Please list methods for extracting bioactive phytochemicals from fruit and their difference and characteristics.
Q. Please list methods for extracting bioactive phytochemicals from fruit and their difference and characteristics.
A. Phytochemicals are plant derived chemicals which may bestow health benefits when consumed, whether medicinally or as part of a balanced diet. Methods of extracting bioactive phytochemicals from fruit are enlisted below:
Liquid-liquid or solid-liquid solvent extraction (SE)
In solvent extraction (SE), pretreated raw material is exposed to different solvents, which takes up compounds of interest and also other agents (flavors and colorings). Samples are usually centrifuged and filtered to remove solid residue, and the extract could be used as additive, food supplement or be destined for the preparation of functional foods.
SE is advantageous compared to other methods due to low processing cost and ease of operation. However, this method uses toxic solvents, requires an evaporation/ concentration step for recovery, and usually calls for large amounts of solvent and extended time to be carried out. Moreover, the possibility of thermal degradation of natural bioactive compounds (NBC) cannot be ignored, due to the high temperatures of the solvents during the long times of extraction.
Pressurized liquid extraction (PLE)
PLE is uses organic liquid solvents at high temperature (50 to 200 °C) and pressure (1450 to 2175 psi) to ensure the rapid extraction rate of compounds. As the temperature increases the dielectric constant of the solvent decreases, consequently lowering the polarity of the solvent. Thus, temperature could be used to match the polarity of a solvent to that of the compounds of interest to be recovered. The high pressure helps the extraction cells to be filled faster and forces liquid into the solid matrix.
These new techniques allow a faster extraction in which less amount of solvents are used and higher yields are obtained in comparison with traditional SE. In addition, the use of PLE allows the attainment of food-grade extracts obtained only when water or other GRAS (generally recognized as safe) solvents, such as ethanol are used. Despite the ...
This solution offers description and comparison of different extraction methods used in bioactive compound extraction from natural resources, along with citation of a comprehensive reference.