Abstract:Six kinds of microcapsule oxygen-indicating composite films were prepared with sodium alginate (SA), methyl cellulose (MC), carboxymethyl chitosan (CMC) as microcapsule wall materials and methylene blue (MB)/TiO2/glycerin (Gly) as oxygen indicator. The suitable screen oxygen wall material system was selected according to the activation, color reversal and reusability of the oxygen-indicating composite films. When the concentration of MC was 20 g/L, and the dosage of MB, TiO2 and Gly was 0.05 g, 1 g and 0.5 mL, respectively, the photocatalytic activation efficiency of MB/TiO2/Gly/MC oxygen-indicating composite film was the best. Under the conditions of air humidity of 75% and temperature of 35 ℃, the color recovery rate of MC/SA/MC and MC/CMC/SA oxygen-indicating composite films at 10 hours was 28.7% and 27.9% respectively, and the color changing was relatively uniform. After repeated use for 3 times, the color recovery rate of MC/SA/MC and MC/CMC/SA oxygen-indicating composite films decreased by only 0.8% and 1.0% respectively, indicating that these two wall material systems are spice wall material with good screen oxygen. These two wall material systems were used to embed rose essential oil by spray drying to prepare spice microcapsules. After 7 days of storage, new substances appeared in the core material embedded in MC/CMC/SA, while no new substances appeared in MC/SA/MC, indicating that the MC/SA/MC system had a better protection effect on rose oil.