• Korean Journal of Food Science and Technology
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• v.38 no.3
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• pp.342-347
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• 2006

Korean pear juice heat-treated at various temperatures (110, 120, 130, 140, and $150^{\circ}C$) and times (1, 2, 3, 4, and 5 hr) was analyzed to determine total polyphenol, total flavonoid, free sugar, and 5-HMF contents, and DPPH free radical-scavenging activity. Total polyphenol, total flavonoid, and 5-HMF contents, and antioxidant activities increased, whereas fructose content decreased with increasing heat treatment temperature and time ($p\;{\pm}\;0.007\;mg/g$ with treatment at $150^{\circ}C$ for 1 hr (unheated pear juice: $0.233\;{\pm}\;0.024\;mg/g$). Highest total flavonoid content was $561.49\;{\pm}\;16.93\;{\mu}g/g$ with treatment at $150^{\circ}C$ for 4 hr (unheated pear juice: $1.50\;{\pm}\;0.20\;{\mu}g/g$). $IC_{50}$ value was highest, $1.93\;{\pm}\;0.01\;mg/g$, at $150^{\circ}C$ for 2 hr, whereas that of unheated pear juice was $64.58\;{\pm}\;0.99\;mg/g$. Glucose content was not affected by treatment conditions, whereas fructose content decreased with treatment at $140^{\circ}C$ for 3 hr. Highest 5-HMF content was $5,594.93\;{\pm}\;6.43\;ppm$ at $150^{\circ}C$ for 5 hr (unheated pear juice: $2.04\;{\pm}\;0.21\;ppm$). Correlation coefficients were observed among total phenolic, total flavonoid, and antioxidant activities, and between fructose and 5-HMF at significance level (p<0.001).

• The Korean Journal of Mycology
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• v.38 no.2
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• pp.184-188
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• 2010

The goal of this study was to screen a useful yeast for Korean traditional pear Yakju (KTPY) brewing and develop its brewing process. Cooked non-glutinous rice and nuruk were mixed, and added into pear juice with various Saccharomyces cerevisiae and then fermented at $25^{\circ}C$ for 7 days. Among several alcohol fermentation yeasts, ethanol contents was the highest in pear Yakju made by S. cerevisiae K-7 and also showed high ethanol content in pear Yakju which was made by commercial S. cerevisiae C-2. Therefore, we selected S. cerevisiae K-7 and S. cerevisiae C-2 as suitable yeasts for brewing of KTPY. Maximal ethanol production (10.4%) was obtained when cooked non-glutinous rice (100 g) and nuruk (30 sp/g) were mixed and added into pear juice (600 ml) with S. cerevisiae K-7 (5%) and fermented at $25^{\circ}C$ for 7 days and also its antihypertensive angiotensin I-converting enzyme (ACE) inhibitory activity was 57.2%. Addition of antihypertensive starchy materials into the mash was not affected in ACE inhibitory activity and total acceptability of KTPY.

• The Korean Journal of Community Living Science
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• v.20 no.4
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• pp.549-558
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• 2009

This study examined the basic information on the native pear c.v. 'Baekwoon' grown in Mt. Baekwoonsan, Gwangyang, to develop as a local specialty product. the sensory characteristics, chemical compositions, and physiological activities of 'Baekwoon' pear were examined and compared with those of 'Niitaka' pear. Hardness of 'Baekwoon' pear was 19.30N, which was higher than 'Niitaka'. The sugar content of 'Baekwoon' was 11.5 $^{\circ}Brix$, which was lower than 'Niitaka'. The total amino acid contents of the fruit skin and flesh of 'Baekwoon' were 222 mg/100g dry weight (DW) and 130 mg/100g DW, respectively, which were much higher than those of 'Niitaka'. Especially, serine contents in fruit skin and flesh of 'Baekwoon' were 75.4 mg/100g DW and 40.2 mg/100g DW, respectively, which were significantly (p<0.05) higher than those of 'Niitaka'. However, physiological activities, such as total phenol content, DPPH radical scavenging activity, total flavonoid content and nitrite scavenging activity, of 'Baekwoon' were lower than or similar to those of 'Niitaka'. Consequently, vitamin and amino acid contents of 'Baekwoon' were better than those of 'Niitaka'. It is suggested to use fruit skin because of its good composition and physiological activities so that it helps to improve the quality and the biological activity.

