The objective of this study was to separate the phenolic compounds that had been converted into free forms by enzymatic liquefaction(2%Viscozyme L+3%Pectinex)from the pomegranate by-products using ultrafiltration.The ...The objective of this study was to separate the phenolic compounds that had been converted into free forms by enzymatic liquefaction(2%Viscozyme L+3%Pectinex)from the pomegranate by-products using ultrafiltration.The effect of two different molecular weight cut-off ranges(5 and 50 kDa)on phenolic content(total,free,bound),hydrolysable tannin content and antioxidant activity(total,free,bound)of the extracts was evaluated through a comparative analysis.The highest total phenolic content(89.45±3.72 mg GAE/g),hydrolysable tannin content(20.31±0.40 mg TAE/g),DPPH radical scavenging activity(476.18±3.86 mg TEAA/g),ferric reducing antioxidant power(236.08±2.03 mg TEAA/g)and cupric reducing antioxidant capacity(389.86±0.65 mg TEAA/g)were determined in retentate of 50 kDa membrane.A strong correlation was observed between the phenolic content and antioxidant activity of samples.The separation of the sample using a 50 kDa membrane resulted in a slight concentration effect in the total and free phenolic content.Although antioxidant rejection of the 50 kDa membrane(118.77%,125.52%,127.00%)was lower than that of the 5 kDa(139.86%,160.76%and 323.90%),the antioxidant concentrations of 50 kDa were higher compared to the concentrations of the 5 kDa(DPPH:252.55 mg TEAA/g,FRAP:183.39 mg TEAA/g,CUPRAC:264.78 mg TEAA/g).These results may be associated with the compounds released by the enzymes,which have affected the membrane fouling by interacting with each other.Overall,this study suggests that the combined enzymatic liquefaction and ultrafiltration approach has potential as a green extraction method for sustainable separation of phenolic compounds from by-products.展开更多
This study aimed to valorize hazelnut press cake,a hazelnut oil industry waste,by producing hazelnut protein isolates using alkaline extraction and isoelectric precipitation.The impact of refractance window drying at ...This study aimed to valorize hazelnut press cake,a hazelnut oil industry waste,by producing hazelnut protein isolates using alkaline extraction and isoelectric precipitation.The impact of refractance window drying at varying temperatures on the physical,chemical,and technological properties of protein isolates was comparatively evaluated in comparison to spray drying.Dry matter content,water activity,protein content,color,particle size,bulk density,tapped density,flow properties,solubility,water and oil holding capacity,surface hydrophobicity,emulsification,and foaming properties of protein isolates were analyzed.Results showed that the drying method and temperature significantly influenced the properties of the protein isolates.Spray drying produced protein isolates with better color,higher solubility,surface hydrophobicity,and foaming properties than refractance window drying.However,refractance window drying resulted in better flow and emulsification properties of protein isolates.The temperature of refractance window drying was found to be effective on protein content,color,particle size,bulk and tapped densities and emulsification properties of protein isolates.These findings suggest that both drying methods offer unique advantages for producing protein isolates from hazelnut press cake with tailored functionalities.展开更多
文摘The objective of this study was to separate the phenolic compounds that had been converted into free forms by enzymatic liquefaction(2%Viscozyme L+3%Pectinex)from the pomegranate by-products using ultrafiltration.The effect of two different molecular weight cut-off ranges(5 and 50 kDa)on phenolic content(total,free,bound),hydrolysable tannin content and antioxidant activity(total,free,bound)of the extracts was evaluated through a comparative analysis.The highest total phenolic content(89.45±3.72 mg GAE/g),hydrolysable tannin content(20.31±0.40 mg TAE/g),DPPH radical scavenging activity(476.18±3.86 mg TEAA/g),ferric reducing antioxidant power(236.08±2.03 mg TEAA/g)and cupric reducing antioxidant capacity(389.86±0.65 mg TEAA/g)were determined in retentate of 50 kDa membrane.A strong correlation was observed between the phenolic content and antioxidant activity of samples.The separation of the sample using a 50 kDa membrane resulted in a slight concentration effect in the total and free phenolic content.Although antioxidant rejection of the 50 kDa membrane(118.77%,125.52%,127.00%)was lower than that of the 5 kDa(139.86%,160.76%and 323.90%),the antioxidant concentrations of 50 kDa were higher compared to the concentrations of the 5 kDa(DPPH:252.55 mg TEAA/g,FRAP:183.39 mg TEAA/g,CUPRAC:264.78 mg TEAA/g).These results may be associated with the compounds released by the enzymes,which have affected the membrane fouling by interacting with each other.Overall,this study suggests that the combined enzymatic liquefaction and ultrafiltration approach has potential as a green extraction method for sustainable separation of phenolic compounds from by-products.
文摘This study aimed to valorize hazelnut press cake,a hazelnut oil industry waste,by producing hazelnut protein isolates using alkaline extraction and isoelectric precipitation.The impact of refractance window drying at varying temperatures on the physical,chemical,and technological properties of protein isolates was comparatively evaluated in comparison to spray drying.Dry matter content,water activity,protein content,color,particle size,bulk density,tapped density,flow properties,solubility,water and oil holding capacity,surface hydrophobicity,emulsification,and foaming properties of protein isolates were analyzed.Results showed that the drying method and temperature significantly influenced the properties of the protein isolates.Spray drying produced protein isolates with better color,higher solubility,surface hydrophobicity,and foaming properties than refractance window drying.However,refractance window drying resulted in better flow and emulsification properties of protein isolates.The temperature of refractance window drying was found to be effective on protein content,color,particle size,bulk and tapped densities and emulsification properties of protein isolates.These findings suggest that both drying methods offer unique advantages for producing protein isolates from hazelnut press cake with tailored functionalities.
