Organic compounds -- part of the class 532-570 series – Organic compounds – Carbohydrates or derivatives
Reexamination Certificate
1998-09-10
2002-10-22
Wilson, James O. (Department: 1623)
Organic compounds -- part of the class 532-570 series
Organic compounds
Carbohydrates or derivatives
C127S065000, C127S071000, C127S032000, C536S045000
Reexamination Certificate
active
06469161
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The object of the present invention is a process for the conversion of starchy material including a dry phase chemical fluidification stage, a stage conducted continuously and in accordance with particular operating conditions.
It also relates to the converted starchy materials obtained in accordance with the said process, some of the said starchy materials constituting moreover new industrial products.
The present invention concerns lastly the industrial uses of the said starchy materials, in particular in the manufacture of paper, adhesives or jellied products.
2. Description of the Prior Art
The conversion of starchy materials involves the use of physical, chemical and/or enzymatic means appropriate to the technical, economic and statutory constraints set by the different industrial sectors for which these products are intended. These sectors are extremely diverse and include notably the food, pharmaceutical, cosmetics, chemical, pesticide, textile and paper industries as well as the fields of packaging, gums and adhesives, building materials or environmental protection.
According to the uses, and application properties required, the conversion of the starchy material may be mainly based on a single process or, on the other hand, necessitate the association of two, or more, processes of every kind, the latter being moreover capable of simultaneous or successive application.
Among the numerous processes which can be applied to starchy materials, chemical fluidification techniques have aroused genuine interest, for more than a century, in numerous branches on industrial activity.
By chemical fluidification is here understood any operation consisting in subjecting a starchy product, and this at a temperature generally lower than 100° C., to the hydrolysing action of a chemical agent, for example an acidic compound or (per)oxidising agent, the said agent being able to be used in a liquid, solid and/or gaseous form. This type of operation is carried out in conditions such that the resulting fluidified product has, compared with the original product, a) generally little or no increase in cold solubility and b) relatively little or no modification in humidity, in all cases kept above 6-7% approximately.
This definition differentiates chemical fluidification techniques from enzymatic hydrolysis techniques, the latter using enzymes, enzymatic cocktails or micro-organisms as the sole or main means of fluidification.
It differentiates them also from the hydrolytic processes of dextrinification or, more broadly, of pyroconversion, which involve, in practice, the application of very high temperatures, i.e. generally somewhere between 120 and 170° C., to particular starchy materials, namely starches generally pre-acidified, pre-dried, and maintained, during the reaction, at maximum humidities of 5% approximately.
These pyroconversion processes give rise for their part to particularly dry, powdery and hygroscopic products (white or yellow dextrines, “British gums”) the cold solubility of which is high, even total, in all cases very significantly increased in relation to the cold solubility of the original starchy material.
Compared with these processes of pyroconversion or dextrinification, chemical fluidification techniques generally have a certain number of technical or economic advantages linked to the operating conditions or to the characteristics of the products to be processed and/or those obtained and in particular:
absence of the need to pre-dry the original starchy material,
use of lower reaction temperatures,
reduction of the risks of explosion,
lower solubility of the processed material, hence a better applicability of the latter to subsequent modifications notably those carried out in a hydrous medium.
When they are applied to native starchy products, i.e. those not yet subjected to any physical, chemical and/or enzymatic process, chemical fluidification techniques additionally enable the preparation of converted products with a range of physio-chemical properties much sought after in particularly diverse fields of activity as for example the food, pharmaceutical, paper, and textile industries, the gums and adhesives industries and the building materials industries.
Such common properties, obtained for example, by the hydrolysing action of inorganic acids (hydrochloric acid, sulphuric acid, phosphoric acid, gaseous HCl, etc.) are generally linked to the reduction in the molecular weight of the product obtained and consist notably of:
reduced intrinsic viscosity and hot viscosity, the hot viscosity being capable of assessment by measuring Water Fluidity or WF,
increased content in reducing sugars,
not significantly modified cold solubility,
increased hot solubility,
increased gel strength and film strength,
All these properties are fully described by:
O. B. WURZBURG in “Modified starches: Properties and uses—Chapter 2, pp 17-40, CRC Press, Inc. 1986”
R. C. ROHWER et al. in “STARCH, 2
nd
ed.—Chapter XV11, pp 529-541, Academic Press, Inc. 1984”, and
J. A. RADLEY in “Starch Production Technology—Chapter 20, pp 449-457, Applied Science Publishers Ltd, 1970”.
One of the main techno-economic advantages of chemically fluidified starchy products consists of their aptitude for being used and processed, particularly of their aptitude for being baked and made to gel, with very highly dried out matter. This is due to their considerably lowered viscosity compared with native products. This aptitude is expressed in energy savings (smaller volumes of water to be eliminated) and technological advantages widely exploited in industry, for example in the manufacture of gums and jellied foodstuffs, the sizing the coating of paper, textile sizing and the finishing or the preparation of adhesives for plaster sheets and corrugated board, as described in the previously mentioned reference works of WURZBURG, ROHWER and RADLEY.
Another advantage of chemical, including acid and oxydative, fluidification techniques lies in the possibility of combining them with other types of modification, in particular with etherification and esterification reactions. Thus, in the context of the conversion of starchy materials, a chemical fluidification stage can be preceded, followed and/or conducted at the same time as other chemical modifications as for example:
a hydroxypropylation reaction as described by K. M. CHUNG et al. In “Die Stärke, 43, No. 11, pp 441-446, 1991,
a hydroxyethylation reaction as described in U.S. Pat. No. 5,362,868,
a cationisation reaction as described in U.S. Pat. Nos. 4,373,099; 4,097,427; 3,654,263 and 4,421,566.
The previously re-stated advantages of chemical fluidification methods and of the products arising from them are, in general, obtained irrespective of whether the said methods are carried out in a hydrous environment or, conversely, in dry phase.
By dry phase is here understood fluidification carried out at he core of a reaction mix (starch included), the humidity of which is in practice less than 25% approximately, preferably somewhere between about 8 and 22%. Hydrous medium methods involve for their part a much more dilute reaction medium, with use of a starch slurry with solid matter generally not exceeding 35 to 40%.
Hydrous medium fluidification methods remain widely used in industry in the context of the conversion of starchy materials. However, they involve the use of an additional filtration stage which has the drawback of giving rise to substantial losses of soluble matter mainly in damaged starch granules, in soluble starch molecules and in salts generated during the prior neutralisation of the fluidified starch. This is expressed both by a reduction in the output of fluidified starchy materials and by an increase in effluent pollution loading.
In addition, chemical fluidification methods carried out in a hydrous medium do not always in practice enable native or modified starches whi
Fuertes Patrick
Lambin Anne
Freres Roquette
Henderson & Sturm LLP
Owens Howard
Wilson James O.
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