Over the past few decades, the determination of antioxidant activity by chemical probe has been widely reported, but in vivo evaluation via model organisms of Drosophila melanogaster and rapid discovery system has not...Over the past few decades, the determination of antioxidant activity by chemical probe has been widely reported, but in vivo evaluation via model organisms of Drosophila melanogaster and rapid discovery system has not been studied adequately. In this study, we determined the antioxidant activity of lees and demonstrated the ability of compounds in lees to scavenge H_2O_2 in vitro and in vivo by different chemical probes. Lees increased the ability of Drosophila against oxidative stress and antioxidant enzyme activity in vivo. Five ingredients of organic acids and flavones in lees extract that rapidly scavenged H_2O_2 were revealed by a post-column-derived HPLC-UV-FLD system based on 4-hydroxyphenylacetic acid（PHPAA）chemiluminescence. Additionally, another fluorescent probe,N-borylbenzyloxycarbonyl-3,7-dihydroxyphenoxazine（NBCD）, was selected to evaluate the reactive oxygen species（ROS） scavenging capacity of lees in living Drosophila melanogaster using a microfluidic injection test coupled with microscopic imaging analysis, and similar effects were observed in flies when they were treated with tartaric acid and caffeic acid. The results demonstrated that the novel integrated system was suitable for screening and evaluating antioxidant ingredients from natural products.展开更多
[ Objective] To produce protein feedstuff by mix fermentation of waste lees. [ Method] Waste lees was fermented by mixture of Aspergillus niger, Trichoderma vinde and Candida tropicalis to produce protein feedstuff. T...[ Objective] To produce protein feedstuff by mix fermentation of waste lees. [ Method] Waste lees was fermented by mixture of Aspergillus niger, Trichoderma vinde and Candida tropicalis to produce protein feedstuff. The fermentation conditions were optimized by single factor test and orthogonal test. [ Result] The optimum fermentation conditions of waste lees are as following： raw materials with fineness of 20 meshes composed of waste lees of 750 g/kg, com meal of 50 g/kg and wheat bran of 200 g/kg; pH value of inoculum culture, 5.0; Aspergillus niger： Trichoderma viHde： Candida tropicalis, 1 ： 1 ： 1 ; inoculum size, 12% （V/V） ; fermentation temperature, 30 ℃; and fermentation time, 6 d. After fermentation, the crude protein content, pure protein content, and crude fiber content were increased by 78.97%, 56.29% and 31.60%, respectively. In addition, the fermented waste lees was rich in beneficial live microorganisms and bioactive substances such as enzymes and vitamins. [ Conclusion] Waste lees can be well fermented to produce protein feedstuff by mix fermentation.展开更多
By the Soxhlet extraction, ethanol is used as extraction solvent of lees to determinate the total phenol content of Xiaoqu spirits lees. Folin-phenol method is handled to extract and to determine the reducing ability ...By the Soxhlet extraction, ethanol is used as extraction solvent of lees to determinate the total phenol content of Xiaoqu spirits lees. Folin-phenol method is handled to extract and to determine the reducing ability of extraction. The total phenolic content in the most suitable condition is determinated by the Folin-phenol method and the optimum extraction technological condition of total phenol is determinated by the experiment. The experimental results show that the optimization conditions of the determination methods of total phenolic content are determined by 3.5 mL for the Folin phenol reagent, 1:1 for the 10% Na2CO3 ratio and 30 min for the chromogenic reaction at room temperature. The optimum extraction technological condition of total phenol from lees is as following: solid-liquid ratio 1:12, ethanol concentration 100%, extraction temperature 80℃, extraction time 10 h.展开更多
In the Republic of Moldova, the viticulture industry is a sector with a high economic impact, and the utilization of secondary products from winemaking represents a growing concern regarding environmental sustainabili...In the Republic of Moldova, the viticulture industry is a sector with a high economic impact, and the utilization of secondary products from winemaking represents a growing concern regarding environmental sustainability. Wine lees, one of the types of wine waste, is less studied in order to valorize it. Currently it is used in the production of ethyl alcohol, as aggregates in the soil and others. The aim of this study was to characterize from a physico-chemical and microbiological point of view the lees