Bio-hydrogen (Bio-H2) production from the organic fraction of solid waste, as fruit and vegetable wastes, constitutes an interesting and feasible technology to obtain clean energy. In spite of the feasibility to produ...Bio-hydrogen (Bio-H2) production from the organic fraction of solid waste, as fruit and vegetable wastes, constitutes an interesting and feasible technology to obtain clean energy. In spite of the feasibility to produce Bio-H2 from fruit/vegetable wastes (FVW), data about its rheological characterization are scarce. This information is useful to establish the hydrodynamic behavior, which controls the overall mixing process when the feedstock for Bio-H2 production process is a mixture of FVW. In this work, the rheological behavior of a vegetable/fruit waste mixture was characterized. The effect of the solids content (%, w/w), temperature, time (tyxotropy effects) and shear rate over the apparent viscosity of the mixture was evaluated. Most of the mixtures showed non-Newtonian behavior. The curves are typical rheofluidizing fluids. The rheological curves were different at increasing solids contents (80%, 60%, 40% and 30%), independent from the temperature. Rheological data were fitted to the power law model. Correlation factors R2 for the different mixtures were 0.991-0.995 for 80%, 0.961 -0.986 for 60%, 0.890 -0.925 for 40%. In the case of 30% of solids, the R2 value was not acceptable, and it was also found that this mixture was very near to the Newtonian behavior. Calculated activation energies (Ea) values were 15.98, 14.89 and 20.96 kJ/mol for the 80%, 60%, 40% mixtures, respectively. FVW purees rheological behavior was well characterized by Carbopol solutions at given concentrations and pH values. This fluid can be used as a model for other studies, e.g. LDA (Laser Doppler Anemometry) and PIV (Particle Image Velocimetry).展开更多
脉冲电场(pulsed electric field,PEF)以其独特的非热特性和短时、高效、节能的加工特性成为果蔬汁杀菌保鲜技术的新趋势,可以在保证果蔬汁微生物安全性的同时保持其“新鲜风味”以及营养属性。该文综述了脉冲电场处理对果蔬汁品质、钝...脉冲电场(pulsed electric field,PEF)以其独特的非热特性和短时、高效、节能的加工特性成为果蔬汁杀菌保鲜技术的新趋势,可以在保证果蔬汁微生物安全性的同时保持其“新鲜风味”以及营养属性。该文综述了脉冲电场处理对果蔬汁品质、钝酶和杀菌等效果的影响以及在果蔬汁加工领域的应用现状,阐述了PEF技术在果蔬汁加工中的劣势以及与其他技术联用的优势,探讨了基于设备选用、工艺参数与食品基质间特异性、微生物亚致死导致的PEF技术的安全性等问题,分析了PEF在果蔬汁加工领域的应用前景和所面临的挑战,以期为PEF技术在果蔬加工领域的深入研究提供参考。展开更多
Background:Dietary supplementation with citrate-containing juices may serve as an effective alternative to potassium citrate therapy for preventing calcium oxalate stone recurrence.This study was performed to evaluate...Background:Dietary supplementation with citrate-containing juices may serve as an effective alternative to potassium citrate therapy for preventing calcium oxalate stone recurrence.This study was performed to evaluate whether consumption of lemon-tomato juice can decrease the tendency for stone formation in the urine of calcium oxalate stone formers.Materials and methods:The study was conducted as a prospective interventional randomized crossover clinical trial with a repeated-measures design.Twenty-two patients with calcium oxalate stones and no metabolic abnormalities in the urine treated with lithotripsy at a tertiary care center from August 2017 to July 2018 were recruited.After a 14-hour overnight fasting,urine samples were collected after the patients consumed either milk only or milk and lemon-tomato juice.Their urine was tested for multiple parameters,including urine pH,specific gravity,calcium-creatinine ratio,and supersaturation with sodium oxalate,followed by optical density measurement via spectrophotometry.Results:There were no significant differences in the background characteristics between the 2 groups.The optical density of the urine samples obtained after consumption of milk only was significantly higher than that after consumption of milk and lemon-tomato juice(mean=0.131 for milk only vs.0.053 for milk and lemon-tomato juice,p<0.001).The urine calcium-creatinine ratio was similar between the groups(mean=0.141 for milk only vs.0.076 for milk and lemon-tomato juice,p=0.019).Conclusions:The addition of lemon-tomato juice as a source of citrate in the diet significantly decreases the established risk factors for calcium oxalate stone formation in patients.This study was prospectively registered at CTRI under number CTRI/2017/04/008312 on April 7,2017.展开更多
基金PROMEP(Project Analisis integral de tratamiento de aguas residuales a traves de procesos biologicos),which supported this work.
