DE102008000623A1 - Process for making rice - Google Patents

Abstract

The invention relates to a process for producing rice, which is produced by drying the rice grains. During the drying of the grains, at least a partial surface of the entire surface of the grains is in a viscoelastic or rubber-like state beyond the glass transition of the grains, at least during a part-time period of the entire duration of the drying process.

Description

The The invention relates to a process for producing rice, especially from Paddy, who made by drying the rice grains becomes.

At the Drying rice is to pay attention that the rice grains during the Drying process possible few impairments such as B. experience cracking.

One excessive drying at high temperature, low relative humidity and strong air circulation causes shrinkage stresses, which usually lead to deformations, Cracks or cracks in the dried rice grains to lead. On this way dried rice grains then easily disintegrate while cooking. In addition, find at one Such "aggressive" drying Maillard reactions on the grains while drying, which may cause discoloration.

Moreover are the drying times achieved so far in the rice drying still unsatisfactory long. It is known that the amorphous structure the rice starch two states can accept. Below a glass transition temperature Tg a glassy and above the glass transition temperature a rubbery state.

Of the Invention is based on the object, dried rice better Quality, especially without cracks and discoloration, in as possible short time, especially with significantly shortened drying process to produce.

to solution To this end, the invention provides a method for the production of rice of the type mentioned, in which when drying the rice grains at least during a partial period of the entire duration of the drying process at least one sub-surface the entire surface the rice grains in a visco-elastic or rubbery state beyond the Glass transition the rice grains located. By doing so leaves not only the extent of shrinkage and Maillard reactions during the Reduce the drying process, so that the rice thus produced has less cracks, but you also achieved a significant Shortening the Duration of the drying process.

preferred embodiments are in the dependent claims disclosed.

Preferably is during the drying process, the relative humidity of the drying environment the rice grains is controlled such that at least in partial areas of the surface of the rice grains a glass transition from the melt-like or rubbery state is prevented in the glassy state. In the fields, in which the grains to be dried not in the glassy state, water molecules can be faster (about 5 to 10 times faster) diffuse, so that the discharge of Water and thus the drying of the grains takes place faster overall. Ideally, a glass conversion by controlling the relative humidity at any temperature during the Drying process prevented.

Especially It is advantageous if the grains undergo glass transformation Control of relative humidity and / or temperature during the entire drying process is prevented. Preferably, this will while at least 90% and more preferably at least 95% of the total Duration of the drying process prevented. This should be at least 50% of the total surface the grains be the case. It is particularly advantageous if they are not in the glassy state present partial surface at least 80% and more preferably at least 90% of the total surface area of the grains is.

Preferably is the entire surface when drying, ideally the entire volume the grains in a visco-elastic or rubbery state beyond the Glass transition. Especially it is preferred if during the grains throughout the entire period of the drying process Visco-elastic or rubbery state beyond the glass transition exhibit.

If both the surface as well as the inside of the grains while the entire drying in a rubbery, so non-glassy Condition can be kept, the drying rate can be significantly across from the drying can be increased in the glassy state, z. At least by 20-25%. In addition, any cracking and discoloration of the grains is prevented.

The grains can while the drying process are moved relative to each other and / or be kept relatively spaced. This will cause caking the grains among themselves prevented.

Ideally, in the invention, both the surface and the interior of the grains remain in the rubbery, ie non-glassy, state up to the midpoint during the entire drying process, ie during the so-called predrying, main drying and stabilization. As a result, the transport of moisture from the interior or from the center of the grains to their surface and from their surface into the surrounding drying air takes place rapidly. Thus one achieves a faster drying saturation. There is no glass over There is no risk of cracking in the husks of the rice grains.

The surface and the interior or center of the grains reach drying the moisture content in equilibrium with the surrounding air. Thus unnecessary also a humidification in the stabilization step.

Claims (17)

A process for producing rice produced by drying the rice grains, characterized in that, during drying of the grains, at least part of the duration of the drying process is at least a partial surface of the entire surface of the grains in a visco-elastic or rubbery state beyond the glass transition of the grains is located. Method according to claim 1, characterized in that that while the drying process, the relative humidity of the drying environment the grains is controlled such that at least in partial areas of the surface of the grains a glass transition from the melt-like or rubbery state is prevented in the glassy state. Method according to claim 2, characterized in that that a glass conversion by controlling the relative humidity at any temperature during the drying process is prevented. Method according to claim 2 or 3, characterized that a glass conversion by controlling the relative humidity while the entire drying process is prevented. Method according to one of claims 1 to 4, characterized that the part-time period is at least 5% of the total duration of the Drying process is. Method according to claim 5, characterized in that that the part-time period is at least 10% of the total duration of the Drying process is. Method according to Claim 6, characterized that the part-time period is at least 90% of the total duration of the Drying process is. Method according to claim 7, characterized in that that the part-time period is at least 95% of the total duration of the Drying process is. Method according to one of claims 1 to 8, characterized that the sub-surface at least 50% of the total surface the grains amounts. Method according to claim 9, characterized that the sub-surface at least 80% of the total surface the grains is. Method according to claim 10, characterized in that that the sub-surface at least 90% of the total surface the grains is. Method according to one of claims 1 to 11, characterized that when drying the entire surface of the grains in a visco-elastic or rubbery state is located beyond the glass transition. Method according to one of claims 1 to 12, characterized that when drying the entire volume of the grains in a visco-elastic or rubber-like state beyond the glass transition located. Method according to one of claims 1 to 13, characterized that while the grains throughout the entire period of the drying process Visco-elastic or rubbery state beyond the glass transition exhibit. Method according to one of claims 1 to 14, characterized that the grains while the drying process are moved relative to each other and / or be kept relatively spaced. Method according to claim 15, characterized in that that the grains while the drying process by means of a vibrating bottom moves become. Method according to claim 16, characterized in that that the grains while be fluidized the drying process by means of a gas flow.