市售生魚片之衛生品質調查與安全之改進

Abstract

本研究係針對臺灣中南部地區最常供應之生魚片魚種，在流通過程可能遭受之微生物污染情形進行抽樣調查，且依據檢驗結果進行產品供應流程之危害分析並制定重要管制點（HACCP）。期望透過本研究之結果，提供生魚片業者一套簡易且容易執行之危害因子監控模式，藉以保障食品安全。 首先經市場抽調結果，台灣地區生魚片流通業者最常供應之魚種依序為鮭魚(77%)、旗魚(74%)、紅魽魚(72%)及鮪魚(71%)。因此擇定鮭魚、旗魚、及鮪魚作為研究魚種，而流通業別則分為：一般海產店、日式料理店、超低溫生魚片專賣店及傳統市場零售攤位等。 調查結果顯示,臺灣中南部地區50件市售生魚片抽樣檢體中，62% (31件) 總生菌數超過衛生標準（10^5 CFU/g），26% (13件)經檢出腸炎弧菌（Vibrio parahaemolyticus）為陽性，10% (5件) 檢出李斯特菌屬陽性，其中2件為 Listeria monocytogenes，3件為Listeria innocua。 不同流通業別在生菌數檢測部分，以一般海產店不合格率（86%）最高，其次市場攤販（69%），最後為日式料理店（17%）；超低溫生魚片專賣店則全數符合規定。生魚片在低溫貯存（-20°C、0°C、5°C）過程生菌數變化不大。因其架貨期在1至2天以內，微生物繁殖期短，惟各流通業別間生菌數之變化差距頗大，此項結果與其是否確實執行食品良好衛生規範（GHP）有關。若無法遵循GHP之規範，則任何一點皆有可能成為主要的CCP點。 當餐飲業者依GHP規範以有效餘氯量200 ppm之氯液對器具採行消毒措施後，砧板、刀具及抹布表面塗抹總生菌數（log（CFU/cm2））可由5.03、3.34及4.50降至2.21、1.86及2.10。手部施以75%酒精噴灑消毒後，則表面塗抹總生菌數（log（CFU/cm2））可由3.94降至2.35。 依據上述調查結果, 各選擇一家一般海產店及日本料理店為對象，依其供應流程圖分析主要CCP點，擬訂改善與監控方法，制定HACCP計劃書，並持續追蹤其改善後產品之衛生情形。研究結果顯示, 實施HACCP計晝後, 其產品總生菌數(TPC log(CFU/g))可由平均6.41降低至3.65，且3個月後仍維持在3.60。 綜合本研究結果, 餐飲業者GHP規範及HACCP之實施，確實有助於市售生魚片之衛生品質之改善以及保障消費者食用之安全性。

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.