The Effect Of Two Sterilization Methods On The Quality Of Honey

Honey,as a natural and traditional food,is rich in nutrients.It can be eaten and be used in medicine,such as anti-inflammatory and wound healing.It is also widely used in the manufacture of cosmetics.Because of the low pH and less water content of honey,only yeast and mould can grow in it.The presence of yeast can make honey produce a large number of white foam affect its quality,even make it corrupt and deteriorate.The sterilization of yeast in honey by ultra high pressure and irradiation technology was studied in this paper.The best condition of ultra high pressure and irradiation sterilization was obtained by using the bactericidal rate as the index,and the effect on the quality of honey under this condition was determined.The results are as follows:The number of yeasts in honey before and after treatment was determined.The best sterilization condition was 550 MPa/15 min with the sterilization rate as the index.Under these conditions,there were significant differences in indexes of Schefflera octophylla honey,including free acid and color(Pfund,B yellow).The free acids before and after ultra high pressure treatment were 8.67±0.44,21.30±0.33,and the Pfund values were 14±0.58 and 52±2.08 respectively,and the Yellow values of B were 16.28±0.89 and 8.72±0.31,respectively.These results showed that the acidity of Schefflera octophylla honey after the 550 MPa/15 min ultra-high pressure was increased and the color was deepened.550 MPa/15 min showed remarkable difference in the lactones and Pfund of buckwheat honey after ultra high pressure treatment.Among them,the lactone acid values were 8.33±0.17 and 10.67±0.33 respectively before and after UHP treatment,and the Pfund values were 108±3.06 and 139.33±10.67,respectively,which showed that the acidity of buckwheat after 550 MPa/15 min ultra high pressure treatment increased and the color deepened.After 550 MPa/15 min,the activity of lactones and amylase in fennel honey showed significant difference.Among them,the lactone acid values were 8.33±0.17 and 10.67±0.33,respectively,and the activity of amylase was 54.16±1.07 and 62.81±0.25,respectively,indicating that the acidity of fennel honey after the treatment of 550 MPa/15 min was increased and the activity of amylase of honey was improved.The acidity increased after three kinds of honey was treated with 550 MPa/15 min with the highest bactericidal rate.The color of eight honey and buckwheat honey was deepened after ultra high pressure treatment,However,the color of fennel honey did not change significantly after ultra-high pressure treatment.The other indexes of three kinds of honey after ultra high pressure treatment:ash,moisture,pH,electrical conductivity,sugar content,hydroxymethyl furfural,and so on,have not changed significantly.In a word,the honey after high pressure treatment,although the acidity increases,does not change the quality of the honey,in which the color vary between different kinds of honey.The number of yeasts in honey before and after irradiation was determined.The best sterilization condition was 6 KGy.Under this condition,the lactone of sunflower honey decreased significantly.The lactone values before and after irradiation were 18.67±0.33,9.83±0.17 respectively.After irradiation of Vitex honey pH,Pfund,moisture,HMF were significantly decreased.Acacia honey in irradiated after the Pfund values increased,indicating that the honey color deepened.From different nectar honey after irradiation,some physicochemical index will change remarkably.But the electrical conductivity,fructose,glucose and maltose content of the three kinds of honey did not change significantly after irradiation.