Experimental Study On Quality Characteristics Of Dry Zea Mays L.under Multi-parameter Control

In recent years,domestic and foreign demand for Zea mays L.has been increasing.At the same time,the country has promoted the reform of corn collection and storage system.The country has promoted the rapid development of corn planting industry.In 2017,the country planted 532 million hectares of corn with a total output of 215,89.1tons.Drying of maize before storage and transportation is an indispensable step.Through thin layer drying laboratory,the drying characteristics and quality of maize can be studied.This laboratory provides a theoretical basis for fine drying operations.In this thesis,stability and systematicness of the thin layer drying test system improves the basis of precision.The experimental determination of growth characteristics(germination rate),nutritional characteristics(unsaturated fatty acid content)and digestive characteristics(in vitro digestibility rate of starch)of maize grains after drying and the establishment of mathematical model were carried out.In this thesis,a more comprehensive test scheme is designed and a more detailed mathematical model of quality characteristics is established.The main innovative contents are as follows:1.The parameters under the condition of thin layer drying,the growth characteristics of corn were determined: based on tetrazolium staining method,five yuan quadratic orthogonal rotating combination design test,the thin layer drying after the determination of the corn grain germination rate,determine the hot air temperature,air humidity,wind speed,initial moisture content and the influence of process parameters on the germination rate order,dry maize germination rate forecast mathematical model is set up.The optimum conditions were obtained as follows: hot-air temperature 38.7 ?,hot-air rheumatism 46.3%,initial moisture content 26.05%,wind speed 0.69m/s,and tempering time ratio 1.34:1.2.Determine the nutritional characteristics of corn grains with thin layer drying under multi-parameter conditions: the dried corn was crushed and extracted by microwave extraction,and the content of unsaturated fatty acids was detected by gas chromatography after methylation.The optimum drying conditions of maize were determined with unsaturated fatty acid content as the system response index.The mathematic model of unsaturated fatty acid prediction was established based on the technological parameters such as hot air temperature,hot air humidity,initial moisture content and wind speed.The optimum conditions were obtained as follows: hot-air temperature 51.3?,hot-air rheumatism 39.4%,initial moisture content 23.52%,wind speed 0.80m/s,and tempering time ratio 1.74:1.3.Measured the digestibility of the thin dry corn grains under multi-parameter conditions: crushed and cooked the dry corn,simulated the digestive process of mouth,stomach and intestines,determined the reducing sugar concentration,and characterized the digestibility rate of starch;A mathematic model for predicting reducing sugar concentration was established by technological parameters such as hot air temperature,hot air humidity,initial moisture content and wind speed.The optimum conditions were obtained as follows: hot-air temperature 51.02?,hot-air rheumatism 39.48%,initial moisture content 24.23%,wind speed 0.75m/s,and tempering time ratio 2.06:1.