A Study Of Technology And Properties Of Lotus Leaf Beverage Concentrate

The manufacture and physical characteristic of lotus leaf beverage main agents which made of folium nelumbinis were researched in this paper.The physical character studied included rheological properties and physicochemical property.The relation between the chromatic value and sensory evaluation and the kinetics model of chromatic was established for predicting the storage life of beverage main agents.It provided the basis data and the scientific references to lotus leaf processing technology and the equipment exploitation.The content of flavonoids and hypercetin of lotus leaf was mensurated by Spectro-photo-meterm and HPLC,the results showed:on May,The content of flavonoids was highest,about 93.22 mg/g;On June lotus leaf turn into the phase of nutrition and procreation;On July,the content was lower.But on August the content of flavonoids is up to 87.08 mg/g,until the lotus leaf is died,about 45.89 mg/g.The content of hypercetin is about 0.347 mg/g～0.1321 mg/g in lotus leaf.The content of alkaloid of lotus leaf was mensurated by Spectro-photo-meterm,the results showed: on August,The content of alkaliod was highest,about 173.9 mg/g;The content of alkaloid is about 92.8 mg/g～173.9 mg/g in lotus leaf.On the base of the single factor experiments,the optimum conditions for the ultrasonic extraction of flavonoids from lotus leaves were determined using response surface methodology(RSM).A central composite design was used to investigate the effects of three independent variables,namely solid-liquid ratio,ultrasonic extraction time and ultrasonic extraction temperature on the response,yield of flavonoids.Data were analyzed using software.Canonical analysis of surface responses revealed that the stationary surface was a maximum.The coefficient of determination was 0.9723. The optimum ultrasonic extraction conditions were:the liquid to solid ratiol:26, extraction time 27 min,extraction temperature 72℃.Under the optimum conditions, the extraction yield of flavonoids was 1.825%.The optimum process condition was concentrated temperature 70℃,vacuum 0.095 Mpa with the method of the vacuum concentrates and the sensory evaluation.Measuring the core temperature of the lotus leaf beverage main agents with the wireless Track Sense Pro verification system,then used the method of sensory evaluation.The reasonable sterilization condition is 5′-10′/121℃.Studying rheological characteristics of the lotus leaf beverage main agents with the DV-Ⅲ~+ rheometer.Beverage main agents of concentration(2,4,6,8,10 ~0Brix) behaved as Non-Newtonian flow.The rheology characteristic could be presentation by the power function.Measuring chromatic value with DC-P3 color-difference meter.The correlation coefficient of the model a~*/L~*/b~* was better than others studied,therefore this model could be used as an index of food quality.The experiment indicated the changes of a~*/L~*/b~* was classed in first order reaction,and got the kinetics equation.The dynamitic model of life-time predication was lgd=20.625-0.0602C,and it obtained at the constant temperature.