Physicochemical Characteristics and Microbial Communities in Gochujang, a Traditional Korean Fermented Hot Pepper Paste

Abstract

Gochujang is a Korean fermented hot pepper paste beneficial to human health by providing various nutrients. In this study, its physicochemical characteristics were identified, and its microbial communities were analyzed by high-throughput sequencing. The interrelationship between physicochemical characteristics and microbial composition was investigated to reveal the properties of gochujang before and after fermentation. After fermentation, all samples showed decreased salt concentration, pH, and reducing sugar content, while the acidity and amino-type nitrogen increased. The water content, salt concentration, amino-type nitrogen, and reducing sugar differed according to the batches of samples. Bacillus, Aerosakkonema, and Enterococcus were identified as the predominant bacterial genera. Furthermore, Aerosakkonema was the most abundant genus before fermentation; however, it was replaced by Bacillus as it decreased after fermentation. For the fungi, Aspergillus dominated before fermentation, whereas Zygosaccharomyces and Millerozyma dominated after fermentation. The high level of amino-type nitrogen in gochujang was related to the relative abundance of B. haynesii/B. licheniformis before fermentation. Additionally, the high abundance of Z. rouxii after fermentation was related to the flavor of gochujang. This comprehensive analysis of the microbial community associated with the physicochemical properties of gochujang could help in understanding the factors affecting the quality of the product.

Quantification of Biogenic Amines in 35 Korean Cottage Industry Traditional Gochujang (Fermented Red Pepper Paste) Products

“…Major factors that affect the quantity of BAs in traditional gochujang products include manufacturing practice, ratio and quality of raw material, the microbial consortium involved during fermentation, fermentation environment, and the duration of the fermentation process. The predominant bacterial species found in gochujang are Bacillus subtilis, followed by Bacillus licheniformis and Bacillus amyloliquefaciens, which are well known producers of BAs due to the presence of decarboxylase enzyme [42,43]. The decarboxylase activities in these bacteria markedly vary between the strains and may be a major cause of the difference in the quantity of BAs in various gochujang products [10].…”

Analysis of Cultivable Microbial Community during Kimchi Fermentation Using MALDI-TOF MS

“…Lactobacillus -related genera, Weissella , and Leuconostoc were the dominant genera during kimchi fermentation, which was consistent with the results of previous studies [ 5 , 13 ]. The composition of these microorganisms was similar to sauerkraut, a fermented cabbage food, but it was different from other fermented soybean foods, such as gochujang [ 15 , 35 ]. The overall change in microbial diversity based on fermentation temperature-time was similar to fermentation at 10 °C and 23 °C, but it was different at 4 °C.…”

“…However, these approaches are time-consuming, expensive, difficult to carry out, labor-intensive, and provide limited information. To overcome these limitations, the high-throughput sequencing approach is used to identify the microbial community in various fermented foods [ 13 , 14 , 15 ]. It provides a comprehensive understanding of the relationship between food and its microorganisms compared to other culture-independent methods, but its taxonomic resolution is only up to the family or genus level because of the use of 16S rRNA gene fragments [ 5 , 13 , 16 ].…”

Bacterial Community and Anti-Cerebrovascular Disease-Related Bacillus Species Isolated from Traditionally Made Kochujang from Different Provinces of Korea

“…from Kochujang and assessed its functionality. These processes are crucial to make Kochujang with specific functionalities and quality control [7]. Therefore, the predominant and beneficial bacteria in Kochujang need to be isolated and the functionalities identified to make inoculated Kochujang with specific functionality.…”