辣子鸡丁贮藏过程中的品质变化

为探究不同贮藏温度对辣子鸡丁品质的影响，本研究分析了该菜肴在4 ℃冷藏和?18 ℃冻藏过程中感官评分、理化指标和菌落总数的变化规律，并采用电子鼻结合全二维气相色谱-质谱（full two-dimensional gas chromatography-mass spectrometry，GC×GC-MS）联用技术对贮藏过程中产品的挥发性风味物质进行分析。结果表明:随着贮藏时间的延长，硫代巴比妥酸（thiobarbituric acid，TBA）值和b*值呈上升趋势，水分含量、质构特性、L*值、a*值和pH显著下降（P<0.05）。4 ℃实验组的菌落总数随贮藏时间延长呈上升趋势，但均低于标准限值，而?18 ℃实验组未出现可见菌落。感官品质在贮藏过程中呈下降趋势，且贮藏温度越高，其感官品质下降速度越快，第30 d时4 ℃实验组的感官评分值下降至59.67分，此时已失去食用价值。采用线性判别分析（Linear Discriminant Analysis，LDA）对电子鼻结果进行处理，不同贮藏时间的样品间的区分度良好。辣子鸡丁在贮藏过程中共检测出183种挥发性风味物质，其中气味活性值分析共得16种主体风味物质，以醇类、醛类、酯类、酮类和杂环类物质为主。因此，辣子鸡丁冷藏时的货架期25 d为宜，而冻藏能够在较长时间内保持产品的品质稳定。

Quality Change of Spicy Diced Chicken during Storage

To explore the effect of different storage temperatures on the quality of spicy diced chicken, the changes in sensory scores, physical and chemical indicators, and the total number of colonies of the dishes during the refrigerated storage (4 ℃) and frozen storage (?18 ℃) were analyzed in this study. And the electronic nose combined with the full two-dimensional gas chromatography-mass spectrometry (GC×GC-MS) technology was used to analyze the volatile flavor compounds of the product. The results showed that thiobarbituric acid (TBA) and the b* value increased gradually with the storage duration, while the content of moisture, texture properties, L* value, a* value, and pH decreased significantly (P<0.05). The total number of colonies in the 4 ℃ group showed an increasing trend, lower than the standard limit. In comparison, no colonies appeared in the ?18 ℃ group. The sensory quality decreased during the storage, and the higher the storage temperature, the faster the sensory quality decreased. On the 30th day, the sensory score of the 4 ℃ group decreased to 59.67, at which time the edible value of the product had been lost. The linear discriminant analysis (LDA) results of the electronic nose showed that the samples with different storage times had good discrimination. A total of 183 volatile flavor substances were detected during the storage of spicy diced chicken, of which 16 main flavor substances were obtained from the analysis of odor activity value, mainly alcohols, aldehydes, esters, ketones, and heterocyclic substances. Therefore, the shelf life of spicy diced chicken under refrigerated storage is 25 days, while frozen storage can keep the quality of the product stable for a long time.