Effect of α-tocopherol on the oxidative stability of horse oil-in-water emulsion during storage.

Horse oil-in-water (O/W) emulsions were prepared and α-tocopherol was added at 0, 100, 200, and 500 ppm (α-T0, α-T100, α-T200, α-T500) to enhance its oxidative stability. Mean particle diameters of the O/W emulsions were 243-299 nm. Zeta potential values increased with the addition of α-tocopherol; however, they decreased during storage at 40 °C for 30 days. Particle size distribution of the O/W emulsion with α-tocopherol remained the same as that of α-T0. For lipid oxidation, the peroxide values of α-T0 and α-T500 were greatly increased from 2.96 and 2.89 to 13.76 and 12.46 mmol/kg oil, respectively, after 30 days. The α-T100 and α-T200 maintained lower peroxide values than other emulsions. Thiobarbituric acid-reactive substance values of α-T0 and α-T500 were higher than those of α-T100 and α-T200. These results indicate that the addition of α-tocopherol from 100 to 200 ppm to the horse oil-in-water emulsion effectively improves its oxidative stability during storage.

Effect of different cooking method on vitamin E and K content and true retention of legumes and vegetables commonly consumed in Korea.

This study investigated the effect of cooking method on the content and true retention of vitamin E and K in legumes and vegetables, which are commonly consumed in Korea. Among eight isomers of vitamin E, α- and γ-tocopherol were detected at 0.44-1.03 and 2.05-2.11 mg/100 g, respectively, in legumes including chick pea, kidney bean, lentil, pea, and sword bean and they were decreased after boiling. Phylloquinone (vitamin K1) was present at a range of 31.33 to 91.34 µg/100 g in legumes and true retention was reduced after boiling. In 21 kinds of vegetables, α-tocopherol and phylloquinone were present at 0.14-1.85 mg/100 g and 34.55-510.83 µg/100 g, respectively. α-Tocopherol and phylloquinone increased in most vegetables after cooking via blanching, boiling, steaming, and grilling. This study revealed that cooking changed vitamin E and K contents of legumes and vegetables and the changes were dependent on the type of food and cooking method. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-022-01206-9.

Factors related to heart rate variability among firefighters.

OBJECTIVES: The aim of this study was to investigate factors associated with heart rate variability in firefighters working in a metropolitan city in South Korea. METHODS: Self-administered questionnaires including Korean Occupational Stress Scale (KOSS) as well as surveys collecting socio-demographic characteristics and work-related factors were given to 962 firefighters. After exclusion for missing data, 645 firefighters were included, and analysis of covaiance adjusted for the general risk factors and job characteristics were used to assess the relationship between heart rate variability and associated factors. RESULTS: SDNN and RMSSD and were decreased in the area of occupational climate of the group with high job stress (p = 0.027, p = 0.036). HF(ln) was decreased in the area of organizational system and occupational climate of the group with high stress that statistically significant level (p = 0.034, p = 0.043). CONCLUSIONS: Occupational climate and organizational system are associated with reduction of heart rate variability. Preventive medical care plans for cardiovascular disease of firefighters through the analysis and evaluation of job stress factors are needed.

Pulmonary function decline in firefighters and non-firefighters in South Korea.

OBJECTIVES: The purpose of this study was to evaluate and compare changes to pulmonary function among firefighters and non-firefighters who were exposed to harmful substances in their work environments. METHODS: Firefighters (n = 322) and non-firefighters (n = 107) in Daegu who received a pulmonary function test in 2008 and 2011 as well as a regular health examination were included. Repeated measures ANOVA was performed to evaluate the pulmonary function of the two groups over the three-year period. RESULTS: After adjusting for age, height, body mass index, duration of exposure, physical activity, and smoking, which were statistically different between the two groups and known risk factors of pulmonary function, the forced expiratory volume in one s FEV1, forced vital capacity FVC, and FEV1/FVC% over the 3 year period were significantly lower among firefighters compared with non-firefighters. CONCLUSIONS: Evaluating the working environment of firefighters is difficult; however, our study revealed that pulmonary function declined in firefighters. Thus, more effort should be made to prevent and manage respiratory diseases early by preforming strict and consistent pulmonary function tests in firefighters.