Endogenous functional compounds in Korean native chicken meat are dependent on sex, thermal processing and meat cut.

BACKGROUND: In this study the effects of sex, meat cut and thermal processing on the carnosine, anserine, creatine, betaine and carnitine contents of Korean native chicken (KNC) meat were determined. Forty 1-day-old chicks (20 chicks of each sex) from a commercial KNC strain (Woorimatdag™) were reared under similar standard commercial conditions with similar diets, and ten birds of each sex were randomly selected and slaughtered at 14 weeks of age. Raw and cooked meat samples were prepared from both breast and leg meats and analyzed for the aforementioned functional compounds. RESULTS: Female KNCs had significantly higher betaine and creatine contents. The breast meat showed significantly higher carnosine and anserine contents, whereas the leg meat had a higher betaine and carnitine content. The content of all functional compounds was significantly depleted by thermal processing. CONCLUSION: This study confirms that KNC meat is a good source of the above-mentioned functional compounds, which can be considered attractive nutritional quality factors. However, their concentrations were significantly affected by thermal processing conditions, meat cut and sex. Further experiments are needed to select the best thermal processing method to preserve these functional compounds.

Escin suppresses migration and invasion involving the alteration of CXCL16/CXCR6 axis in human gastric adenocarcinoma AGS cells.

Escin, a natural mixture of triterpene saponins isolated from horse chestnut, has been reported to possess anticancer activity in many human cancer cells. However, the effect of escin on the metastasis has not been studied. The present study examined the effect of escin on the migration and invasion of AGS human gastric cancer cells. To examine the effects of escin on metastatic capacities of gastric cancer cells, AGS cells were cultured in the presence of 0-4 µmol/L escin. Escin inhibited cell migration and invasion in AGS cells. However, escin did not affect the viability of these cells at these concentrations. The chemokine receptor and its ligands play an important role in cancer metastasis. Escin decreased the production of soluble C-X-C motif chemokine (CXCL)16 but increased the expression of trans-membranous CXCL16. The expression of C-X-C chemokine receptor (CXCR)6 was not affected by escin treatment. Exogenous CXCL16 reversed escin-induced migration inhibition. In addition, escin inhibited the phosphorylation of focal adhesion kinase and Akt. These results demonstrate that escin inhibited the migration and invasion of AGS cells, which is associated with altered CXCL16/CXCR6 axis. These findings suggest that escin has potential as an antimetastatic agent in gastric cancer.

Comparison of the amounts of taste-related compounds in raw and cooked meats from broilers and Korean native chickens.

This study was aimed at comparing the taste-related compound content in the breast and leg meat from 100-d-old Korean native chickens (KNC-100) and 32-d-old commercial broilers (CB-32) and determining the changes in these compounds during cooking. Cocks from certified meat-type commercial broiler (Ross) and Korean native chicken (Woorimatdag) strains were raised under similar standard commercial conditions, and a total of 10 birds from each breed were slaughtered at 32 and 100 d of age, which represents their market ages, respectively. Raw and cooked meat samples were prepared separately from the breast and leg and analyzed. The KNC-100 showed significantly higher concentrations of inosine 5'-monophosphate, reducing sugars, glutamic acid, linoleic acid, arachidonic acid, and docosahexaenoic acid than CB-32 did. Additionally, significantly higher inosine 5'-monophosphate, cysteine, arachidonic acid, and docosahexaenoic acid concentrations were observed in the breast meat, whereas the leg meat had higher concentration of glutamic acid, oleic acid, and linoleic acid (P < 0.05). Significant depletions in the concentration of all taste-related compounds occurred during the cooking process, except oleic and linoleic acids. We suggest that the higher levels of taste-related compounds present in KNC-100 meat compared with CB-32 meat may result in the unique taste of the former meat, as has been previously reported. In addition, the results of this study may provide useful information for selection and breeding programs.

Changes in endogenous bioactive compounds of Korean native chicken meat at different ages and during cooking.

