Traditional Thermal Extraction Methods

Bioactive extraction requires selection of the right extraction method based on the food matrix, solvent, temperature, and so forth. Extraction methods are used for qualitative and quantitative studies. Traditional extraction methods utilised high temperatures. These include solid-liquid extraction, liquid-liquid extraction, solid phase microextraction, as discussed in this chapter. Traditional methods come with some limitations such as long extraction time, amount of solvent utilised, the number of extraction steps required, and effect of heat on the bioactive. Some examples of bioactive extraction from food sample using traditional methods are discussed as case studies. Grapes, garlic, beetroot, olive, and black plum are some food samples used for extraction of polyphenols, glucosinolates, carotenoids, vitamins, terpenoids, and saponins. Nonetheless, traditional methods are used as reference methods for developing advanced or novel extraction methods. The molecular affinity between solvent and solute, mass transfer, co-solvent, environmental safety and toxicity, and techno-economic feasibility are some concerns to be addressed while developing an extraction method. An advanced thermal method, microwave-assisted extraction is also discussed in this chapter.