Starches and modified starches
Starch is a white to slightly yellowish, odorless powder. Starch is a complex carbohydrate derived from plants (corn, potato, cassava, wheat, ..). In the world, starch can be extracted from more than 50 plants. Starch is called “starch” when extracted from tubers or roots.
modified tapioca starch are natural ingredients of human nutrition. In addition to their nutritional and energy value specific to carbohydrates, starches have multiple properties: bind, thicken, texture, stabilize, gel.
The starches can be used as is (native starch) or after modifications: modified starches or pregelatinized starches.
The modified starches are obtained from native starches which have been modified chemically and / or physically to give them particular properties.
Modified starches therefore have nothing to do with genetically modified products (GMOs). To avoid confusion, they are also called “processed starches”.
The consumption of modified starches is not dangerous for health, they are included in Annex I of the additives authorized without restriction in the European Directive 95/2 / EC.
Properties of modified starches
Unlike native starches, modified starches do not need to be cooked to develop their properties. The transformed starches are cold soluble. They are very handy for binding a cold sauce or salad dressing, or for giving viscosity or binder to a preparation.
The modified rice starch can be used as cornstarch but does not require cooking. It is ideal for “catching up” with a cold sauce that is a bit too liquid.
It is also perfect for frozen fruit: rolling the frozen fruit in a little processed starch, this then prevents the fruit juice from sinking during thawing and that the pie base does not soften.
Modified starch also has the property of improving the water relation of the starch and thus the stability of the texture of the products in which it is incorporated. Thus, the incorporation of modified starch into a preparation makes it possible to avoid the release of water during a freeze / thaw cycle (syneresis).
The modified starch is odorless and neutral in taste, its addition does not change the flavor of a dish.
Determination of modified starch in culinary preparations
In cooking and baking, the usual use dose of the modified food starch varies from 0.5% to 3.5%, more rarely up to 10%, depending on the desired texture and consistency.
Native starches and modified food starches
An abundant nutritional compound, starch represents a considerable source of energy for animals. It is also an important part of human nutrition, since the food industry makes very high consumption, such as gelling, thickening, binder … After the presentation of its composition, this article details the phenomena involved in its thermal transformation . The diversity of its physical and chemical modifications makes this compound a little complex.
Starch is the main carbohydrate reserve substance of higher plants. It represents a significant weight fraction in a large number of agricultural raw materials such as cereals (30% to 70%), tubers (60% to 90%) and legumes (25% to 50%).
Starch is the main source of energy for animal life and 50% of industrially produced starch is for human consumption. It is an abundant, renewable, inexpensive nutritional compound, which finds in foods multiple functions like thickener, gelling, binder in the form of granular starch powders and as sweetening, binding substances, carrier when used in hydrolysed form.
The term starch is kept for cereals (maize, wheat, rice) while the term starch is preferred for starches of tuber (potato) or root (cassava).
The starch industry is a heavy industry because of the tonnages treated and investments required in terms of equipment, skills and research.
It is a highly concentrated industry with five groups accounting for more than 85% of starch production in Europe (see Economic aspects).
The different origins of the crossed starches with the chemical and physical modifications that are applicable can in principle make the approach of the starches more complex and put off the formulator.
Also the article proposes to give the useful elements on the structure, the behaviors during the cooking and on the interest of the various modifications in order to facilitate the use of the starches.
Examples, application details and tables for selecting modified starches will help to familiarize the reader with the world of starch.