This study aimed to examine the effect of bird age on the contents of endogenous bioactive compounds, including carnosine, anserine, creatine, betaine, and carnitine, in meat from a certified meat-type commercial Korean native chicken strain (KNC; Woorimatdag). Additionally, the effects of the meat type (breast or leg meat) and the state of the meat (raw or cooked) were examined. Cocks of KNC were raised under similar standard commercial conditions at a commercial chicken farm. At various ages (10, 11, 12, 13, and 14 wk), breast and leg meats from a total of 10 birds from each age group were obtained. Raw and cooked meat samples were then prepared separately and analyzed for bioactive compounds. The age of the KNC had a significant effect only on the betaine content. The breast meat of KNC had higher amounts of carnosine and anserine but had lower amounts of betaine and carnitine than the leg meat (P < 0.05). The KNC meat lost significant amounts of all bioactive compounds during cooking (P < 0.05). Leg meat had high retention percentages of carnosine and anserine after cooking, whereas breast meat showed almost complete retention of betaine and carnitine. The results of this study provide useful and rare information regarding the presence, amounts, and determinants of endogenous bioactive compounds in KNC meat, which can be useful for selection and breeding programs, and also for popularizing indigenous chicken meat.

Cow's Milk Intake and Risk of Coronary Heart Disease in Korean Postmenopausal Women.

Numerous studies have reported conflicting results associated with cow's milk intake and coronary heart disease (CHD). However, studies involving postmenopausal women are very limited. This study was therefore undertaken to identify the relationship between cow's milk intake and CHD risk in postmenopausal women, using data from the 6th period of the Korea National Health and Nutrition Examination Survey (2013−2015). A total of 1825 postmenopausal women, aged 50−64 years old, were included in the final analysis. The frequency of cow's milk consumption for each subject was determined using the semi-quantitative food frequency questionnaire, and was classified into four groups (Q1−Q4): Q1, group that did not drink milk (no milk, n = 666); Q2, 0 < frequency of milk intake per week ≤ 1 (n = 453); Q3, 1 < frequency of milk intake per week ≤ 3 (n = 319); and Q4, frequency of milk intake >3 times per week (n = 387). General characteristics, such as education, living area, household income, and obesity level, were compared between the four groups. Percentages of daily nutrient intake compared to the dietary reference intake for Koreans (KDRIs) were determined, and the Framingham Risk Score (FRS), atherogenic index (AI), and atherogenic index of plasma (AIP) were determined as the CHD risk indicators. Except household income, no significant difference was obtained among the four groups with respect to age, education, living area, or obesity. Compared to KDRIs, the intake ratio of calcium, phosphorus, and riboflavin were significantly higher in the Q4 group than in the Q1−Q3 groups. Blood HDL-cholesterol was significantly higher in Q4 than in Q1. The CHD risk factors FRS (%), AI, and AIP were significantly lower in the Q4 group as compared to the other groups (CHD risk (%): Q1 9.4, Q4 8.5; AI: Q1 3.06, Q4 2.83; API: Q1 0.37, Q2 0.31, Q4 0.32). FRS was determined to be significantly and positively correlated to AI or AIP, and negatively correlated with the cow's milk intake frequency and calcium intake. In conclusion, compared to women who do not consume cow's milk, postmenopausal women who consume cow's milk frequently have a better nutritional status of calcium, phosphorus, and vitamin B12, higher HDL levels, and a lower level of CHD risk indicators, such as FRS, AI, and AIP, contributing to decreased CHD risk in a 10-year period. Therefore, to prevent the risk of CHD in postmenopausal women, there needs to be a greater emphasis for cow's milk consumption four or more times per week.

The Combined Effects of Milk Intake and Physical Activity on Bone Mineral Density in Korean Adolescents.

The purpose of this study was to examine the combined effects of milk intake and physical activity on bone mineral density in adolescents. This study was conducted using data from the 2009-2011 Korea National Health and Nutrition Examination Survey (KNHANES), which provided measurements of bone mineral density (BMD) in addition to basic health-related data. This study included 1061 adolescents aged 13 to 18 years (557 males and 504 females) whose data on milk intake and participation time in moderate to vigorous physical activity were available. BMD was measured by dual-energy X-ray absorptiometry (DXA). Milk intake was assessed using the 24-h recall method, and the levels of physical activity were examined using a questionnaire. The physical activity questions of 2009-2011 KNHANES were based on the Korean version of the International Physical Activity Questionnaire (IPAQ) short form. The subjects were classified into four groups according to milk intake and physical activity level: no milk intake + low-level physical activity group (MnoPlow), no milk intake + high-level physical activity group (MnoPhigh), milk intake + low-level physical activity group (MyesPlow), and milk intake + high-level physical activity group (MyesPhigh). The results of partial correlation controlling for age, body mass index (BMI), and energy intake showed that the BMD variables were associated significantly with physical activity in both males and females. Among males, the MnoPlow group had the lowest BMD in all BMD variables, showing a significant difference from the high-level physical activity groups (MnoPhigh, MyesPhigh) by multiple logistic regression analysis. Among females, the MyesPhigh group showed a significantly higher lumbar BMD value than the other groups. The MnoPlow group had approximately 0.3 to 0.5 times lower odds ratio for median or higher BMD values, compared to MyesPhigh group. These results show that milk intake and physical activity have a combined effect on BMD, and suggest that to achieve healthy bone growth, it is important to encourage both moderate to vigorous physical activity and milk intake during adolescence.