sediments obtained after the primary fermentation of three types of individualized red wines made from autochthonous grapes varieties. It was found that residual yeasts represent a valuable raw material containing carbohydrates (from 14.35% ± 0.19% to 25.11% ± 1.51% SU), lipids (from 4.61% ± 0.21% to 9.41% ± 2.04% SU), proteins (from 42.62% ± 1.57% to 77.62% ± 9.14% SU), anthocyanins (from 9.18 ± 0.15 to 22.78 ± 1.60 mg cianid) and beta-glucans (from 12.84% ± 0.01% to 17.42% ± 0.02%). The pH value of wine lees ranges from 3.49 ± 0.0 to 3.083 ± 0.01, the dry matter from 9.62% ± 0.22% to 25.06% ± 0.42% and the ash from 0.03% ± 0.42% to 0.035% ± 0.21%. The microbiological study confirmed the presence of live yeasts of the genus Saccharomyces cerevisiae, which remain active due to the presence of residual sugars and oxygen. The results of the research are promising and encourage the obtaining of new products with special purpose and added value.展开更多
Succinic acid is valued as a potential starting point for the production of chemicals of the C4 family or in the prepara-tion of biodegradable polymers. For sustainable development in this era of petroleum shortage, p...Succinic acid is valued as a potential starting point for the production of chemicals of the C4 family or in the prepara-tion of biodegradable polymers. For sustainable development in this era of petroleum shortage, production of succinic acid by microbial fermentation of renewable feedstock has attracted great interest. In this study, pretreatment with sulfuric acid and biotin supplementation were used to enhance succinic acid production by Actinobacillus succinogenes 130Z from sake lees, a byproduct of Japanese rice wine. Pretreatment with sulfuric acid resulted in little change of glucose, total nitrogen and succinic acid content in the sake lees hydrolysate but had a positive effect on succinic acid fermentation, which caused a 25.0% increase in succinic acid yield in batch fermentation. Biotin supplementation was used to further enhance the fermentability of sake lees hydrolysate. As a result, a 30 h batch fermentation of 0.5% sulfuric acid pretreated sake lees hydrolysate with 0.2 mg/L biotin gave a succinic acid yield of 0.59 g/g from 61.6 g/L of glucose, with a productivity of 1.21 g/(L?h). A 22.9% increase in succinic acid yield and a 101.7% increase in succinic acid productivity were obtained compared with untreated sake lees hydrolysate.展开更多
Objectives:Lees are the major by-product of Huangjiu brewing and are prone to decomposition due to abundant protein residues.This study aims to convert the lees into high-value peptides with umami and antioxidant difu...Objectives:Lees are the major by-product of Huangjiu brewing and are prone to decomposition due to abundant protein residues.This study aims to convert the lees into high-value peptides with umami and antioxidant difunctionals.Materials and Methods:Herein,a one-step hydrolysis method combined with favorzyme followed by amylase pretreatment was developed and optimized.The target peptide fraction was collected and evaluated after ultrafltration and ethanol precipitation,and then identifed by nanohigh-performance liquid chromatography-tandem mass spectrometry.The target peptides were fltered through virtual screening,sensory,and radical scavenging verifcation.Results:The results show that 80 U/g amylase and 3500 U/g favorzyme synergistic hydrolysis at 50°C for 3 h performed best for umami intensity and antioxidant activity.A total of 5266 peptides was identifed from the 80%ethanol precipitation fraction,fnally secreened 7 umami peptides.The umami recognition threshold of the 7 peptides ranged from 0.38 to 0.66 mmol/L in water.Among them,DPDGW and DNPNW exhibited good DPPH antioxidant ability with IC_(50) values of 0.6982 mg/mL and 0.4315 mg/mL,respectively.Additionally,molecular docking studies indicated that all umami peptides tend to interact with the T1R3 receptor through hydrogen bonds and van der Waals forces,involving key residues such as ASN68,SER104,HIS145,SER276,VAL277,GLU301,ALA302,THR305,and HIS387.Conclusion:This study shows that Huangjiu lees is a potential resource for favor and bioactive peptide development,which provides a reference for other waste protein recycling.展开更多
