Biobased smart packaging is been the most interesting research field.In this study,pH-sensitive films based on anthocyanin molecules from red cabbage and sepiolite mineral nano-clay as functional additives were studie...Biobased smart packaging is been the most interesting research field.In this study,pH-sensitive films based on anthocyanin molecules from red cabbage and sepiolite mineral nano-clay as functional additives were studied.The films were fabricated by casting method of blend polymer Chitosan/Poly(Vinyl Alcohol)at two fillers loading(5wt.%and 10wt.%).The structural,morphological,thermal,optical,hygroscopic,and mechanical properties as well as the pH sensitivity of films were investigated.The thermal properties confirm that the amount of the anthocyanin in sepiolite was around 6.4%.The tensile strength and the young’s modulus of produced composites at 10wt.%sepiolite–anthocyanin content was increased to 8.90 MPa and 163 MPa,respectively.The maximum water absorption that the films may absorb was 12.3%.pH sensitivity analysis showed that the Smart films change the color by changing the pH level,from pink at pH lower than 6 to yellow at pH higher than 6.Thus,the developed pH-sensitive films show band gaps in visible light that make them useful for monitoring milk spoilage.展开更多
探讨在不同温度和pH条件下紫甘蓝花色苷的热稳定性和降解动力学。以80%乙醇浸提,D-101大孔吸附树脂分离纯化制备紫甘蓝花色苷,在50、60、70、80℃温度范围内,于不同pH(2.0~6.0)体系中测定不同时间点的花色苷含量,研究其热降解动力学参...探讨在不同温度和pH条件下紫甘蓝花色苷的热稳定性和降解动力学。以80%乙醇浸提,D-101大孔吸附树脂分离纯化制备紫甘蓝花色苷,在50、60、70、80℃温度范围内,于不同pH(2.0~6.0)体系中测定不同时间点的花色苷含量,研究其热降解动力学参数和褐变指数。结果表明,紫甘蓝花色苷热稳定性和褐变反应受温度和pH的影响,且其降解速率与时间呈良好线性关系,符合一级动力学模型。随着温度的升高,不同pH下花色苷的半衰期t1/2均呈下降趋势,最大值为83.51 h(50℃,pH3.0),最小值为4.43 h(80℃,pH6.0),且各pH(2.0~6.0)体系的活化能Ea依次为42.30、45.31、38.85、26.83、31.20 k J/mol。此外,其褐变指数随热处理时间延长、温度升高及pH增大而增大。展开更多
The effects of acidic electrolysed water(AEW)as‘green’technology on the microbiological and physicochemical properties of fresh-cut red cabbages were studied.Fresh-cut red cabbages and artificially inoculated red ca...The effects of acidic electrolysed water(AEW)as‘green’technology on the microbiological and physicochemical properties of fresh-cut red cabbages were studied.Fresh-cut red cabbages and artificially inoculated red cabbages with Salmonella typhimurium DT104 were washed with distilled water(DW)and different available chlorine concentrations(ACC)of AEW for different times.AEW treatments significantly reduced the populations of native aerobic bacteria,molds,and yeasts,and artificially inoculated S.typhimurium DT104 compared with the DW-treated and untreated red cabbage samples.The effectiveness of AEW treatments was greatly enhanced with increasing ACC and treatment times.S.typhimurium DT104 were not detected in the washing water that were collected after the red cabbages treated by AEW.The surface colour,pH,and total phenolic contents did not significantly change when the red cabbages were washed with DW and AEW containing 100 mg/L available chlorine for 3 min.The anthocyanin contents and antioxidant activities of red cabbage were significantly reduced by 18.5 per cent for cyanidin,22.1 per cent for pelargonidin,and 11.2 per cent for 2,2-diphenyl-1-picrylhydrazyl(DPPH)radical scavenging activity,however,the impacts on the nutritional benefits of red cabbage were considered as limited and acceptable.The optimal process condition of AEW for washing red cabbage was 100 mg/L ACC for 3 min.In these conditions,most of the native microflora were inactivated,and artificially inoculated S.typhimurium DT104 on the red cabbage were reduced by 40.2 per cent[3.67 log CFU/g(log10 colony-forming units per gram)]and with minimal losses of nutrients and antioxidant activity,as well as no requirement of decontamination treatment on the washing water after AEW treatment.展开更多
