This study compared and analyzed the effects of pure-bred fermentation (PF) of artificial inoculation and natural fermentation (NF) on the edible quality and safety of bacteria-fermented Douchi. The results showed that Bacillus spp. was the dominant microorganism. The total number of Bacillus spp. in PF and NF were 1.62×107-1.89×109 CFU/g and 1.74×105-3.80×107 CFU/g respectively, and each accounted for 87.23%-101.3% and 67.26%-83.25% in the total bacterial count. The pH was alkaline after 24 h in PF and remained stable in delayed fermentation. The pH in NF increased slowly at first and rose rapidly after 36 h. The color change in PF was higher than that in NF. The valley value of hardness, adhesiveness, springiness, and chewiness in PF appeared in 24-36 h, and remained stable in delayed fermentation, and all these indicators were lower than that in NF. The food hygiene indexes like thiobarbituric acid (TBA), peroxide and peroxide value (POV), total volatile basic nitrogen (TVB-N) ,and nitrite were 1.09-2.64, 43.37-72.64, 18.17-49.95 mg/100 g, and 2.66-10.08 μg/g in PF, and 1.76-3.30, 50.28-117.75, 16.07-169.79 mg/100 g, and 1.79-9.14 μg/g in NF. The values of TBA, POV and TVB-N in pure fermentation were lower than those in natural fermentation, and the content of nitrite was slightly higher than that in natural fermentation, especially that nitrite and POV were lower than the relevant standard during the whole fermentation. Free amino acids, total acids, and reducing sugars increased gradually with the extension of fermentation time, but there was no distinct difference between methods. The protease activity and viscous substance content in PF were 27.44-91.95 U/g and 13.32%-16.48% dry basis, and in NF were 9.99-92.26 U/g and 5.92%-9.65% dry basis. The protease activity and viscous substance content in PF were higher, and remain stable in delayed fermentation. These results showed that PF Douchi had better quality. In delayed fermentation, the variation of quality indicators in PF was smaller than that in NF. While delayed fermentation could improve the freshness and sour taste of Douchi, the continuous increase of TBA value and TVB-N value was not conducive to its quality. This study provides a reference for the control of fermentation time in different fermentation methods and also the safe consumption and commercial development of Douchi.
[1] 蒋立文. 发酵豆豉的研究进展[J].食品安全质量检测学报, 2013, 4(6):1803-1809.
JIANG L W.Research progress of Douchi fermentation[J].Journal of Food Safety & Quality, 2013, 4(6):1803-1809.
[2] 包启安. 细菌型豆豉的特性及其功能性[J].中国酿造, 2001, 20(5):1-4;9.
BAO Q.Characteristics and functionality of bacterial Douchi[J].China Brewing, 2001, 20(5):1-4;9.
[3] 李祥. 细菌型豆豉生产的研究[J].中国调味品, 1999(10):14-17.
LI X.Resarch on the production of bacterial Douchi[J].Chinese Condiments, 1999(10):14-17.
[4] FAN Y X, TIAN Y J, ZHAO X Y, et al.Isolation of acetoin-producing Bacillus strains from Japanese traditional food—Natto[J].Preparative Biochemistry & Biotechnology, 2013, 43(6):551-564.
[5] CHANDRASEKARAN S D, VAITHILINGAM M, SHANKER R, et al.Exploring the in vitro thrombolytic activity of nattokinase from a new strain Pseudomonas aeruginosa CMSS[J].Jundishapur Journal of Microbiology, 2015, 8(10):e23567.
[6] KUROSAWA Y, NIRENGI S, HOMMA T, et al.A single-dose of oral nattokinase potentiates thrombolysis and anti-coagulation profiles[J].Scientific Reports, 2015, 5(1):1-7.
[7] 满丽莉, 向殿军.来源于豆豉的枯草芽孢杆菌MX-6所产纳豆激酶的稳定性研究[J].中国调味品, 2019, 44(7):25-28;33.
MAN L L, XIANG D J.Study on stability of nattokinase produced by Bacillus subtilis MX-6 from fermented soya beans[J].China Condiment, 2019, 44(7):25-28;33.
[8] 杨胜远, 韦锦, 杨兵, 等.细菌型黑豆豆豉发酵工艺及其功能性成分研究[J].核农学报, 2014, 28(4):670-676.
YANG S Y, WEI J, YANG B, et al.Fermentation process and functional ingredients analysis of bacterial black bean lobster sauce[J].Journal of Nuclear Agricultural Sciences, 2014, 28(4):670-676.
[9] 刘佳慧, 王修俊, 艾静汶, 等.贵州特色水豆豉制曲工艺及生长因子优化的研究[J].食品科技, 2015, 40(7):290-294.
LIU J H, WANG X J, AI J W, et al.Study on koji making process of natto and optimized of growth factor[J].Food Science and Technology, 2015, 40(7):290-294.