文摘Bio-hydrogen (Bio-H2) production from the organic fraction of solid waste, as fruit and vegetable wastes, constitutes an interesting and feasible technology to obtain clean energy. In spite of the feasibility to produce Bio-H2 from fruit/vegetable wastes (FVW), data about its rheological characterization are scarce. This information is useful to establish the hydrodynamic behavior, which controls the overall mixing process when the feedstock for Bio-H2 production process is a mixture of FVW. In this work, the rheological behavior of a vegetable/fruit waste mixture was characterized. The effect of the solids content (%, w/w), temperature, time (tyxotropy effects) and shear rate over the apparent viscosity of the mixture was evaluated. Most of the mixtures showed non-Newtonian behavior. The curves are typical rheofluidizing fluids. The rheological curves were different at increasing solids contents (80%, 60%, 40% and 30%), independent from the temperature. Rheological data were fitted to the power law model. Correlation factors R2 for the different mixtures were 0.991-0.995 for 80%, 0.961 -0.986 for 60%, 0.890 -0.925 for 40%. In the case of 30% of solids, the R2 value was not acceptable, and it was also found that this mixture was very near to the Newtonian behavior. Calculated activation energies (Ea) values were 15.98, 14.89 and 20.96 kJ/mol for the 80%, 60%, 40% mixtures, respectively. FVW purees rheological behavior was well characterized by Carbopol solutions at given concentrations and pH values. This fluid can be used as a model for other studies, e.g. LDA (Laser Doppler Anemometry) and PIV (Particle Image Velocimetry).
文摘脉冲电场(pulsed electric field,PEF)以其独特的非热特性和短时、高效、节能的加工特性成为果蔬汁杀菌保鲜技术的新趋势,可以在保证果蔬汁微生物安全性的同时保持其“新鲜风味”以及营养属性。该文综述了脉冲电场处理对果蔬汁品质、钝酶和杀菌等效果的影响以及在果蔬汁加工领域的应用现状,阐述了PEF技术在果蔬汁加工中的劣势以及与其他技术联用的优势,探讨了基于设备选用、工艺参数与食品基质间特异性、微生物亚致死导致的PEF技术的安全性等问题,分析了PEF在果蔬汁加工领域的应用前景和所面临的挑战,以期为PEF技术在果蔬加工领域的深入研究提供参考。
基金grant from the State Board for Medical Research,Government Medical College,Thiruvananthapuram,Kerala,India,a government funding agency,under grant number A2/SBMR(2016-2017)/27717/2016/MCT.
文摘Background:Dietary supplementation with citrate-containing juices may serve as an effective alternative to potassium citrate therapy for preventing calcium oxalate stone recurrence.This study was performed to evaluate whether consumption of lemon-tomato juice can decrease the tendency for stone formation in the urine of calcium oxalate stone formers.Materials and methods:The study was conducted as a prospective interventional randomized crossover clinical trial with a repeated-measures design.Twenty-two patients with calcium oxalate stones and no metabolic abnormalities in the urine treated with lithotripsy at a tertiary care center from August 2017 to July 2018 were recruited.After a 14-hour overnight fasting,urine samples were collected after the patients consumed either milk only or milk and lemon-tomato juice.Their urine was tested for multiple parameters,including urine pH,specific gravity,calcium-creatinine ratio,and supersaturation with sodium oxalate,followed by optical density measurement via spectrophotometry.Results:There were no significant differences in the background characteristics between the 2 groups.The optical density of the urine samples obtained after consumption of milk only was significantly higher than that after consumption of milk and lemon-tomato juice(mean=0.131 for milk only vs.0.053 for milk and lemon-tomato juice,p<0.001).The urine calcium-creatinine ratio was similar between the groups(mean=0.141 for milk only vs.0.076 for milk and lemon-tomato juice,p=0.019).Conclusions:The addition of lemon-tomato juice as a source of citrate in the diet significantly decreases the established risk factors for calcium oxalate stone formation in patients.This study was prospectively registered at CTRI under number CTRI/2017/04/008312 on April 7,2017.
