Study On Comprehensive Utilization Technology Of Okra Fermented Wine Pomace

Wine pomace,also known as wine lees,wine vinasse,is a mixture residue of fermented pomance of wine after distillation.There are many pectic polysaccharides and insoluble dietary fiber in the okra fermented wine pomace.Further utilization of the okra fermentated wine pomance can turn waste into treasure.In this study,the extraction process of pectic polysaccharides in okra fermented wine pomance was optimized.The physicochemical properties,monosaccharide composition and rheological properties of the extracted products were studied.The residue after extraction of pectic polysaccharides was further processed into okra insoluble dietary fiber ultrafine powder.The preparation technology was optimized and its physicochemical properties,hygroscopicity,particle size and apparent morphology were studied.The results are as follows:1.Pectic polysaccharides were extracted by enzymatic method.The single factor experiment and response surface design were used to optimize the extraction process.The optimum conditions were:using 1%cellulase,extraction temperature 44.5℃,solution pH=5.14,liquid-solid ratio=1:35.7,extraction time 10h，extracting two times.The extraction rate of pectic polysaccharides under this protocol was 6.85%.2.The physical and chemical properties of pectic polysacchrides were detected:degree of esterification is 74.45%,galacturonic acid content is 20.07%,ash contant is 8.52%,protein content is 2.24%,loss of drying weight rate is 18.06%and pH is 6.47.A method for the determination of seven monosaccharides by PMP precolumn derivatization HPLC method was established.The method was used to determine the pectic polysacchrides.The results showed that the molar ratio of monosaccharides was Mannose:Rhamnose:Glucuronic acid:Galacturonic acid.Glucose:Galactose:Arabinose=5.2:8.8:0.8:25.6:30.6:20.4:8.7.Based on the monosaccharide component,the calculated result of Rhamnogalacturonan I(RG I)structure was 46.74%and the Homogalacturonan(HG)structure was 16.76%.We speculated that the RG I structure has a longer side chain.3.The rheological propertion of pectic polysacchrides from okra wine pomancewas studied.The intrinsic viscosity[η]of the pectic polysaccharide was measured using an Ubbelohde viscometer and it was 4.66 dL/g.The viscosity average molecular weight was 2.47×105 g/mol.The flow sweep experiments showed that the pectic polysaccharides from okra fermented pomance was a pseudoplastic fluid of non-Newtonian fluids and has signally shear thinning behavior.The flow curve was fitted to the Cross model.Combined with the double logarithmic curve,we obtain a critical concentration c*which was about 4 g/dL,and the space occupancy was about 20.Oscillation amplitude experiments showed that the linear viscoelastic region was within 3%-10%strain.The results of oscillation temperature ramp experiment showed that the pectic polysacchrides is a weak gel with no obvious gel point(G’=G")in the experimental temperature range.Oscillation frequency experiments showed that loss modulus was greater than storage modulus,and that it had more viscous characteristics of the liquid.By contrast,pectin from raw okra had more solid properties.The fitting of the Cox-Merz formula shows that the compound viscosity of at a lower rate is greater than the shear viscosity,indicating that there may be new structures between the molecules.4.The pomance residue after pectin extracted was prepared insoluble dietary fiber ultrafine powder using a colloid mill,a high-pressure homogenizer and a spray dryer.The effects of homogenization times,inlet air temperature,feed rate,and solids content on the product property were studied.The optimized process was colloid mill treatment 3 times,high pressure homogenization 3 times at 40 MPa,solids content 7%,inlet air temperature 210℃,feed rate 1000 mL/h.The product under this protocol has a low moisture content,uniform particle size,and a high yield rate.The properties of ultra-fine powder products and raw pomance residue are determined,including water holding capacity,moisture content,powder properties,and ash;the color difference,hygroscopicity,and particle size of the product are determined.Size and appearance under electron microscope.The results show that most of the properties after ultrafine procedure had significant changes.