Kraft lignin(KL)is a promising additive for obtaining multifunctional biodegradable packaging.However,the hydrophobic properties of lignin hinder its dispersion in hydrophilic matrices.The prior alkaline solubilizatio...Kraft lignin(KL)is a promising additive for obtaining multifunctional biodegradable packaging.However,the hydrophobic properties of lignin hinder its dispersion in hydrophilic matrices.The prior alkaline solubilization of lignin before adding it to the filmogenic dispersion could be an alternative to overcome this limitation.In this sense,this study aimed to produce whey protein isolate(WPI)multifunctional films incorporated with different concentrations of KL,ranging from 0%to 8%,previously solubilized in alkaline solution,and characterize them in terms of morphological,molecular,mechanical,optical,hydrophobicity,thermal,sealability,antioxidant,and UV-blocking properties.The prior solubilization of KL allowed the obtainment of homogeneous films of a dark color with greater resistance to fracture,higher hydrophobicity,higher glass transition temperature than the control film,and a slightly greater thermal stability:the initial and maximum degradation temperature of 166.1℃and 305.3℃,respectively.Lignin presence in the matrix also gave the films functionalities compared to the control:the films added with 2%of KL blocked 95%of UVA and 100%UVB radiation without impairing the passage of visible light,and the films with 8%of KL showed 34.69%of antioxidant activity in DPPH analysis.However,the films were not heat sealable,which was an undesirable outcome.Nevertheless,lignin solubilization in alkali proved to be an efficient methodology for producing multifunctional WPI films,with potential appli-cation on foods susceptible to oxidation.展开更多
The aim was to develop films with a new mixture of collagen fiber plus polyvinyl alcohol added of oregano or rosemary essential oils at different levels (0%, 2%, 4% and 6%), as well as to assess the antimicrobial acti...The aim was to develop films with a new mixture of collagen fiber plus polyvinyl alcohol added of oregano or rosemary essential oils at different levels (0%, 2%, 4% and 6%), as well as to assess the antimicrobial activity, physical, optical, microstructure and molecular properties in the films. An interaction between the ingredients was observed at the molecular level by FTIR. The amide II and amide III bands, which are important to verify collagen conformation, showed intense peaks in the films. The formation of a network through collagen fibers was produced, acting as a reinforcement in matrix. The films with essential oil had an expressive antimicrobial activity by the steam contact method (micro-atmosphere), mainly for Escherichia coli and Staphylococcus aureus. The mixture of collagen fiber plus polyvinyl alcohol added of essential oils is a promising matrix for application in food as active packaging.展开更多
基金Research Support Fund(FAPEMIG)for financial assis-tance(grant number 12622)financed in part by the Coordenaçāo de Aperfeiçoamento de Pessoal de Nível Superior-Brasil(CAPES)-Finance code 001.
文摘Kraft lignin(KL)is a promising additive for obtaining multifunctional biodegradable packaging.However,the hydrophobic properties of lignin hinder its dispersion in hydrophilic matrices.The prior alkaline solubilization of lignin before adding it to the filmogenic dispersion could be an alternative to overcome this limitation.In this sense,this study aimed to produce whey protein isolate(WPI)multifunctional films incorporated with different concentrations of KL,ranging from 0%to 8%,previously solubilized in alkaline solution,and characterize them in terms of morphological,molecular,mechanical,optical,hydrophobicity,thermal,sealability,antioxidant,and UV-blocking properties.The prior solubilization of KL allowed the obtainment of homogeneous films of a dark color with greater resistance to fracture,higher hydrophobicity,higher glass transition temperature than the control film,and a slightly greater thermal stability:the initial and maximum degradation temperature of 166.1℃and 305.3℃,respectively.Lignin presence in the matrix also gave the films functionalities compared to the control:the films added with 2%of KL blocked 95%of UVA and 100%UVB radiation without impairing the passage of visible light,and the films with 8%of KL showed 34.69%of antioxidant activity in DPPH analysis.However,the films were not heat sealable,which was an undesirable outcome.Nevertheless,lignin solubilization in alkali proved to be an efficient methodology for producing multifunctional WPI films,with potential appli-cation on foods susceptible to oxidation.
文摘The aim was to develop films with a new mixture of collagen fiber plus polyvinyl alcohol added of oregano or rosemary essential oils at different levels (0%, 2%, 4% and 6%), as well as to assess the antimicrobial activity, physical, optical, microstructure and molecular properties in the films. An interaction between the ingredients was observed at the molecular level by FTIR. The amide II and amide III bands, which are important to verify collagen conformation, showed intense peaks in the films. The formation of a network through collagen fibers was produced, acting as a reinforcement in matrix. The films with essential oil had an expressive antimicrobial activity by the steam contact method (micro-atmosphere), mainly for Escherichia coli and Staphylococcus aureus. The mixture of collagen fiber plus polyvinyl alcohol added of essential oils is a promising matrix for application in food as active packaging.
