| Schizochytrium is a unicellular fungal marine microalgae.Schizochytrium oil is a functional oil extracted from Schizochytrium algae,mainly triglycerides,and the content of unsaturated fatty acids exceeds 60%,of which the content of DHA is about 30% to50%.Schizochytrium oil is easily affected by oxygen-promoting factors such as temperature,oxygen,light,and metal ions,resulting in oxidative rancidity,and negatively affecting the quality of algal oil.In this experiment,Schizochytrium was used as raw material,and the whole process of enzymatic hydrolysis to extract Schizochytrium oil was filled with nitrogen for protection,and the effect of perilla extract on improving the oxidative stability of Schizochytrium oil was studied.The chytrid oil microcapsule powder was optimized and the process conditions were optimized.At the same time,the stability of the Schizochytrium oil microcapsule powder was studied.The main research contents and results are as follows:(1)In the process of water-enzymatic extraction of Schizochytrium oil,nitrogen was supplemented,and the extraction rate of oil and the oil content of the emulsified phase were used as evaluation indicators,and the optimal level range of process conditions was determined through the results of single-factor experiments,and combined with the central composite response surface design Model,it was determined that under the conditions of solid-liquid ratio of 1:6 g/mL,pH of 7,enzyme amount of2000 U/g,and nitrogen ventilation rate of 60 mL/min,the oil extraction effect of enzymatic hydrolysis for 3 h was the best.,the highest extraction rate of Schizochytrium oil was 93.60%.According to food safety standards,the physicochemical properties of the extracted Schizochytrium oil and the composition of unsaturated fatty acids such as DHA were detected and analyzed.The detection result of peroxide value was 0.67 meq/kg,the detection result of acid value was 0.45 mg/g,and the moisture content was 0.05.%,DHA content was 45%,and all indicators meet the national food safety standard of GB26400-2011.(2)To study the effect of perilla alcohol extract on the oxidation stability of Schizochytrium oil,and compare the antioxidant effect of Schizochytrium oil with the commonly used antioxidants TBHQ and tea polyphenols in food,POV value,TBA value,anisidine value,dienevalue and DHA content changes were used as indicators to evaluate the oxidative stability of oils and fats.The results showed that the purple hydrazine was effectively inhibited the POV value of the lysate,TBA value,anise amine value,conjugated diene value,adding 0.10% purple alcohol-ranging lygave algae DHA and The saturated fatty acid content has increased by 27.83%,28.10% respectively,and the purple glycolipotids had a positive role in improving the oxidative stability of the lyshase kettle.The oxidative stability of the oil with 0.10% Perilla ethanol extract was slightly lower than that with 0.02% TBHQ,but significantly higher than that with0.04% tea polyphenol oil,which provided a basis for the enhancement of the oxidative stability of the oil with 0.10% Perilla ethanol extract.(3)Microcapsule powder was prepared by spray-drying and entrapping Schizochytrium oil.Taking the entrapment rate as an investigation factor,the single factor experiment combined with the response surface test to optimize the preparation process of Schizochytrium oil microencapsulation.The best preparation conditions: the solid concentration was 16%,the mass ratio of wall material(β-cyclodextrin: gum arabic)wass 1:2.82,the mass ratio of core wall was 1:2.3,the air inlet temperature of spray drying was 167℃,and the feeding speed was 15.5 r/min,the encapsulation rate of Schizochytrium oil microcapsule powder prepared under this condition was 94.87%.(4)Analysis of physicochemical properties of Schizochytrium oil microcapsule powder.The moisture content of Schizochytrium oil microcapsule powder was2.73±0.03%,the solubility was 90.17±0.20%,the average particle size was 22.38 μm,and it had a good complex water stability;The results of scanning electron microscopy and infrared spectroscopy showed that gum arabic and β-cyclodextrin were used as composite wall materials to effectively embed Schizochytrium oil.The fatty acid composition of schizochytrium oil before and after microencapsulation was analyzed,and it was proved that the microencapsulation preparation by spray drying would not affect the composition of unsaturated fatty acids in schizochytrium oil.Functional ingredients;thermal stability analysis results showed that the microcapsule powder of split algae oil has good thermal stability;The storage test results showed that the storage stability of the oil microcapsule powder with Perilla alcohol extract was significantly better than the oil without embedding,the oil with Perilla alcohol extract and the oil with only microencapsulation at 60±2℃;The storage stability test results of the modulated milk powder verified that the Schizochytrium oil microcapsule powder had good oxidative stability. |
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