软烤扇贝加工源头的细菌控制研究

Control of Bacteria in Lightly Baked Scallop from the Management of Raw Materials

目的研究鲜活扇贝经不同处理得到的扇贝肉原料的细菌及相关理化特性。方法对样品的水分含量、pH值、菌落总数、耐热菌数、大肠菌群进行测定,并对细菌类别和菌群进行了定性和定量分析。结果鲜活扇贝经过汽蒸热处理4、6和8min后,pH值均为6.58左右,水分含量降低较明显,并依次降低1%;菌落总数均为103CFU/g,耐热菌数均为102CFU/g,并呈依次降低趋势;大肠菌群均未检出;细菌类别均为耐热的G+杆菌和球菌;菌相比较单一,芽孢杆菌占60%左右,并呈依次增加趋势,葡萄球菌和微球菌约占1/3,并呈依次降低趋势,还残存少量棒状杆菌。综合数据表明,汽蒸处理6min为最好的原料处理方法。企业处理原料水分含量76.80%,pH值接近中性,均偏高;菌落总数接近104CFU/g,耐热菌数为102CFU/g,检出大肠菌群。结论结合生产现场考察表明,企业鲜活扇贝清洗和加热方法有待改进,加热强度应该增加。市售原料样品数据表明其处理过程不良,不宜用于软烤扇贝加工。另外分析了企业使用的调味配料、加工用水、包装材料的有关性状,发现调味配料细菌较多,可能增加控制困难。

Objective To observe the bacterial and chemical characteristics of scallop raw materials which were treated by differently ways from fresh scallop and prepared for lightly baked scallop. Method The water content, pH values, total viable count, heat-resistant bacterial count and coliforms in samples were determined. Meanwhile, bacterial species and flora were also qualitatively and quantitatively determined. Results The pH values of scallops steamed for 4 rain, 6 min or 8 min was all about 6.58. The water content of samples decreased for 1% in turn. Total viable count （TVC） of bacteria in samples was 10^3 CFU/g. The heat-resistant bacteria count was 10^2 CFU/g and presented in a reduction tendency in turn. Coliforms were not detected. The bacteria species in samples were Gram-positive bacillus and coccus. The bacterial phases were much simplex. Bacillus spp. accounted for 60% and ascended in turn; Staphylococcus spp. and Micrococcus spp accounted for one third of the total bacteria, and presented in a reduction tendency; and Corynebacterium spp. accounted for a small percentage. It was indicated from the integrated data that the scallop steamed for 6 min was the best way of processing. The water content of samples treated by enterprises was 76. 80% ; pH values were in neutral; TVC and heat-resistant bacteria counts were 10^4 CFU/g and 10^2 CFU/g respectively; and coliforms were detected. Conclusion Based on the visits to processing sites, the methods for cleaning and heat treatment of fresh scallops needed to be improved. The results indicated that the processing procedures have not been under good control and the raw materials were not suitable for processing lightly baked scallop. On the other hand, the bacteria counts in flavoring ingredients, the water for processing and packing materials were many, which might increase difficulties for the quality control of lightly baked scallop.