Extraction Technologies for Medicinal and Aromatic ... - Capacity4Dev

EXTRACTION TECHNOLOGIES FOR MEDICINAL AND AROMATIC PLANTS
4
Hydrolytic Maceration, Expression
and Cold Fat Extraction
Abstract
A. K. Singh
The incorporation of bioactive ingredients without loss of activity into foods, fl avors,
pharmaceuticals, pesticides and cosmaceutical products is very important. Extraction
of active constituents from raw materials is an important and critical step in maintaining
bioactivity. A number of methods are available for extraction, and these are
selected in such a way that the activity of the phytoconstituents is retained. This paper
discusses the processes of hydrolytic maceration, expression and cold fat extraction.
4.1 Introduction
The extraction of active constituents from plants is one of the
most critical steps in the development of natural products for commercial
use. The simplest example of extraction may be brewing a cup of coffee,
wherein caffeine and tannins are extracted from coffee beans in hot water.
All living organisms contain complex mixtures of chemicals, usually held
within cellular structural material (protein, lipid, polysaccharides etc.) of
which some are desired while others are not. Thus, taking out the desired
part from the whole crude drug is referred to as extraction and it is done in
solvents where ingredients move from one phase to another.
A number of methods are available for extraction and the choice
among them is dictated by the physicochemical properties and stability of
the phytoconstituents to be obtained. For the extraction of essential oils,
the simplest methods are hydrodistillation and steam distillation while other
methods also employed are cold fat extraction, expression, maceration and
solvent extraction. Nowadays, more advanced technologies are used, such
as supercritical fl uid extraction, solid phase micro-extraction and phytonic
extraction. The present article deals with extraction by hydrolytic maceration,
expression and cold fat extraction.
4.2 Hydrolytic Maceration
The word maceration is derived from the Latin word maceratus,
which means to soften. In reference to medicinal and aromatic plants,
maceration refers to the preparation of a solution by soaking plant material
in vegetable oil or water. Maceration methods are based on the immersion
of crude drug in bulk solvent, while percolation methods depend on the fl ow
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