It has been reported that betalains from Amaranthus (Cai et al., 2003) and beet roots (Escribano et al., 1998) demonstrated antiradical and antioxidant activity. Betanin, from red beet, effectively inhibited lipid peroxidation and heme decomposition, suggesting that these pigments may provide protection against certain oxidative stress- related disorders (Kanner, et al., 2001). Polyphenolics, on the other hand, play an
important role in antioxidant activity. They have evidently shown antiproliferative activity or cytotoxicity to human oral cancer cells (Seeram, Adams, Hardy, & Heber, 2004), melanoma cells (Rodriguez et al., 2002), and lung metastasis induced by B16F10 melanoma cells (Menon and Kuttan, 1995).
2.3 Soxhlet Extraction Process
A Soxhlet extractor is a piece of laboratory apparatus invented in 1879 by Franz von Soxhlet (Dingler's et al., 1879). It was originally designed for the extraction of a lipid from a solid material. However, a Soxhlet extractor is not limited to the extraction of lipids. Typically, a Soxhlet extraction is only required where the desired compound has only a limited solubility in a solvent, and the impurity is insoluble in that solvent. If the desired compound has a high solubility in a solvent then a simple filtration can be used to separate the compound from the insoluble substance. Figure 2.3 shows example of Soxhlet extractor.
According to the Soxhlet's procedure, oil and fat from solid material are extracted by repeated washing (percolation) with an organic solvent, usually hexane or petroleum ether, under reflux in a special glassware.