• Food Science and Preservation
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• v.17 no.1
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• pp.66-71
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• 2010

In the Joseon Dynasty, various fruit teas were popularized to promote health, with spread of Donguibogam and Hyangyag gugeupbang. As interest in fruit tea has recently increased, studies on its manufacture have become necessary. We used response surface analysis for rediscovery and commercialization of grape tea. Major materials of traditional grape tea are grape juice, pear juice, ginger juice, and honey, and the sugar contents of these materials were 12.3, 14.1, 3.3 and 75 $^{\circ}Brix$, respectively. When sensory examinations were conducted with subjects aged 40-60 years, the difference between dilution ratios of 100% and 150% was not significant, but tea diluted by 150% showed somewhat higher scores than did tea diluted by 100%. Ginger taste and sweetness were found to have the greatest effect on overall acceptance. Regression analysis on color, flavor, taste, and overall acceptance values, with reference to ginger juice and honey as independent variables, revealed that the $R^2$ values were 0.8411, 0.6717, 0.9499, and 0.9015, respectively. Contour maps were superimposed to obtain an optimal combination of ingredients for traditional grape tea, and the indicated levels of ginger juice and honey were 0.46-0.69% and 3.85-5.20%, in combination with grape juice, pear juice, and water concentrations of 28%, 9% and 60% (all w/w), respectively. Thus, it is now possible to prepare traditional grape tea.

• The Korean Journal of Mycology
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• v.41 no.4
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• pp.255-260
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• 2013

In order to develop new valuable pear marc nuruk and further, reduce environmental pollution by pear marc from pear juice processing, we prepared pear marc nuruk by incubation of Aspergillus oryzae into pear marc containing 50% of moisture at $30^{\circ}C$ for 7 days. ${\alpha}$-Amylase and glucoamylase activities of the pear marc nuruk were 320.2 IU and 442.8 IU, respectively and its acidic protease activity was showed 142.6 IU. After brewed makgeolli by using the pear marc nuruk, cooked rice and Saccharmyces cerevisiae, its physicochemical characteristics was investigated. Ethanol content of pear marc nuruk-makgeolli was 6.8% after fermentation at $25^{\circ}C$ for 10 days and also pear marc makgeolli showed 45.6% of antihypertensive angiotensin I-converting enzyme (ACE) inhibitory activity. In conclusion, pear marc nuruk had high amylase activity and pear marc-makgeolli had also good fermentation characteristics and antihypertensive ACE inhibitory activity. Therefore, it has the potential to become a new nuruk for brewing makgeolli.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.8
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• pp.1226-1231
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• 2005

In order to improve qualities of traditional kochujang, pear juice was added to kochujang, and the physicoche-mical and microbial characteristics of pear-added kochujang were investigated for 2 months of fermentation at 30$^{\circ}C$. Moisture contents of pear-added kochujangs increased except of 9$\%$ pear-added kochujang and crude protein contents of them decreased as the fermentation proceeded. Total sugar contents of pear-added kochujangs did not change during the fermentation period, and reducing sugar contents of them increased remarkably from early stage of fermentation. The pH of pear-added kochujangs decreased and titratable acidity of them increased during fermentation. Amino-nitrogen contents of pear-added kochujangs increased remarkable after 45 days of fermentation. Viable cells counts of yeasts in pear-added kochujangs increased to 2.2$\∼$2.9$\times$$10^{3}$CFU/g, and bacterial cell counts were in relatively constant range of 2.1$\∼$2.9$\times$$10^{7}$CFU/g at the late stage of fermentation. Color of pear-added kochujangs had no difference and 'a' value decreased slightly during fermentation. The result of sensory evaluation showed that 6$\%$ pear added kochujang were more acceptable than others.

