发酵方式对山药泡菜理化特性及微生物变化的影响

对比研究山药自然发酵、混料自然发酵、山药接种发酵、混料接种发酵等4 种发酵方式对山药泡菜理化指标和微生物数量动态变化的影响，并对其感官品质进行评价。结果显示：接种发酵泡菜与自然发酵泡菜的发酵周期分别为11 d和14 d；与自然发酵泡菜相比，接种发酵山药泡菜的pH值下降快、总酸含量高、亚硝酸盐含量低，乳酸菌数量多、菌落总数和大肠菌群数少，但其脆度与感官评分偏低；混料发酵山药泡菜口味纯正、品质优良，pH值为3，总酸含量为8.01 mg/kg。其中混料自然发酵亚硝酸盐含量1.4 mg/kg、乳酸菌数7.33（lg（CFU/mL））、菌落总数3.2（lg（CFU/mL））、大肠菌群数15 MPN/100 g、脆度2 975.00 g、感官评分89.10；混料接种发酵产品的亚硝酸盐含量1.2 mg/kg、乳酸菌数9.04（lg（CFU/mL））、菌落总数2.1 （lg（CFU/mL））、大肠菌群数6 MPN/100 g、脆度2 765.00 g、感官评分86.26。

Effects of Fermentation Methods on Physicochemical and Microbiological Characteristics of Pickled Chinese Yam

The effect of four different fermentation methods, i.e., spontaneous fermentation, spontaneous mixed fermentation,
inoculated fermentation, and inoculated mixed fermentation on physicochemical and microbiological characteristics of
pickled Chinese yam was studied. Sensory quality of final pickles was also evaluated. Results showed that the periods of
spontaneous fermentation and inoculated fermentation were 11 and 14 days, respectively. Compared with spontaneous
fermentation, pickle from inoculated fermentation showed lower pH and nitrite content, reduced number of aerobic bacteria
and coliform, and decreased hardness and sensory evaluation scores. Contrarily, total acid content and the number of lactic
acid bacteria were increased. Pickle from mixed fermentation obtained good sensory evaluation, and its pH value was 3.0
and total acid content 8.01 mg/kg. Nitrite content, the numbers of lactic acid bacteria, aerobic bacteria and coliform, hardness
and sensory evaluation score were 1.4 mg/kg, 7.33 (lg(CFU/mL)), 3.2 (lg(CFU/mL)), 15 MPN/100 g, 2 975.00 g and 89.10,
respectively in spontaneously mixed fermented pickle, while those were 1.2 mg/kg, 9.04 (lg(CFU/mL)), 2.1 (lg(CFU/mL)),
6 MPN/100 g, 2 765.00 g, and 86.26 in inoculated mixed fermented pickle, respectively. Therefore, inoculated fermentation
can be considered as a promising fermentation method for Chinese yam pickle.