Predicting Shelf Life of Lactose-free Ultra-high Temperature Milk by a Arrhenius Model

The objective of this work was to predict shelf life of lactose-free ultra-heat treated(UHT)milk using modern sensory evaluation techniques such as electronic eye,electronic nose and electronic tongue,combined with Arrhenius model of accelerated food storage life test(ASLT). Lactose-free UHT milk was stored at 37,27 and 4℃,color and smell and taste were taken as the main indicators to comprehensively analyze the changes between quality and storage time of lactose-free UHT milk at different storage temperatures,and Arrhenius formula was t=0.109×e^-5.1882 applied to establish shelf life model. The results showed that,lactose-free UHT milk stored at 37℃ and 27℃,the color of had changed significantly(P<0.05)for 24 days and 33 days,respectively;The bitter had changed significantly(P<0.05)for 24 days and 27 days,and there was no significant change in odor(P>0.05)for 60 day. Lactose-free UHT milk stored at 4℃,there was no significant change in color,odor,and taste(P>0.05)for 60 day. Taking bitter as one evaluation indicator,the shelf life model fitted with Arrhenius formula was and the errors between the model and the actual shelf life were 9.5% and 12.5% at 37℃ and 27℃,respectively,with small errors. The predicted value of shelf life of lactose-free UHT milk at 4℃ was 71 days based on this model. Therefore,the shelf life prediction model based on sensory indicators can be used to predict the shelf life of lactose free UHT milk.