This study reports the protease production from Aspergillus tamarii using agroindustrial residues as substrate for solid-state fermentation (SSF) and biochemical characterization. The highest protease production was o...This study reports the protease production from Aspergillus tamarii using agroindustrial residues as substrate for solid-state fermentation (SSF) and biochemical characterization. The highest protease production was obtained using wheat bran as substrate at 72 h fermentation with maximum proteolytic activity of 401.42 U/mL, collagenase of 243.0 U/mL and keratinase of 19.1 U/mL. The protease exhibited K<sub>M</sub> = 18.7 mg/mL and Vmax = 28.5 mg/mL/min. The optimal pH was 8.0 and stable in a wide pH range (5.0 - 11.0) during 24 h. The optimum temperature was 40°C. The proteolytic activity was inhibited by Cu<sup>2+</sup> (33.98%) and Hg<sup>2+</sup> (22.69%). The enzyme was also inhibited by PMSF (65.11%), indicating that is a Serine Protease. These properties suggest that alkaline protease from A. tamarii URM4634 is suitable for application in food industries and leather processing. Additionally, the present findings opened new vistas in the utilization of wheat bran and other effective agroindustrial wastes as substrates for SSF.展开更多
Grape processing generates residues rich in bioactive compounds with potential application in the meat industry.However,these substances are unstable and needs to be treated to allow their action during the processing...Grape processing generates residues rich in bioactive compounds with potential application in the meat industry.However,these substances are unstable and needs to be treated to allow their action during the processing and storage of meat products.In this sense,a phenolic-rich extract from grape pomace was microencapsulated and evaluated for its potential to inhibit the oxidative process in raw and precooked beef burgers during cold storage.Three hamburger formulations containing lyophilized extract(LEB),microencapsulated extract(MEB)and synthetic antioxidant sodium erythorbate(SEB)were prepared,pre-cooked,and evaluated for lipid and protein oxidation.The microencapsulation,with 95.0%efficiency,provided a material with a crystalline structure,rich in phenolics and with high antioxidant potential,showing 377.4±0.01,1768.1±0.07 and 1185.0±0.20μmol TEAC.100 g^(−1) for DPPH,ABTS and FRAP,respectively.Lower values of malonaldehyde were found in LEB and MEB(2.9±0.3 and 1.4±0.5 mg MDA.kg^(−1),respectively)at the end of storage,with emphasis on for the hamburgers that received the microencapsulated extract.Similar behavior was observed for the analysis of carbonyl compounds,with values of 11.1±1.1,8.7±1.4 and 6.8±1.0 nM carbonyl.mg^(−1) in SEB,LEB and MEB,respectively.Thus,the freeze-dried and microencapsulated grape extracts showed superior results when compared to the synthetic antioxidant,increasing the oxidative stability of hamburgers,and avoiding significant color changes during the cold storage.The results indicate the high potential of the microencapsulated material to be used as a natural antioxidant in the meat industry.展开更多
文摘This study reports the protease production from Aspergillus tamarii using agroindustrial residues as substrate for solid-state fermentation (SSF) and biochemical characterization. The highest protease production was obtained using wheat bran as substrate at 72 h fermentation with maximum proteolytic activity of 401.42 U/mL, collagenase of 243.0 U/mL and keratinase of 19.1 U/mL. The protease exhibited K<sub>M</sub> = 18.7 mg/mL and Vmax = 28.5 mg/mL/min. The optimal pH was 8.0 and stable in a wide pH range (5.0 - 11.0) during 24 h. The optimum temperature was 40°C. The proteolytic activity was inhibited by Cu<sup>2+</sup> (33.98%) and Hg<sup>2+</sup> (22.69%). The enzyme was also inhibited by PMSF (65.11%), indicating that is a Serine Protease. These properties suggest that alkaline protease from A. tamarii URM4634 is suitable for application in food industries and leather processing. Additionally, the present findings opened new vistas in the utilization of wheat bran and other effective agroindustrial wastes as substrates for SSF.
基金funded in part by the Coordination for the Improvement of Higher Education Personnel-Brazil(CAPES)for the scholarship awarded to the first author-Finance Code 001“Fundaç˜ao de Apoio`a Pesquisa do Estado da Paraíba”(FAPESQ-PB)for the financial support through project 005/2019.
文摘Grape processing generates residues rich in bioactive compounds with potential application in the meat industry.However,these substances are unstable and needs to be treated to allow their action during the processing and storage of meat products.In this sense,a phenolic-rich extract from grape pomace was microencapsulated and evaluated for its potential to inhibit the oxidative process in raw and precooked beef burgers during cold storage.Three hamburger formulations containing lyophilized extract(LEB),microencapsulated extract(MEB)and synthetic antioxidant sodium erythorbate(SEB)were prepared,pre-cooked,and evaluated for lipid and protein oxidation.The microencapsulation,with 95.0%efficiency,provided a material with a crystalline structure,rich in phenolics and with high antioxidant potential,showing 377.4±0.01,1768.1±0.07 and 1185.0±0.20μmol TEAC.100 g^(−1) for DPPH,ABTS and FRAP,respectively.Lower values of malonaldehyde were found in LEB and MEB(2.9±0.3 and 1.4±0.5 mg MDA.kg^(−1),respectively)at the end of storage,with emphasis on for the hamburgers that received the microencapsulated extract.Similar behavior was observed for the analysis of carbonyl compounds,with values of 11.1±1.1,8.7±1.4 and 6.8±1.0 nM carbonyl.mg^(−1) in SEB,LEB and MEB,respectively.Thus,the freeze-dried and microencapsulated grape extracts showed superior results when compared to the synthetic antioxidant,increasing the oxidative stability of hamburgers,and avoiding significant color changes during the cold storage.The results indicate the high potential of the microencapsulated material to be used as a natural antioxidant in the meat industry.
