Survival analysis and cut-off point to estimate the shelf life of refrigerated fish burgers

Abstract The consumption of fish in Brazil is below the world average. In order to change this scenario, considering the high nutritional value of this meat, one of the strategies is to turn fish into a convenient product, such as burgers. Since fish burgers are not yet established in the market, it requires investigation of the shelf life. To that end, survival analysis and cut-off point (COP) methodologies access the perception of consumers and trained panels. Thus, the objective of this study was to estimate the shelf life of grass carp burgers, by means of the survival analysis and cut-off point. A trained sensory panel and consumers evaluated the burgers during a refrigerated storage of 30 days. Simultaneously, the pH and the reactive substances of thiobarbituric acid (TBARS) were evaluated. The TBARS results corroborated rancidity observed both with exponential growth and with correlation coefficients above 0.98. The survival analysis determined the end of the shelf life of the fish burgers after 21 days, with the COP technique indicating 17 days. Both methodologies were efficient in estimating the shelf life of the product analyzed, considering the lower result from COP adequate, since it establishes the value were the acceptability begins to decrease.

摘要 巴西鱼类消费量低于全球平均水平。鉴于鱼肉具有较高的营养价值，为改善这一现状，相关优化策略之一是将鱼类加工为便捷即食产品，例如鱼堡。鉴于当前鱼堡尚未在市场上形成成熟品类，因此有必要对其货架期开展研究。为此，本研究采用生存分析（survival analysis）与分界点（cut-off point, COP）方法，对消费者及经过培训的感官评价小组的主观感知进行分析，旨在估算草鱼鱼堡的货架期。在30天冷藏储存期间，由培训合格的感官评价小组与消费者对鱼堡进行感官评价，同时对pH值与硫代巴比妥酸反应物质（thiobarbituric acid reactive substances, TBARS）进行检测。TBARS检测结果证实了酸败现象的发生，其含量随时间呈指数增长趋势，相关系数均高于0.98。生存分析结果显示，鱼堡的货架期终止于21天；而COP技术则判定其货架期为17天。鉴于COP技术所得结果更低，且其界定的是消费者可接受性开始下降的临界值，因此两种方法均能有效估算受试产品的货架期。