Citric acid, first analysis

Sensory Analysis. A paired comparison test was run to determine if the difference in oil droplet size in the emulsion changed the perceived intensity of the orange flavor. The coarsest emulsion (3.87 pM) and the Microfluidized sample (0.90 pM) from the third set of spray dried samples were compared. The solutions were prepared using 200 ppm flavor in a 10% (w/v) sucrose solution with 0.30% of a 50% citric acid solution added. The amount of each powder required to attain 200 ppm orange oil was calculated on the basis of percent oil in each powder (determined by Clevenger analysis). A pair of samples at approximately 10 C was given to each of 24 untrained panelists. The samples were coded with random numbers. Half the panelists were asked to taste the coarsest sample first while while the other half tasted the Microfluidized sample first. This was done to determine whether or not adaptation was a factor. The panelists were asked to indicate which sample had the most intense orange flavor. 

In the past 10 years, a wide variety of resins have been used to fractionate humates. Interest in these resins originates from a search for methods to concentrate materials from natural waters. It is necessary to mention the first resin used to fractionate humates charcoal (Forsyth, 1947). Carbohydrates and proteins were preferentially separated by this method. Anderson and Russell (1976) purified fulvic acid by a charcoal separation. Elemental analysis showed this fulvic acid to be identical to a direct citric acid extract of the soil. 

Lee et al. (2005) proposed a method for analysis of flavonols in grape by performing berry extraction with acidified methanol (0.01% of 12 N HC1). After filtration, the solvent is removed under vacuum and the residue is dissolved in a 0.1 M citric acid buffer with pH 3.5. First, polyphenols are fractionated on a reverse-phase Ci8 cartridge (e.g., Sep-Pak 5g), then on a Sephadex LH-20 3-g cartridge (a cross-linked dextran-based stationary phase used for gel permeation, normal-phase partition, and adsorption chromatography). Four fractions finally are recovered by ethyl acetate and methanol, as shown in the f >w diagram Fig. 6.5. 

The Legal reachon forms the basis of the citrate identificahon test, and exactly the same methodology is used in the test 3.21. Lactates. In the first part of analysis the citric acid is oxidized to a substance that is susceptible to the nitroprusside reagent. 

Thermal analysis studies of decomposition process started with the Wendlandt and Hoiberg [67] investigatiom Differential thermal analysis (DTA) showed three peaks at 170, 185 and 210 °C, all of them indicating endothermic reactions. First peak was attributed to the fusion of citric acid and other peaks to deeomposition... 

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