IMPROVED FLOUR

Abstract: The shelf-life of flour containing bran or other non-­ endosperm millings is improved by selectively suppressing enzyme activity in the non-endosperm components of the flour, especially by heat treatment. Grain may be heated, milled and the bran combined with flour extract from untreated grain.

Description: IMPROVED FLOUR This invention relates to improved flour and flour compositons especially dry baking mixes, doughs and batters and cooked products thereof, especially bread. Highly refined flour consists of the endosperm of the grain, almost completely separated in the extraction process of milling from the remainder. The desirability of retaining the separated, non-endosperm fractions of the grain in the diet is becoming widely acknowledged and accordingly the demand is increasing for wholemeal flour in which these fractions are recombined with the endosperm, and for wholemeal baked goods. Whereas normally extracted flour has good shelf-life, the shelf-life of wholemeal flour is poor. This is attributable in large measure to the activity of lipolytic and proteolytic enzymes occurring almost exclusively in the non-endosperm fractions. The former reacts with flour lipids to form peroxides which eventually impart off-flavours to the flour and the latter with protein in the endosperm, breaking it down and destroying its capacity to form gluten, the visco-elastic properties of which are essential for breadmaking. Enzyme activity can be suppressed by heat treatment, but this produces an undesirable effect on the properties of flour by suppressing the activity of amylase enzymes. Amylase is found in the endosperm and breaks down amylopectin and amylose to maltose and other carbohydrate fractions on which the yeast feeds in breadmaking, and also dextrins yielding flavour, texture and colour characteristics. Steam treatment of grain is described in BP 12736 with the object of improving extraction and the quality of the flour, which is itself substantially unaffected by the treatment, the treatment merely conditioning the wheat. British patents 332847 and 401941 disclose heat treatment of wheat germ to remove enzyme activity in the absence of endosperm. The present invention provides a flour composition including dietary fibre comprising an added non-endosperm milled grain fraction which is characterised by the fact that the enzyme activity of the fraction is selectively suppressed. The composition of the present invention therefore comprises a mixture of conventionally extracted flour with unimpaired amylase activity, and a non-endosperm milled grain free from enzyme activity, the combination providing a composition which may contain all the components used in wholemeal flour but which exhibits substantially longer shelf-life owing to the suppression of enzyme activity in the non-endosperm part of the flour. The non-endosperm fractions may be recovered from grain which has been heated, preferably by steam, thereby suppressing enzyme activity of both the endosperm and non-endosperm parts of the grain. Other methods of suppressing enzyme activity in the grain may be used eg, heating especially in the micro- or infra-red range. The period and intensity of the treatment should be controlled to prevent any significant deterioration in the treated fractions. Treatment of separated non-endosperm components for this purpose is less convenient. The flour recovered from the endosperm extract of the treated grain may be utilised as a thickening ingredient in soup mixes, its effectiveness being dependent upon the presence of amylopectin and amylose which remain intact with the suppression of enzyme activity. The endosperm component of the flour mixture according to the invention may be obtained at various levels of extraction including so-called patent flour and may be bread or other quality flour. An important advantage of the present invention is that the composition it provides need contain no added ingredient such as salt which has in the past been added to confer improved shelf-like to flour. The percentage of treated non-endosperm component which is combined with the flour extract may be varied from as low as 10% to as high as 25% or even higher. The compositions of the present invention may include part or all of the components of traditional milled feeds, including the wheat bran, middlings, mill run, shorts, wheat feed and germ meal. The components of the flour products of the invention may be derived from the same or different wheat sources and these may be so-called weak wheat for cakes and strong wheat for breadmaking. The effective improvement in stability provided by the invention will of course depend upon the completeness or otherwise of the separation of wheat. Thus the flour component being untreated will be less stable if it contains a residue of unseparated wheat bran and other enzyme-rich parts of the milled grain and as far as possible therefore these parts should be effectively separated from the flour. The invention also provides a method of preparing wholemeal flour of improved shelf-life comprising milling separate grain feedstocks, one of which is treated to suppress enzyme activity, and combining the flour extract from the untreated grain with the bran and other non-endosperm fractions from the treated grain. Preferably the treated grain is heated, eg, with steam. Wholemeal flour by definition prescribed by law contains the entire composition of all the fractions recovered from milling and recombined and an important advantage of the present invention is that this requirement can be met in a product with much improved shelf-life and without recourse to stabiliser additives. The invention also includes added materials customarily used in culinary mixtures containing flour, for example sugar, dried or whole eggs, leavening agents, flavouring and other conventional additives. Examples of mixtures containing the flour composition of the invention include bread, scone and cake mixes, pizza and doughnut mixes and batters for cakes, pancakes and the like.

Claims: CLAIMS 1. Shelf-stable flour composition comprising a blend of extracted flour and dietary fibre comprising a non-endosperm milled grain fraction with suppressed enzyme activity. 2. Wholemeal flour composition according to Claim 1, which comprises the total non-endosperm extract from milled grain. 3. Composition according to Claim 1 or 2 comprising endosperm and non-endosperm fractions from separately milled and respectively heat-treated grain feedstock supplies. 4. Composition according to Claim 1, 2 or 3 which the percentage of the non-endosperm fraction is from 10 to 25%. 5. Shelf-stable flour composition as claimed in Claim 1 substantially as herein before described. 6. Culinary mixtures including improved flour as claimed in any of the preceding claims together with sugar and other conventional agents present in cake, bread and pizza mixtures, batters and doughnut mixes. 7. Method of preparing flour of improved shelf-life comprising milling separate grain feedstocks, one of which is heated to suppress enzyme activity, and combining the flour extract from the untreated grain with the non-endosperm fractions from the treated grain. 8. Method of preparing compositions comprising wholemeal flour according to Claim 7 wherein the total non-endosperm fraction milled from the heated, grain feedstock is recombined with 10 to 25% treated endosperm fraction. 9. Method according to Claim 7 substantially as herein before described. 10. Flour - containing compositions wherever prepared by a method as claimed in Claims 7, 8 or 9. 11. Baked farinaceous goods including bread, cakes, pizzas and pancakes, prepared from a composition as claimed in Claims 1-6 and 10.

Inventors: YOELL, RICHARD WILLIAM
Applicants: UNILEVER NV
Application year: 1983
Main classification: A21D6
IPC codes: A21D10, A23L1, A21D6, A21D2