148
of high rhamnose content. But again due to its emulsifying properties and its ability
to form covalently cross-linked hydrogels, it is used in various commercial applications. Apart from sugar beet pectin, other commercial sources like apple pectin gel
displays visco-elastic properties. Also citrus pectin gel is more elasto-brittle in
nature. Its noteworthy to mention that inter-chain association is limited by the presence of neutral sugars but as these branches are often removed during purification
or extraction, so these have less significance in commercial pectins.
Rheology of Mixed Pectin Systems
In order to enhance the textural and rheological properties of the pectin, synergistic
approaches may be exploited. These synergistic mixed gels are finding a great use
in industry. This involves mixing of HMP, LMP and/or ALMP which can form
stronger mixed gel. In such mixed systems, the value of G’ is higher as reported by
Löfgren and Hermansson (2007) who reported higher G’ values for mixed HMP/
LMP as compared to HMP gels. They further reported that the presence of calcium
and sucrose during the association of LM pectin has a marked effect on the storage
modulus of mixed gels. The storage modulus was increased by thirty times. The
rheological behaviour of HMP gels having higher concentration of sugar coincides
with that of mixed gels. The addition of ALMP to HMP increased the viscosity and
reduced the pseudo plasticity (Sato et al. 2008). The food industry employs two
major components i.e. polysaccharides and proteins in order to manipulate the
structural and textural stability. When the different or even the same components/
biopolymers (carbohydrate–carbohydrate or protein-protein) are mixed, it can cause
the phase separation. This separation can be divided into two cases: segregative, in
which there is an unmixing of two phases and associative, which can form the complexes between the two biopolymers. The latter has been exploited widely in cosmetic, pharmaceutical, biotechnological, medical and food industries. The stability
and rheology of the dairy products can be altered by generating he pectin-casein
system in which pectin can either prevent the association of casein micelles or can
lead to the aggregation (Maroziene and de Kruif 2000). The interaction of the pectin
and milk protein can be brought by the calcium bridges between the two as these are
generally not considered compatible at neutral pH. Similarly, Sadahira et al. (2016)
reported that there was an increase in the foam stability and continuous phase viscosity as a result of the formation of complexes between egg white and pectin. Also
when pectin was incorporated in low fat spreads with fish gelatin, there was an
increase in the melt ability and consistency of such systems. The more the content
of pectin in such spreads, more better was the performance in relation to melt in
mouth and instant in-mouth flavour release effects.
N. Noor et al.
of high rhamnose content. But again due to its emulsifying properties and its ability
to form covalently cross-linked hydrogels, it is used in various commercial applications. Apart from sugar beet pectin, other commercial sources like apple pectin gel
displays visco-elastic properties. Also citrus pectin gel is more elasto-brittle in
nature. Its noteworthy to mention that inter-chain association is limited by the presence of neutral sugars but as these branches are often removed during purification
or extraction, so these have less significance in commercial pectins.
Rheology of Mixed Pectin Systems
In order to enhance the textural and rheological properties of the pectin, synergistic
approaches may be exploited. These synergistic mixed gels are finding a great use
in industry. This involves mixing of HMP, LMP and/or ALMP which can form
stronger mixed gel. In such mixed systems, the value of G’ is higher as reported by
Löfgren and Hermansson (2007) who reported higher G’ values for mixed HMP/
LMP as compared to HMP gels. They further reported that the presence of calcium
and sucrose during the association of LM pectin has a marked effect on the storage
modulus of mixed gels. The storage modulus was increased by thirty times. The
rheological behaviour of HMP gels having higher concentration of sugar coincides
with that of mixed gels. The addition of ALMP to HMP increased the viscosity and
reduced the pseudo plasticity (Sato et al. 2008). The food industry employs two
major components i.e. polysaccharides and proteins in order to manipulate the
structural and textural stability. When the different or even the same components/
biopolymers (carbohydrate–carbohydrate or protein-protein) are mixed, it can cause
the phase separation. This separation can be divided into two cases: segregative, in
which there is an unmixing of two phases and associative, which can form the complexes between the two biopolymers. The latter has been exploited widely in cosmetic, pharmaceutical, biotechnological, medical and food industries. The stability
and rheology of the dairy products can be altered by generating he pectin-casein
system in which pectin can either prevent the association of casein micelles or can
lead to the aggregation (Maroziene and de Kruif 2000). The interaction of the pectin
and milk protein can be brought by the calcium bridges between the two as these are
generally not considered compatible at neutral pH. Similarly, Sadahira et al. (2016)
reported that there was an increase in the foam stability and continuous phase viscosity as a result of the formation of complexes between egg white and pectin. Also
when pectin was incorporated in low fat spreads with fish gelatin, there was an
increase in the melt ability and consistency of such systems. The more the content
of pectin in such spreads, more better was the performance in relation to melt in
mouth and instant in-mouth flavour release effects.
N. Noor et al.