8 Oleochemistry Products
217
and partitioning the agents in between the core membrane and solubilize the membrane as a result and that causes lyse of the cells. The growth inhibition test with
gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli and
Pseudomonas aeruginosa) bacteria were used to determine the toxicity of single
and mixed surfactants. Certain mixed surfactants have lower minimum inhibition
concentration (MIC) as compared to the single surfactants. Besides that, it was also
found that alkyl chain length and the mixing ratios of the surfactants play a significant
role in determining the mixture inhibitive power [233].
A bio-surfactant was produced by Vaz et al. [222] through using Bacillus subtilis
strain isolated from crude oil and it was characterized for its properties which were
comparable to those of commercially available chemical surfactants. The emulsification indexes showed that the bio-surfactant possesses equal or superior capacity
to form emulsions with n-hexadecane as compared to the commercial chemical surfactants. The bio-surfactant showed antimicrobial activity against Staphylococcus
aureus and Escherichia coli. Nevertheless, no particular trend or special effect could
be assigned to the use of commercial chemical surfactants as anti-adhesives. Suggesting that the bio-surfactant recovered from B. subtilis EG1 constitutes an interesting alternative to the commercial chemical surfactants with potential use in several
industries [222].
Baphia nitida oil was extracted, characterized and used in the production of
diethanolamide and epoxidized diethanolamide via transamidation reaction. Oil had
C18:2 (50.00 ± 0.20%) fatty acid as the most abundant fatty acid. The epoxidized
diethanolamide was synthesized by peroxyformic acid generated in situ by reacting
formic acid and hydrogen peroxide with the oil of B. nitida. The formation of the
diethanolamide and epoxidized diethanolamide was monitored and confirmed using
FTIR and 1H NMR. The epoxidized diethanolamide showed better surface-active
properties than the diethanolamide in terms of emulsion stability, and foaming power
[2].
Sterols
Sterols are a more novel class of surfactant raw materials from a natural origin.
It is derived either from plant or animal sources and its structure is a perhydrocyclopentanophenanthrene nucleus with a side chain in position C17, consisting of
8–10 carbon atoms. The steroid nucleus has a rather rigid character due to the condensed ring structure. The carbon side chain, on the other hand, is of a much more
flexible character. The chemical structure of the carbon chain varies for the different
components, as shown in Fig. 8.6. The most common sterol derived from animals
(zoosterol) is cholesterol while the sterols synthesized by vegetable organisms are
called phytosterols. Phytosterol is a general name for different sterol derivatives
present in the unsaponifiables of different plants. The main components are usually
β-sitosterol, campesterol, stigmasterol and tocopherol. A common source for these
components is tall oil or sulfate soap from the pulping of wood. Other common
sources for phytosterols are, e.g. maize, rapeseed, sesame, soybean, sunflower and
avocado [69].
217
and partitioning the agents in between the core membrane and solubilize the membrane as a result and that causes lyse of the cells. The growth inhibition test with
gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli and
Pseudomonas aeruginosa) bacteria were used to determine the toxicity of single
and mixed surfactants. Certain mixed surfactants have lower minimum inhibition
concentration (MIC) as compared to the single surfactants. Besides that, it was also
found that alkyl chain length and the mixing ratios of the surfactants play a significant
role in determining the mixture inhibitive power [233].
A bio-surfactant was produced by Vaz et al. [222] through using Bacillus subtilis
strain isolated from crude oil and it was characterized for its properties which were
comparable to those of commercially available chemical surfactants. The emulsification indexes showed that the bio-surfactant possesses equal or superior capacity
to form emulsions with n-hexadecane as compared to the commercial chemical surfactants. The bio-surfactant showed antimicrobial activity against Staphylococcus
aureus and Escherichia coli. Nevertheless, no particular trend or special effect could
be assigned to the use of commercial chemical surfactants as anti-adhesives. Suggesting that the bio-surfactant recovered from B. subtilis EG1 constitutes an interesting alternative to the commercial chemical surfactants with potential use in several
industries [222].
Baphia nitida oil was extracted, characterized and used in the production of
diethanolamide and epoxidized diethanolamide via transamidation reaction. Oil had
C18:2 (50.00 ± 0.20%) fatty acid as the most abundant fatty acid. The epoxidized
diethanolamide was synthesized by peroxyformic acid generated in situ by reacting
formic acid and hydrogen peroxide with the oil of B. nitida. The formation of the
diethanolamide and epoxidized diethanolamide was monitored and confirmed using
FTIR and 1H NMR. The epoxidized diethanolamide showed better surface-active
properties than the diethanolamide in terms of emulsion stability, and foaming power
[2].
Sterols
Sterols are a more novel class of surfactant raw materials from a natural origin.
It is derived either from plant or animal sources and its structure is a perhydrocyclopentanophenanthrene nucleus with a side chain in position C17, consisting of
8–10 carbon atoms. The steroid nucleus has a rather rigid character due to the condensed ring structure. The carbon side chain, on the other hand, is of a much more
flexible character. The chemical structure of the carbon chain varies for the different
components, as shown in Fig. 8.6. The most common sterol derived from animals
(zoosterol) is cholesterol while the sterols synthesized by vegetable organisms are
called phytosterols. Phytosterol is a general name for different sterol derivatives
present in the unsaponifiables of different plants. The main components are usually
β-sitosterol, campesterol, stigmasterol and tocopherol. A common source for these
components is tall oil or sulfate soap from the pulping of wood. Other common
sources for phytosterols are, e.g. maize, rapeseed, sesame, soybean, sunflower and
avocado [69].