Title: Quality changes of fish from catch to processing and during storage with focus on cooling practices and practical application in Sierra Leone

Author(s): Hoki Massaquoi
Type:
Final project
Year of publication:
2011
Publisher:
UNU-FTP
Place of publication:
Reykjavík
Number of pages:
45
Supervisors: Kolbrun Sveinsdottir
Keywords:
quality changes; Sierra Leone; sensory evaluation; cooling techniques; shelf life

Abstract

Sierra Leone has rich resources of fish, shrimp, lobsters and other cephalopods. However, these cannot be exported to EU Markets because of the lack of quality infrastructure and control in Sierra Leone. The purpose of this project was to assess the quality changes in fish from catch to processing and compare the effects of different cooling methods; super chilling (SC) and conventionally chilled with ice (NC). The fish quality was evaluated with sensory evaluation, including Quality Index Method (QIM), Quantitative Descriptive Analysis (QDA), Torry Freshness Score Sheet and chemical and microbial analysis after 1, 4, 6, 11, 14 and 18 days after catch. The mean ambient temperature was -1.3°C for the SC and -1.4°C for the NC group. The product temperature for the NC group ranged from -1°C to -0.5°C and from -1°C to -0.9°C for the SC. Sensory evaluation with QIM showed that the scores for all the quality attributes increased with storage time with some differences in a few quality parameters between the SC and NC groups. The sum of scores, the Quality Index (QI) increased linearly with storage time and was similar for SC and NC during the storage time. The QDA results show minor differences between the groups until day 18, when scores for spoilage related to odour and flavour attributes became more evident for the NC group. The Torry Scores were in line with the QDA results, after 18 days the NC was past shelf life and the SC at the end of shelf life. Microbial results showed that the total viable counts (TVC) were similar for the two groups on storage day 18, though slightly higher for NC and the number of H2S producing bacteria was higher for NC. The TVB-N values for NC were higher on storage day 18 compared to SC. Thus, the above results show that the SC cooling having longer shelf life extension than the NC group.

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