重铬酸盐剂量计在食品辐照加工中的应用

重铬酸盐剂量计是国内食品辐照加工行业普遍使用的一种液体化学剂量计。介绍了其工作原理、组成、校准过程等,并简要阐述了重铬酸盐剂量计在食品辐照加工确认和加工控制中的应用,为其今后在国内食品辐照加工中的广泛应用提供参考。     

UV-C inactivation of Escherichia coli and dose uniformity on apricot fruit in a commercial setting

A UV-C treatment system (two treatment chambers connected by an inclined belt to rotate apricots between chambers) was tested in a commercial setting. Escherichia coli ATCC 25922, used as a surrogate for E. coli O157:H7 to determine the system's antimicrobial efficacy, was inoculated onto fruit surfaces at a population of 6.8 log CFU/fruit. UV-C dosage was evaluated by attaching film dosimeters to six fixed locations on each apricot. Results suggested that reduction of inoculated E. coli ATCC 25922 populations on the apricot fruit by UV-C treatment was small (only 0.5–0.7 logs). There were large variations in UV-C doses among varying apricot surface locations. Approximately 1/3 of apricots had individual surfaces receiving less than 0.2 kJ m⁻² UV-C exposure, even though fruit received, on average, more than 1 kJ m⁻². Low reductions of E. coli may be attributed, in part, to non-uniform UV-C exposure. This study demonstrates the need to use a fruit rotation device more capable of delivering uniform UV-C dosage to the surface of apricots for inactivating bacteria in a commercial setting.