Study On Extraction Technology Of Corn Yellow Pigment And Zein Of Corn Gluten Meal

Corn gluten meal which contains rich maize yellow pigment and zein is one of the by-products of the processing of corn starch.Maize yellow pigment is a natural fat soluble compounds.Zein can be soluble in 60%⁹5%of alcohol solution.Corn gluten meal is often used as a"industrial waste"or roughage to discharge or dispose of,this great waste of resources and also pollute the environment.Therefore,the extraction of maize yellow pigment and zein from corn gluten meal,not only can improve the utilization rate of corn gluten meal and reduce the waste of resources,but also can protect environment.Extraction of yellow pigment and zein from corn gluten meal was mainly studied in this research.1)The single factor experiment and Box-Benhnken response optimized the extraction of maize yellow pigment from corn gluten meal by ultrasonic assisted and microwave assisted.The optimum extraction conditions of ultrasonic assisted extraction for ratio of solid to liquid,the pH value,the ultrasonic time were 1∶6,5 and 26 min,respectively,and the maximum yield of maize yellow pigment was 0.284 5 mg/g.The optimum extraction conditions of microwave assisted extraction for ratio of solid to liquid,the pH value,the microwave power,the microwaves time were 1∶6,5,640 W and 20 s,respectively,and the maximum yield of maize yellow pigment was 0.265 0 mg/g.Compared with the ultrasonic assisted,the yield of maize yellow pigment by microwave assisted was lower than that.The results of this research could provide reference for the commercial extraction of maize yellow pigment from corn gluten meal.2)This research also studied the stability of maize yellow pigment.The results showed that maize yellow pigment has certain antioxidant capacity for lower concentration of oxidizing agent.The reducing agent Na₂SO₃ on maize yellow pigment could play a protective role.Na⁺,K⁺,Fe²⁺,containing food additives commonly used in oxygen anions,citric acid and potassium sorbate on maize yellow pigment did not affect the basic.Zn²⁺,Ca²⁺and Mg²⁺had certain effect on maize yellow,but little impact.Effect of A1³⁺on maize yellow pigment maximum,Fe³⁺and Cu²⁺followed by.Maize yellow pigment to light,heat had bad stability,light resistance was poor,but heat resistance.Stable in weak acidic and neutral range.Sucralose had certain effect on Maize yellow.Vitamin C had a strong protective effect on Maize yellow.3)The orthogonal experiment optimized the corn gluten meal residue which after discoloring to extract zein,determined the optimum extraction conditions for the temperature,the ratio of solid to liquid,the ethanol concentration,the extraction time were55℃,1∶5,75%and 2.5 h,respectively,and the maximum yield was 34.64%.