Spoilage changes in the deep water fish, smooth oreo dory during storage in ice

Abstract

Smooth ore0 dory (Pseudocyttus rnaculatus), a deep water fish, was monitored for changes during storage in ice. Based on the sensory evaluation of the cooked flesh the storage life was 8 days for acceptable quality fish.Bacterial counts of flesh and surface, the loss of inosine monophosphate (IMP) and the K value showed significant changes during the storage life. Therefore these were found to be useful for monitoring loss of freshness and development of spoilage. After 13 days there were off flavours in the cooked fish, dephosphorylation of IMP had levelled off, and the K value had reached 70%.The changes that occurred during storage of this deep water species in ice were similar to those changes commonly observed in demersal species from shallow temperate coastal waters. KeywordsDescriptive analysis, nucleotides, off-flavours, Pseudocyftus maculatus, sensory quality, TRA values. * Correspondent. Fax: +64 98 493660. Scott et al. 1984;Dhananjaya, et al., 1986). The proximate composition of ore0 dory has been reported by Vlieg (1983). Buisson el al. (1982) showed that, like orange roughy, ore0 dory has a high proportion of wax ester in the lipid fraction. D. N .The purpose of this study was to examine the sensory, chemical, and microbiological changes which occur during the storage in ice of whole smooth ore0 dory. Materials and methods Raw materials and samplingUndamaged smooth ore0 dory were selected from the net after a 1 h 30min tow on 19 March 1987 on board the F.V. Arrow (Sealord Products Ltd, Welson, New Zealand). The fish were caught in Area C on the northern edge of the Chatham Rise off the east coast of New Zealand at a depth of 1060 metres by bottom trawling. The water temperature at 1000 metres was 6°C and the surface water temperature was 18°C. The fish were at 16.5"C prior to icing. Over 100 kg of fish were packed in ice and landed at Nelson on the following morning.Six whole fish were used for proximate compositional analysis. Thirty-four fish were weighed, measured, sexed and processed to frozen shatter pack fillets within 8 h of landing. These were stored at -70°C as reference samples for sensory evaluation. After 1 day storage in ice five randomly selected fish were examined for raw sensory attributes, then sampled for pH, TBA number, and nucleotide analyses. The remaining fish were stored in a chiller under melting ice until required.Iced fish and reference fillets were sampled 4, 8, 11, 13, 15, and 18 days after capture. On each sampling occasion, 11 fish were randomly selected and analysed. Sensory evaluationRaw Jish. Five whole fish were evaluated by three people experienced in the description of raw fish quality. The resilience of the fish flesh was determined by finger pressure. The odour of the gills and the appearance of the skin, gills, eyes, and surface slime were also described.Cooked fish. The attributes of cooked smooth ore0 dory were evaluated by 17 -20 panellists who had been trained in the descriptive evaluation of fish (Scott & Hogg, 1985).Reference samples were thawed rapidly...

Quality assessment of Mediterranean horse mackerel (Trachurus mediterraneus) and blue jack mackerel (Trachurus picturatus) during storage in ice

“…However, as high cell concentrations of 10 8 -10 9 cfu/g of SSO are normally required to cause spoilage of ice-stored Wsh (Gram & Huss, 1996;Huss et al, 1997), it was assumed that these organisms were not major spoilers in the present study for both Wsh species. Our results are similar to results from other storage trials on iced whole Wsh (Lougovois et al, 2003;Paarup et al, 2002;Ryder, Buisson, Scott, & Fletcher, 1984;Ryder, Fletcher, Stec, & Seelye, 1993;Scott, Fletcher, Charles, & Wong, 1992;Scott, Fletcher, Hogg, & Ryder, 1986). An average level of 10 6 cfu/g of SSO would be probably indicative of marginal quality Mediterranean horse mackerel and blue jack mackerel.…”

Quality changes of anchovy (Stolephorus heterolobus) under refrigerated storage of different practical industrial methods in Thailand

“…The number of mesophilic aerobic bacteria remained lower than 7.0 logCFU/g during refrigerated storage of anchovy with ice and without ice even if they were unacceptable according to the results of sensory analysis. In this study, psychrophilic aerobic bacteria counts were around 5.0 logCFU/g per sample, and fish were accepted as spoilage based on sensory evaluations on the 6th and 4th days of iced and without iced storage when TVB-N and TMA-N values reached the limit of fish spoilage (Scott et al 1992;Köse and Erdem 2004). According to the results, have concentrated on sensory and chemical changes rather microbiological associated with anchovy during refrigerated storage with ice and without ice.…”

Cod and rainbow trout as freeze–chilled meal elements

“…It has previously been concluded that pH is not useful for monitoring quality changes in a variety of species stored in ice. 39,40 For MAP-packed frozen-thawed cod fillets, there were also no changes in pH for up to 20 days at +2…”