Participation in the School Milk Program Contributes to Increased Milk Consumption and Dietary Nutrient Intake by Middle School Students in South Korea.

Milk is considered to be one of the main food sources of calcium for promoting growth and bone health in children and adolescents. This study investigated whether or not participation in a school milk program affected milk consumption and nutrient intake by middle school students in South Korea. In total, 692 middle school students aged 13-16 years old were enrolled in two groups: the school milk program participant group (n = 346) and the non-participant group (n = 346). The survey examined normal milk consumption status in both groups. The diet record method was applied to analyze the amount of nutrient intake levels. Milk/dairy product consumption was significantly higher in the school milk program participant group for both boys and girls (p < 0.001). The school milk program participant group also generally showed higher energy and dietary nutrient intake levels as compared to the non-participant group for both genders (p < 0.05). No differences were observed in milk consumption at home or outside school, and calcium intake from animal-derived foods was higher in the school milk program participant group (p < 0.001). Therefore, it can be assumed that participating in the school milk program directly resulted in higher calcium intake. Hence, we can report that participating in the school milk program contributes to increased milk consumption and improved the overall nutrient intake.

Dietary nutrient intake of Korean adolescent distance runners.

This study examined the dietary nutrient intake of Korean adolescent distance runners and analyzed the difference between weekdays and weekends. The participants were 40 male middle- and long-distance runners aged 13 to 18 years, 36 of whom were analyzed. The 3-day diet records including 2 weekdays and 1 weekend day, were investigated according to the food record method and analyzed using the computer-aided nutritional analysis program. A paired t-test was used to compare the energy and nutrient intakes of the weekdays and weekends, and the chi-square test was used to compare the distribution of the nutrient intake below the estimated average requirement. The results showed that the energy intake per day was quite low at 2,051.0±304.3 kcal, with a body mass index percentile of 16.8±9.8. The nutrients that showed remarkably lower levels than the dietary reference intakes for Koreans were vitamin D, vitamin C, vitamin B2, and calcium, among which calcium was the highest at 86.1% in the proportion of those who consumed less than the estimated average requirement. The intakes of vitamin C and calcium, in particular, showed a significant decrease during the weekends. Therefore, to improve the dietary nutrient intake of adolescent male runners, appropriate management of the weekend diet as well as school meals should be considered.

Relationships between milk consumption and academic performance, learning motivation and strategy, and personality in Korean adolescents.

BACKGROUND/OBJECTIVES: A healthy diet has been reported to be associated with physical development, cognition and academic performance, and personality during adolescence. This study was performed to investigate the relationships among milk consumption and academic performance, learning motivation and strategies, and personality among Korean adolescents. SUBJECTS/METHODS: The study was divided into two parts. The first part was a survey on the relationship between milk consumption and academic performance, in which intakes of milk and milk products and academic scores were examined in percentiles among 630 middle and high school students residing in small and medium-sized cities in 2009. The second part was a survey on the relationships between milk consumption and learning motivation and strategy as well as personality, in which milk consumption habits were collected and Learning Motivation and Strategy Test (L-MOST) for adolescents and Total Personality Inventory for Adolescents (TPI-A) were conducted in 262 high school students in 2011. RESULTS: In the 2009 survey, milk and milk product intakes of subjects were divided into a low intake group (LM: ≤ 60.2 g/day), medium intake group (MM: 60.3-150.9 g/day), and high intake group (HM: ≥ 151.0 g/day). Academic performance of each group was expressed as a percentile, and performance in Korean, social science, and mathematics was significantly higher in the HM group (P < 0.05). In the 2011 survey, the group with a higher frequency of everyday milk consumption showed significantly higher "learning strategy total," "testing technique," and "resources management technique" scores (P < 0.05) in all subjects. However, when subjects were divided by gender, milk intake frequency, learning strategy total, class participation technique, and testing technique showed significantly positive correlations (P < 0.05) in boys, whereas no correlation was observed in girls. Correlations between milk intake frequency and each item of the personality test were only detected in boys, and milk intake frequency showed positive correlations with "total agreeability", "organization", "responsibility", "conscientiousness", and "intellectual curiosity" (P < 0.05). CONCLUSION: Intakes of milk and milk products were correlated with academic performance (Korean, social science, and mathematics) in Korean adolescents. In male high school students, particularly, higher milk intake frequency was positively correlated with learning motivation and strategy as well as some items of the personality inventory.

