Study On Functional Components And Powder Technology Of Prunus Mira Koehne

The study was aimed to investigate functional components and quality characteristics of Prunus mira Koehne by comparing with commercial peach at optimum maturity stage.Effects of diverse pretreatments,including supersonic treatment(ST),instant controlled pressure drop(ICPD)and steam blanching treatment(SBT)on functional components extracted from Prunus mira Koehne were evaluated.The best method and its parameters were elected to preserve functional components of Prunus mira Koehne.Freeze-drying combined with superfine grinding was employed to prepare the powder of Prunus mira Koehne.Characterstics of Prunus mira Koehne powder were determined by laser particle size analyzer,scanning electron microscope,FT4 powder rheometer,dynamic vapor sorption intrinsic and so on.By analyzing the retention rate of polyphenols,flavonoids,polysaccharides,and pectin,the optimal process parameters of superfine grinding technology was obtained.Therefore,this research was to provide theoretical basis and technical support for the intensive processing of Prunus mira Koehne.The results of this study were as following:1.Compared with commercial peach,Prunus mira Koehne was richer in functional components such as polyphenols,flavonoids,polysaccharides and so on(p>0.05).As the results showed,the polyphenols content of Prunus mira Koehne(2716.09 14.10 mg GAE/100g d.b.)was 3-5 times that of commercial peach.And the main monophenols of Prunus mira Koehne were catechin,chlorogenic acid,and neochlorogenic acid.Moreover,the flavonoids and polysaccharides content of Prunus mira Koehne were 2179.21±11.20 mg RE/100g d.b.and 9393.81±284.97 mgGE/100g d.b.,which were higher two times and one time than commercial peach respectively.2.Compared to the control group,ST induced a significant decline in contents of antioxidant substances(polyphenol,flavonoid,and polysaccharide)and their antioxidant capacity except pectin(p<0.05);ICPD could increase contents of polysaccharide and pectin and improve their antioxidant activities.However,ICPD had adverse effects on contents of polyphenol and flavonoid;SBT induced a remarkable increase in contents of functional components and enhanced their antioxidant capacity(p<0.05).Higher contents of chlorogenic acid,catechin and neochlorogenic acid were reserved when Prunus mira Koehne was steam blanched for 3 min.3.Prunus mira Koehne powder was prepared by coarse grinding combined with freeze drying after Prunus mira Koehne treated with steam blanching.Compared to the control group,the L*value of powder was decreased from 86.47 to 85.21 when Prunus mira Koehne was treated with steam blanching for 3 min,and the a*value was increased from-0.03 to 0.42.Steam blanching pretreatment could increase powder volume density and fluidity,but decrease powder compressibility as powder particle size decreasing.The treatment group powder appeared aggregation to some extent with its hygroscopicity increasing.Hydration properties of exprimental group,including water-holding capacity,oil-holding capacity,and swelling capacity,were enhanced.Compared to control group,the pectin content of treatment group was increased to 3 mg GalA/g AIR,and the polysaccharide content was increased about 12 mg Glu/g d.b..4.Prunus mira Koehne powder was prepared by superfine grinding.With superfine grinding time increasing,the particle size of Prunus mira Koehne powder became smaller than coarse powder,and the size distribution span decreased from 6.58±0.54 to 2.86±0.09.A significant decline in the compressibility was observed,while both bulk density and basic fluidity energy increased.Superfine grinding technology could improve hydration characteristics of the powder.When relative humidity was less than 50%,the powder hygroscopicity did not show significant difference.The antioxidant activity of polyphenol and polysaccharide extracted from Prunus mira Koehne powder prepared by superfine grinding technology didn't show any significant difference(p>0.05).Content of water soluble pectin extracted from Prunus mira Koehne powder was decreased,however,its antioxidant activity was significantly increased(p<0.05).