Interaction with carbohydrates

3 Possible interactions between butyl amine and pectin or alginate [6,111 

The amylopectin fraction is also involved in flavour binding. With higher concentration of volatile flavouring substances, the outer branches of the amylopectin form helical structures - as with amylose - in which flavouring substances are entrapped [141 

Different starches show varying flavour binding capacity. Starches with a low amy-lose content (e.g. tapioca at 17%) and waxy starches consisting only of amylopectin have only a weak binding capability those with a high amylose content (like potato or maize) have a greater one. Gelatinized potato starch has been researched best. 

The model tests were carried out both iso-thermally (i.e. at constant temperature) and in temperature gradients (from warm to cold). Alcohols (e.g. ethanol, hexanol, octa-nol, decanol), aldehydes (e.g. decanal), ketones (e.g. diacetyl), acids (e.g. caproic acid), esters (e.g. ethyl acetate), terpenes (e.g. menthol, menthone, 6-pinene, limonene), amines (e.g. butyl amine), pyrazines and other classes of substances have been investigated as flavouring substances [6,9,11,13-18]. Fig. 5.6 shows the forma- 

Studies in temperature gradients (e.g., from 80°C down to 20°C) showed that in the case of many volatile flavouring substances the number of inclusion complexes after cooling to 20°C was the same as that formed under isothermal conditions simply at 20°C. In other words, the prior warming does not increase the amount of flavouring substance which is bound after cooling. This is illustrated, using decanal as an example, in Fig. 5.7. 

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X-ray crystallography of lectin-sugar complexes shows the detailed complementarity between the two molecules, which accounts for the strength and specificity of their interactions with carbohydrates. 

There are two major mechanisms by which the microwave electric field is converted to heat within a food. The first, the ionic interaction, comes from the linear acceleration of ions by the field. These ions are primarily from various salts within the product. The second interaction is molecular rotation of polar molecules, primarily water, as well as weaker interactions with carbohydrates and fats. 

Lectins are proteins known to interact with carbohydrates noncovalently but in a reversible and highly specific manner. Most plant lectins are simple and are formed as homo- or heterooligomers. The sizes of the subunits are moderate (molecular weight is usually below 40kDa) and may contain more than one carbohydratebinding site. Because many lectins have been well studied and are available in large quantities, they are invaluable tools for chemical biology and functioned as model systems in the study of carbohydrate-protein interactions [31, 32],... 

Hemagglutinating activity in the common lentil (Lens culinaris or Lens esculenta) was first reported by Landsteiner and Raubitschek.439 Several laboratories have since isolated the lentil lectin in pure form, and studied its physical-chemical properties and interaction with carbohydrates.138,142,143,440 442... 

Karamanska R, Clarke J, Blixt O, MacRae JI, Zhang JQ, Crocker PR, Laurent N, Wright A, Flitsch SL, Russell DA, Field RA (2008) Surface plasmon resonance imaging for real-time, label-free analysis of protein interactions with carbohydrate microarrays. GlycoconJ J 25 69-74... 

Use of porphyrin-based receptors for sugar recognition provides some advantages because the sensitive probing ability of porphyrins greatly helps in the detection of interaction with carbohydrates, which are, in general, spectroscopically poor substrates. 

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