Study On The Effect Of Ice Structuring Protein On Freeze-dried Perilla Oil Microcapsule Powder

In this study,microcapsules were prepared by using perilla oil obtained from Heilongjiang Jiusan Agricultural Kenshengjiang Perilla Planting Cooperatives,obtained through shelling and low temperature cold pressing,and the effects of different drying methods on the physical and chemical properties of perilla oil microcapsules were discussed.The microcapsule emulsion was prepared with SPI and MD as the wall material and perilla oil as the core material.Using the stability of the emulsion as an indicator,determine the ratio of the compound emulsifier Tween 80 and Span 60 as 7:3,and the HLB value of the agent is 11.91,and the addition amount is 1%;use the microscope observation as an auxiliary indicator to determine the homogenization time It is 3 min and the homogenization speed is6000 r/min.The best preparation conditions obtained through single factor and response surface experiment optimization are: the wall material ratio is 1.5:1,the emulsification temperature is 70℃,the solid content is 20%,and the core wall ratio is 1:1.The stability of the capsule emulsion is high.Based on the embedding rate,microcapsules were prepared with ISPs,trehalose,and glycerol as freeze-drying antifreeze protective agents,and with no addition group as a control.The results show that when ISPs are antifreeze protective agents,the embedding rate of microcapsules is the highest,reaching 69.3%,and the addition amount of ISPs is determined to be 1%.Adding ISPs to the wall material,the microcapsule emulsion has no obvious ice crystals and delamination.The basic physical and chemical properties of perilla oil microcapsules obtained by different drying methods were determined.The results showed that the addition of ISPs as antifreeze protection agents during the freeze-drying process resulted in better microcapsules with better color,odor and dispersibility.Spray drying has stronger physical and chemical properties than freeze-dried microcapsules.When ISPs are added to freeze-drying,it can protect the microcapsules and effectively improve the physical and chemical properties of the microcapsules.FTIR spectrum analysis results show that there is no physical reaction between the wall material,core material and antifreeze protection agent except for the composite wall material,and no new substances are produced.According to TG analysis,the weight loss rate of microcapsules in the group with ISPs added during freeze-drying was the lowest,indicating the highest thermal stability.Measured by laser particle size analyzer,the particle size distribution of ISPs added in freeze-drying is concentrated in 2-6μm,the particle size of 6μm accounts for 17.48%,and the particle size is smaller than that of freeze-drying and spray drying groups.Observation of the morphology of the microcapsules by SEM showed that the surface morphology of the spraydried oil microcapsules was poor and the particle size was uneven.The surface of the freezedried microcapsules is smooth,the structure is dense,and there is no obvious damage,but a large amount of adhesion occurs between the microcapsules.After adding ISPs in freezedrying,the microcapsules are in good shape without damage or wrinkles,and the particle size is uniform.The in vitro simulated digestion experiment showed that the microencapsulated perilla oil played a slow-release and controlled-release role in the digestion process.After freeze-drying and adding ISPs,the release rate of microcapsules in SIF and GIF was the slowest and the digestion time was the longest.The final release amount reached 92.97%.It shows that ISPs,as antifreeze protective agents,can effectively protect the microcapsule wall,so that the core nutrients can be absorbed by the human body to the greatest extent.The influence of oxygen,temperature and light conditions on the stability of the microcapsules was investigated.The results showed that the storage stability of the microcapsules prepared by the spray drying method was greatly affected by the environment.The storage stability of the freezedried microcapsules was always higher than that of the spray drying group.After that,the rate of decrease in the embedding rate of freeze-dried microcapsules decreased.The POV value of perilla oil and microcapsules was determined by the accelerated oxidation test.The results show that microencapsulation can improve the oxidation stability of perilla oil,and the freezedried microcapsules have stronger anti-oxidation effect than spray drying.After adding ISPs,they can effectively reduce the oxidation rate of oil and fat,prolong the storage time and shelf life of perilla oil.