• Food Science and Biotechnology
• /
• v.14 no.6
• /
• pp.743-746
• /
• 2005

A dipstick-type immunochemical biosensor for the detection of the organophosphorus insecticide fenthion was developed using a screen-printed electrode system as an amperometric transducer with polyclonal antibodies against fenthion as a bioreceptor. The assay of the biosensor involved competition between the pesticide in the sample and pesticide-glucose oxidase conjugate for binding to the antibody immobilized on the membrane. This was followed by measurement of the activity of the bound enzyme by the supply of the enzyme substrate (glucose) and amperometric determination of the enzyme reaction product ($H_2O_2$). The activity of the bound enzyme was inversely proportional to the concentration of pesticide. The optimized sensor system showed a linear response against the logarithm of the pesticide concentration ranging from $10^{-2}$ to $10^3\;{\mu}g/L$.

• Journal of the East Asian Society of Dietary Life
• /
• v.15 no.3
• /
• pp.315-322
• /
• 2005

In this study we report on the estrogen activity of silkworm pupa and herb extracts in vitro. The estrogenic activity of these resources was investigated by competition binding assays with estrogen receptor $\alpha(ER{\alpha})\;or\;ER{\beta}$, and viability of MCF-7 cells, a human breast cancer cell line. Saturation ligand-binding analysis of $ER{\alpha}\;and\;ER{\beta}$ revealed that all plant extracts competed with estrogen ligand for binding to both ER subtypes with a similar preference and degree and competed stronger with ligand for binding to $ER{\beta}\;than\;to\;ER{\alpha}$. The highest $ER{\alpha}-binding$ sample was silkworm pupa aqueous extract The highest $ER{\beta}-binding$ sample was silkworm pupa oil. These samples were further tested for bioactivity based on their ability to regulate cell growth rate in ER(+) breast cancer cell line, MCF-7 cells. Our studies showed that silkworm pupa, soritae, sesame, yam, pueraria, malt, ginseng, Polygonum multiflorum, and Curcuma longa significantly stimulated the growth of MCF-7 cells (P<0.05). In summary, these results suggested that silkworm pupa and herbs might be useful as potential phytoestrogens.

• The Korean Journal of Food And Nutrition
• /
• v.29 no.5
• /
• pp.643-654
• /
• 2016

The purpose of this study was to investigate the purchasing behavior and selection attributes for Home Meal Replacement (HMR) and to identify the selection attributes affecting purchasing frequency and purchasing costs of married women living in a city. Among 837 questionnaires distributed to HMR married women consumers, 752 complete questionnaires (89.8%) were analyzed. The younger married women group showed higher frequency of purchasing HMR than the older age group. The 20s and 30s age groups showed higher purchasing costs for HMR than the 40s and older age groups. A higher proportion of employed married women purchased HMR three or more times per week and spent an average of more than 20,000 won per purchase in comparison with unemployed married women. HMR selection attributes were classified into five factors: 'taste and sanitation', 'economic efficiency', 'health and nutrition', 'convenience', and 'reliability and awareness'; mean scores of these factors' importance levels were 4.28, 3.93, 3.59, 3.54, and 3.50 out of 5 points, respectively. The importance level of 'taste and sanitation' factor was significantly greater as married women's age decreased. However, the importance level of 'health and nutrition' factor was significantly greater as married women's age increased. The results of the logistic regression analyses indicate that the 'taste and sanitation' and 'health and nutrition' factors affected frequency of purchasing HMR. The 'reliability and awareness' factor had the most significant impact on cost per purchasing HMR. Therefore, a product differentiation strategy according to married women's age and employment status should be applied. Product qualities and brand value should be improved to enhance competition in the HMR market.

• Nutrition Research and Practice
• /
• v.14 no.1
• /
• pp.45-54
• /
• 2020

BACKGROUND/OBJECTIVES: This study aimed to examine differences in weight control practices, beliefs, self-efficacy, and eating behaviors of weight class athletes according to weight control level. SUBJECTS/METHODS: Subjects were weight class athletes from colleges in Gyeong-gi Province. Subjects (n = 182) responded to a questionnaire assessing study variables by self-report, and data on 151 athletes were used for statistical analysis. Subjects were categorized into High vs. Normal Weight Loss (HWL, NWL) groups depending on weight control level. Data were analyzed using t-test, ANCOVA, x²-test, and multiple logistic regressions. RESULTS: Seventy-three percent of subjects were in the HWL group. The two groups showed significant differences in weight control practices such as frequency (P < 0.01), duration and magnitude of weight loss, methods, and satisfaction with weight control (P < 0.001). Multiple logistic regression showed that self-efficacy (OR: 0.846, 95% CI: 0.730, 0.980), eating behaviors during training period (OR: 1.285, 95% CI: 1.112, 1.485), and eating behaviors during the weight control period (OR: 0.731, 95% CI: 0.620, 0.863) were associated with weight control level. Compared to NWL athletes, HWL athletes agreed more strongly on the disadvantages of rapid weight loss (P < 0.05 - P < 0.01), perceived less confidence in controlling overeating after matches (P < 0.001), and making weight within their weight class (P < 0.05). HWL athletes showed more inappropriate eating behaviors than NWL athletes, especially during the weight control period (P < 0.05 - P < 0.001). CONCLUSIONS: Self-efficacy was lower and eating behaviors during pre-competition period were more inadequate in HWL athletes. Education programs should include strategies to help athletes apply appropriate methods for weight control, increase self-efficacy, and adopt desirable eating behaviors.

