Chemical and Functional Properties of Food Saccharides

© 2004 by CRC Press LLC
sucrose esters are added to an oil–water mixture, they are adsorbed at the interface
between water and oil and orient themselves so that the hydrophilic portions toward
water and the lipophilic portions toward oil, thereby reducing surface tension.
Sucrose fatty acid esters from lauric (C12:0) to docosanoic acid (C22:0) have
surfactant properties to reduce surface tension of water. Lower fatty acid esters than
lauric do not possess significant surfactant properties. The monoesters are soluble
in many organic solvents but only slightly in water. Because of toxicological clearance,
the U.S. FDA has approved only sucrose esters blended with mono-, di-, and
triglycerides of palmitic and stearic acids. They are completely absorbed and metabolized
surfactants. Surfactant properties depend on the number of the esterified
groups and the length and degree of saturation of the fatty acid chain. Sucrose esters
with a shorter, more unsaturated fatty acid and fewer esterified groups show a greater
hydrophilic function. 29
Little research compares the emulsification properties among different sucrose
ester isomers. Husband et al. 30 reported that both pure sucrose 6-monolaurate and
sucrose 6'-monolaurate exhibited similar foaming and interfacial properties, and
sucrose dilaurate displayed inferior foaming properties and higher surface tension
than did sucrose monolaurates.
3.7.4.2 Complex Formation of Sucrose Esters with Starch and
Proteins
Osman et al. 31 observed a reduced iodine affinity of amylose, indicative of complex
formation, in the presence of sucrose esters and suggested that the ability of sucrose
esters to form complexes was related to the percentage of the fatty acid portion.
Later, Matsunaga and Kainuma 32 reported that sucrose esters had the ability to
prevent starch retrogradation by forming a helical complex with amylose. The
Brabender peak viscosity, peak time, and maximum set back viscosity of maize,
tapioca, or wheat starch were higher in the presence of sucrose esters (HLB9-16),
supporting the inclusion complex formation, which retarded the migration of amylose
from the starch granule. 33
It has been suggested that sucrose esters function as dough conditioners by
interacting with flour protein. Results of the study by Hoseney et al. 34 suggested that
sucrose simultaneously bound to glutenin by hydrophobic bonding and to gliadin
by hydrogen bonding. Krog 35 proposed two possible mechanisms for sucrose esters
to function as dough conditioners: (1) hydrophobic and/or hydrophilic binding with
gluten protein, or (2) interaction in bulk form with the water phase of the dough. It
is likely that both mechanisms are involved because considerable evidence supports
both hypotheses.
3.7.4.3 Antimicrobial Properties of Sucrose Fatty Acid Esters
The antimicrobial activity of sucrose esters comes from the interaction of esters with
cell membranes of bacteria, which causes autolysis. The lytic action is assumed to
be due to stimulation of autolytic enzymes rather than to actual solubilization of
cell membranes of bacteria. Both gram-positive and gram-negative bacteria are