Chapter 9: Complex Carbohydrates Part 2

Since it has a grainy mouthfeel

Structurally by chemical or mechanical means

Wheat, corn, soy

Sweetness, viscosity, mouthfeel and appearance

Cross-linked starch is changed chemically so bonding takes place between starch molecules

a molecular network, more resistant to acids and more stable during freezing/thawing, will not lead water on standing, and do not continue to thicken during food storage

Acids

baby foods, salad dressings, cream-style corn, fruit pie fillings

1) Cold Water Paste
2) Starch and Fat
3) Starch and Sugar

Made by quickly stirring the starch while adding at least an equal amount of cold water
Must be heated while stirring

Gravy, soups

Separates starch granules with melted fat, uses equal amounts of fat and starch

White sauce and gravy

Gravy made from starch heated in fat until the starch turns a reddish brown
Mixture of equal amounts by weight of flour and fat that is cooked to varying degrees of doneness.

Adds distinctive flavours to gravies and sauces

| Requires low heat and constant stirring

Sugar helps separate starch granules and prevents them from sticking

• Abundant and economical source of E

| - Needed in the diet to allow fat to be used for E and prevent ketosis

The brain's only E source

Fibre, bran, bulk on food labels

Crispiness/Mouthfeel

Slow staling and improve loaf volume

Aids in digestion/elimination of waste

| Helps maintain a feeling of fullness

• Provides bulk for digestive processes

• Decreases bile reabsorption

• Lowers cholesterol levels in blood

• Promotes the utilization of fats

Amylose: 15-35%
Amylopectin: 65-85%

Gums and pectins

Gum arabic: surrounds flavour particles, protecting them from moisture absorption, evaporation, or chemical oxidation.

Pectin molecules will dehydrate, then acid will cause hydrogen bonding to occur between negatively charged molecules, thus creating a thickened structure

To break intermolecular bonds. Starch molecules relax and expose polar structures to water, which allows H-bonds to form between the starch molecules and water. It increases the amount of water the molecule can trap.

Pregelatinized: allows it to gel, or set, at the T of cold milk. The starch in regular pudding mixes will not gelatinize until the mixture is hot enough to boil. Then it will not gel until it is chilled

It will decrease the strength and viscosity of the gel and increase the translucency of the paste

2.0 to 3.5

Retrogradation, viscosity, stability, opacity versus translucency and texture

In a three-dimensional network which keeps the molecules from shifting positions.
Two Hs bond together: junction
Long starch chains form firmer gels that are more stable in heat

Amylose: set rapidly and form firm gels upon cooling (elastic)
Amylopectin: forms thinner gels or no gels at all (rigid)

Tendency of amylopectin starches to become rigid (combined with moisture loss)

Least – Sols, Pastes, Gels - Most

Since acids hydrolyze starch, which will weaken or break down gels. Lemon juice is added after the starch has thickened the lemon pie's filling. The filling is then cooled rapidly to minimize the thinning effect of acid in lemon.

Molecular size, shape, and charge

Linear are more viscous because they will not roll over easily unless they are parallel to the direction of flow.

Substituting 30% of the flour in cookies with pure wheat starch (protein removed) will increase the spreading action of the batter

Waxy maize starch

Translucent sauce: cornstarch, potato starch, and arrowroot

| Opaque: wheat flour

Mixture of equal amounts by weight of butter and flour. The mixture can be added to hot soups to thicken the broth. The heat of the broth melts the fat. This allows the starch from the flour granules to disperse into the broth with little risk of lumping.

Large, heavy and branched

| The more branched the glycogen is, the more glucose units the body can release at a time

The amount of carbohydrates consumed and how frequently the individual exercises. The more you exercise, the more energy the muscles will store

The fibre tetrasaccharide stachyose -> gas
Minimize by taking a special digestive enzyme, but less positive fibre effects
So, eat high fibre foods and eat yogurt -> growth of beneficial bacteria