Sub-Critical Water Extraction for the Isolation of Polyphenolics from Fruits

During the typical juicing process, many polyphenolics of potential nutritive or functional value are left in the often underutilized pomace. Methods involving the use of acetone or ethanol are commonly used to further extract these compounds. However, these compounds are used as bioactive ingredients in dietary supplements and functional foods, or as natural colorants. Thus the health conscious target market has considerable objections to the use of solvents in production. Moreover, the complexity and cost-prohibitive nature of these processes cause many processors to simply discard the pomace and thus a potentially valuable source of phytochemical compounds (anthocyanins, flavones and catechins). Research has previously been conducted on the utilization of critical fluids as an environmentally friendly alternative to solvent extraction of valuable agricultural components. It is proposed that Sub-Critical Water Extraction can effectively extract polyphenolics from fruit pomaces. The alteration of the physical properties of water through increases in temperature and pressure allow it to function in a manner similar to less polar solvents such as acetone and alcohol. The evaluation of various conditions and extraction substrates can also demonstrate the feasibility of a Sub-Critical Water Extraction process to compete with solvent extraction in a cost-effective manner.