Accelerated storage and isothermal microcalorimetry as methods of predicting carrot juice shelf-life

The possibility of predicting the shelf-life of pasteurized carrot juice by isothermal microcalorimetry or change in pH was investigated and compared with traditional plate count results. A small increase in thermal power (2 muW), maximal increase of and acceleration of thermal power all gave rapid, well-correlated results for the shelf-life, as did pH, during accelerated storage. The effect of accelerated storage (17degreesC) on the microbial flora of pasteurized carrot juice was also compared with the flora from storage at 8degreesC, and it was found that accelerated storage is feasible for the rapid evaluation of shelf-life, but that the microbial flora in the spoilt juice will be different. (C) 2004 Society of Chemical Industry.