Microbial Quality Investigation and Safety Improvement of Sliced Raw Fish (Sashimi) in Taiwan

• Main Authors: Mei-Liang Lin, 林美良
• Other Authors: Wen-Zhe Hwang
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/32146304875153722658

碩士 === 國立中興大學 === 食品科學系 === 90 === Microbial quality of sliced raw fish (sashimi) from different distribution channels in Central and Southern Taiwan was investigated in this study. Based on the investigation results, Hazard Analysis Critical Control Point (HACCP) system was introduced for the safety improvement of sashimi providers. The objective of this study is to provide a simple and easily performing monitor system for sashimi distribution channels to control the potential risk factors, so as to guarantee the food safety. Market study showed that the major fish species used as sashimi in Taiwan area were salmon (77%), swordfish (74%), greater amberjack (72%) and tuna (71%). Salmon, swordfish and tuna were then chosen as the study species. Market study also showed that the major sashimi distribution channels included Taiwanese-style seafood restaurant, Japanese-style restaurant, frozen sashimi shops and traditional market stalls. Microbial total counts of 50 sashimi samples showed 62% (31 samples) unqualified. The incidence of Vibrio parahaemolyticus was 26% (13 samples) and Listeria spp was 10% (5 samples). Listeria species were further identified as L. monocytogenes (2 samples) and L. innocua (3 samples). Microbial quality investigation of different sashimi distribution channels indicated the unqualified ratios of Taiwanese-style seafood restaurant (86%), traditional market stall (69%) and Japanese-style restaurant (17%); On the other hand, samples from the frozen sashimi shops were all qualified. There was no significant different change (p＜0.05) in total plate counts and psychrophilic bacteria counts of sashimi samples under different temperatures (-20°Ｃ, 0°Ｃ, 5°Ｃ) during the storage period. Since the shell life of sashimi was less than 2 days, the microbial propagation was very limited. The microbial quality of sashimi was greatly depended on the hygiene condition of different distribution channels. According to the Good Hygiene Practice (GHP) regulation, chlorine solution (200 ppm) and alcohol solution (75%) were used to enhance the sanitation condition of kitchen equipments and worker’s hands in sashimi restaurants. The surface total counts from cutting board, cutter and wiper were decreased from 5.03, 3.34 and 4.50 log (CFU/cm2) to 2.21, 1.86 and 2.10 log (CFU/cm2) respectively with the treatment chlorine solution. Surface total counts of worker’s hands were reduced from 3.94 to 2.35 log (CFU/cm2) after the application of 75% alcohol solution. Based on above investigation, one Taiwanese-style seafood restaurant and one Japanese-style restaurant were chosen for the implementation of HACCP system. Critical control points of service flowchart were determined by decision tree, and HACCP plan was applied to improve the hygiene condition. With the introduction of HACCP plan, microbial total counts of sashimi samples in those restaurants were decreased from 6.41 to 3.65 log (CFU/cm2), and kept at 3.60 log (CFU/cm2) for 3 months. In conclusion, the introduction of GHP and HACCP system into sashimi distribution channels could contribute to the hygiene quality and safety improvement, and gave a safety assurance to food consumers.