As the first leavening agent in bread production, sourdough has an important role in cuisine and culture all over the world. Traditionally, sourdough was made from flour and water, allowed to ferment using the microorganisms presented naturally inside the grain and in the air. Sourdough becomes acidic when lactic acid bacteria take over the fermentation and play important role. The activities of such microorganism determine the sourdough characteristics in terms of lactic acid fermentation, proteolysis, synthesis of volatile, anti-nutrient and antifungal compounds. As the results, sourdough bread are more nutritious, tasty, coloury, fragrant and more stable during storage in comparison with breads made only by baker?s yeasts or baking powder. In general, Lactobacillus spp. are the common bacteria associated in sourdough starter. In this research, pure lactic acid bacteria were obtained from the isolation of naturally fermented sourdough samples that were collected in Can Tho City. The bacterial species giving the highest acid yields was selected and characterized. The effects of conditions during the sourdough fermentation, such as bacterial inoculation level, fermentation temperature and fermentation time, as well as the shelf life of fermented sourdough bread were also examined. As results, five strains of lactic acid bacteria were purely isolated. By morphological and biochemical tests, these five strains were identified belonging to genus Lactobacillus, family Lactobacillaceae, order Lactobacillales, class Bacilli, phylum Firmicutes. Of which, the strain of LAB-4 performed the highest activity during sourdough fermentation. This target strain was selected due to the highest total acid produced, the lowest pH and good sensory scores and it was identified as Lactobacillus plantarum, with 96% of similarity of 16S region genome by comparing the 16S-rRNA sequence. Based on statistical analysis, the results on effect of fermentation conditions showed that the favourable fermentation conditions for sourdough starter preparation were defined as follows: inoculation level at 109 cells/mL, incubation temperature at 37°C and incubation time for 4 hours. During the storage tests, based on the sensory evaluation of the ability to synthesis antifungal compounds of lactic acid bacteria, sourdough bread that was made by Lactobacillus plantarum had a longer shelf life (9 days) to compare with the treatment of bread made by baker?s yeast (6 days). Probably Lactobacillus plantarum has the ability to synthesize some compounds which have antifungal activities such as lactic, phenyl lactic acids, dipeptides cycle (L-Leu-L-Pro) and cycle (L-Phe-trans-4-OH-L-Pro), and these compounds can inhibit the outgrowth of contaminated microorganisms.
Ngô Thị Phương Dung, Huỳnh Xuân Phong, Bùi Duy Nhân, 2012. SảN XUấT MEN RƯợU Từ SACCHAROMYCES CEREVISIAE Và ENZYME AMYLASE TRONG MầM LúA. Tạp chí Khoa học Trường Đại học Cần Thơ. 21a: 11-18
Ngô Thị Phương Dung, Huỳnh Xuân Phong, Lý Huỳnh Liên Hương, 2011. PHÂN LẬP, TUYỂN CHỌN NẤM MEN VÀ XÁC ĐỊNH ĐIỀU KIỆN ẢNH HƯỞNG QUY TRÌNH LÊN MEN RƯỢU VANG DƯA HẤU. Tạp chí Khoa học Trường Đại học Cần Thơ. 18b: 137-145
Ngô Thị Phương Dung, Đặng Bích Tuyền, Phạm Hồng Quang, 2011. ĐẶC TÍNH HÌNH THÁI, DI TRUYỀN VÀ ĐIỀU KIỆN NUÔI CẤY MEO GIỐNG CỦA NẤM BÀO NGƯ. Tạp chí Khoa học Trường Đại học Cần Thơ. 18b: 146-156
Ngô Thị Phương Dung, Huỳnh Xuân Phong, Huỳnh Thị Yến Ly, 2011. PHÂN LẬP VÀ TUYỂN CHỌN VI KHUẨN LACTIC CÓ KHẢ NĂNG SINH CHẤT KHÁNG KHUẨN. Tạp chí Khoa học Trường Đại học Cần Thơ. 19a: 176-184
Ngô Thị Phương Dung, Huỳnh Xuân Phong, Nguyễn Ngọc Thạnh, 2013. XÁC ĐỊNH MẬT SỐ VÀ PHÂN LẬP VI SINH VẬT TRONG LÊN MEN CA CAO. Tạp chí Khoa học Trường Đại học Cần Thơ. 25: 271-280
Dung, N.T.P., Doi, N.M. and Phong, H.X., 2015. Preparation of fungal alcoholic starter using rice malt as substrate. Can Tho University Journal of Science. 1: 47-52.
Tạp chí: The Final Joint Seminar on Establishment of an international research core for bio-research fields with microbes from tropical areas; Yamaguchi University Japan; 2nd – 4th December 2018
Tạp chí: The Final Joint Seminar on Establishment of an international research core for bio-research fields with microbes from tropical areas; Yamaguchi University Japan; 2nd – 4th December 2018
Tạp chí: International Symposium on Microbial Research and Biotechnology for Biomass Utilization. JR Hakata City, Fukuoka, Japan. 12th – 13th November, 2015
Tạp chí khoa học Trường Đại học Cần Thơ
Lầu 4, Nhà Điều Hành, Khu II, đường 3/2, P. Xuân Khánh, Q. Ninh Kiều, TP. Cần Thơ
Điện thoại: (0292) 3 872 157; Email: tapchidhct@ctu.edu.vn
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