Papaya pulp is very perishable and has a short shelf life. Manually sliced papayas were treated with 0%, 0.25%, 0.5%, and 1% chitosan (non-micronized and micronized) aqueous solutions;placed into plastic trays, and ov...Papaya pulp is very perishable and has a short shelf life. Manually sliced papayas were treated with 0%, 0.25%, 0.5%, and 1% chitosan (non-micronized and micronized) aqueous solutions;placed into plastic trays, and over-wrapped with PVDC film and then stored at 4°C. Color, soluble solid content, water loss, and total plate count of samples were evaluated. Chitosan coating had the ability to maintain the lightness of the sliced papayas. The a* values of the micronized chitosan-coated sliced papayas were significantly lower than those of the-coated. The sliced papayas that had been treated with 1% MC had a higher total soluble solid content and lower b* value after four days of storage. Also, the chitosan coating on the sliced papaya effectively retarded water loss and inhibited the growth of microorganisms. The results reveal that applying a chitosan coating effectively maintained the quality attributes and prolonged the shelf life of the sliced papayas.展开更多
The antioxidant activity of chitosan before micronization (BMC, average particle size of 1850 ± 26.3 μm) and after micronization (AMC, average particle size of 1.37 ± 0.2 μm) in grape juice was studied. An...The antioxidant activity of chitosan before micronization (BMC, average particle size of 1850 ± 26.3 μm) and after micronization (AMC, average particle size of 1.37 ± 0.2 μm) in grape juice was studied. Antioxidant activity was determined, including that of DPPH radicals, hydrogen peroxide and superoxide anion radicals, as well as ABTS radicals of BMC or AMC in grape juice. AMC exhibits stronger scavenging activity toward DPPH radicals, superoxide anion radicals and hydrogen peroxide than BMC. At a concentration of 1.0 mg/mL, AMC in grape juice exhibited 90.0%, 97.3% and 88.7% scavenging activities toward DPPH radicals, hydrogen peroxide and superoxide anion radicals, respectively. The TEAC (Trolox Equivalent Antioxidant Capacity) values of AMC (3.94 ± 0.19) greatly exceeded those of BMC (2.21 ± 0.10) in grape juice. The in vitro results in this investigation suggest the possibility that AMC can increase the antioxidant activity in grape juice. However, comprehensive studies must be performed to ascertain the in vivo safety of AMC in experimental animal models.展开更多
文摘Papaya pulp is very perishable and has a short shelf life. Manually sliced papayas were treated with 0%, 0.25%, 0.5%, and 1% chitosan (non-micronized and micronized) aqueous solutions;placed into plastic trays, and over-wrapped with PVDC film and then stored at 4°C. Color, soluble solid content, water loss, and total plate count of samples were evaluated. Chitosan coating had the ability to maintain the lightness of the sliced papayas. The a* values of the micronized chitosan-coated sliced papayas were significantly lower than those of the-coated. The sliced papayas that had been treated with 1% MC had a higher total soluble solid content and lower b* value after four days of storage. Also, the chitosan coating on the sliced papaya effectively retarded water loss and inhibited the growth of microorganisms. The results reveal that applying a chitosan coating effectively maintained the quality attributes and prolonged the shelf life of the sliced papayas.
文摘The antioxidant activity of chitosan before micronization (BMC, average particle size of 1850 ± 26.3 μm) and after micronization (AMC, average particle size of 1.37 ± 0.2 μm) in grape juice was studied. Antioxidant activity was determined, including that of DPPH radicals, hydrogen peroxide and superoxide anion radicals, as well as ABTS radicals of BMC or AMC in grape juice. AMC exhibits stronger scavenging activity toward DPPH radicals, superoxide anion radicals and hydrogen peroxide than BMC. At a concentration of 1.0 mg/mL, AMC in grape juice exhibited 90.0%, 97.3% and 88.7% scavenging activities toward DPPH radicals, hydrogen peroxide and superoxide anion radicals, respectively. The TEAC (Trolox Equivalent Antioxidant Capacity) values of AMC (3.94 ± 0.19) greatly exceeded those of BMC (2.21 ± 0.10) in grape juice. The in vitro results in this investigation suggest the possibility that AMC can increase the antioxidant activity in grape juice. However, comprehensive studies must be performed to ascertain the in vivo safety of AMC in experimental animal models.
