Effect Of Blanching And Drying Methods On Micro Structure And Physicochemical Properties Of Lily

Lily bulbs are rich in nutrients and active ingredients,such as starch,protein,vitamins and alkaloids,saponins.It have important edible and medicinal values.In this study,lily bulbs from longshan was graded with thick outer(TKO),thick inner(TKI),thin outer(TNO)and thin inner(TNI),blanching with boiling water and steam to study the inactivation rate of polyphenol oxidase(PPO)and peroxidase(POD),also the microstructure of lily slices.At the same time,taking the thick pieces to study the effects of blanching/non-blanching and different temperatures of hot air drying(50 ℃,70 ℃,90 ℃)on the microstructure and physicochemical properties of lily.The main conclusions are as follows:The PPO of lily bulbs has higher activity than POD,while POD has higher thermal stability than PPO.Lily should be blanched by hot water and steam for 60 s and 120 s respectively,which can inactivate enzyme and retains its nutritional.Thick lily pieces for example,the average particle size of unblached lily powder is 17.31 μm.The average particle size D50,volume average particle size D(4,3)and surface area average particle size D(3,2)increasing first and then decreasing with the blanching time prolonged.The average particle size of lily powder treated with boiling water and steam blanching reached the maximum at 40 s and 60 s,respectively,which were 78.97 μm and 66.53 μm,respectively;The light transmittance of the whole lily powder treated with hot treatment decreased with the prolongation of storage time,and the solubility and swelling degree showed different changes according to the temperature.The gelatinization enthalpy of the unheated lily was(5.40±0.81)J/g.The blanching value of the lily was reduced by blanching.After 20 s and 60 s of boiling water and steam respectively,the gelatinization value of lily powder was not detected.The protein content of non-blanched lily powder was(10.83±0.13)%.With the prolonged blanching time,the protein content decreased first and then increased.Thick lily pieces for example,the degree of gelatinization of the internal starch grains increases as the drying temperature of the unheated lily increases.The size of lilies treated by blanching is larger than that of non-blanched lilies;the unsweetened lilies are dried at 50 ℃,70 ℃,and 90 ℃ in hot air,and their average powder content increases as the drying temperature increases.The particle size,volume average particle size D(4,3),and surface area average particle size D(3,2)gradually increased,and the average particle size increased from 22.92 μm to 39.83 μm,and different degree of gelatinization was observed.For the blanched Lily,the average particle size of the dried at 70℃ is the largest,and the average particle size at 90℃.is the smallest;the light transmittance of the lily powder at different drying temperatures decreases with the extension of the storage time,and the degree of swelling and solubility are based on the blanching.There are different changes in the drying temperature;the thermodynamic properties of dried lily powder after blanching are not detected,and the difference in protein content between the three drying temperatures is different(P<0.05).