• Journal of Nutrition and Health
• /
• v.37 no.10
• /
• pp.881-887
• /
• 2004

Elevated plasma homocysteine is an independent risk factor for the development of cardiovascular disease. Exercise is generally believed to reduce the plasma homocysteine levels and therefore, being beneficial for cardiovascular disease (CVD). However, there is a possibility that athletes undergoing strenuous training and competition which increase oxidative stress may suffer from increased plasma homocysteine levels. The purpose of this study was to investigate the influence of endurance training on the plasma concentrations of B vitamins and homocysteine in 23 male adolescent field hockey players. Data collection and blood sampling was performed during the training period and non-training period. Following the training period, significant changes in energy and vitamin B6 intakes were observed in these subjects. Plasma vitamin B2, pyridoxal phosphate (PLP) and homocysteine levels were significantly higher during the training period than non-training period, whereas no difference was observed in plasma folate and vitamin B12 levels. Positive correlation was observed between plasma folate and folic acid intakes. When energy, B vitamin intakes were adjusted there was a significant negative correlation between plasma homocysteine levels and plasma riboflavin, folate and vitamin B12 levels. In conclusion, it is suggested that athletes with oxidative stress by strenuous exercise may need B vitamins since riboflavin, folic acid and vitamin Bl2 were shown to be negatively correlated with plasma homocysteine in athletes during the training period.

• Journal of Nutrition and Health
• /
• v.36 no.7
• /
• pp.729-735
• /
• 2003

This study was performed to evaluate the effect of iron supplement for 4 weeks on iron status, immunity, and antioxidant status of national female soccer players (n = 25). This study was performed at summer hard training period right before competition. A single blind design was used to divide the subjects into iron-supplement (IS) or placebo group (P). Iron-supplement group was supplemented with iron (40 mg/d) for 4 weeks. The mean age of the subjects was 23.3 $\pm$ 2.5 years old. Mean height and body weight of the subjects were 164.4 $\pm$ 5.7 em and 57.4 $\pm$ 4.6 kg, respectively. The mean carrier as soccer player was 11.0 $\pm$ 2.6 years and mean training time was 7.0 $\pm$ 1.3 hr/day. The mean hemoglobin, hematocrit, total iron binding capacity and ferritin concentrations before iron supplementation were not different between two groups. After 4 weeks of summer training and iron supplementation, serum ferritin level was significantly increased only in IS group after supplementation. Mean corpuscular volume and total iron binding capacity were significantly decreased in both groups. Meanwhile, hemoglobin and red blood cell count were significantly lowered only in placebo group. The IgM concentration increased significantly in both groups, but IgG concentration had increasing tendency only in IS group (p < 0.064). Therefore, iron supplementation during hard training period may be helpful to improve work capacity of the athletes by improving ferritin status and humoral immune responses.

• Journal of Distribution Science
• /
• v.20 no.3
• /
• pp.83-93
• /
• 2022

Purpose: This study aims to investigate the relationship between ESG activities (Environment, Social, Governance) of coffee shops and their brand image, purchase intention. Research design, data and methodology: To test the hypothesis, a survey was conducted for about one month from May to June, 2021, and a total of 311 people responded to the survey, and the responses from 311 copies were used for the analysis. Validity and reliability analysis were performed, and the relationship between latent variables was empirically analyzed using the structural equation modelling. Results: The results of the study are as follows. First, among the ESG activities of coffee shops, the environmental and social sectors had a significant positive (+) effect on the brand image, but the governance aspect showed no significant effect on the brand image. Second, it was found that the symbolic image and the empirical image had a significant positive (+) effect on the purchase intention, but the functional image did not have a significant effect on the purchase intention. Conclusions: The results of this study suggest that as the number of coffee shops and the heated competition are increasing, it is possible to build a differentiated brand image through ESG activities rather than relying on the functions and services of competing products.

