Chemical and Functional Properties of Food Saccharides

© 2004 by CRC Press LLC
starches, especially those with an amylose content over 25%, and cross-linked
starches contribute to the paste viscosity with high η and gels with high elasticity
after cooling. This is a result of restricted swollen granules and retrogradation in
soluble matrices. 69 In dry mixes and instant pudding, pregelatinized, “cook-up,” and
roll-dried starches provide benefits of easy cooking, high hydration, and rapid
thickenings. Hydroxypropylated or acetylated waxy maize starches generally help
products have high freeze–thaw stability. 47 Products with oxidized starches generally
have an adhesive and a soft to hard texture, depending on the extent of oxidization
(and degradation) of the starch used. 46 In starch-based confectionery, gum tragacanth,
34 gum arabic, pectin, sodium alginate, 46 CAR, 46,59 MCC, 59 and gelatin 46 are
incorporated to modify starch texture, increase storage stability, reduce syneresis,
or create fat-like smooth texture (for MCC). Generally, high-moisture starch systems
consist of soluble matrices and dispersed granules. Changes in elastic modulus
resulting from addition of starch compositions to natural starch products may be
interpreted as involving the isostrain or isostress Takayanagi’s polymer blending
rule. 70 The isostrain system is a composite containing a strong continuous matrix
dispersed with weak particles. Its overall elasticity equals the weighted average of
the individual elasticities. The isostress composite with weak matrices and strong
fillers exhibits the overall compliance equivalent to the weighted average of individual
compliances. It has been found that the gelatinized starch blend systems
without shear disintegration or before retrogradation follow the isostress model. 71
Heat-induced gels from whey protein isolate–starch mixtures show an elastic modulus,
with a maximum when the weight fraction of starch is 0.2 to 0.3. 72
11.3.1.2 Low-Moisture Starch Products
For low-moisture starch products (Table 11.4), mixing native starches with different
amylose content can produce the desired texture and structure for dough and noodles.
Formulations with a higher amylose content tend to increase hardness, elasticity,
and integrity of the products, and reduce the oil absorption of fried foods. 47,48 This
is mainly due to amylose retrogradation. Pregelatinized starch cross-linked starch
blends are chosen for snacks made by extrusion, baking, or frying. 47 In addition to
conditioning starch formulation, alginate, or alginate blends with different glucuronic
acid compositions and molecular weights, gum karaya, CAR, CMC, or GG generally
retard staling and increase freeze–thaw stability. 33,34,37–75,76 CMC and GG are especially
good for preparation of high-fiber breads, 75,76 whereas HPMC can improve
the eating quality of gluten-free breads based on rice flour and potato starch, 76
possibly relating to its thermoreversible gelation property. 41,42
11.3.2 GELS, DRINKS, DAIRY, AND EMULSIFIED PRODUCTS
Table 11.5 to Table 11.8 list the wide applications of polysaccharide blends in
confectionery gels, drinks, emulsions, whipped, and dairy goods. Benefits of using
polysaccharide blends in these products include controlling organoleptic texture;
reducing cost due to their synergy in gel strength or elasticity; increasing the suspension
stability on preparation and storage; improving effectiveness of flavor