So, crushed tea leaves were allowed to oxidize in a pre-heated incubator settled at the various couples of temperature /time as defined by the experimental design (Table 2). Drying of black tea Fermented tea leaves were dried at 120 ºC for 27 min. Dried tea samples were allowed to cool at room temperature. The cold dried samples were ground and sieve to obtain powder with particle size ≤ 500μm which were used to prepare tea extracts. Preparation of tea extracts To prepare tea extracts, 0.5 g of each tea powder was introduced into a round bottom flask and extracted twice with 25 mL of ethanol 80% on a magnetic stirrer for 30 min.
Acid-Base Extraction and The Extraction of Caffeine from Tea Bags and Purification by Sublimation. Summary: The isolation of organic compounds in a solution can be performed due to the difference in solubility in different liquids. The extraction of the benzoic acid ,3-nitroaniline and 9-flourene mixtures by adding different amounts of solvents and extracting the acidic, basic and the organic solvents the purity of the samples were then determined by comparing them to the literature value of the melting point. The percent recovery for the benzoic acid was 81.1%, the 3-nitroaniline was 52.9% and the organic extract was 158.8% this was cause by a large number of impurities that had occurred whilst conducting the experiment. The benzoic acid was found in the acidic extract while the 3-nitroaniline was found in the basic extract and the organic extracted contained the 9-flourene, this was determined by the comparison of the melting point range to the actual value.
1- Extraction method No. 1: Fifty grams of powdered aerial parts of portulaca oleracea were hydrolyzed by using reflux for 9 hr. with 300 ml of 2N hydrochloric acid then the extract cool at room temperature ,filter and wash the residue with 2N of ammonia solution. The residue dried overnight at 60ºC ,the final step involve the extraction of the residue with 250 ml of chloroform by using soxhlet ,the final extract cool at room temperature ,then filter and evaporate to dryness by using rotatory evaporator at 40ºC to yield (2.264 gm),as show in scheme (2-1). 18.104.22.168-Extraction method No.2: Fifty grams of powdered aerial parts of portulaca oleracea extracted by soxhlet with 500ml 0f 70% ethanol for 8 hr.
petroleum ether, chloroform, methanol, n-butanol, ethyl acetate and water. After solvent extraction, it was evaporated to obtain a powdered extract for various biochemical analysis. Preliminary phytochemical screening of the extracts was performed for the presence of alkaloids, flavonoids, steroids, tannins, saponin, phenol and by the standard procedures. Alkaloids: To 1 ml of extract, 2-3 drops of Wagner’s reagent were
Subsequently, monochloroacetic acid (60 g) was added, in five equal portions, at 1 min intervals. Heat was then applied to bring the reaction mixture to a temperature of 60 oC and stirring at this temperature was continued for 3 h. Afterward, the reaction mixture was filtered and the filtered solid product (CMCS) was thoroughly rinsed with methanol. The resultant CMCS was dried in an oven at 60 oC. The Mw of the produced
Caffeine, tannins (phenolic substances) and a little chlorophyll can also be found in tea leaves. Hot water extraction can be used to separate caffeine from the tea leaves (mainly cellulose) as water can form hydrogen bonds with water and solubilise (water has higher solubility at higher temperatures). However, tannins are also water soluble but they display acidic properties instead. Thus, a basic salt like sodium carbonate can be added to bind to tannins to form a salt. Although now both the tannins salt and caffeine are water soluble, using an organic solvent, dichloromethane, renders tannins salt insoluble.
One unit (U) of glucoamylase is defined as the amount that liberates 1 µmol of reducing sugar as glucose/ml/min under the assay condition. One ml of the diluted enzyme extract was added to 1.0 ml of 5% soluble starch solution prepared in acetate buffer (pH 4.8). The enzyme substrate mixture was incubated at 60 0 C for one hour. Then 2 ml of Dinitrosalicylic acid reagent (DNS) was added to each test tube. The test tubes were placed in boiling water for 5 minutes and cooled to room temperature.
The acidified solution was steam distilled until no more oily drops were collected. The distillate was extracted with ether (3x30mL). Most of ether was removed by distillation. The residue, which contains thymol and thymolaldehyde was transfered to a small glass stoppered flask and about twice the volume of saturated sodium metabisulphite solution was added. The solution was stirred vigoursly for ½ h and allowed to stand for 1 h. The paste of bisulphite compound was filtered and washed with little ethanol and finally with little ether.
(PE) Sodium benzoate has the antimicrobial properties and is used in the oral formulation as preservative. Sodium citrate dihydrate act as alkalizing agent, buffering agent, complexing agent and emulsifying agent. Buffering agent controls and maintains the pH of the formulation to avoid degradation of drug during manufacturing, reconstitution and storage. (5) Next, citric acid monohydrate also acts as buffering agent and antioxidant. Antioxidant inhibit or delay the oxidation process of the ingredients in the formulation.
For the preparation of nanoparticles, the tea waste was washed with ethanol and DIW. Then it was oven-dried at 80°C for 24 h. The sludge was collected from common effluent treatment plant (CETP) near Ranipet. The pH and total chromium concentration of the sludge were found to be 8.4 and 24.2 g/kg respectively. The concentration of trivalent chromium and hexavalent chromium in the sludge was 23.23 g/kg and 0.968 g/kg respectively. SYNTHESIS OF ZVIN PARTICLES 17 mL of 0.1% SDS solution were mixed with 100 mL of tea waste extract (The tea waste extract was prepared by boiling 2.6 g of tea waste in 100 mL of DIW) and stirred for five minutes.