Phase change material microcapsules (MicroPCMs) with nano composite structures (NC-MicroPCMs) were fabricated to meet higher demand of thermal stability and hold core better. Degree of crystallinity (DOC) of the NC-Mi...Phase change material microcapsules (MicroPCMs) with nano composite structures (NC-MicroPCMs) were fabricated to meet higher demand of thermal stability and hold core better. Degree of crystallinity (DOC) of the NC-MicroPCMs was evaluated by the differential scanning calorimeter (DSC). The effectiveness of some processing variables, in terms of formaldehyde and melamine molar ratio F/M, weight ratio of core and shell material C/S, and the dosage of silver nano particles D(%), were analyzed statistically. It was found that: (1) DOC was dependent on these processing variables; (2) doping silver nano particles was beneficial to the formation of shell crystallite structure; and (3) higher F/M was helpful in getting a higher DOC for both NC-MicroPCMs and MicroPCMs. Also, DOC was found to be associated with thermal stability and the two features were confirmed, which showed a closely positive correlation.展开更多
The stability of β-carotene microcapsules using Maillard reaction products（MRPs） derived from whey protein isolate（WPI） and galactose as coating materials, was studied under the varying environmental conditions o...The stability of β-carotene microcapsules using Maillard reaction products（MRPs） derived from whey protein isolate（WPI） and galactose as coating materials, was studied under the varying environmental conditions of temperature, pH, air, incandescent light, and ultraviolet（UV） light.Scanning electron microscopy showed that microcapsules prepared by WPI-galactose MRPs displayed a smooth and less concave-convex surface and that the particle size（D_（50）） of the microcapsules made with WPI-galactose MRPs was smaller than those made with WPI-galactose mixture.The storage stability of β-carotene microencapsulated in WPI-galactose MRPs was remarkably better than that of β-carotene microencapsulated in the WPI-galactose mixture and that of β-carotene crystal, in respect of temperature, pH, air, incandescent light, and UV light measurements.When the storage temperature was increased from 5 to 105 ℃, the retention rate of β-carotene microcapsules significantly decreased（P〈0.05）.When p H values were increased from 1 to 12, the β-carotene retention rate of the microcapsules significantly increased and afterward decreased.Compared with the retention rate of β-carotene microencapsulated in a WPI-galactose mixture, the retention rate of β-carotene microencapsulated in WPI-galactose MRPs was at a maximum between pH 8 and 9.Under the actions of air, incandescent light, and UV light, the retention rates of β-carotene microcapsules in WPI-galactose MRPs and WPI-galactose mixture, as well as in β-carotene crystal, decreased significantly as the storage time increased（P〈0.05）.Therefore, the use of WPI-galactose MRPs as coating materials can aid in improving the storage stability of β-carotene microcapsules.展开更多
The antifungal activity and encapsulation properties of cinnamaldehyde-loaded microcapsules by tannic acid were investigated.The results showed that cinnamaldehyde exhibited a high in vitro antifungal effect against A...The antifungal activity and encapsulation properties of cinnamaldehyde-loaded microcapsules by tannic acid were investigated.The results showed that cinnamaldehyde exhibited a high in vitro antifungal effect against Aspergillus brasiliensis through altering the morphology of the hyphae,and its inhibition zone diameter(IZD)exceeded 15 mm with a minimum inhibitory concentration of 1.0 mg/mL.Cinnamaldehyde-loaded microcapsules crosslinked with tannic acid have a high encapsulation efficiency(92.53±5.20%)and antifungal activity(37.82±0.63 mm),and the retention rate was 2.5 times of that of unencapsulated cinnamaldehyde after 30-d storage at 37℃.Furthermore,the antifungal stability was enhanced(IZD 25.37 mm)after 60-d storage at 37℃ as compared with that of cinnamaldehyde(IZD 22.07 mm).The results of cell membrane integrity and the extracellular protein content also indicated that the microencapsulation could effectively protect cinnamaldehyde,delay the decrease of antifungal effect and improve its long-term antifungal activity against A.brasiliensis by increasing the retention rate of cinnamaldehyde after storage.展开更多
基金Education Commission of Shaanxi Province for Providing Funding Support,China ( No. 2010JS006)
文摘Phase change material microcapsules (MicroPCMs) with nano composite structures (NC-MicroPCMs) were fabricated to meet higher demand of thermal stability and hold core better. Degree of crystallinity (DOC) of the NC-MicroPCMs was evaluated by the differential scanning calorimeter (DSC). The effectiveness of some processing variables, in terms of formaldehyde and melamine molar ratio F/M, weight ratio of core and shell material C/S, and the dosage of silver nano particles D(%), were analyzed statistically. It was found that: (1) DOC was dependent on these processing variables; (2) doping silver nano particles was beneficial to the formation of shell crystallite structure; and (3) higher F/M was helpful in getting a higher DOC for both NC-MicroPCMs and MicroPCMs. Also, DOC was found to be associated with thermal stability and the two features were confirmed, which showed a closely positive correlation.