Ethanol extract of Innotus obliquus (Chaga mushroom) induces G1 cell cycle arrest in HT-29 human colon cancer cells.

BACKGROUND/OBJECTIVES: Inonotus obliquus (I. obliquus, Chaga mushroom) has long been used as a folk medicine to treat cancer. In the present study, we examined whether or not ethanol extract of I. obliquus (EEIO) inhibits cell cycle progression in HT-29 human colon cancer cells, in addition to its mechanism of action. MATERIALS/METHODS: To examine the effects of Inonotus obliquus on the cell cycle progression and the molecular mechanism in colon cancer cells, HT-29 human colon cancer cells were cultured in the presence of 2.5 - 10 µg/mL of EEIO, and analyzed the cell cycle arrest by flow cytometry and the cell cycle controlling protein expression by Western blotting. RESULTS: Treatment cells with 2.5 - 10 µg/mL of EEIO reduced viable HT-29 cell numbers and DNA synthesis, increased the percentage of cells in G1 phase, decreased protein expression of CDK2, CDK4, and cyclin D1, increased expression of p21, p27, and p53, and inhibited phosphorylation of Rb and E2F1 expression. Among I. obliquus fractions, fraction 2 (fractionated by dichloromethane from EEIO) showed the same effect as EEIO treatment on cell proliferation and cell cycle-related protein levels. CONCLUSIONS: These results demonstrate that fraction 2 is the major fraction that induces G1 arrest and inhibits cell proliferation, suggesting I. obliquus could be used as a natural anti-cancer ingredient in the food and/or pharmaceutical industry.

Comparison of Bioactive Compounds and Quality Traits of Breast Meat from Korean Native Ducks and Commercial Ducks.

The aim of this research was to compare the bioactive compound content and quality traits of breast meat from male and female Korean native ducks (KND) and commercial ducks (CD, Cherry Valley). Meat from three 6-wk old birds of each sex from KND and CD were evaluated for carcass and breast weights, pH, color, cooking loss, shear force, and bioactive compound (creatine, carnosine, anserine, betaine, and L-carnitine) content. KND showed significantly higher carcass weights than CD whereas no such difference (p>0.05) was found between male and female ducks. The breed and sex had no significant effects on the breast weight, pH value, and shear force. However, KND had significantly lower cooking loss values than did CD. Creatine, anserine, and L-carnitine contents were significantly higher in KND than in CD and were predominant in female ducks compared to males. The results of this study provide rare information regarding the amounts and the determinants of several bioactive compounds in duck meat, which can be useful for selection and breeding programs, and for popularizing indigenous duck meat.

Identification and quantification of antitumor thioproline and methylthioproline in Korean traditional foods by a liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry.

A liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometric method (LC-APCI-MS/MS) has been developed for the sensitive determination of antitumor thioproline and methylthioproline from fermented foods. Thioproline and methylthioproline were derivatized in one step with ethyl chloroformate at room temperature. These compounds were identified and quantified in various traditional Korean fermented foods by LC-APCI-MS/MS. The concentration range of thioproline of each food was found for doenjang (0.011-0.032mg/kg), gochujang (0.010-0.038mg/kg), and ganjang (0.010-0.038mg/kg). Those of methylthioproline of each food was found for doenjang (0.098-0.632mg/kg), gochujang (0.015-0.112mg/kg), and ganjang (0.023-1.468mg/kg). A prolonged aging time leads to an increase in both the thioproline and methylthioproline contents, suggesting that the storage time plays a key role in the formation of thioproline and methylthioproline in Korean traditional foods. The results here suggest that thioproline and methylthioproline are related to the biological activities of traditional Korean fermented foods.

