Relationship between exterior environment and quality characteristics of the traditional Gochujang produced in 2018 by eight regions in Korea

Abstract

The objective of this study was to investigate the quality and environment properties of traditional Gochujang produced by 56 rural farms in 8 regions of Korea for evaluating the relationship between the components and environmental factors. Based on the regional means at the initiatory and after fermentation, the ranges of moisture content, salinity, pH, and acidity of Gochujang were determined to be from 46.87±7.09% to 43.80±7.17%, from 7.52±2.21% to 8.53±2.57%, from 5.01±0.30 to 4.63±0.34, and from 1.13±0.50% to 1.43±0.58%, respectively. The mean contents of reducing sugar and amino-type nitrogen were from 16.46±7.63% to 20.48±7.57% and from 140.06±78.00 mg% to 198.68±87.11 mg%, respectively. Hunter color values (L, a, and b) of Gochujang were from 26.16±9.27 to 22.49±9.02, from 21.87±6.31 to 20.14±7.58, and from 19.43±11.94 to 19.18±12.06, respectively. Total aerobic number was increased from 6.50±1.29 log CFU/g to 8.15±0.88 log CFU/g, while the fungal number was steadily decreased after fermentation. Next generation sequencing analysis to investigate the microbial communities revealed that

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

“…Differences in the yeast count were observed among all the samples; the yeast cell count in gochujang before fermentation was in the range of 2.81–5.39 log CFU/g. Coliform did not appear in all samples similar to the previous study (Baek et al, 2019 ).…”

“…The overall pH values of the UJ and YJ samples were slightly lower than the other samples, while the acidity of the YJ and GR samples was slightly higher than other samples. Amino-type nitrogen is closely related to the quality of gochujang and is an index to determine the degree of fermentation (Baek et al, 2019 ; Chun et al, 2020 ). The content of amino-type nitrogen increased during the fermentation, peaked and after fermentation at a concentration of 182.9 mg%, which was ~1.6 times higher than before fermentation, except for the GR sample ( Figure 1E ).…”

“…These are similar to the microbial communities of doubanjiang, a traditional Chinese food fermented with red pepper and meju (Zhang et al, 2020 ). The certification system for the quality of traditional foods in Korea stipulates that the water content of gochujang and amino-type nitrogen after fermentation should be <50% and more than 160 mg%, respectively (Baek et al, 2019 ). According to this standard, the water content and amino-type nitrogen of all samples used in this study met the regulation.…”

“…Gochujang is a traditional Korean fermented food made from fermented soybean (meju), red pepper powder, and glutinous rice. It is a popular flavoring condiment in East Asian countries along with doenjang (Korea), doubanjiang (China), and miso (Japan) (Baek et al, 2019 ; Chun et al, 2020 ). Gochujang creates a unique flavor by combining the spicy taste of red pepper powder with the sweetness and savory taste produced by the hydrolysis of carbohydrates and soybean proteins (Jang et al, 2011 ).…”

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].…”