Analysis of Free Sugar, Organic Acid and Free Amino Acid in Commercial Makjang

For analyzing the useful components in kanpei and natsumi, volatile as well as non-volatile components were analyzed using HPLC and GC/MS. Kanpei and natsumi juices contain free sugars and organic acids which are involved in imparting sweet and sour flavors. Analysis of the free sugar content revealed that the sucrose content was 6.53±0.31 g/100 g and 7.36±0.28 g/100 g in kanpei and natsumi, respectively. The content of citric acid, which is an organic acid, in kanpei and natsumi was 0.99±0.04 g/100 g and 0.87±0.06 g/100g, respectively.The analysis of 20 different free amino acids revealed that arginine was the most abundant at 65.27 mg/100 g and 38.09 mg/100 g, respectively. Essential amino acids contents were 13.59 mg/100 g and 17.93 mg/100 g, accounting for 5.95% and 14.3% of the total amino acids for kanpei and natsumi, respectively. Narirutin and hesperidin were identified as the major flavonoids in the juice and peel. Furthermore, nobiletin and tangeretin, which are present only in citrus species, were identified in the peels. The analysis of volatile components revealed that kanpei and natsumi had a high content of limonene>γ-terpinene>linalool, while natsumi was characterized by the abundance of limonene>γ-terpinene>β -myrcene. As a result of this study, many functional components were found in large amounts in kanpei and natsumi. This result can be used as cultivar characteristics evaluation.

Section: The Contents Of Glucose Fructose Sucrose and Citric Acidmentioning

confidence: 99%

Phytochemical profiles of Citrus hybrid kanpei and Citrus reticulata natsumi : Analysis of volatile and non-volatile components

Kim¹,

Park²,

Park³

et al. 2022

Comparison of the quality characteristics and microbial community of traditional doenjang across fermentation places

Lee¹,

Lim²,

Lee³

et al. 2022

We investigated the quality characteristics and microbial community found in traditional outdoor-type doenjang fermented at different temperatures. The quality characteristics that were highly correlated with fermentation temperature were analyzed. The average temperature of doenjang in the summer was highest in the order of fermentation by field in Damyang (JDF), fermentation by smart management facility in Damyang (JDS), and fermentation by field in Pyeongchang (JDFP), and in winter was the highest in the order JDS, JDF, and JDFP. The b* value and the degree of browning were highest in the order of JDF, JDS, and JDFP. Among the quality characteristics that affect the degree of fermentation and taste, samples with high summer temperature showed high ammonia nitrogen content, α-amylase activity, sugar content, organic acid content, and acidity and samples with high winter temperature showed high protease activity, amino nitrogen content, biogenic amine content, and alcohol content. Regarding the microbial community, the level of the Enterococcus genus was high in the samples with low winter temperatures, while the level of the Bacillus genus was high in the samples with high winter temperatures. Additionally, the genus Wickerhamiella and Zygosaccharomyces were highest in the samples with the lowest temperatures in summer and winter. Furthermore, acidity, biogenic amine content, glucose content, and lactic acid content were analyzed as major factors influencing the quality characteristics of doenjang according to the ripening region and location.

Changes in quality characteristics of makjang depending on fermentation location and complex starters

Park,

Han,

Jeong

et al. 2023

This study aimed to investigate the quality and microbial population changes for 90 days under two fermentation conditions, outdoors and indoors (35°C), with starters (single or mixed) in soybean paste. Bacillus velezensis NY12-2 (S1), Debaryomyces hansenii D5-P5 (S2), Enterococcus faecium N78-11 (S3), and their mixtures (M) were used for the makjang fermentation. The content of amino-type nitrogen among the makjang samples was highly shown in the indoors, followed by M, S3, and S2. The glutamic and aspartic acid contents in the M sample fermented in the indoors showed the highest values of 867.42±77.27 and 243.20±15.79 mg/g, respectively. By the electronic tongue analysis, the M sample fermented in the indoors exhibited lower saltiness and higher umami than the others. Consequently, we expect that using mixed strains, such as Bacillus, Debaryomyces, and Enterococcus, under constant conditions showed potential to the quality improvement of soy products.