| Honey,which is collected from flowers nectar or secretions of the living part of the plants or animals(such as aphid), processed, brewed, mixed and stored by honeybee, is a sweet substance and is a natural nutrient-rich tonic. Honey is a colloidal liquid with high water content, There are acidic components in honey which can corrode metal containers in the transport, and easily change into crystalloid after conventional storage, so there are some inconvenience in the honey transport, storage and usage.Because of its stickiness, we must transfer honey into easily spray-drying liquid with the method of adding some material. When honey spray dried, it was sent out in tiny drops within a few seconds by the atomizer,which was exposed to the hot air with greatly increasing surface area, then it was spray-dried into honey powder with its water rapidly evaporating. As a result,honey weight is reduced and nutritional content is maintained. This paper mainly studied the process and formula of honey powder, the results are as follows:1. The optimal formula of honey powder was studied. Based on the single factor test, regarding moisture content,yield and solubility as indexes,it was selected the L9(34)orthogonal table to go on the experiment with four factors of ratios of malto dextrin and soluble starch, honey content,β-cyclodextrin content and gelatin content , and three levels. Firstly,the results of orthogonal test on water content did't show that the effects of four factors on water content were significant, and thus the selection of the optimal formula neglected this index. Finally, it was showed the optimum formula of honey powder spray is A2B1C3D2 regarding yield and solubility as indexes.So the optimum formula were ratios of malto dextrin and soluble starch of 3:2, honey content of 55%,β-cyclodextrin content of 6% and gelatin content of 0.5%.2. Based on optimal formula, process of spray drying was selected with a dual quadratic rotary combinative design using moisture content,yield and solubility as indexes.It was not showed that the quadratic regression models in moisture content and yield fitted to practice, so we neglected this two indexes. Finally, the math regression models of Y of sense and the inlet air temperature X1, the flow rate X2, air flow X3, a dual quadratic was obtained, which was Y=9.1043+0.0949X1-0.1232X2-0.1917X3-0.5538X12-0.2533X22+0.1250X1X2 +0.0500X1X3-0.0750X2X3. When the sensory evaluating score reached its maximum, the optimal combination of the inlet air temperature, the flow rate and air flow were 180℃, 50% and 650 L﹒h-1 respectively. Then we measured HMF from honey powered. We found that the content of HMF was changed relatively to the pre-spray honey, but the content did't exceed the national standards.3. Based on optimization formula and spray drying process, we selected longan honey, Chinese date honey, sweet scented osmanthus honey and hyakuhana honey to spray dry. The result showed that although the every index in the point of sense, water content, solubility , yield, and HMF concentration of four honey powder were different, their differences were not significant.
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