Preparation Of Lecithin/SMS Oleogel And Its Application In Meat Products

As one of the three nutrients,fat plays an important physiological function in human body.However,excessive intake of fat will cause health hazards,so the replacement of fat in food is the current research hotspot.Oleogel formed by gelatinizing vegetable oils is considered bulk fat materials and a new substitute for saturated and trans-fatty acids,which contain large amounts of edible liquid oils(even above 97 wt%)and can imitate the properties of fats.Oleogels can be formed from a single component or a mixture of different structural agents,but because of the complex structure of fats,a single system of oleogels is unlikely to mimic the multiple functional properties of fats.On this basis,we used lecithin and span 60 to construct a composite oleogel system and optimized the preparation process of oleogel.We studied rheological and thermodynamic property of SMS oleogels adding with lecithin,and explored application in meat products.The main contents are as follows:The preparation process of oleogel was optimized.We used canola oil as raw material,with oil loss as index,and determined the addition ratio of lecithin and SMS was 2:8 through single factor test Then we taken the amount of gelling agent,heating temperature and heating time as factors combining with response surface test,and determined the influence factor of oleogel oil loss is heating time>the amount of gelling agent>heating temperature.The optimal preparation process of oleogel was:30%gelling agent amount,85? heating temperature,35min heating time.Under these conditions,the average oil loss was 1.48%.Comparing the physicochemical indexes and fatty acid composition of canola oil and oleogel,we found that there was little difference in physicochemical indexes between them.The content of saturated fatty acids in oleogel was low,accounting for 22.93%of the total fatty acids,but still lower than the traditional oils.The effect of lecithin on the gelling properties of oleogels was investigated.The addition of lecithin improved the physical properties of oleogel,and It showed the oil loss decreased and the hardness increased when the amount of lecithin is added.The results of rheological measurements showed that the elastic modulus(G')of all the oleogels with lecithin was higher than the viscous modulus(G"),indicating that all the samples formed gel structure,and the oleogels had higher elastic and viscous modulus when the ratio of lecithin to SMS was 2:8.Infrared spectroscopy showed that the formation of gel network was mainly hydrogen bonding.The results of XRD analysis showed that the addition of a certain proportion of lecithin could promote the crystallization of the oleogel.Thermodynamic analysis found that the composite oleogel had a lower enthalpy change,i.e.lower thermal stability,which was a shortcoming of the oleogel,but the oxidation stability was greatly improved.The feasibility of using oleogel instead of animal fat(sheep fat)to reduce saturated fat content in sausage was studied.25,50,75 and 100%oleogel were used to replace sheep fat in sausage,and their nutritional,oxidative and sensory properties were evaluated.The water,protein and ash of the reconstituted sausage did not change significantly,while the fat content and cooking loss decreased significantly(P<0.05).The texture analysis showed that the hardness,elasticity,chewiness and resilience of the reconstituted sausage were significantly decreased(P<0.05),while the cohesiveness did not change significantly.From the fatty acid composition,the UFA/SFA value increased significantly(P<0.05)from 1.12 to 3.38 with the increase of oleogel substitution,indicating the change of fatty acid composition and the improvement of nutritional value.The color analysis corresponded to the sensory evaluation,and the final sensory evaluation data showed that the overall acceptability of the product with 50%oleogel replacement was not significantly different from that of the control group,indicating that the oleogel can replace 50%fat in sausage products without negative effects on the product.