The objective of the present study was the recovery and selective separation of phenolics from grape marc and lees, two primary wastes from wine-making industry, with solvent extraction method, optimized using One-Fac...The objective of the present study was the recovery and selective separation of phenolics from grape marc and lees, two primary wastes from wine-making industry, with solvent extraction method, optimized using One-Factor-at-a-Time method (OFAT) and Response Surface Methodology (RSM). Phenolics from the whole fresh grapes have been studied in previous work, but not the valorization of wine wastes and their phenolic content. Extraction resulted in 19, 15 and 10 mg/g (dry weight) total phenolics with 96%, 87% and 64% antioxidant activity from red, white marc and white lees, respectively. Extracts thus obtained were subsequently treated with several sorbents followed by HCl-desorption. NaOH and CH3OH treated zeolite and aluminum oxide, respectively, performed better, separating phenolics up to 93% from total sugars. The latter resulted in a fraction containing up to 50% of the initial phenolics holding the antioxidant activity (up to 85%) of the initial extract. The results indicate the significance of the applied methodology being fast and low cost for the selective recovery of phenolics from wine wastes.展开更多
Starch nanoparticles are used as a matrix with natural rubber for tire making, alternative adsorbents for wastewater treatment, drug carriers, packaging materials, emulsion stabilizers and fat replacers. The objective...Starch nanoparticles are used as a matrix with natural rubber for tire making, alternative adsorbents for wastewater treatment, drug carriers, packaging materials, emulsion stabilizers and fat replacers. The objective of this study is to prepare the starch nanoparticles from cassava peel by mineral acid hydrolysis using hydrochloric and sulfuric acids and perform the characterization of starch nanoparticles with Fourier transform infrared (FTIR),X-ray diffraction (XRD) and scanning electron microscope (SEM)It was found that the obtained yield of starch nanoparticles by H2SO4was higher than that by HCl.展开更多
Exploiting light to drive redox reactions is currently a hot topic since light is considered as an environmentally friendly source of energy.Consequently,cyanobacteria,which can use light e.g.,for generating NADPH,are...Exploiting light to drive redox reactions is currently a hot topic since light is considered as an environmentally friendly source of energy.Consequently,cyanobacteria,which can use light e.g.,for generating NADPH,are in the focus of research.Previously,it has been shown that various heterologous redox enzymes could be expressed in these microorganisms.Here we demonstrated the successful inducer-free expression of𝛼-keto-acid dehydroge-nases(L-HicDH and D-HicDH)from Lactobacillus confusus DSM 20196 and Lactobacillus paracasei DSM 20008 in Synechocystis sp.PCC 6803ΔhoxYH mutant using replicative plasmids.While the L-HicDH showed poor activity limited by the amount of expressed enzyme,the D-HicDH was applied both in vivo and in vitro,transforming the selected𝛼-keto acids to the corresponding optically pure(R)-𝛼-hydroxy acids(ee>99%)in up to 53%and 90%conversion,respectively.展开更多
文摘The objective of the present study was the recovery and selective separation of phenolics from grape marc and lees, two primary wastes from wine-making industry, with solvent extraction method, optimized using One-Factor-at-a-Time method (OFAT) and Response Surface Methodology (RSM). Phenolics from the whole fresh grapes have been studied in previous work, but not the valorization of wine wastes and their phenolic content. Extraction resulted in 19, 15 and 10 mg/g (dry weight) total phenolics with 96%, 87% and 64% antioxidant activity from red, white marc and white lees, respectively. Extracts thus obtained were subsequently treated with several sorbents followed by HCl-desorption. NaOH and CH3OH treated zeolite and aluminum oxide, respectively, performed better, separating phenolics up to 93% from total sugars. The latter resulted in a fraction containing up to 50% of the initial phenolics holding the antioxidant activity (up to 85%) of the initial extract. The results indicate the significance of the applied methodology being fast and low cost for the selective recovery of phenolics from wine wastes.
文摘Starch nanoparticles are used as a matrix with natural rubber for tire making, alternative adsorbents for wastewater treatment, drug carriers, packaging materials, emulsion stabilizers and fat replacers. The objective of this study is to prepare the starch nanoparticles from cassava peel by mineral acid hydrolysis using hydrochloric and sulfuric acids and perform the characterization of starch nanoparticles with Fourier transform infrared (FTIR),X-ray diffraction (XRD) and scanning electron microscope (SEM)It was found that the obtained yield of starch nanoparticles by H2SO4was higher than that by HCl.
文摘Exploiting light to drive redox reactions is currently a hot topic since light is considered as an environmentally friendly source of energy.Consequently,cyanobacteria,which can use light e.g.,for generating NADPH,are in the focus of research.Previously,it has been shown that various heterologous redox enzymes could be expressed in these microorganisms.Here we demonstrated the successful inducer-free expression of𝛼-keto-acid dehydroge-nases(L-HicDH and D-HicDH)from Lactobacillus confusus DSM 20196 and Lactobacillus paracasei DSM 20008 in Synechocystis sp.PCC 6803ΔhoxYH mutant using replicative plasmids.While the L-HicDH showed poor activity limited by the amount of expressed enzyme,the D-HicDH was applied both in vivo and in vitro,transforming the selected𝛼-keto acids to the corresponding optically pure(R)-𝛼-hydroxy acids(ee>99%)in up to 53%and 90%conversion,respectively.
