Physical Chemistry of Foods

acomplex coacervate, and a phase depleted of polymer. A hypothetical phase diagram is in Figure 6.19b. Also forB 23 &0, comp ...

between amylose and amylopectine in fairly dilute (gelatinized) starch solutions. The solvent quality also affects phase separat ...

the phases is very small, 10^7 to 10^4 N?m^1 , being higher for greater incompatibility. An important case of incompatibility ...

increases with increasing ionic strength (see Section 7.3). Two polyelec- trolytes of equal charge density may show segregative ...

6.6 STARCH In this section a particular food polymer will be discussed in some detail. Starch is a very important nutrient, prov ...

is still a matter of some debate; a fairly well-established model is in Figure 6.21. The average length of the branches is a few ...

refractive index is higher. The sign observed in a starch granule indicates that the molecules have a roughly radial orientation ...

upon close packing. As soon as polymer molecules take part in such crystallites, the remainder of each molecule loses much of it ...

shape; concentrations of nonstarch components; amylose/amylopectin ratio; molecular structure of amylopectin; type of molecular ...

starch is physically and chemically inert, and it shows little digestion in the human gut. To change it into a functional produc ...

solvent mixtures: 1 TmðjÞ  1 Tm^0 ¼ R DHm q½ð 1 jÞwð 1 jÞ^2 Šð 6 : 14 Þ whereTm^0 is the melting temperature of the pure pol ...

structure disappears. Considerable entanglement of amylopectin chains will persist, and possibly even part of the large helix st ...

shaped granules are still observed, but they should not be envisaged as having a wall or membrane: the amylopectin is held toget ...

Note The reader may be cautioned that the term gelatinization temperature is used rather indiscriminately. The method used to ob ...

reduced, and at starch concentrations of 2–4%(depending on starch type), the chain overlap concentration for amylose will be rea ...

per g of starch, are much smaller than those for native starchð12–22 J?g^1 Þ. The crystallinity obtained after gelatinization a ...

the presence of other components also play a role. It is often assumed that lipids may have considerable effect. As mentioned, s ...

Polyelectrolytes, i.e., polymers containing charged groups (negative or positive or both), show some specific relations. Due to ...

generally smaller for a higher concentration, greater stiffness, and higherb value. Phase separation in mixturesof polymers espe ...

A brief and lucid discussion of the properties of polymers in solution is in the introductory chapter of G. J. Fleer, M. A. Cohe ...