• The Korean Journal of Community Living Science
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• v.26 no.4
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• pp.661-673
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• 2015

This study examines the effects of a low-calorie raw juice diet on the level of serum ferritin in adults and analyzes nutrient intake from the diet. There were significant differences between juices; the highest calorie was provided by pear juice, highest crude protein, vitamin A, and vitamin B2 levels were from green Juice 1; and highest vitamin C and vitamin B1 levels were from fruit juices. The ratio of estimated energy requirements (EER) for the participants was 56.2% from the raw juice diet. The percentages of recommended intake (RI) from the raw juice diet of protein (57.9%), dietary fiber (19.1%), niacin (6.2%), calcium (0.1%), and magnesium (0.2%) were lower than 75%. However, those of RI of vitamin A, vitamin B1, vitamin B2, vitamin B6, and vitamin C were 1796.5%, 7481.7%, 1915.5%, 30858.7%, and 7500%, respectively, exceeding the tolerable upper intake level (UL) for vitamin A, vitamin B6, and vitamin C. There were significant decreases in weight, the body mass index (BMI), body fat mass, and skeletal muscle mass in males and females. After the diet program, serum iron and SOD (superoxide dismutase) showed significant decreases, whereas RBC, hemoglobin, hematocrit, and serum ferritin showed significant increases. There were negative correlations between serum ferritin and weight and between serum ferritin and skeletal muscle mass for all participants. There were negative correlations between serum ferritin and skeletal muscle mass for males and between serum ferritin and body fat mass for females. These results suggest that a raw juice diet can supplement a regular diet to prevent excess or deficient nutrient intake.

• Korean Journal of Breeding Science
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• v.51 no.4
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• pp.424-427
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• 2019

A persimmon (Diospyros kaki L. Thunb.) cultivar, 'Chosi', which was a cross between 'Johongsi' and 'Nishimurawase' in 2000, was finally selected in 2010. 'Chosi' persimmon fruits were harvested in Sept. 19 in Naju, with a medium fruit size of 161 g, on average, and high soluble solids of approximately 15.3 °Bx. The flesh tastes good, with a crispy texture, and the juice is rich. The shape of the fruit is round oblate, and the skin color is orange; the appearance is graceful. Physiological disorders, such as stylar-end cracking or skin fine cracking, rarely occur in this cultivar. (Registration No. 7075)

• The Korean Journal of Pesticide Science
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• v.12 no.3
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• pp.256-261
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• 2008

Recently, Ussur brown katydid outbreaks caused a serious pest problem in areas of Yeongdong, Chungbuk. This study was performed to control the pest with environment-friendly method. Trap was made of PET plastic bottles that easily found near farmhouse. Attractant materials such as oak (Quercus acutissima) leaf, fruits (peach, apple, grapefruit and pear) sarcocarp or its juices, rice wine (makgeolli) and fish meal were directly applied into the manufactured trap and investigated for the attraction efficacy compared with the funnel trap. During one day, manufactured trap (fish trap) attracted the Ussur brown katydid more than funnel trap. The efficacy of attractant materials were as follows: peach juice (32.7 adults) > rice wine+fish meal (31.3 adults) > rice wine (27.0 adults) > pear juice (19.0 adults) > apple juice (17.2 adults) > fish meal (16.7 adults) > grapefruit juice (14.4 adults) > oak leaf (2.3 adults). The attractive efficacy of fruit juices to ussur brown katydid was more than fruit carcocarps, and the trap hangover 1m in height more than that on ground. The composition of rice wine and fish meal prolonged its efficacy when treated with disinfectant.

• Korean Journal of Food Science and Technology
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• v.27 no.4
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• pp.439-444
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• 1995

Preparative conditions and characteristics of six-vegetable and fruit juice were studied for the effects of mixing ratio, heat treatment and addition of sugar, salt and organic acid. The vegetables and fruit used were carrot(Ct), cabbage(Cg), pear(Pr), cucumber(Cr), celery(Cy) and dongchimi(Di). From the sensory results of mixing ratio of three of binary mixtures of Cg-Pr(1:3):Ct-Di(1:4):Cr-Cy(3:1), two ratios of 5.0:2.5:2.5(V-6A) and 6.0:2.0:2.0(V-6B) were suggested optimal for six-vegetable and fruit juice. Addition of 2% sucrose and 0.3% NaCl improved the preference significantly. The pH 4.0 for V-6A and pH 3.5 for V-6B were more prefered when pH was adjusted by citric acid. Heating the juice at $100^{\circ}C$ for 100 minutes slightly decreased pH and increased the acidity. Total solids and viscosity were also decreased by heating. All of those changes were more significant in V-6B than V-6A, probably due to lower pH. Heating the juice resulted in a slight decrease in L value and an increase in a and b values. Heating at $100^{\circ}C$ caused an increase in moldy flavor and a decrease in fresh vegetable flavor while heating at $80^{\circ}C$ for 20 minutes changed them little.