文摘Biobased smart packaging is been the most interesting research field.In this study,pH-sensitive films based on anthocyanin molecules from red cabbage and sepiolite mineral nano-clay as functional additives were studied.The films were fabricated by casting method of blend polymer Chitosan/Poly(Vinyl Alcohol)at two fillers loading(5wt.%and 10wt.%).The structural,morphological,thermal,optical,hygroscopic,and mechanical properties as well as the pH sensitivity of films were investigated.The thermal properties confirm that the amount of the anthocyanin in sepiolite was around 6.4%.The tensile strength and the young’s modulus of produced composites at 10wt.%sepiolite–anthocyanin content was increased to 8.90 MPa and 163 MPa,respectively.The maximum water absorption that the films may absorb was 12.3%.pH sensitivity analysis showed that the Smart films change the color by changing the pH level,from pink at pH lower than 6 to yellow at pH higher than 6.Thus,the developed pH-sensitive films show band gaps in visible light that make them useful for monitoring milk spoilage.
文摘探讨在不同温度和pH条件下紫甘蓝花色苷的热稳定性和降解动力学。以80%乙醇浸提,D-101大孔吸附树脂分离纯化制备紫甘蓝花色苷,在50、60、70、80℃温度范围内,于不同pH(2.0~6.0)体系中测定不同时间点的花色苷含量,研究其热降解动力学参数和褐变指数。结果表明,紫甘蓝花色苷热稳定性和褐变反应受温度和pH的影响,且其降解速率与时间呈良好线性关系,符合一级动力学模型。随着温度的升高,不同pH下花色苷的半衰期t1/2均呈下降趋势,最大值为83.51 h(50℃,pH3.0),最小值为4.43 h(80℃,pH6.0),且各pH(2.0~6.0)体系的活化能Ea依次为42.30、45.31、38.85、26.83、31.20 k J/mol。此外,其褐变指数随热处理时间延长、温度升高及pH增大而增大。
文摘The effects of acidic electrolysed water(AEW)as‘green’technology on the microbiological and physicochemical properties of fresh-cut red cabbages were studied.Fresh-cut red cabbages and artificially inoculated red cabbages with Salmonella typhimurium DT104 were washed with distilled water(DW)and different available chlorine concentrations(ACC)of AEW for different times.AEW treatments significantly reduced the populations of native aerobic bacteria,molds,and yeasts,and artificially inoculated S.typhimurium DT104 compared with the DW-treated and untreated red cabbage samples.The effectiveness of AEW treatments was greatly enhanced with increasing ACC and treatment times.S.typhimurium DT104 were not detected in the washing water that were collected after the red cabbages treated by AEW.The surface colour,pH,and total phenolic contents did not significantly change when the red cabbages were washed with DW and AEW containing 100 mg/L available chlorine for 3 min.The anthocyanin contents and antioxidant activities of red cabbage were significantly reduced by 18.5 per cent for cyanidin,22.1 per cent for pelargonidin,and 11.2 per cent for 2,2-diphenyl-1-picrylhydrazyl(DPPH)radical scavenging activity,however,the impacts on the nutritional benefits of red cabbage were considered as limited and acceptable.The optimal process condition of AEW for washing red cabbage was 100 mg/L ACC for 3 min.In these conditions,most of the native microflora were inactivated,and artificially inoculated S.typhimurium DT104 on the red cabbage were reduced by 40.2 per cent[3.67 log CFU/g(log10 colony-forming units per gram)]and with minimal losses of nutrients and antioxidant activity,as well as no requirement of decontamination treatment on the washing water after AEW treatment.
