Compositional analysis, glycosidic

Compositional analysis. Juice or skin glycoside hydrolysates (equivalent to 250 mL of juice or skin extracts) were spiked with a standard solution of 1-octanol and 2,5-dimethylphenol in ethanol (to a concentration for skin hydrolysates 0.12 mg/L, for juice hydrolysates 0.06 mg/L) and extracted with 1 1 etheripentane (3x10 mL). The organic extracts were dried with magnesium sulfate and concentrated by fractional... 

Glycosyl-residue compositions were determined by GC-CIMS analysis of the per-O-trimethylsilylated methyl glycosides [23] separated on a fused-silicaDB-1 capillary column. The identity of each peak was confirmed by CIMS on a HP-5989 MS Engine (Hewlett-Packard). 

The monosaccharide composition of all the samples was determined by GLC analysis of the trimethylsilyl methyl glycoside derivatives [1]. 

For fruits and their products, HPLC techniques for phenolics have been used to study the effect of processing, concentration, and storage on the phenolic composition of juices as well as a potential precursor for an off-flavor compound in juices. Phenolic analysis has been further applied to the detection of economic adulteration and especially to verify the authenticity of fruit juices. This is especially important when cheaper fruits can be added to more expensive ones in a fraudulent manner. In most fruits, the nonanthocyanin flavonoids consist mainly of flavonols and flavanols, with trace amounts of flavones. Glycosides are the predominant forms present. These most often are separated by reversed-phase HPLC on Cl8 columns with gradients consisting of acidified H20 and ACN, MeOH, or EtOH. 

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