基金Project supported by the Natural Science Foundation of Heilongjiang Province of China(No.C2017029)the Academic Research Program of Northeast Agricultural University(No.16XG21)the National“Twelfth Five-Year”Plan for Science and Technology Support Program of China(No.2013BAD18B06)
文摘The stability of β-carotene microcapsules using Maillard reaction products（MRPs） derived from whey protein isolate（WPI） and galactose as coating materials, was studied under the varying environmental conditions of temperature, pH, air, incandescent light, and ultraviolet（UV） light.Scanning electron microscopy showed that microcapsules prepared by WPI-galactose MRPs displayed a smooth and less concave-convex surface and that the particle size（D_（50）） of the microcapsules made with WPI-galactose MRPs was smaller than those made with WPI-galactose mixture.The storage stability of β-carotene microencapsulated in WPI-galactose MRPs was remarkably better than that of β-carotene microencapsulated in the WPI-galactose mixture and that of β-carotene crystal, in respect of temperature, pH, air, incandescent light, and UV light measurements.When the storage temperature was increased from 5 to 105 ℃, the retention rate of β-carotene microcapsules significantly decreased（P〈0.05）.When p H values were increased from 1 to 12, the β-carotene retention rate of the microcapsules significantly increased and afterward decreased.Compared with the retention rate of β-carotene microencapsulated in a WPI-galactose mixture, the retention rate of β-carotene microencapsulated in WPI-galactose MRPs was at a maximum between pH 8 and 9.Under the actions of air, incandescent light, and UV light, the retention rates of β-carotene microcapsules in WPI-galactose MRPs and WPI-galactose mixture, as well as in β-carotene crystal, decreased significantly as the storage time increased（P〈0.05）.Therefore, the use of WPI-galactose MRPs as coating materials can aid in improving the storage stability of β-carotene microcapsules.
基金greatly appreciate the joint support for study by projects of the National key R&D program(2016YFD0400801)National First-class Discipline of Food Science and Technology(JUFSTR20180204)program of "Collaborative innovation center of food safety and quality control in Jiangsu Province".
文摘The antifungal activity and encapsulation properties of cinnamaldehyde-loaded microcapsules by tannic acid were investigated.The results showed that cinnamaldehyde exhibited a high in vitro antifungal effect against Aspergillus brasiliensis through altering the morphology of the hyphae,and its inhibition zone diameter(IZD)exceeded 15 mm with a minimum inhibitory concentration of 1.0 mg/mL.Cinnamaldehyde-loaded microcapsules crosslinked with tannic acid have a high encapsulation efficiency(92.53±5.20%)and antifungal activity(37.82±0.63 mm),and the retention rate was 2.5 times of that of unencapsulated cinnamaldehyde after 30-d storage at 37℃.Furthermore,the antifungal stability was enhanced(IZD 25.37 mm)after 60-d storage at 37℃ as compared with that of cinnamaldehyde(IZD 22.07 mm).The results of cell membrane integrity and the extracellular protein content also indicated that the microencapsulation could effectively protect cinnamaldehyde,delay the decrease of antifungal effect and improve its long-term antifungal activity against A.brasiliensis by increasing the retention rate of cinnamaldehyde after storage.
