罐头微生物检验讲解课件.ppt

1、Canned foodsCanned foodsSpoilage manifestations in low-acid productsGroup of organismsClassificationManifestationsFlat-sour bacteria平酸菌平酸菌Can flatPossible loss of vacuum on storageProductAppearance not usually altered;pH markedly lowered,sour;may have slightly abnormal odor;sometimes cloudy liquorTh

2、ermophilic anaerobe嗜热厌氧菌嗜热厌氧菌Can swellsMay burstProductFermented,sour,cheesy or butyric odorSulfide spoilage硫化腐败菌硫化腐败菌Can flatH2S gas absorbed by product ProductUsually blackened;rotten egg odorPutrefactive anaerobe致腐性厌氧菌致腐性厌氧菌Can swellsMay burstProductMay be partially digested;pH slightly above normal;typical putrid odorAerobic sporeformers需氧芽孢菌需氧芽孢菌Can flat or swollenUsually no swelling,except in cured meats when nitrate and sugar present;coagulated evaporated milk,black beets无菌试验中，若无菌试验中，若发现发现细菌细菌怎么办？怎么办？那得看到底是那得看到底是哪一类细菌喽哪一类细菌喽