辐照对峰甘板栗货架品质的影响

摘要

The effect and underlying mechanism of60Co-γ irradiation on sterilization, sensory quality, and physiological and biochemical indices of ‘Fenggan’ chestnut namely raw ready-to-eat chestnut was examined and the optimal dose of irradiation to extend shelf life was determined. Total bacterial count, mold and yeast, coliform bacteria, and pathogenic bacteria (Salmonella), some sensory attributes and physical and chemical indicators of ‘Fenggan’ chestnut irradiated with different doses of60Co-γ were measured after 0, 10, 15, 20 and 30 days of storage. Results showed that the total count of bacteria in60Co-γ treated ‘Fenggan’ chestnut was much lower than that in the untreated one, and irradiation doses in the range of 3.5–5.0 kGy were able to cause a good bactericidal effect on ‘Fenggan’ chestnut, especially 4.0 kGy dose. Together sensory quality evaluation and physiological and biochemicalanalyses indicated that exposure dose of 4.0 kGy could not only effectively inactivate microorganisms and prolong the shelf life of ‘Fenggan’ chestnut, but also could improve sensory quality and maintain physiological and biochemical quality during its shelf life. This preliminary study indicated that the irradiation dose of 4.0 kGy can extend the shelf life by at least 20 d at 4℃ in terms of microbial safety limits.%研究60Co-γ射线辐照对真空包装峰甘板栗货架期指标的影响及其机制，初步确定延长货架期的最佳辐照剂量。通过60Co-γ射线以0、0.5、1.0、3.0、3.5、4.0、4.5、5.0 kGy剂量辐照峰甘板栗，分别在贮存0、10、15、20、30 d时检测样品的微生物指标（菌落总数、霉菌及酵母数、大肠菌数、沙门氏菌数）、感官指标和理化指标。结果表明：辐照处理对峰甘板栗能够起到很好的杀菌作用；结合峰甘板栗感官品质评定及生理生化数据分析，辐照剂量为4.0 kGy时，可改善峰甘板栗感官质量并保持理化营养指标。初步认为，在4℃条件下，辐照剂量为4.0 kGy时，在微生物安全限量方面，使货架期延长至少20 d。