66
oleoresin, rose oil, etc. (Wang et al. 2014). The native and hydrolyzed starches have
poor emulsifying properties that poses some limitations for its use in encapsulation
process. However the chemical modification namely esterification reaction can
introduce the functional hydrophobic and hydrophilic groups onto starch involving
in effective emulsification properties (Henry and Alistair 1995). There are several
possible mechanisms for OSA starches to stabilize emulsion systems like charged
OSA starches can stabilize the emulsion by electrostatic stabilization. Several
reports on OSA starch production via esterification in different sources of starches
from lima bean starch, waxy maize, potato starch and amaranth starches have been
used for encapsulation of volatile flavors, such as orange oil, meat flavor and black
pepper oleoresin (Wang et al. 2014). The major problem associated with the use of
OSA starch in encapsulation is the poor protection of core ingredients against oxidation. To overcome this, OSA starch is frequently used in combination with hydrolyzed starches or other carriers to obtain optimal emulsification and oxidation
resistant properties (Reineccius 2004).
Resistant Starch as Encapsulating Agent
Resistant starch (RS) is the fraction of starch that escapes digestion due to its resistance to digestive enzymes in gastrointestinal conditions and does not release monosaccharide within the small intestine. However, it is fermented to a large extent by
microbiota in the colon, resulting in the production of short-chain fatty acids (Bird
et al. 2007). The starch may be physically inaccessible, retrograded, or chemically
modified to resist the digestive enzymes RS occurs naturally in some foods or can
be prepared as result of several processing conditions like hydrothermal treatments,
annealing, partial gelatinization and ecrystallization, autoclaving, pullulanase debranching, temperature-cycled retrogradation, phosphorylation, hydroxypropylation,
acetylation, oxidation, and citric acid modification (Ashwar et al. 2018; Sang et al.
2010). Generally, RS is subdivided into five categories like (1) RS1, which is physically entrapped starch found in cereals within the whole or partially milled seeds
due to lack of cell-wall-degrading enzymes in gastrointestinal tract (Raigond et al.
2015). (2) RS2 is non gelatinized native starch granule found in raw potato, green
banana, and native high-amylose maize starch; It is protected from digestion by
their compact conformation or structure comprising of amylopectin crystals of
uncooked native starch granules and is usually in B- or C-type crystalline polymorph (Englyst and Cummings 1987a, b). (3) RS3 is retrograded starch can be
produced by gelatinization (i.e., a process of disruption of the granule structure by
heating with an excess of water) and retrogradation (i.e., a process of slow recrystallization of starch molecules upon cooling or dehydration) during food processing
(Englyst et al. 1992); (4) RS4 is chemically modified starch and prepared by etherification, esterification, and cross-linking, (Lunn and Buttriss 2007); (5) RS is an
amylose-lipid complexed starch which is formed from high AM starches that require
higher temperatures for gelatinization and are more susceptible to retrograde
M. Ahmad et al.
oleoresin, rose oil, etc. (Wang et al. 2014). The native and hydrolyzed starches have
poor emulsifying properties that poses some limitations for its use in encapsulation
process. However the chemical modification namely esterification reaction can
introduce the functional hydrophobic and hydrophilic groups onto starch involving
in effective emulsification properties (Henry and Alistair 1995). There are several
possible mechanisms for OSA starches to stabilize emulsion systems like charged
OSA starches can stabilize the emulsion by electrostatic stabilization. Several
reports on OSA starch production via esterification in different sources of starches
from lima bean starch, waxy maize, potato starch and amaranth starches have been
used for encapsulation of volatile flavors, such as orange oil, meat flavor and black
pepper oleoresin (Wang et al. 2014). The major problem associated with the use of
OSA starch in encapsulation is the poor protection of core ingredients against oxidation. To overcome this, OSA starch is frequently used in combination with hydrolyzed starches or other carriers to obtain optimal emulsification and oxidation
resistant properties (Reineccius 2004).
Resistant Starch as Encapsulating Agent
Resistant starch (RS) is the fraction of starch that escapes digestion due to its resistance to digestive enzymes in gastrointestinal conditions and does not release monosaccharide within the small intestine. However, it is fermented to a large extent by
microbiota in the colon, resulting in the production of short-chain fatty acids (Bird
et al. 2007). The starch may be physically inaccessible, retrograded, or chemically
modified to resist the digestive enzymes RS occurs naturally in some foods or can
be prepared as result of several processing conditions like hydrothermal treatments,
annealing, partial gelatinization and ecrystallization, autoclaving, pullulanase debranching, temperature-cycled retrogradation, phosphorylation, hydroxypropylation,
acetylation, oxidation, and citric acid modification (Ashwar et al. 2018; Sang et al.
2010). Generally, RS is subdivided into five categories like (1) RS1, which is physically entrapped starch found in cereals within the whole or partially milled seeds
due to lack of cell-wall-degrading enzymes in gastrointestinal tract (Raigond et al.
2015). (2) RS2 is non gelatinized native starch granule found in raw potato, green
banana, and native high-amylose maize starch; It is protected from digestion by
their compact conformation or structure comprising of amylopectin crystals of
uncooked native starch granules and is usually in B- or C-type crystalline polymorph (Englyst and Cummings 1987a, b). (3) RS3 is retrograded starch can be
produced by gelatinization (i.e., a process of disruption of the granule structure by
heating with an excess of water) and retrogradation (i.e., a process of slow recrystallization of starch molecules upon cooling or dehydration) during food processing
(Englyst et al. 1992); (4) RS4 is chemically modified starch and prepared by etherification, esterification, and cross-linking, (Lunn and Buttriss 2007); (5) RS is an
amylose-lipid complexed starch which is formed from high AM starches that require
higher temperatures for gelatinization and are more susceptible to retrograde
M. Ahmad et al.