Research On The Heat Hump Technique Parameter Optimized Of Snap Bean

The dehydrated vegetable was a deep machining product, which was got after washing and drying processing for the fresh vegetables to decrease the humidity, but the original color and nutritional components remained unchanged basically. It was not only easy to store and transport, but also to effectively regulate the vegetable season production. So, it was popular with consumers. But if the vegetable processing was improper or the technical do not up to grade, the result was not only to affect the quality of products and nutrients, and but also to lead to the fresh vegetables losing the original color also. In recent years, there were a lot of researches for drying vegetables by vacuum and freeze-drying technology. But drying vegetables by heat pump was seldom reported. Therefore, the snap bean of Heilongjiang as the raw material, the properties of heat pump drying was studied in this paper. The main beans nutrient composition and sensory quality were comprehensive assessed. The purpose of this paper was to optimize the snap beans drying technology process by heat.By the methods of the combination of theoretical analysis and experimental study, the influence of drying characteristics and drying conditions on the nutrient composition and sensory quality and the heat pump technology were studied, and the relevant conclusions were gained in this paper. The main results and contents were as following:1 The effect of blanching conditions for the green-bean was studied. Blanching not only could inactivate enzymes of chlorophyll, but also reduced the amount of microbes. The types and amount of green-agent, blanching time and temperature for maintaining effect of snap bean and the quality control process were studied in the paper. And the optimal color technology was got. The results showed that the suitable conditions was under solution 100 mg/Kg Na₂SO₃ and 100 mg/Kg CuSO₄ soak for 30 minutes and blanching at 60℃for 120 minutes.2 The heat pump drying snap bean single factor and the snap bean heat pump drying characteristics were studied. The parameters the heat pump drying temperature, drying time and the width of the wire snap bean were determined. Form the experimental studied by the dry heat pump, heat pump drying in different temperature, drying time and wire width of beans, the characteristics of snap bean in heat pump were got. The results showed that the snap bean after the initial drying stage, under the conditions of three different drying temperature, drying rate increased from zero to the maximum value, all to a constant speed drying stage. This paper maked the drying temperature of 32℃as the best choice for different wire width of the snap bean. The tests indicated that when the width of snap bean was 8mm, the heat pump drying would have best results. Also at the heat pump drying temperature of 32℃, width of the wires snap bean of 8mm , the dehydration test analysis of different water temperature (30℃, 60℃, 90℃) were and water performance curves done. The best method for softening the water temperature at 60℃, dehydrating time of 120 minutes was determined.3 On the basis of heat pump drying single-factor tests of snap bean, according to the protein content snap bean, Vitamin C content, rehydration and sensory quality after drying for evaluation. The multivariate analysis for a heat pump drying technology of Snap beans was completed. This study used three factors and five levels two orthogonal rotation mix design , a total of 23 group tests. The analysis was done by Reda software for the protein content and Vitamin C content rehydration and sensory evaluation, and through frequency analysis the range of factors to determine the better was decided. And on the basis of mathematical models between evaluation and factors, using Fuzzy Mathematics Integrated weighted scoring method to construct a comprehensive assessment equation R concerning the protein content and Vitamin C, rehydration and sensory quality, and the optimal use of the frequency factor analysis parameters were determined. Snap beans heat pump drying process so as to achieves the optimal solution.