2 Industrial Plant Oil Extraction
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2.6 Novel Technology of Oil Extraction
2.6.1 Simultaneous Extraction of Oil and Tea Saponin
from Camellia Oleosa Seeds Using Subcritical Water
Camellia oleifera is an oilseed with high oil content and it is an excellent source
of polyunsaturated fatty acids. The world’s total plant area of Camellia is around
3.3 million ha, of which approximately 3.0 million ha in China stands for about
90% of the global total. Camellia oil is considered to be nutritious and healthy,
owing to its fatty acid composition and the presence of bioactive compounds, such
as tea polyphenol, tea saponin, and squalene. The content of these bioactive minor
components varies with geographic origin, seasonal variation, stress experienced by
the plant due to soil and environmental factors, and oil processing methods.
Camellia oleifera seed is a good source of oil and tea saponin. Generally, Camellia
seed contains 13.7–42.84% of edible oil and 7.28–16.24% tea saponin. During the
production of camellia oil in the past, the tea saponin were often discarded with the oil
cake or used for low-value-added fertilizer in the traditional oil processing method.
Actually, the tea saponin has good characters such as a strong foaming, emulsifying,
dispersing, and wetting performances and anti-cancer, anti-inflammatory, antibacterial, and other biological activities; it could be widely used in food, medicine,
pesticides, and other fields.
In recent years, there is steady progress in extraction technology with the development of new and simpler sample preparation methods such as supercritical fluid
extraction, microwave-assisted extraction, and subcritical water extraction which
have been widely used in extracting bioactive compounds such as flavonoids,
polyphenol, and essential oil. And more and more studies of subcritical water extraction (SWE) focus on oil and oil-soluble compounds because SWE provided significant advantages in terms of crude oil yields and simultaneously maximization of
valuable bioactive compounds.
Subcritical water, which is defined as liquid water at 100–374 °C under pressurized
conditions, had attracted worldwide attention due to its own merits such as shorter
extraction time with higher quality and productivities, low energy consumption as
well as being environmentally friendly.
Since the increase of temperature has multiple positive effects on mass transfer
during SWE, extractions should be performed at the highest temperature not causing
significant degradation of target compounds. There have been some reports on SCW
extraction of vegetable oils such as soybean oils, palm oils, and sunflower oils on
a lab scale. However, Camellia oleosa seeds oil and tea saponin were simultaneously extracted under SWE conditions by varying the temperature, time, pressure,
and the liquid-to-solid ratios. Three levels, three variables, Box–Behnken experimental design (BBD) with the response surface methodology (RSM) was used for
optimization of the subcritical water extraction process. Temperature (X 1 : 110–150
°C), extraction time (X 2 : 20–40 min), and solvent to material ratios (X 3 : 5:1–15:1)
were investigated as independent variables. The response variables were fitted to
63
2.6 Novel Technology of Oil Extraction
2.6.1 Simultaneous Extraction of Oil and Tea Saponin
from Camellia Oleosa Seeds Using Subcritical Water
Camellia oleifera is an oilseed with high oil content and it is an excellent source
of polyunsaturated fatty acids. The world’s total plant area of Camellia is around
3.3 million ha, of which approximately 3.0 million ha in China stands for about
90% of the global total. Camellia oil is considered to be nutritious and healthy,
owing to its fatty acid composition and the presence of bioactive compounds, such
as tea polyphenol, tea saponin, and squalene. The content of these bioactive minor
components varies with geographic origin, seasonal variation, stress experienced by
the plant due to soil and environmental factors, and oil processing methods.
Camellia oleifera seed is a good source of oil and tea saponin. Generally, Camellia
seed contains 13.7–42.84% of edible oil and 7.28–16.24% tea saponin. During the
production of camellia oil in the past, the tea saponin were often discarded with the oil
cake or used for low-value-added fertilizer in the traditional oil processing method.
Actually, the tea saponin has good characters such as a strong foaming, emulsifying,
dispersing, and wetting performances and anti-cancer, anti-inflammatory, antibacterial, and other biological activities; it could be widely used in food, medicine,
pesticides, and other fields.
In recent years, there is steady progress in extraction technology with the development of new and simpler sample preparation methods such as supercritical fluid
extraction, microwave-assisted extraction, and subcritical water extraction which
have been widely used in extracting bioactive compounds such as flavonoids,
polyphenol, and essential oil. And more and more studies of subcritical water extraction (SWE) focus on oil and oil-soluble compounds because SWE provided significant advantages in terms of crude oil yields and simultaneously maximization of
valuable bioactive compounds.
Subcritical water, which is defined as liquid water at 100–374 °C under pressurized
conditions, had attracted worldwide attention due to its own merits such as shorter
extraction time with higher quality and productivities, low energy consumption as
well as being environmentally friendly.
Since the increase of temperature has multiple positive effects on mass transfer
during SWE, extractions should be performed at the highest temperature not causing
significant degradation of target compounds. There have been some reports on SCW
extraction of vegetable oils such as soybean oils, palm oils, and sunflower oils on
a lab scale. However, Camellia oleosa seeds oil and tea saponin were simultaneously extracted under SWE conditions by varying the temperature, time, pressure,
and the liquid-to-solid ratios. Three levels, three variables, Box–Behnken experimental design (BBD) with the response surface methodology (RSM) was used for
optimization of the subcritical water extraction process. Temperature (X 1 : 110–150
°C), extraction time (X 2 : 20–40 min), and solvent to material ratios (X 3 : 5:1–15:1)
were investigated as independent variables. The response variables were fitted to