Background Wine lees are defined as the residue formed at the bottom of the container during the wine fermentationstage. It consists of a solid phase composed of yeasts and bacteria responsible for vinification. In ge...Background Wine lees are defined as the residue formed at the bottom of the container during the wine fermentationstage. It consists of a solid phase composed of yeasts and bacteria responsible for vinification. In general, winelees, despite being a material rich in polyphenols, are underused or discarded. In this context, the aim of this reviewis to present an overview of the use of wine lees in the food industry and other sectors, by means of scientific andtechnological surveys.Methodology Bibliographical searches of the main works published on wine lees or grapes were carried out inarticles selected in the Scopus and SciELO databases, while the search for the technology protected or described inpatent documents involving wine lees and their main applications was carried out through the Espacenet onlinedatabase combined with the private platform from Questel company: Orbit^(®).Main text Wine lees represent an important fraction of winemaking by-products and contain several high-valuecomponents with potential to be exploited in industrial sectors, such as phenolic compounds. Through the Technological Prospection, it was demonstrated that wine lees are still poorly studied, with few patents filed on the technological/nutritional properties of wine lees. In 2016, there was a peak of patent filing growth and China was the countrywith the highest number of patents, totaling 31 deposits. Regarding the area of application, agriculture was themost common, followed by beverage production. Most of the inventors are of Asian origin, corroborating the resultspreviously discussed regarding the distribution of patents per country, and this might probably be related to the highinvestment of these countries in various stages of education and technological research.Conclusion The study suggests that different applications should aim at developing an integrated approach aimedat extracting from wine lees the highest number and quantities of compounds with possible applications in differentsectors.展开更多
Tapuy is an indigenous wine produced in the Philippines.Rice wine fermentation produces a by-product of rice leftover and microbial biomass,collectively called lees,which usually is discarded as a waste product.Howeve...Tapuy is an indigenous wine produced in the Philippines.Rice wine fermentation produces a by-product of rice leftover and microbial biomass,collectively called lees,which usually is discarded as a waste product.However,studies have shown the potential value of lees as a healthy food source.We wanted to determine the nutritional profile of tapuy wine and its lees and their abilities to extend lifespan in Caenorhabditis elegans.Tapuy lees(7.65 g/100 g dry weight)was 18.5-fold greater in protein content compared to tapuy wine.Its sugar content(27.66 g/100 g dry weight)is similar to the tapuy wine’s sugar content(23.465 g/100 g dry weight).Through LC-MS/MS,18.75%and 12.39%of spectral peaks in tapuy wine and lees were matched,respectively,to specific compounds,and several of them are associated with beneficial health effects.Furthermore,the phenolic content in tapuy lees(19,475.526 Gallic Acid Equivalent)is 6.5-fold greater compared to tapuy wine.Surprisingly,the DPPH and FRAP antioxidant assays show that tapuy lees had a lesser antioxidant ability compared to tapuy wine.However,C.elegans fed with supplementation of tapuy lees extract showed a 16.24%increase in mean lifespan,which is higher compared to the 6.10%increase in mean lifespan when supplemented with tapuy wine.Taking all these findings together,our study revealed that tapuy lees has a greater nutritional value than tapuy wine,and this underutilized and wastefully discarded product can be repurposed as a potential functional food.展开更多
Biographical Literature Issue 2,2025 Tsung Dao Lee:Do Something Useful for the Motherland This topic invites Professor Huang Qingqiao from the School of Marxism of Shanghai Jiao Tong University to review Tsung Dao Lee...Biographical Literature Issue 2,2025 Tsung Dao Lee:Do Something Useful for the Motherland This topic invites Professor Huang Qingqiao from the School of Marxism of Shanghai Jiao Tong University to review Tsung Dao Lee’s educational career and experience of studying abroad,as well as his decades of hard work for tiie cause of science and education in China,and to summarize Tsung Dao Lee's efforts.展开更多
