Effect Of Temperature, Time Storage On Physico-Chemical, Bioactive Properties Of Honeys From Different Localities In Vietnam

Abstract

This study aimed to investigate the influence of and storage conditions on the content of moisture, pH, HMF, total phenolic, the flavonoid in the U Minh forest, Longan, Coffee honey stored at 4°C, room temperature(27°C), 45°C for 80 days. Samples were stored in transparent glass containers, on shelves exposed to natural light during the daytime and in the dark during night time. The effect of storage conditions and localities were investigated. The quality obtained by U Minh forest honey (19.76% moisture content; pH 4.00; 6.98mg/kg HMF; 108.75mgGAE/100g total phenolic content; 39.48mg RE/100g total flavonoid content) resulted in significantly higher (p<0.05) than Longan honey and Coffee honey. According to the obtained data, the lowest rate of decrease in the content of total flavonoids and phenolics and changes in moisture content, pH, 5-hydroxymethyl-2-furfural in honey samples were obtained at 27°C: the moisture content in honey was reduced at 4°C which was beneficial for export, but it reduced the quality and nutrients more than at 27°C: Moisture content of U Minh forest honey increased 8.05% with 2.2% 5-hydroxymethyl-2-furfural and decreased 32.2% total phenol content and 39.48% total flavonoid content compared with an increase of 1.67% moisture content, 1.7% 5-hydroxymethyl-2-furfural, 21.8% of total phenol content and 25% of total flavonoid content at 27°C. Besides, the honey becomes more acidic at high temperatures. Storage time is the main reason for determining the cleanliness and quality of honey through the amount of HMF. Average monthly HMF growth in U Minh forest honey (17.8%) at 27 ° C which requires less than 2 years of storage to not exceed allowable level (HMF< 40mg / kg honey, Codex Alimentarius, 2001). The results were used to determine the influence of honey type, storage temperature, and storage time on different physicochemical and bioactive in honey samples.