Antimicrobial Effect of Calcium Chloride Alone and Combined with Lactic Acid Injected into Chicken Breast Meat.

Chicken breast meat was injected with calcium chloride alone and in combination with lactic acid (0.01% and 0.002%, respectively). The inhibitory effects of the treatments on microbial growth were determined in the injected chicken breast meat stored at 4°C under aerobic packaging condition for 0, 3, and 7 d. Calcium chloride combined with 0.002% and 0.01% lactic acid reduced microbial counts by 0.14 and 1.08 Log CFU/g, respectively, however, calcium chloride alone was unable to inhibit microbial growth. Calcium chloride combined with 0.01% lactic acid was the most effective antimicrobial treatment and resulted in the highest initial redness value. Calcium chloride alone and combined with lactic acid suppressed changes in pH and the Hunter color values during storage. However, injection of calcium chloride and lactic acid had adverse effects on lipid oxidation and sensory characteristics. The higher TBARS values were observed in samples treated with calcium chloride and lactic acid when compared to control over the storage period. Addition of calcium chloride and lactic acid resulted in lower sensory scores for parameters tested, except odor and color, compared to control samples. Therefore, the formulation should be improved in order to overcome such defects prior to industrial application.

Effect of milk and milk products consumption on physical growth and bone mineral density in Korean adolescents.

This study was conducted to investigate the relationship among the current status of calcium intake from milk and milk products, physical growth and bone mineral density in 664 male and female middle school and high school students aged 15-17 years. In the study, the current status of calcium intake from milk and milk products was analyzed, and the height, body composition, and bone mineral density of the right heel bone (calcaneus) were measured. The daily calcium intake of milk and milk products was calculated as the 'dairy equivalent of calcium', which is the calcium content in 200 mL of white milk. The cutoffs of tertiles of the dairy equivalent of calcium were calculated and then the subjects were categorized into 3 groups according to the tertiles, Q1 group (lower intake group), Q2 group (middle intake group) and Q3 group (upper intake group). The daily calcium intake of milk and milk products in Q1, Q2 and Q3 groups was 16.2 mg, 99.7 mg, and 284.0 mg, respectively, and the ratio of milk and milk product consumption to the daily total calcium intake was 5.4%, 27.4%, and 49.7%, respectively. The ratio of total calcium intake to the daily recommended intake in study subjects was 30.5% in Q1, 42.3% in Q2, and 60.7% in Q3, with significant differences (P < 0.05). Height, body weight, BMI, and % of body fat in three tertile groups (Q1, Q2 and Q3) were not significantly different. However, the T scores for bone mineral density in female students in three tertile groups (Q1, Q2 and Q3) was significantly different (P < 0.05). The study showed that the intake of milk and milk products in adolescents, particularly in girls, can improve the bone mineral density without increasing body weight, and thus confirmed that milk intake is important in adolescence.

Chestnut extract induces apoptosis in AGS human gastric cancer cells.

In Korea, chestnut production is increasing each year, but consumption is far below production. We investigated the effect of chestnut extracts on antioxidant activity and anticancer effects. Ethanol extracts of raw chestnut (RCE) or chestnut powder (CPE) had dose-dependent superoxide scavenging activity. Viable numbers of MDA-MD-231 human breast cancer cells, DU145 human prostate cancer cells, and AGS human gastric cancer cells decreased by 18, 31, and 69%, respectively, following treatment with 200 µg/mL CPE for 24 hr. CPE at various concentrations (0-200 µg/mL) markedly decreased AGS cell viability and increased apoptotic cell death dose and time dependently. CPE increased the levels of cleaved caspase-8, -7, -3, and poly (ADP-ribose) polymerase in a dose-dependent manner but not cleaved caspase-9. CPE exerted no effects on Bcl-2 and Bax levels. The level of X-linked inhibitor of apoptosis protein decreased within a narrow range following CPE treatment. The levels of Trail, DR4, and Fas-L increased dose-dependently in CPE-treated AGS cells. These results show that CPE decreases growth and induces apoptosis in AGS gastric cancer cells and that activation of the death receptor pathway contributes to CPE-induced apoptosis in AGS cells. In conclusion, CPE had more of an effect on gastric cancer cells than breast or prostate cancer cells, suggesting that chestnuts would have a positive effect against gastric cancer.