Study On The Fat Reduction,Activity Improvement And Sterilization Of Mayonnaise By Ultra-high Pressure

Traditional mayonnaise is rich in nutrition and has smooth texture, the fat content is about 65%≤80%, pH≤4.2. High fat diet is not good for human health, low fat has been the general trend. But low fat leads products to rough texture and stability decrease; the increase of non fat components put forward higher requirements for sterilization; lysozyme with antibacterial and hygienical efficacy in mayonnaise reduces the activity in high sour environment. Ultra-high pressure (UHP) as the effective way enhances the comprehensive quality of food processing, strengthens food emulsion dispersion, increases enzyme activity and sterilizes with non thermal.In order to create more green, safe and delicious low fat mayonnaise, author has studied to improve the quality, increase enzyme activity, non thermal sterilize and keep fresh without preservative by UHP technology. The main research results are as follows:1) UHP improved the viscosity, smoothness and stability of the low fat mayonnaiseUnder the condition of adding no thickener, UHP enhanced the physical properties of low fat mayonnaise optimum conditions were oil volume of 50%, pressure of 400 MPa and holding time of 10 min. After this treatment, viscosity of low fat mayonnaise was increased more than 5 times; the median diameter was decreased to 6.88+0.09 μm, the dispersion was improved; centrifugal demulsification rate was decreased to 9.3% significantly and stability was improved compared with untreated low fat mayonnaise, sensory characteristics were better than thermal treatment low fat mayonnaise too.2) UHP improved activity of lysozyme in low fat mayonnaiseThe optimum conditions of increasing the lysozyme activity by UHP under the oil volume of 50% of low fat mayonnaise were pressure of 300 MPa, holding time of 15 min. co-temperature of 20℃. After this treatment, the lysozyme activity of low fat mayonnaise was approximately 50% increased compared with untreated low fat mayonnaise. The activity of lysozyme was decreased under the pressure over 300 MPa.3) UHP replaced thermal sterilization and the sterilizing effect was significantThe safety and health index of low fat mayonnaise met the requirements of 《GB 29921-2013 Food safety standards pathogenic bacteria limited in food》, 《DBJ 440100/T 33-2009 Hygienic standard for semi-solid(sauce) seasoning》 and 《DBS 41/001-2015 Food safety local standard compound seasoning》 on the pressure of 300 MPa, holding time≥5min, co-temperature of 20℃; The total number of colonies≤580 CFU/g, mould≤35 CFU/g, yeast≤30 CFU/g, staphylococcus aureus≤19 CFU/g, E.coil≤30 MPN/100g, the sterilizing effect was significant.4) After 300 MPa-15 min-20℃ treatment,75 d storage at room temperature, product was in good qualityThe optimum conditions of UHP low fat mayonnaise were pressure of 300 MPa, holding time of 15min, co-temperature of 20 ℃ by comprehensive index of the total number of colonies and sensory evaluation. After this treatment, in 75 d storage at room temperature, the health and safety, shape, color, taste, texture of low fat mayonnaise were good.