Ocean mixing is a consequence of essential dynamic processes such as internal tides and lee waves that occur near the seafloor topography.Internal tides and lee waves are generated by barotropic tidal currents and geo...Ocean mixing is a consequence of essential dynamic processes such as internal tides and lee waves that occur near the seafloor topography.Internal tides and lee waves are generated by barotropic tidal currents and geostrophic flows,respectively.Ocean current is composed of multiple flows;thus,internal tides and lee waves occur concurrently in the real ocean.In this paper,the Massachusetts Institute of Technology general circulation model(MITgcm)is used to conduct 2D numerical experiments.By varying background flow intensities,the energy and dissipation relationship between internal tides and lee waves are investigated.The results reveal that the internal tide beams become asymmetric due to the influence of Doppler shift.The lee wave structure gradually leads the wave field when the background flow velocity rises constantly.The presence of a background flow increases the energy portion of the high-mode wave by up to 15%-20%.Moreover,strong shear,owing to the background flow,considerably increases dissipation.When the background flow velocity is higher than the barotropic tidal current velocity,the isopycnal overturn triggered by the lee wave generates a dissipation of the same order of magnitude as the shear.展开更多
基金financially supported by the Collaborative Innovation Center of Research on Functional Ingredients from Agricultural Residues (Guangxi University of Chinese medicine,No. CICAR 2015-B2)
文摘Over the past few decades, the determination of antioxidant activity by chemical probe has been widely reported, but in vivo evaluation via model organisms of Drosophila melanogaster and rapid discovery system has not been studied adequately. In this study, we determined the antioxidant activity of lees and demonstrated the ability of compounds in lees to scavenge H_2O_2 in vitro and in vivo by different chemical probes. Lees increased the ability of Drosophila against oxidative stress and antioxidant enzyme activity in vivo. Five ingredients of organic acids and flavones in lees extract that rapidly scavenged H_2O_2 were revealed by a post-column-derived HPLC-UV-FLD system based on 4-hydroxyphenylacetic acid（PHPAA）chemiluminescence. Additionally, another fluorescent probe,N-borylbenzyloxycarbonyl-3,7-dihydroxyphenoxazine（NBCD）, was selected to evaluate the reactive oxygen species（ROS） scavenging capacity of lees in living Drosophila melanogaster using a microfluidic injection test coupled with microscopic imaging analysis, and similar effects were observed in flies when they were treated with tartaric acid and caffeic acid. The results demonstrated that the novel integrated system was suitable for screening and evaluating antioxidant ingredients from natural products.
基金supported by the grants from Project of Liquor Making Bio-Technology & Application of Key Laboratory of Sichuan Province (NJ2008-14)Research Project of Sichuan University of Science & Engineering (2007ZR011)
文摘[ Objective] To produce protein feedstuff by mix fermentation of waste lees. [ Method] Waste lees was fermented by mixture of Aspergillus niger, Trichoderma vinde and Candida tropicalis to produce protein feedstuff. The fermentation conditions were optimized by single factor test and orthogonal test. [ Result] The optimum fermentation conditions of waste lees are as following： raw materials with fineness of 20 meshes composed of waste lees of 750 g/kg, com meal of 50 g/kg and wheat bran of 200 g/kg; pH value of inoculum culture, 5.0; Aspergillus niger： Trichoderma viHde： Candida tropicalis, 1 ： 1 ： 1 ; inoculum size, 12% （V/V） ; fermentation temperature, 30 ℃; and fermentation time, 6 d. After fermentation, the crude protein content, pure protein content, and crude fiber content were increased by 78.97%, 56.29% and 31.60%, respectively. In addition, the fermented waste lees was rich in beneficial live microorganisms and bioactive substances such as enzymes and vitamins. [ Conclusion] Waste lees can be well fermented to produce protein feedstuff by mix fermentation.
文摘By the Soxhlet extraction, ethanol is used as extraction solvent of lees to determinate the total phenol content of Xiaoqu spirits lees. Folin-phenol method is handled to extract and to determine the reducing ability of extraction. The total phenolic content in the most suitable condition is determinated by the Folin-phenol method and the optimum extraction technological condition of total phenol is determinated by the experiment. The experimental results show that the optimization conditions of the determination methods of total phenolic content are determined by 3.5 mL for the Folin phenol reagent, 1:1 for the 10% Na2CO3 ratio and 30 min for the chromogenic reaction at room temperature. The optimum extraction technological condition of total phenol from lees is as following: solid-liquid ratio 1:12, ethanol concentration 100%, extraction temperature 80℃, extraction time 10 h.