[10] 梁叶星, 张玲, 高飞虎, 等.重庆水豆豉发酵过程中NaCl、还原糖和氨基酸变化与滋味的形成[J].食品与发酵工业, 2019, 45(18):27-34.
LIANG Y X, ZHANG L, GAO F H, et al.Changes in NaCl, reducing sugar and amino acids and formation of tastes in Chongqing Shuidouchi during fermentation[J].Food and Fermentation Industries, 2019, 45(18):27-34.
[11] 张帆, 刘立恒.植物乳杆菌和戊糖片球菌活菌计数检测[J].饲料广角, 2002(21):38-39.
ZHANG F, LIU L H.The determination of viable count of Lactobacillus plantarum and Pediococcus pentosus[J].Feed China, 2002(21):38-39.
[12] 陈晨. 豆豉功能微生物的筛选与应用[D].长春:吉林大学, 2015.
CHEN C.Screening and application of functional microorganisms from Douchi[D].Changchun:Jilin University, 2015.
[13] 王燚. 抗氧化肉品发酵剂的筛选及其在羊肉香肠中的应用[D].雅安:四川农业大学, 2008.
WANG Y.Screening of antioxidant meat starter and its application in mutton sausage[D].Ya'an:Sichuan Agricultural University, 2008.
[14] 章佳佳, 陈雪, 刘欢, 等.半干鲐鱼片冷风干燥工艺优化及货架期预测[J].食品工业科技, 2018, 39(1):285-292.
ZHANG J J, CHEN X, LIU H, et al.Optimization of the cold air drying conditions and prediction on shelf-life of half-dried Scomber japonicus fillets[J].Science and Technology of Food Industry, 2018, 39(1):285-292.
[15] 谭小琴. 西南地区传统细菌型豆豉品质特点及微生物群系研究[D].重庆:西南大学, 2021.
TAN X Q.Study on quality characteristics and microbial flora of traditional bacterial Douchi in southwest China[D].Chongqing:Southwest University, 2021.
[16] 张敏, 高秀丽, 鲍鹏.大豆与豆豉中游离氨基酸总量测定[J].贵阳医学院学报, 2006, 31(5):418-419;423.
ZHANG M, GAO X L, BAO P.The dertermination of total amounts of free amino aacids in fermented and un-fermented soybean[J].Journal of Guiyang Medical College, 2006, 31(5):418-419;423.
[17] 索化夷, 赵欣, 骞宇, 等.永川豆豉发酵过程中总糖和氨基酸变化与滋味的形成[J].食品科学, 2015, 36(21):100-104.
SUO H Y, ZHAO X, QIAN Y, et al.Changes in total sugar and amino acids, and formation of taste compounds in Yongchuan Douchi during fermentation[J].Food Science, 2015, 36(21):100-104.
[18] 贾东旭, 吴拥军, 李耀中, 等.细菌型豆豉发酵芽孢杆菌的筛选与鉴定[J].食品科学, 2009, 30(5):217-221.
JIA D X, WU Y J, LI Y Z, et al.Screening and identification of Bacillus for lobster sauce fermentation[J].Food Science, 2009, 30(5):217-221.
[19] 鞠蕾, 马霞, 徐弇豪.γ-聚谷氨酸提取条件的优化[J].食品工业科技, 2012, 33(4):299-303.
JU L, MA X, XU Y H.Optimization of γ-polyglutamic acid extraction conditions[J].Science and Technology of Food Industry, 2012, 33(4):299-303.
[20] 林榕姗. 细菌型豆豉发酵机理及功能性研究[D].泰安:山东农业大学, 2012.
LIN R S.Study on fermentation mechanism and functionality of bacterial Douchi[D].Tai'an:Shandong Agricultural University, 2012.
[21] 房翠兰. 豆豉加工过程中蛋白质和膳食纤维生物学变化的研究[D].重庆:西南大学, 2007.
FANG C L.Study on biological changes of protein and dietary fiber in Douchi processing[D].Chongqing:Southwest University, 2007.
[22] 杨娟, 丁晓雯, 秦樱瑞, 等.豆豉、腐乳蛋白质降解物限量标准研究[J].食品科学, 2016, 37(6):210-215.
YANG J, DING X W, QIN Y R, et al.Limit standards for protein decomposition products in sufu and Douchi[J].Food Science, 2016, 37(6):210-215.
[23] 罗珍岑, 段珍珍, 谭小琴, 等.Nisin对酸肉常温贮藏中营养卫生及感官品质的影响[J].食品与发酵工业, 2019, 45(23):176-182.
LUO Z C, DUAN Z Z, TAN X Q, et al.Effects of Nisin on nutritional hygiene and sensory quality of sour pork stored at room temperature[J].Food and Fermentation Industries, 2019, 45(23):176-182.
