Proanthocyanidins sample extraction

Figure 8.3 Sample extraction and purification steps for proanthocyanidin analysis.

Proanthocyanidins need to be extracted from food samples and undergo purification steps before HPLC analyses, and various extraction... 

Sample Preparation for Determination of the Mean Polymerization Degree (mDP) of Proanthocyanidins in Skins and Seeds Extracts and in the Wine... 

There is a general consensus that analysis of fresh material yields results which come closest to the natural distribution pattern in plants. Since this approach is not feasible in most cases suitable preservation procedures must be employed. Advantages and disadvantages of such procedures with respect to polyphenol analysis have been reviewed by several authors [47-49]. The procedure keeping the chemical composition as close as possible to the natural state is lyophilization. A study of the extractability of proanthocyanidins in the bark of several pines (Pinus sp.) showed no difference between freshly collected samples and freeze-dried samples. On the other hand drying at room temperature resulted in an increase in extractability in one sample [50]. Increased extractability after drying at room temperature compared to fresh material has also been... 

Bate-Smith was the first to note the correlation of woodiness with proanthocyanidins. In his early surveys of leaf extracts, he found, in a sample of about 800 species that included most major plant families, that 61% of the woody families had proanthocyanidins, whereas only 15% of herbaceous families were shown to contain these constituents (7). Bate-Smith (9) later formalized these observations, and his words are worth quoting here . . but the presence or absence of leuco-anthocyanins (denoted a and 3., respectively) is highly significant taxonomically. Similarly, the presence or absence (denoted b and bo, respectively) of the vie-... 

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