文摘In the Republic of Moldova, the viticulture industry is a sector with a high economic impact, and the utilization of secondary products from winemaking represents a growing concern regarding environmental sustainability. Wine lees, one of the types of wine waste, is less studied in order to valorize it. Currently it is used in the production of ethyl alcohol, as aggregates in the soil and others. The aim of this study was to characterize from a physico-chemical and microbiological point of view the lees sediments obtained after the primary fermentation of three types of individualized red wines made from autochthonous grapes varieties. It was found that residual yeasts represent a valuable raw material containing carbohydrates (from 14.35% ± 0.19% to 25.11% ± 1.51% SU), lipids (from 4.61% ± 0.21% to 9.41% ± 2.04% SU), proteins (from 42.62% ± 1.57% to 77.62% ± 9.14% SU), anthocyanins (from 9.18 ± 0.15 to 22.78 ± 1.60 mg cianid) and beta-glucans (from 12.84% ± 0.01% to 17.42% ± 0.02%). The pH value of wine lees ranges from 3.49 ± 0.0 to 3.083 ± 0.01, the dry matter from 9.62% ± 0.22% to 25.06% ± 0.42% and the ash from 0.03% ± 0.42% to 0.035% ± 0.21%. The microbiological study confirmed the presence of live yeasts of the genus Saccharomyces cerevisiae, which remain active due to the presence of residual sugars and oxygen. The results of the research are promising and encourage the obtaining of new products with special purpose and added value.
文摘Succinic acid is valued as a potential starting point for the production of chemicals of the C4 family or in the prepara-tion of biodegradable polymers. For sustainable development in this era of petroleum shortage, production of succinic acid by microbial fermentation of renewable feedstock has attracted great interest. In this study, pretreatment with sulfuric acid and biotin supplementation were used to enhance succinic acid production by Actinobacillus succinogenes 130Z from sake lees, a byproduct of Japanese rice wine. Pretreatment with sulfuric acid resulted in little change of glucose, total nitrogen and succinic acid content in the sake lees hydrolysate but had a positive effect on succinic acid fermentation, which caused a 25.0% increase in succinic acid yield in batch fermentation. Biotin supplementation was used to further enhance the fermentability of sake lees hydrolysate. As a result, a 30 h batch fermentation of 0.5% sulfuric acid pretreated sake lees hydrolysate with 0.2 mg/L biotin gave a succinic acid yield of 0.59 g/g from 61.6 g/L of glucose, with a productivity of 1.21 g/(L?h). A 22.9% increase in succinic acid yield and a 101.7% increase in succinic acid productivity were obtained compared with untreated sake lees hydrolysate.
基金supported by the National Key Research and Development Program of China(No.2021YFD2100102-4 and No.2022YFD2101204)the National Natural Science Foundation of China(22138004).
文摘Objectives:Lees are the major by-product of Huangjiu brewing and are prone to decomposition due to abundant protein residues.This study aims to convert the lees into high-value peptides with umami and antioxidant difunctionals.Materials and Methods:Herein,a one-step hydrolysis method combined with favorzyme followed by amylase pretreatment was developed and optimized.The target peptide fraction was collected and evaluated after ultrafltration and ethanol precipitation,and then identifed by nanohigh-performance liquid chromatography-tandem mass spectrometry.The target peptides were fltered through virtual screening,sensory,and radical scavenging verifcation.Results:The results show that 80 U/g amylase and 3500 U/g favorzyme synergistic hydrolysis at 50°C for 3 h performed best for umami intensity and antioxidant activity.A total of 5266 peptides was identifed from the 80%ethanol precipitation fraction,fnally secreened 7 umami peptides.The umami recognition threshold of the 7 peptides ranged from 0.38 to 0.66 mmol/L in water.Among them,DPDGW and DNPNW exhibited good DPPH antioxidant ability with IC_(50) values of 0.6982 mg/mL and 0.4315 mg/mL,respectively.Additionally,molecular docking studies indicated that all umami peptides tend to interact with the T1R3 receptor through hydrogen bonds and van der Waals forces,involving key residues such as ASN68,SER104,HIS145,SER276,VAL277,GLU301,ALA302,THR305,and HIS387.Conclusion:This study shows that Huangjiu lees is a potential resource for favor and bioactive peptide development,which provides a reference for other waste protein recycling.
基金supported by the National Council for Scientific Development(CNPq-Project number 21055)in the Institutional Scientific Initiation Scholarship Program(PIBIC)supported by the National Council for Scientific Development(CNPq-Project number 21049)in the Institutional Program for Initiation Scholarships in Technological Development and Innovation(PIBITI)+2 种基金supported by the Bahia State Research Support Foundation(FAPESB-Proc.0203/2020)COS is a Technological Development fellow from CNPq(Proc.313641/2019-6)MAUG(Proc.304747/2020-3).