• Preventive Nutrition and Food Science
• /
• v.1 no.2
• /
• pp.262-268
• /
• 1996

In Korea, the health authorities and food industry emphasize the need of sanitary food production, which in mainly resulted from the recent growing of consumer's interest in the safety of food. For the reason, development of a new alternative technology to chemicals, currently used for decontamination and disinfestation, has become and urgent task in the domestic and worldwide food industry. Furthermore, the improvement of quality and manufacturing process of processed food is a requisite for winning the competition in export fields. Irradiation technology being practically applicable in the food industry has been well established on the basis of more than 40 years of R&D work in the fields of the increasing availability of food-stuffs, sanitary food production and quarantine treatment in the food trade. The wholesomeness of irradiation foods has been officially approved in 38 countries, of which 30 countries are commercially utilizing food irradiation technology. The first commercial irradiator in Korea(18.5PBq:500k{TEX}$Ci^{60}${/TEX} Co, max. cap; 4MCi) was established at Yeoju-gur, Kyung Ki-do with the technical assistance of Korea Atomic Energy Research Institute in June 1987. As of 1996, thirteen irradiated food groups (over 25 items)have been domestically approved for human consumption and an industrial irradiation facility is also available. However, the domestically approved for human consumption and an industrial irradiation facility is also available. However, the promotion of consumer acceptance to toward ir-radiated foods is considered as a confronted subject to be studied for a commercial utilization.

• Asian-Australasian Journal of Animal Sciences
• /
• v.31 no.1
• /
• pp.47-53
• /
• 2018

Objective: The objective of this experiment was to investigate the effects of heat stress on milk protein and blood amino acid profile in dairy cows. Methods: Twelve dairy cows with the similar parity, days in milk and milk yield were randomly divided into two groups with six cows raised in summer and others in autumn, respectively. Constant managerial conditions and diets were maintained during the experiment. Measurements and samples for heat stress and no heat stress were obtained according to the physical alterations of the temperature-humidity index. Results: Results showed that heat stress significantly reduced the milk protein content (p<0.05). Heat stress tended to decrease milk yield (p = 0.09). Furthermore, heat stress decreased dry matter intake, the concentration of blood glucose and insulin, and glutathione peroxidase activity, while increased levels of non-esterified fatty acid and malondialdehyde (p<0.05). Additionally, the concentrations of blood Thr involved in immune response were increased under heat stress (p<0.05). The concentration of blood Ala, Glu, Asp, and Gly, associated with gluconeogenesis, were also increased under heat stress (p<0.05). However, the concentration of blood Lys that promotes milk protein synthesis was decreased under heat stress (p<0.05). Conclusion: In conclusion, this study revealed that more amino acids were required for maintenance but not for milk protein synthesis under heat stress, and the decreased availability of amino acids for milk protein synthesis may be attributed to competition of immune response and gluconeogenesis.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.13 no.1
• /
• pp.117-126
• /
• 1984

Aflatoxins are toxic and carcinogenic secondary metabolites which are produced by trains of A. flavus and A. parasiticus during their growth on foods and feedstuffs. Aflatoxins are a group of closely related heterocyclic compounds of which $B_1$, $B_2$, and $G_2$ are the major members. Aflatoxins are synthesized via a polyketide pathway in which the general steps are acetate, an-thraquinones, xanthone and aflatoxins. Aflatoxin formation is favored by high moisture or high $a_w$(0.95${\sim}$0.99). The limiting $a_w$ for aflatoxin production on agricultural commodities is 0.83. Optimum temperature for aflatoxin production by the molds is $25{\sim}30^{\circ}C$ and the incubation time for the maximum production of the toxin is 7${\sim}$15 days. The limiting temperatures for aflatoxin production are ${\leq}7.5^{\circ}C\;and\;\geq40^{\circ}C$. Cycling temperatures may or may not stimulate aflatoxin production depending on the amplitude of cycling, substrate and strains of molds. Aflatoxin pro-ducing molds are aerobic organisms and thus have a requirement for oxygen. A decreasing $O_2$ concentration and/or increasing concentrations of $CO_2$ or $N_2$ depress the mold growth and aflatoxin formation. A. flavus grows competitively or associatively in the presence of other microorganisms and occasionally loses the competition with other microorganisms. Some lactic acid bacteria have been shown to reduce growth and aflatoxin production by A. parasiticus. Carbon source is the most important nutritional factors affecting aflatoxin formation by the molds. Sucrose, fructose and glucose are the most favorable carbon sources. Food substrates of plant derived products which have high carbohydrate content such as agricultural commodities and their products are most vulnerable to contamination by aflatoxins.