Studies On Spraying Drying Process Optimization And Immune Modulation Of Longan Water Soluble Extracts

Longan is China well known Subtropical Fruit , and is a major cash crop in south China.Both of cultivation area and production rank first in world for longan.But, at present, there are serious problems with our china longan industry which are Lacking of deep processing ,lacking of a robust theoretical support base for Mechanism of Health in morden medicine.Research and development longan functional foods could solve the deep processing problem of longan industry and reveal the mechanism of health in Modern Medical Theory.and it is of great significance for developing agriculture.1 Optimization of extraction process of longan bioactive substances . The results showed that using the dried longan pulp (13.62% moisture content) as the material, extracted at temperature 80℃, ratio of dried longan pulp to water 1:12, time 2 hours, the extraction rates of the total soluble solids and longan polysaccharide in dried longan pulp were 73.24% and 40.28%, respectively and extracted with pectinase and cellulose enzyme, pH3.1, temperature 52℃, time 160min, pectinase 0.6‰, cellulose 0.05‰, the total soluble solids extraction rate could reached up to 85.26%.Longan water soluble extraction Free radical scavenging IC₅₀ is 2.2g/L.The extraction of longan extracted by Enzymatic who free radical scavenging capacity is higher than the extraction extracted by hot water.2 To study the effects of longan extracts on immune modulation and anti-oxidation activity in normal mice.Both the two doses of longan extracts compared to normal control group greatly improved hemolysin value of blood serum and indexes of spleen lymphocyte transformation ,but the longan slurry couldn't. And high longan extracts enhanced NK cell activity obviously, both the two doses of longan slurry couldn't either. High longan slurry reduced the MDA of blood serum, but the longan extracts. T-AOC was increased by high longan slurry and high longan extracts respectively.3 In order to establish the processing technology of longan pulp powder yeild(Y1), the response surface methodology was used to optimize the spray drying parameters inlet Temperature(A),hot air flow(B), Feed flow rate(C). The best fitting regression equation for estimating optimal processing is: Y₁=44.80+1.87A-1.99C-2.85AB-1.00AC-1.80A²- 1.63B².When the total soluble solids content reached 25%, maltodextrin was used as filler (M:TSS,0.8:1), spray drying was conducted at hot air temperature of 185℃, hot air flow rate of 26.47 m3·h-1 and feeding rate of 0.20 L·h-1, the yeild of longan powder of 48.58% was obtained, with the moisture content of the longan powder <5%.4 In order to study the hot air temperature and hot air flow rate on powder physical properties of longan impact. The results show that: Spray-drying process parameters hot air temperature and hot air rate affect moisture content and particle morphology of longan powder. Moisture content and particle morphology impact its dust density, stickiness, solubility, water sorption properties and glass transition temperature. The monolayer moisture content of longan powder is different which prepared under different conditions from 5.70 to 6.32g per 100g longan powder. the Safe storage of highest moisture of the longan powder is 6.11g per 100g longan powder which produced by inlet temprature was 180℃.With improveing the inlet temperature or hot air flow rate the glass transition temperature of longan powder inreasing from 38.57℃to 47.50℃. The maine aroma components in longan powder is (Z)-13, 7-dimethyl-3, 6-octatriene.Main innovations: Optimized and established the processing conditions of enzymatic extraction of longan soluble bioactive substances, evaluated its Free radical scavenging capacity. Cell-mediated immunity and humoral immunity found and confirmed the effects of longan soluble extraction in immune regulation and in vivo antioxidant on normal mice. Comprehensive analysised the factors of spray drying producing longan powder and optimized the optimum conditions,and discussed the effcets of spray drying processing parameter on longan powder physical and chemical properties.Tht results of this study has great valve on the extraction of longan soluble bioactive substances, processing good longan powder and evaluation of immunomodulation .It has important significance in deep processing and utilization longan and inproving longan industry value added.