The Effects Of Honey Processing On The Content Of Phenolic Compounds And Antioxidant Activity

Honey is the nature sweet substance produced by honey bees from nectar of blossoms or from secretions of living parts of plants or secretions of plant sucking insects on the living parts of plants, which honey bees collect, transform and combine with specific substances of their own, store and leave in the honey comb to ripen and mature. The effects of different steps in honey production on phenolic compounds and antioxidant activity are investigated. The content of this article consisted of five chapters, and the author's work are in the following four aspects.1. The effects of various unit operations on the content of phenolic compounds, antioxidant activity and HMF content are investigated. The results showed phenolic compounds in honey are lost after each stage including preheating, filtration, heating and vacuum concentration. Among these four stages, preheating step had the significant effects on the content of phenolic compounds. The loss rates of gallic acid, caffeic acid and ferulaic acid in honey are about 52.2%,48.9% and 33.4%, respectively.2. The effects of different temperature and time on the content of phenolic compounds, antioxidant activity and the content of HMF have been investigated. The results showed that the content of phenolic compounds decreased, however, antioxidant activity and the content of HMF increased with increase of temperature and time. The effect of temperature and time on the content of phenolic compounds has been evaluated by orthogonal experiment. The results showed time is the main factor and temperature is the secondary factor.3. The effects of microwave processing on honey sterilization is compared with aqueous bath processing to get optimize product condition. In this experiment, honey should be treated 15 second at the microwave power 20 w/g. The honey temperature is about 56℃. The sterilization effectiveness is similar to aqueous bath and HMF content is almost only half of the aqueous bath. Microwave processing can retain most of the phenolic compounds in honey and the antioxidant activity after microwave heating is similar to raw honey. 4. Honeys samples can be evaluated for phenolic acids contents by high performance liquid chromatography using electrochemical detection (HPLC-ECD), to provide the scientific quality assessment. The phenolic acids components in Acacia honey from different areas are similar, but the phenolic acid content is differences.