1. Green Processing of Oil Seeds: A Way to Produce Healthy Oil
Said P. P., Pradhan R.C. & Sharma N.
Department of Farm Engineering, Institute of Agricultural Sciences,
Banaras Hindu University, Varanasi –
ABSTRACT
The awareness about health benefits of eating of food enriched bioactive lipid components such as ω-3 & ω-6 fatty acids, phytosterols, tocopherols, tocotrineols, carotenoids, etc have been increased. Also, consumer became aware of health hazards associated with residues of organic solvents used in food processing. The desire of consumer to buy natural products and food industries aim to obtain health beneficial natural compound of high value, purity, which is of excellent quality causes encouragement to develop & commercialize “green” technologies.
Supercritical Fluid Extraction (SFE) is the process of separating one component (solute) from another (the matrix) using supercritical fluids as the extracting solvent.
Carbon dioxide gas cylinder
Chiller
Cold heat exchanger
High pressure CO2 Pump
Hot heat exchanger
Pressure gauge
Extraction vessel
Automatic back pressure regulator
Separation/collection vessel
Veil for collecting extracted sample
Vent
CO2 Exhaust
Pressure control valve
Advantages
SC-CO2 technology have faster extraction rate compare. It also has better recovery of oil.
It can provide quantitative or complete extraction of quality product at the end of extraction process
Operating parameters such as pressure and temperature can be altered to enhance salvation power.
Thermally liable compounds can be extracted without damage.
SC-CO2 extraction dose not leave any solvent residue as it is free of solvents, hence very pure.
The technology does not need any extra unit operation after extraction of oil such as deodorization, deacidification, degumming, etc.
Figure 1. Supercritical Fluid Extraction Plant
Table 1. Supercritical CO2 Extraction of oil from oil seeds
Grape
(10-12 %)
Moringa oleifera
(8-36 %)
Tobacco
(8-10 %)
Sesame
(26-30 %)
Hazelnut
(56-60 %)
Evening primrose
(28-30 %)
Corn germ
(45-55 %)
Borage
(26-32 %)
Hemp
(39-44%)
Canola
(16-19%)
Jatropha
( %)
Linseed
(35-45 %)
Pumpkin
(42-54 %)
Walnuts
(65-89%)
Wheat germ
(8-14 %)
Cotton
(2-43 %)
Limitations
Recovery systems must be well engineered
Elevated pressure required
Capital costs for equipments are very high
(Note: Values in parentheses indicates amount of oil yield through SFE)
CONCLUSION
SFE has the potential to be an environmentally friendly “green” processing technique, and in some cases, replacing the traditional organic solvent. Extracts from natural sources are key elements in the manufacturing of health-promoting functional foods and ingredients, thus, the development and use of “green” separation processes and technology will likely continue to be widely employed in the processing of bioactive components, especially for use as supplements for health-promoting foods.