不同发酵剂和工艺环节对发酵牛肉调味基料抑菌性的影响

Effect of Different Starter Cultures and Processing Stages on Bacteriostatic Properties of Fermented Beef Flavoring

为研究不同发酵剂和工艺条件对发酵牛肉调味基料(fermented beef flavorings,FBF)抑菌性的影响,以金黄色葡萄球菌(Staphylococcus aureus)、鼠伤寒沙门氏菌(Salmonella typhimurium)、铜绿假单胞菌(Pseudomonas aeruginosa)、大肠杆菌(Escherichia coli)和乙型副伤寒沙门氏菌(Salmonella paratyphi B)为目标菌,添加10%FBF于目标菌中,37℃培养12 h,计算其对不同目标菌的抑制率。设计3组实验:CK组(热压浸提-酶解-美拉德反应);2)反应Ⅰ组(热压浸提-酶解-发酵),在发酵环节接种15种商业复合菌或单株菌;3)反应Ⅱ组(热压浸提-酶解-发酵-美拉德反应),在反应Ⅰ的基础上继续进行美拉德反应。结果表明:不同工艺制得的处理组FBF,其抑菌能力从强到弱依次为反应Ⅱ组>反应Ⅰ组>CK组;CK组对P. Aeruginoosa和S. paratyphi B无抑菌能力,对E. coli的抑制率最高(61%),其次是S. aureus(20%)和S. typhimurium(11%);反应Ⅰ制得的FBF除对P. Aeruginoosa无抑制能力外,对其余4株目标菌的抑制率均提高,其中,以清酒乳杆菌为发酵剂制得的FBF对S. typhimurium的抑制率可达55%;反应Ⅱ制得的15种FBF对5株目标菌均有较强的抑菌性,以清酒乳杆菌为发酵剂制得的FBF对S. typhimurium的抑制率达85%,对E. coli的抑制率达53%,以WBL-45为发酵剂制得的FBF对E. coli的抑制率达100%,对S. paratyphi B的抑制率达85%。最终选定WBL-45、清酒乳杆菌为制作FBF的发酵剂,采用热压浸提-酶解-发酵-美拉德反应工艺制作FBF,得到的产品抑菌性较强。

The effect of different starter cultures and processing conditions on the antibacterial properties of fermented beef flavorings(FBF) was studied in this investigation. Staphylococcus aureus, Salmonella typhimurium, Pseudomonas aeruginosa, Escherichia coli, Salmonella paratyphi B were used as target bacteria, and 10% FBF was added to the target bacteria, which were then cultured for 12 hours(37 ℃). The percentage of inhibition of bacterial growth was calculated from optical density at 600 nm(OD600 nm). Three experimental groups were designed: control(pressurized hot water extraction of powdered bones with attached meat followed by enzymatic hydrolysis and Maillard reaction), reaction Ⅰ(pressurized hot water extraction followed by enzymatic hydrolysis and fermentation with mixed or pure cultures of 15 commercial strains,and reaction Ⅱ(pressurized hot water extraction followed by enzymatic hydrolysis, fermentation and Maillard reaction).The results showed that the antimicrobial activity of FBF prepared by different processes was in the following decreasing order: reaction Ⅱ > reaction Ⅰ > control. The control had no antimicrobial activity against P. Aeruginoosa or S. paratyphi B,and it showed the highest percentage inhibition against E. coli(61%), followed by S. aureus(20%) and S. typhimurium(11%).FBF produced by reaction Ⅰ had no inhibitory effect against P. Aeruginoosa, while the inhibitory effect against four other target bacteria was increased as compared with the control;the percentage of inhibition of S. typhimurium by FBF fermented by Lactobacillus sake was up to 55%. Fifteen FBFs obtained from reaction Ⅱ showed strong antimicrobial activity against all target bacteria. FBF fermented by Lactobacillus sake exhibited a percentage inhibition of 85% and 53% against S. typhimurium and E. coli, respectively. The percentage of inhibition of FBF fermented by WBL-45 was as high as 100%for E. coli and 85% for S. paratyphi B. Finally, WBL-45 and Lactobacillus sake were selected as appropriate starter cultures for FBF, and FBF with strong antibacterial activity was prepared by pressurized hot water extraction followed by enzymatic hydrolysis, fermentation and Maillard reaction.