octopus (Hurtado et al 2001) and vacuum packaging as well as addition of oregano essential oil on the shelf life of octopus (Atrea et al 2009).…”