Physical Chemistry of Foods

original network, thereby blocking these pores, greatly diminishing the permeability. Because the crystals aggregate unhindered ...

FIGURE 17.23 Various stages in the formation of a fat crystal network. Approximate scale: the edge of a frame would be severalmm ...

in a more even and compact network. The same mechanism may explain the steepness of the relations with logj, since for a higher ...

most 1%, the linearity extends to, for instance, e¼ 10
^4 ,3? 10
^4 and 14? 10
^4 , for hydrogenated palm oil crystals in oil ...

the stress, whereas the sintered bonds that are broken do not reform, at least not within a short time. Stress overshoot. Here, ...

can occur, which will be a slow process. The original value ofsyis not reached. Especially a multicomponent fat exhibitssetting, ...

solid crystal network. This is regularly scraped off the surface, whereby it is strongly worked and hence made soft. If now the ...

17.4 CLOSELY PACKED SYSTEMS Several types of food systems may be considered as highly concentrated dispersions of soft solid par ...

drainage of the foam layer then leads to a high volume fraction of gas. A highly concentrated O–W emulsion is more difficult to ...

value is higher and the topping has a sufficiently high yield stress. Other toppings contain gelling agents, so thatjcan be smal ...

amylose and the gel resembles a polymer gel of the general type depicted in Figure 17.10b. When the starch concentration is mark ...

generally has a negligible yield stress. Some rheological properties at a time scale of about 1 s would be very roughly Dynamic ...

concentrating the system further increases the modulus, presumably until it would reach the value of a homogeneous gel of the sa ...

Themodulusof the particles. This is clearly shown by the difference between curves (b) and (c), where the particles have about t ...

Cheese. Several fully ripened cheese varieties can be considered closely packed systems. When freshly made, the structure resemb ...

Some Theory. We will only consider air-filled systems. Development of theory generally begins with a simple two-dimensional arra ...

FIGURE17.29 Uniaxial compression of regular cellular structures; the cells are presumed to be open. (a) Structure of the undefor ...

The relation between stress and strain is in principle as given in frame (d). It shows a sharp buckling point, beyond which the ...

Figure 17.30a shows results on the modulus of wafers, made at various gas contents. Equation (17.21) is precisely obeyed. Wafers ...

bread is deformed. The matrix material is rubbery, and the stress–strain curve is comparable to that in Figure 17.29d, although ...