Myoglobin (Mb) was isolated from the dark muscle of the milkfish (Chanos chanos) by Sephadex G‐75 gel filtration chromatography. The molecular weight of milkfish Mb is 15, 900 Da. The tristimulus color values (L, a and b) of Mb solutions changed significantly depending upon the form of Mb. With the formation of metmyoglobin (metMb), the L value increased gradually with the increase in the percentage of metMb, while a values decreased and Mb aggregation gradually increased along with incubation time. The autoxidation of milkfish Mb proceeded as a first‐order reaction, and the autoxidation rate constant increased with decreasing pH in a range of 5.5–7.0. The free energy for unfolding (Δ GD) of Mb at acidic pH was smaller than at neutral pH, with values of 5.8 kcal/mol at pH 6.63 and 6.0 kcal/mol at pH 7.05. A higher rate of autoxidation and lower values of free energy were observed at acidic pH than at neutral pH.

SummaryIn recent years, the prevalence and problem of overweight and obesity in Taiwanese children have increased. There are many reports that the excessive intake of sugar increases the risk of lifestyle-related disease. However, sugar intake in Taiwanese children is not known. In this study, we investigated sugar intake from sugar-sweetened beverages, snacks and desserts among school-age children in Kaohsiung, Taiwan. We also tried to determine the relationship between sugar intake and body mass index (BMI). We contacted all the public elementary schools (10 schools) in a district, Kaohsiung, and obtained permission from 3 schools. The survey subjects were 410 (210 boys, 200 girls) school-age children (7, 10 and 12 y old). A nutrition survey was conducted using 3 non-consecutive days of the 24 h dietary recall method for sugar-sweetened beverages, snacks and desserts. Height and weight were measured. Sugar intakes were not significantly different among the different genders or ages (p.0.05) and average intake of all was 51.6 g/d. Percentages of each sugar in total intake were sucrose 60%, glucose 18%, fructose 16%, and lactose 6%. The intake of glucose and fructose may have come from isomerized sugar. Contributions of sugar-sweetened beverages and snacks (desserts) were 83.5% and 16.5%, respectively. Among the sugar-sweetened beverages the top 3 sources were tea (22%), milk tea (19%) and milk beverages (18%). A relationship between sugar intake and BMI was not observed. In conclusion, sugar intake of the children was higher than the WHO recommendation due to the high intake from beverages; however, sugar was not the cause of the high obesity rate.