Browsing Food Programme by Subject "Salmon"
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Efficacy of ultraviolet light (UV-C) and pulsed light (PL) for the microbiological decontamination of raw salmon (Salmo salar) and food contact surface materialsThe decontamination effect of two light-based technologies on salmon, polyethylene (PE) and stainless steel (SS) was evaluated. Optimization of treatment conditions for ultraviolet light (UV-C) and pulsed light (PL) was carried out on raw salmon, obtaining inactivation levels of 0.9 and 1.3 log CFU/g respectively. The effects of treatments on several microbial groups present in salmon were then evaluated. For both technologies, Pseudomonas spp. were found to be the most resistant group of microorganisms tested. Three different strains from within this group were isolated and speciated, including a P. fluorescens strain which was selected for subsequent studies. PE and SS surfaces were inoculated with a suspension of the P. fluorescens suspended in a ‘salmon juice’ solution, and treated with UV-C and PL at different doses (mJ/cm2). PE surfaces were effectively decontaminated a low doses for both technologies, with a reduction of >4 log cycles observed. Decontamination of SS was also effective when treated with PL, although at higher doses than for PE. When SS was treated with UV-C, the maximum reduction of P. fluorescens achieved was 2 log cycles, even at the highest dose.
Freeze-chilling and gas flushing of raw fish filletsFreeze-chilling involves freezing and frozen storage followed by thawing and chilled storage. Trials with whiting and mackerel fillets/portions (Part 1) indicated no difference in odour scores (raw samples) between freeze-chilled and chilled samples; however, freeze-chilled salmon portions were inferior to chilled in terms of odour. Fresh fillets received the highest acceptability scores as cooked samples followed by frozen, chilled and freeze-chilled fillets. Freshness indicators were the same for the three species. Freeze-chilled fillets had the highest free fatty acid and peroxide values but the levels were low and did not influence sensory response. The effects of the four treatments on the colour and texture of the raw fillets were small in practical terms and typical shelf-lives in the chill phase of the freeze-chill process were 3 to 5 days. In Part 2, modified atmosphere packaging (MAP) was combined with freezechilling to further extend the shelf-life of raw whiting, mackerel and salmon fillets/portions. Typical shelf-lives in the chill phase for the freeze-chilled fillets were 5 (whiting and mackerel) and 7 (salmon) days. Good manufacturing practice coupled with HACCP and careful tempering (thawing) are essential for the successful freeze-chilling of raw fish fillets. Packs should be labelled ‘previously frozen’ for consumer information. It is concluded that freeze-chilling with MAP is a suitable technology for extending the shelf-life of raw fish fillets.
Overview of seafood research at Ashtown food research centre (1990 - 2007)In recent years, the Irish seafood industry has faced stringent quotas and dwindling fish stocks. The introduction of fish farming added a new dimension but falling prices also created difficulties for this sector. However, the recent report of the Seafood Industry Strategy Group on ‘Steering a New Course’ and the Sea Change Programme of the Marine Institute will add new impetus to the industry. The current report summarises R&D on seafood conducted at Ashtown Food Research Centre (AFRC) in the period 1990-2007 and represents a major portion of seafood R&D conducted nationally during that period.
Shelf-life extension ingredient and processing technologies applied to Atlantic salmon (Salmo salar)These current studies explore the possibility of improving analytical methods to assess freshness in seafood and to investigate the antimicrobial potential of a range of natural ingredients both alone and in combination with packaging and chilled storage temperatures to extend the shelf life of Atlantic salmon. The aims of this research study were; • To investigate bacterial growth on Atlantic salmon stored under chilled aerobic conditions thus providing data which may be used to assess which bacterial groups and concentrations are most appropriate for shelf-life determination. • To characterize the microbiota present in the GI tract of Atlantic salmon, using Miseq Illumina high throughput sequencing • To develop and validate rapid sensory (QIM and QDA) and ATP derivative based methods for assessing the freshness of Atlantic salmon. • To investigate the effects of a natural antimicrobial immersion treatment on microbial growth for Atlantic salmon fillets during chilled storage. • To examine the effects of either a natural antimicrobial immersion or spray treatment on mean bacterial counts in combination with packaging technologies for Atlantic salmon fillets during chilled storage. • To assess the effects of skin packaging with retail and sub-zero temperatures on the mean bacterial counts for Atlantic salmon fillets.