Superchilling is an emerging technology for meat preservation;however,the temperature changes during the process have been commonly ignored.Thus,the effects of temperature fluctuations on meat quality during superchil...Superchilling is an emerging technology for meat preservation;however,the temperature changes during the process have been commonly ignored.Thus,the effects of temperature fluctuations on meat quality during superchilling are yet to be evaluated.In our study,pork loins and salmon fillets were stored for several days(0,8,15,23,and 30 d)under different temperature fluctuations based on−3.5℃ as the target temperature.The results showed that after 15 d of superchilling storage,the values of total volatile basic nitrogen,total viable count,and lipid oxidation were significantly(P<0.05)altered in the±2.0℃ fluctuation group compared with the constant temperature group.On the contrary,there was no significant difference in these parameters between the±1.0℃ fluctuation group and the constant temperature group after 30 d of storage.In addition,irregular temperature changes significantly accelerated the modulation of various indicators.In brief,temperature fluctuations and irregular temperature changes accelerated the destruction of muscle structural integrity,increased the water loss,gradually widened the water loss channels,and thereby reduced the edibility by accelerating the spoilage of meat.展开更多
Objectives:This study was conducted to investigate the xanthine oxidase(XO)inhibitory activities of 18 monomeric anthocyanins from berry fruits and roselle,and to illustrate the underlying mechanism of the most active...Objectives:This study was conducted to investigate the xanthine oxidase(XO)inhibitory activities of 18 monomeric anthocyanins from berry fruits and roselle,and to illustrate the underlying mechanism of the most active anthocyanin delphinidin-3-O-sambubioside.Materials and Methods:Eighteen monomeric anthocyanins were prepared and purified in our laboratory.The inhibitory properties of anthocyanins were investigated by in vitro inhibitory activity studies and fluorescence quenching studies;the inhibitory mechanism was explored through kinetic studies,fluorescence quenching studies,circular dichroism analysis and computational docking simulations.Results:XO inhibitory activities of anthocyanins were related to the structures of B rings and glycosides.Among all the tested anthocyanins,delphinidin-3-O-sambubioside showed the most potent inhibitory activity with an IC_(50) of 17.1μmol/L,which was comparable to the positive control allopurinol.Spectroscopic results revealed that delphinidin-3-O-sambubioside could spontaneously interact with XO and induce conformational changes.Computational docking study indicated that delphinidin-3-O-sambubioside could bind to XO with a proper orientation,stably formed π-π interactions and hydrogen bonds with key residues,thus preventing the substrate from entering the active pocket.Conclusions:In brief,our study identified delphinidin-3-O-sambubioside as a potent XO inhibitor from natural anthocyanins,which is potentially applicable for prevention and treatment of hyperuricemia.展开更多
Refrigeration is considered a prime technology for preserving meat products.Temperature alterations are commonly ignored by industry during refrigeration,which have impacts on product quality.Thus,we conducted researc...Refrigeration is considered a prime technology for preserving meat products.Temperature alterations are commonly ignored by industry during refrigeration,which have impacts on product quality.Thus,we conducted research on pork loin and salmon fllets that were preserved for o,5,9,12,and 15 d,where different temperature fluctuations and shocks were established on 4℃.Data revealed that several meat parameters such as total volatile basic nitrogen,total viable count,and lipid oxidation were significantly changed in the±2 C fluctuations group compared with the constant temperature group.Additionally,both the temperature fluctuations and shocks groups had accelerated myofibril protein degrad-ation,while desmin expression and species richness/diversity of bacteria were significantly reduced in the±2℃fluctuations group compared with the constant temperature group.Briefly,temperature fluctuations and shocks accelerated the destruction of muscle structural integrity.Furthermore,both conditions accelerated meat spoilage by progressively expanding the water-loss channels,which can reduce meat edibility.This study provides a new theoretical basis for the proper use of refrigerated temperatures for storing meat products.展开更多
基金This work was supported by the Starry Night Science Fund of Zhejiang University Shanghai Institute for Advanced Study(No.SN-ZJU-SIAS-0013)the National Key Technology R&D Program of China(No.2016YFD0401201).
文摘Superchilling is an emerging technology for meat preservation;however,the temperature changes during the process have been commonly ignored.Thus,the effects of temperature fluctuations on meat quality during superchilling are yet to be evaluated.In our study,pork loins and salmon fillets were stored for several days(0,8,15,23,and 30 d)under different temperature fluctuations based on−3.5℃ as the target temperature.The results showed that after 15 d of superchilling storage,the values of total volatile basic nitrogen,total viable count,and lipid oxidation were significantly(P<0.05)altered in the±2.0℃ fluctuation group compared with the constant temperature group.On the contrary,there was no significant difference in these parameters between the±1.0℃ fluctuation group and the constant temperature group after 30 d of storage.In addition,irregular temperature changes significantly accelerated the modulation of various indicators.In brief,temperature fluctuations and irregular temperature changes accelerated the destruction of muscle structural integrity,increased the water loss,gradually widened the water loss channels,and thereby reduced the edibility by accelerating the spoilage of meat.
文摘Objectives:This study was conducted to investigate the xanthine oxidase(XO)inhibitory activities of 18 monomeric anthocyanins from berry fruits and roselle,and to illustrate the underlying mechanism of the most active anthocyanin delphinidin-3-O-sambubioside.Materials and Methods:Eighteen monomeric anthocyanins were prepared and purified in our laboratory.The inhibitory properties of anthocyanins were investigated by in vitro inhibitory activity studies and fluorescence quenching studies;the inhibitory mechanism was explored through kinetic studies,fluorescence quenching studies,circular dichroism analysis and computational docking simulations.Results:XO inhibitory activities of anthocyanins were related to the structures of B rings and glycosides.Among all the tested anthocyanins,delphinidin-3-O-sambubioside showed the most potent inhibitory activity with an IC_(50) of 17.1μmol/L,which was comparable to the positive control allopurinol.Spectroscopic results revealed that delphinidin-3-O-sambubioside could spontaneously interact with XO and induce conformational changes.Computational docking study indicated that delphinidin-3-O-sambubioside could bind to XO with a proper orientation,stably formed π-π interactions and hydrogen bonds with key residues,thus preventing the substrate from entering the active pocket.Conclusions:In brief,our study identified delphinidin-3-O-sambubioside as a potent XO inhibitor from natural anthocyanins,which is potentially applicable for prevention and treatment of hyperuricemia.
基金supported by the Starry Night Science Fund of Zhejiang University Shanghai Institute for Advanced Study(No.SN-ZJU-SIAS-0013)the National Key Technology Research and Development Program of China(No.2016YFD0401201).
文摘Refrigeration is considered a prime technology for preserving meat products.Temperature alterations are commonly ignored by industry during refrigeration,which have impacts on product quality.Thus,we conducted research on pork loin and salmon fllets that were preserved for o,5,9,12,and 15 d,where different temperature fluctuations and shocks were established on 4℃.Data revealed that several meat parameters such as total volatile basic nitrogen,total viable count,and lipid oxidation were significantly changed in the±2 C fluctuations group compared with the constant temperature group.Additionally,both the temperature fluctuations and shocks groups had accelerated myofibril protein degrad-ation,while desmin expression and species richness/diversity of bacteria were significantly reduced in the±2℃fluctuations group compared with the constant temperature group.Briefly,temperature fluctuations and shocks accelerated the destruction of muscle structural integrity.Furthermore,both conditions accelerated meat spoilage by progressively expanding the water-loss channels,which can reduce meat edibility.This study provides a new theoretical basis for the proper use of refrigerated temperatures for storing meat products.
