Jeong Sil Choi

This study investigated developmental changes in phenolic compounds and condensed tannin structure in the berry skins of three table grape cultivars, ‘Rosetta’ (RT), ‘Shooting Star’ (SS), and ‘Hongju Seedless’ (HS), from flowering to harvest. Spectrophotometric analyses were used to quantify total phenolic, proanthocyanidin, polymeric tannin, and anthocyanin contents, while high-performance liquid chromatography coupled with thioacidolysis was applied to characterize flavan-3-ol composition and determine the mean degree of polymerization (mDP) of condensed tannins. Phenolic accumulation exhibited distinct cultivar-dependent developmental patterns. Total phenolics and flavan-3-ol monomers generally decreased as berries matured, whereas anthocyanins accumulated after veraison in RT and HS. Polymeric tannins increased during the early developmental stage and subsequently declined, while mDP showed an overall tendency to increase toward maturity, particularly in RT, although the effects of cultivar, developmental time, and their interaction on mDP were not statistically significant. HS maintained high flavan-3-ol concentrations during early development, whereas SS exhibited comparatively low phenolic accumulation together with relatively limited variation in mDP. These findings provide the first comprehensive characterization of developmental changes in flavan-3-ol composition, polymeric tannin structure, and mDP in newly developed Korean table grape cultivars and a structural basis for understanding cultivar-dependent phenolic changes during berry development.

Jeong-Sil Choi and Se-young Ju. Journal of the Korean Society of Food Science and Nutrition 2024;53:1304-15. https://doi.org/10.3746/jkfn.2024.53.12.1304

Jeong-Sil Choi, Youn-Young Hur, Byeong-Hyeon Yun, Jung-Ho Noh, and Dongjun Im. Journal of the Korean Society of Food Science and Nutrition 2024;53:1185-92. https://doi.org/10.3746/jkfn.2024.53.11.1185

This study aimed to investigate the wine properties of new Korean grape cultivar Ageude. To this end, wine was produced using five grape cultivars including Campbell Early and Muscat Bailey A, which are commonly used for winemaking in Korea and Pinot Meunier and Gamay, which are European wine grape cultivars. We conducted a comprehensive analysis of wine quality properties, color, and phenolic compounds and compared the variations observed among these cultivars. The pH and total acid contents were in the ranges of 3.75-4.57 and 0.39-0.58%, respectively. Specifically, the total acid content of Ageude was 0.47% which was not high, when compared to those of other wines. However, the soluble solid content was 7.85 °Brix, which was higher than those of the other wines. In terms of color, the redness, color intensity, and hue values were all considerably high. Moreover, the total phenolic content and total anthocyanin content of Ageude were notably higher than those of the other cultivars. However, it is worth noting that proanthocyanidin was not detected. Based on these findings, Ageude is an excellent cultivar for producing red wine, owing to its high total anthocyanin content and redness due to the absence of proanthocyanidin, it is more suitable for producing short-term aging wine rather than long-term aging wine.

한국식품저장유통학회지(Korean Journal of Food Preservation)

This study aims to evaluate the importance and performance level of knowledge about sanitary management among foodservice employees in childcare centers that were registered at Center for Children’s Food Service Management in Chungju city according to their work duration, type of childcare center, and number of enrolled children. The self-administered questionnaire was conducted to examine food safety attributes of sanitary management at 150 childcare centers without qualified dietitians registered at Center for Children’s Food Service Management of Chungju city. The questionnaire consisted of 15 questions about perceived importance and performance regarding sanitation management (personal hygiene, ingredient control, temperature control of food, facility, equipment, and utensils sanitation) using IPA (importance–performance analysis). The results show that overall mean scores of the importance and performance of sanitary knowledge were 4.71 and 4.67 out of 5, respectively. ‘Checking the center temperature at 75 °C for 1 min in the thickest part of meat (3 times or more check for each serving)’ (p = 0.047) and ‘Keeping preserved meals (at least 100 g of each menu) for 144 h. with −18 °C or less’ (p < 0.001) show significantly lower scores of performance than those of importance. The results of importance and performance for sanitary management according to work duration of foodservice employees show that those who have worked more than 10 years had the highest scores of importance and performance for overall sanitary management among them. For the types of childcare centers, the overall performance scores of national/public employees for sanitary management were lower than those of private or home type (p < 0.001). Additionally, the result showed that the overall importance (p < 0.001) and performance scores (p < 0.001) of employees for sanitary management in centers with <50 children were higher than those in centers with ≥50 children. This result should provide more useful information to develop food safety programs for employees and sustainable foodservice management in childcare centers.

