DEVELOPMENT OF A FUSED SENSOR SYSTEM FOR THE MEASUREMENT OF FISH FRESHNESS

由于鱼类的保鲜是生产优质产品的必要条件，因此建立一种简便、快速、准确、经济的鱼类新鲜度测定方法是海洋食品行业的迫切需求。以挥发性盐基氮、氨、多胺和K值（HxR和Hx在总ATP相关化合物中的百分比）为参数，已经提出了各种化学方法来测定鱼的新鲜度。然而，鱼类肌肉的死后变化是复杂的。因此，很难准确地确定鱼新鲜度由单一的指标，如建议，我们已经开发了5通道生物传感器系统的基础上丝网印刷电极和SMO传感器系统来评估鱼新鲜度。将5个酶电极组装成5通道生物传感器系统，用于测定K值、IMP、谷氨酸、乳酸和葡萄糖。用该传感器系统测定鱼肉中的三种成分，与常规方法测定结果比较，具有良好的一致性。SMO传感器系统由三个具有不同灵敏度的半导体金属氧化物（SMO）传感器组成。传感器显示二甲胺，三甲胺，挥发性酸性化合物和醛，被认为是鱼的降解产物的特征响应。总细菌和K值的活菌计数提供了与SMO传感器结果良好相关的结果。这些传感器系统被应用于比目鱼，鲣鱼，竹荚鱼，黄鳍金枪鱼和条纹猪鱼的鱼新鲜度的估计。利用SMO传感器响应、5通道生物传感器系统测定的鱼肉组分和细菌总数的活菌计数，通过主成分分析法可以识别鱼肉品质随贮藏时间的劣化。对第一主成分和第二主成分的贡献率分别为50.61%和29.91%。

Since the retention of fish freshness is necessary for the production of good-quality products, the establishment of a simple, rapid, accurate and economical method for the determination of fish freshness is required in marine food industry. Various methods have been proposed to chemically determine the freshness of fish using volatile basic nitrogen, ammonia, polyamine and K value (the percentage of HxR and Hx in the total ATP-related compounds) as parameters. However postmortem changes of fish muscle are complicated. Therefore, it is difficult to determine fish freshness accurately by a single indicator as proposed.We have developed the 5-channel biosensor system based on screen-printing electrode and SMO sensor system to evaluate fish freshness. The 5-channel biosensor system was assembled with five enzyme electrodes for the determination of K value, IMP, glutamate, lactic acid and glucose. Good comparative results were observed between there components in fish muscle determined by the 5-channel biosensor system and the conventional methods. The SMO sensor system consists of three semiconducting metal-oxide(SMO) sensors with various sensitivities. The sensors showed characteristic responses for dimethylamine, trimethylamine, volatile acidic compounds and aldehydes that are assumed to be fish degradation products. Viable counts of total bacteria and K value provided results that correlated well with SMO sensor results. These sensor systems were applied to the estimation of fish freshness of flatfish, skipjack, horse mackerel, yellow fin tuna and striped pigfish. The deterioration offish quality with storage time could be identified by a method of principal component analysis using the SMO sensor responses, the components in fish muscle determined by the 5-channel biosensor system and viable counts of total bacteria. The contribution rates to the first principal component and the second principal component were 50.61% and 29.91%, respectively.