Development And Application Of Rapid Detection Techniques For Some Quality Indicators In Honey

Honey is not only a natural health food but also has many unique physiological and pharmacological functions. People are paying more and more attentions to the quality of honey along with the improvements of living standards. In recent years, poor quality or adulterated honey are found frequently in the market, causing the damage to consumer’ interests and the reduction of competitiveness of honey products in the international market. Large precision instruments such as mass spectrometry and chromatography are accurate and reliable. However, they are time-consuming, expensive and complicated. Therefore, on-site rapid techniques for the detection of quality indicators of honey are quite desired. The aim of this study is to develop rapid detection techniques based on a combination of reagent kits and colorimetric cards for the determination of amylase value, hydroxymethylfurfural (HMF) and proline in honey. The results are as follows.1. Optimal chromogenic system for the determination of the amylase levels in honey was studied. Starch solution with a concentration of 0.04%,6.6mL volume of terminated liquid and 2.5mL iodine application solution were chosen. The hydrolysis temperature was set at 25℃ or 40℃. The reagent kit and colorimetric cards were developed based on above system. The results obtained by this method are well agreed with that of the national standard method. The relative standard deviation (RSD) of the method was between 1% and 4%. The reagent kit can be stored for more than 5 months. The detecting range of colorimetric cards was 0-24 mL/(g-h). The whole detection process was no more than twenty minutes. These results indicated that this method was simple, rapid and accurate, and suitable for the semi-quantitative detection of amylase value in honey.2. Optimal chromogenic system for the determination of the content of HMF in honey was selected. The maximum absorption wavelength was 550nm. The best concentrations for paratoluidine and barbituric acid were 0.15g/mL and 5 mg/mL, respectively. The two solutions were mixed at a ratio of 5:1 before added into the system. The temperature and time for color reaction were 25℃ and 5 min, respectively. The results obtained by this method are well agreed with that of the national standard method with a good precision. The detecting range of colorimetric card was 0-60 mg/kg with a detection time no more ten minutes. The kit can be stored for about 15 days. The total volume of agent was 4mL. It showed that the method was high in accuracy, good in precise and low in cost, and suitable for the rapid semi-quantitative detection of HMF in honey.3. The chromogenic system for the determination of proline in honey was optimized. The maximum absorption wavelength was 510nm. The concentration of ninhydrin solution used was 2%, which was prepared by a mixture of formic acid and ethylene glycol monomethyl ether at a ratio of 1:1. The stability of the chromogenic system was successively improved by replacing isopropyl alcohol with acetone solution. The reaction took place in the boiling water for 15 min. The reagent kit and colorimetric card were developed based on above system. The method had a high accuracy and good precise when used to detect the proline in honey. The detecting range of colorimetric cards was 0-50 mg/100g. The whole detection process was less than twenty minutes. The kit can be stored for more than one month. The above results indicated that the method developed was simple, rapid, constant, and suitable for the semi-quantitative detection of proline in honey.