Extraction
Contents
• Pressurized
liquid/fluid extraction
• Enzyme
assisted extraction
Objectives
At the end of the session, student will be able to
• Discuss
the principle of Pressurized liquid/fluid extraction and enzyme assisted
extraction
• Explain the advantages and disadvantages
Pressurized liquid/fluid extraction and EAE
Pressurized liquid/fluid extraction
Ø Pressurized liquid extraction (PLE
or PFE in case of a general fluid) is a novel and eco-friendly approach for the
recovery of bioactives from plants
Ø This method often requires water as
the solvent and so it can keep away from the environmental and health risks due
to the use of organic solvents
Ø At elevated temperatures there is a
reduction of the viscosity of the solvent that can better penetrate the matrix
extracting the analytes of interest
Ø The elevated pressure permits
maintaining the solvent in the liquid phase and the disruption of plant cells
wall exerting pressure on the matrix
Ø In place of organic solvents, it is
possible to use additives like non-ionic surfactants, antioxidants like
ascorbic acid
Ø Furthermore, PLE apparatus protects
light sensitive and oxygen sensitive products from degradation
Enzyme-assisted extraction
• An alternative approach to classical
solvent extraction techniques is the enzyme-assisted extraction
• This method is innovative and
convenient
• Enzymes catalyze reactions in a
specific way without operating under strong conditions that could lead to the
degradation of the desired products.
• cellulases, hemicellulases and
pectinases disrupt cell wall with the hydrolysis of its components leading to a
major permeability and allowing an easier release of the metabolites from
plants
• The application of enzymes such as
lipases, proteases, phospholipases, permits to reduce the use of the solvent
for the extraction
• For oil extraction from plants,
cellulase, α-amylase and pectinase are the most used enzymes. These proteins
can be obtained from fungi, bacteria, animals, and vegetables or from genetic
engineering methods
• They can be used to recover a
specific bioactive compound in high yields without wasting too much energy
• Nevertheless, there are some
limitations due to the cost of the enzymatic approach, the incomplete
disruption of the cell wall and the complicated application in a commercial
scale because of the different behaviour of the enzymes according to the
environmental circumstances such as the amount of oxygen, the variety of
nutrients and the operating temperature
Summary
Ø Pressurized liquid extraction (PLE
or PFE in case of a general fluid) is a novel and eco-friendly approach for the
recovery of bioactives
Ø Water as the solvent and so it can
keep away from the environmental and health risks
• An alternative approach to classical
solvent extraction techniques is the enzyme-assisted extraction
• Enzymes catalyze reactions in a
specific way without operating under strong conditions
• Lipases, proteases, phospholipases,
permits to reduce the use of the solvent for the extraction
• For oil extraction from plants,
cellulase, α-amylase and pectinase are the most used enzymes
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