We analyzed the physicochemical properties of commercially available top-fermented beer (ale) and bottom-fermented beer (lager) marketed in Korea to compare the quality characteristics. The following characteristics of beer were analyzed for their soluble solid content, pH, total acid content, alcohol content, volatile acid content, reducing sugar content, amino acidity, and color. As results, the pH ranged from 4.01 to 4.77, 0.10-0.23 (%) for total acid and 0.25-1.47 (mL/10 mL) for amino acidity. The alcohol content was in the range of 3.10-5.70 (%) for ale and 3.80-5.20 (%) for lager. The volatile acid content was in the range of 28.67-97.93 (mg/L) for ale and 32.80-78.87 (mg/L) for lager. Regarding the color, the EBC value of the ale beers was in the 4.78-93.98 range, and that of lager beers were in the 5.48-11.98 range. Comparison of the quality characteristics of the two types of beer, revealed differences in pH, amino acidity, total acid content, reducing sugar content, and color. In particular, total acid content (t=−3.782, p⟨0.05), reducing sugar content (t=−11.744, p⟨0.05), and color (t=−2.882, p⟨0.05) of ale beer showed significantly higher than those of lager beer.

This study demonstrated the effects of different commercially available Saccharomyces cerevisiae yeasts i.e., Fermivin®, La Parisienne, Songcheon, Ottogi, and Chungmoo, on the variation in the quality of yakju samples under accelerated aging (45°C, 14 d). The analyses of physicochemical properties of the yakju samples were performed for, soluble solid content (°Brix), pH, total acid content (%, as acetic acid), alcohol (v/v%), volatile acid (mg/L), reducing sugar content (mg/mL), amino acidity (mL), brownness (A430), and hunter color value before and after aging. By comparing the results, significant differences in the properties of the yakju samples before and after aging were observed. The yakju sample fermented with wine-yeast Fermivin® exhibited no significant change in color after aging; furthermore, the reducing sugar content (1.20±0.01-1.32±0.03 mg/mL) and amino acidity (4.06±0.07-4.80±0.04 mL) of this sample were lower than those of the other samples. The yeast of Fermivin® resulted in a negligible residual sugar content owing to complete fermentation, thereby minimizing the variation in quality during aging. The using of different yeasts for fermentation induced significant differences in the contents of organic acid, free nitrogenous components, and volatile components before and after aging. The obtained results indicated that the properties of yakju such as odor and browning, could be regulated based on the type of yeast used for fermentation.

This study investigated changes in the quality of the Korean sparkling rice wine, ‘Makgeolli’ prepared by independent two-step fermentation and stored at 10, 15, and 25°C for 91 days. The contents of total acid, volatile acid, and amino acidity increased as the storage period and temperature increased. The total acid content was 0.14% on day 0, and 0.33%, 0.35% and 0.40% at 91 days of storage at 10°C, 15°C, and 25°C, respectively. The pH was 3.86 on day 0 of storage and tended to decrease at all temperatures over the storage period, but the soluble solid and alcohol content did not significantly differ. Color significantly differed when stored at 15°C and 25°C (p<0.05), but not at 10°C. Consequently, the quality of ‘Makgeolli’ was altered during storage for 91 days, and the change was more rapid at higher storage temperatures.

This study aimed to investigate the effects of the degrees of milling of rice (0-50%) on the physicochemical properties and enzymatic activities of rice ‘Nuruk’. As results, the contents of the general components of milled rice, except for the starch value (85.13-90.99%) decreased as the degree of milling increased. The moisture content of rice with different degrees of milling ranged from 11.04 to 12.68% and significantly decreased as the degree of milling increased. Furthermore, the hydration rate increased as the degree of milling increased. The pH of rice ‘Nuruk’ was the lowest at 5.32 in the 0% milled rice ‘Nuruk’ and highest at 5.98 in the 30% milled one, which indicated no correlation between pH and degree of milling. By contrast, the soluble solid and reducing sugar contents which are correlated with the starch value of rice increased as the degree of milling increased. For the enzymatic activities of each rice ‘Nuruk’, there was no clear trend for the α-amylase and acidic protease activities with respect to the degree of milling, whereas the glucoamylase activity decreased with increasing degree of milling. Correlation analyses indicated that the activity of glucoamylase decreased as the starch value of rice increased, but increased as the crude protein content of rice increased. The activity of acidic protease had a negative correlation with the crude lipid content of rice.