Study On The Quality And Efficacy Of Aloe Vera Gel Based On The Ultra-high Pressure Technology

Aloe vera is a traditional medicinal and edible plants, its mesophyll is aloevera gel that can be used as medicine, food and cosmetic ingredients. Aloe vera gelis nutrient-rich, traditional heat treatment process can sterilize and inactivateenzyme, but it will destroy heat-sensitive active ingredients, such as aloin, and cancause the change of the color, aroma also. Ultra-high Pressure (UHP) is a new typeof non-thermal process technology, it can sterilize and inactivate enzyme, andmaintain the original quality of the products also. Ultra-high Pressure makes up forthe defects of the heat treatment process.In this thesis, Aloe barbadensis Miller was used as the material, effects ofUHP processing on quality and efficacy of the aloe vera gel were investigated, UHPprocessing of the aloe vera gel was optimized, and the best storage condition wasdetermined. The main contents and the results are as follows:The effects of the degassing time, pressure, dwell time, collaborativetemperature on the quality of the aloe vera gel were investigated. The resultsshowed that the retention rates of aloin increased with the increasing degassingtime, and gradually reduced with the increase of pressure, dwell time andco-temperature; when the pressure was400MPa, the dwell time of15min, theco-temperature at30℃，retention rate of aloin was44.65%higher than that of theheat-treated sample; the retention rates of aloe polysaccharide increased with theincreasing degassing time; both of the retention rates of aloe polysaccharide andviscosity reached maximum when the pressure, the dwell time, and theco-temperature were400MPa,15min and30℃respectively; when the pressurewas400MPa, the dwell time of15min, the co-temperature at30℃, retention rateof aloe polysaccharide was31.78%higher than that of the heat-treated sample; thetotal numbers of colonies met the requirements of national health standards whenthe pressure was300MPa and the dwell time was over10min.The effects of pressure on the efficacy of aloe vera gel were investigated,antioxidant synergistic mechanism of aloe vera gel by UHP processing was preliminary explored. The results indicated that the moisturizing, antibacterial andantioxidant capacity of aloe vera gel by UHP processing were significantly betterthan the heat-treated sample; moisturizing and antioxidant capacity of aloe vera gel by400MPa pressure were better than samples which processed by100~300MPa; the DPPH· scavenging rate of aloe vera gel by400MPa pressure was higher thanthe untreated sample; antioxidant synergistic mechanism of aloe vera gel by UHPprocessing may be increasing of aloe polysaccharide dissolution and decreasing ofthe molecular weight of aloe polysaccharide, so that the antioxidant capacityenhanced.UHP processing of the aloe vera gel was optimized, the critical processparameters of the high activated aloe vera gel were degassing time of20min,pressure of400MPa, dwell time of15min, co-temperature of30℃. Changes of thetotal numbers of colonies, the retention rates of aloin, the retention rates of aloepolysaccharides and aloe vera gel viscosity were investigated under differentstorage conditions, the results indicated that more appropriate storage conditionwas dark-preservation at4℃, in which aloe vera gel could be stored for80days inthis environment.