文摘Background Wine lees are defined as the residue formed at the bottom of the container during the wine fermentationstage. It consists of a solid phase composed of yeasts and bacteria responsible for vinification. In general, winelees, despite being a material rich in polyphenols, are underused or discarded. In this context, the aim of this reviewis to present an overview of the use of wine lees in the food industry and other sectors, by means of scientific andtechnological surveys.Methodology Bibliographical searches of the main works published on wine lees or grapes were carried out inarticles selected in the Scopus and SciELO databases, while the search for the technology protected or described inpatent documents involving wine lees and their main applications was carried out through the Espacenet onlinedatabase combined with the private platform from Questel company: Orbit^(®).Main text Wine lees represent an important fraction of winemaking by-products and contain several high-valuecomponents with potential to be exploited in industrial sectors, such as phenolic compounds. Through the Technological Prospection, it was demonstrated that wine lees are still poorly studied, with few patents filed on the technological/nutritional properties of wine lees. In 2016, there was a peak of patent filing growth and China was the countrywith the highest number of patents, totaling 31 deposits. Regarding the area of application, agriculture was themost common, followed by beverage production. Most of the inventors are of Asian origin, corroborating the resultspreviously discussed regarding the distribution of patents per country, and this might probably be related to the highinvestment of these countries in various stages of education and technological research.Conclusion The study suggests that different applications should aim at developing an integrated approach aimedat extracting from wine lees the highest number and quantities of compounds with possible applications in differentsectors.
基金funded by the Philippine Institute of Traditional and Alternative Health Care(PITAHC).
文摘Tapuy is an indigenous wine produced in the Philippines.Rice wine fermentation produces a by-product of rice leftover and microbial biomass,collectively called lees,which usually is discarded as a waste product.However,studies have shown the potential value of lees as a healthy food source.We wanted to determine the nutritional profile of tapuy wine and its lees and their abilities to extend lifespan in Caenorhabditis elegans.Tapuy lees(7.65 g/100 g dry weight)was 18.5-fold greater in protein content compared to tapuy wine.Its sugar content(27.66 g/100 g dry weight)is similar to the tapuy wine’s sugar content(23.465 g/100 g dry weight).Through LC-MS/MS,18.75%and 12.39%of spectral peaks in tapuy wine and lees were matched,respectively,to specific compounds,and several of them are associated with beneficial health effects.Furthermore,the phenolic content in tapuy lees(19,475.526 Gallic Acid Equivalent)is 6.5-fold greater compared to tapuy wine.Surprisingly,the DPPH and FRAP antioxidant assays show that tapuy lees had a lesser antioxidant ability compared to tapuy wine.However,C.elegans fed with supplementation of tapuy lees extract showed a 16.24%increase in mean lifespan,which is higher compared to the 6.10%increase in mean lifespan when supplemented with tapuy wine.Taking all these findings together,our study revealed that tapuy lees has a greater nutritional value than tapuy wine,and this underutilized and wastefully discarded product can be repurposed as a potential functional food.
文摘Biographical Literature Issue 2,2025 Tsung Dao Lee:Do Something Useful for the Motherland This topic invites Professor Huang Qingqiao from the School of Marxism of Shanghai Jiao Tong University to review Tsung Dao Lee’s educational career and experience of studying abroad,as well as his decades of hard work for tiie cause of science and education in China,and to summarize Tsung Dao Lee's efforts.
基金supported by the National Natural Science Foundation of China(No.41876015)。
文摘Ocean mixing is a consequence of essential dynamic processes such as internal tides and lee waves that occur near the seafloor topography.Internal tides and lee waves are generated by barotropic tidal currents and geostrophic flows,respectively.Ocean current is composed of multiple flows;thus,internal tides and lee waves occur concurrently in the real ocean.In this paper,the Massachusetts Institute of Technology general circulation model(MITgcm)is used to conduct 2D numerical experiments.By varying background flow intensities,the energy and dissipation relationship between internal tides and lee waves are investigated.The results reveal that the internal tide beams become asymmetric due to the influence of Doppler shift.The lee wave structure gradually leads the wave field when the background flow velocity rises constantly.The presence of a background flow increases the energy portion of the high-mode wave by up to 15%-20%.Moreover,strong shear,owing to the background flow,considerably increases dissipation.When the background flow velocity is higher than the barotropic tidal current velocity,the isopycnal overturn triggered by the lee wave generates a dissipation of the same order of magnitude as the shear.
