This invention relates to a coating for foodstuffs which is cookable or reheatable by means of a microwave oven. The invention relates particularly but not exclusively to microwave cookable batters or breaded coatings.

Microwave ovens are commonly used for heating food products which have been pre-prepared by a foodstuff manufacturer. Pre-prepared products include batter coated foodstuffs in which the basic foodstuff for example meat, fish, poultry, vegetables, fruit or iced products, has been coated in batter optionally coated with crumbs and then deep fried and then frozen for supply to a consumer.

Heating in a microwave oven may complete the cooking process or simply reheat a previously cooked product. Microwave cookable coatings have particular requirements. Steam released from the food can cause the batter to become soggy, detracting from the texture and taste of the product.

WO88/06007 disclosed a batter composition and method of preparation wherein the foodstuff is predusted with high amylose starch and methyl cellulose. The batter includes high enzyme soya flour. WO93/03634 disclosed an improved predust composition including a mixture of particulate starch and particulate cellulose gum which gels on heating in the presence of moisture. Such a predust can form a dense high viscosity barrier to absorption of oil and migration of moisture. The barrier also provides a stable environment for any seasoning and can enhance bonding with the batter. Although high enzyme soya flours afford generally acceptable products, variations in their enzyme content have given rise to inconsistent and occasionally undesirable flavours.

According to a first aspect of the present invention a microwave cookable or reheatable foodstuff coating comprises an aqueous mixture including the following ingredients by dry weight:

(i) starch, preferably high amylose starch 30 - 60% (ii) cellulose gum 1 - 5%

(iii) flour 25 - 60%

(iv) an enzyme additive, and (v) ancillary ingredients,

-including one or more emulsifiers and one or more reducing sugars balance to 100% wherein the enzyme additive comprises one or more alpha- amylases optionally together with one or more further enzymes, buffers and stabilisers.

Use of the enzyme additive in accordance with the present invention has the advantage that use of soya flour is not essential. A mixture of soya flour and other flour, for example wheat, rye, oats, buckwheat, maize, rice or potato flour may be employed. Alternatively the soya flour may be replaced entirely with one or more other types of flour. The flour may be selected to provide a range of flavours which were not previously available. Gluten free flours are preferred. The enzyme additives may be selected in accordance with flour employed.

The starch may comprise high amylose starch. Alteratively or in addition pea or maize starch may be employed.

The invention finds use in manufacture of coated foodstuffs. However alterative applications include pancakes including filled pancakes. Preferred formulations for manufacture of pancakes do not include soya flour.

Preferred coating comprises the following ingredients by dry weight :

(i) high amylose starch 35 - 50%

(ii) cellulose gum 1 - 5%

(iii) glyceryl monostearate or other emulsifier .5 - 3% (iv) dried egg 7 - 15%

(v) D-xylose or other reducing sugar 1 - 5%

(vi) flour 30 - 50%

(vii) an enzyme additive, and (viii) ancillary ingredients balance to 100%

Preferred alpha amylases include maltogenic amylases including those expressed by Bactillus subtilis strains. A preferred enzyme additive is available under the Trade Mark Novamyl MG manufactured by Novo Nordisk. Preferred enzyme additives act on the starch fraction of flour, modifying the starch to create low molecular weight sugars eg amylose and dextrins which improve the water retention capacity of the batter. However Novamyl amylases reduce any tendency to retrogradation or undesirable further hydrolysis during cooking or reheating.

Additional enzymes may include proteases for example endopeptidases such as Alkalase manufactured by Novo Nordisk; pentosanase, for example Pentopan 200 MG manufactured by Novo Nordisk and metaloproteases, for example Neutrase manufactured by Novo Nordisk. Beta glucanases or other proteases serve to degrade polypeptides such as gluten during incubation of the batter.

Conventional buffers may be employed although use of phosphates is especially preferred. Preferred additives also incorporate gluconolactone. The stabiliser may be ammonium bicarbonate although alternative stabilisers may be employed. Ammonium bicarbonate is preferred because it also serves to reduce undesirable odours.

Emulsifiers which may be used may comprise one or more of the following: glyceryl monostearate, lecithin, milk powder, dried whole egg, dried egg white and dried egg yolk. Use of lecithin is especially preferred to optimise fluid properties and emulsion stability of the batter. Especially preferred compositions incorporate mixtures of egg, glyceryl monostearate and lecithin. Preferred lecithins include soya lecithin filtered and a low iron soya lecithin, activated soya lecithin, lyso-lecithin and phosphatidylchoine.

The reducing sugar is preferably D-xylose. Alterative reducing sugars which may be employed instead of or in addition to xylose are xylitol, sorbitol and L-rhamnose.

Coating compositions in accordance with this invention are preferably blended by mixing under high shear, followed by

being allowed to stand for about one hour. Heat generated during mixing promotes enzyme activity. A preferred method includes mixing at a rate to cause heating to 30 to 60"C.

The invention is further described by means of example but not in any limitative sense.

Example 1 The following formula was employed.

INGREDIENTS % by weight

High amylose starch 48

Cellulose gum 2

Glyceryl monostearate 1

Dried whole egg 13

D-xylose 2

Enzyme additive 3

Soya Flour 31

100

The Enzyme Additive Comprised

Glucono-D-lactone 18

Sodium Acid pyrophosphate 10

(pH - 4.2)

Mono sodium phosphate 50

(pH - 4.5)

Ammonium bicarbonate 19 x-Amylase (Novamyl) 3

100

The batter was prepared by placing the starch into a mixer, dispersing the gum, emulsifiers, enzyme additive and xylose into the mixture, followed by addition of the egg and

flour and further mixing to ensure complete dispersion. The batter was packaged in moisture proof containers for storage before use.

The powdered batter mixture (1 part) was added to water (3 parts) or less water according to the desired viscosity of the batter.

The pH of the batter mix was 4.5 to 5.0.

Pieces of reformed chicken were coated with a predust designed in accordance with the moisture content of the substrate. The predusted chicken pieces were fed mechanically with a conventional batter application (for example a Stein or Koppens apparatus) . The battered particles were then fed into a crumb applicator preferably a Japanese-style applicator, from which the coated product was then transferred to a standard frying line and cooked for a period of approximately 45 to 60 seconds depending on the desired colour of the coating. The product was then fed into a cryogenic or other freezer and frozen to give a core temperature of at most -20 ^* C preferably - 50 ^* C. The frozen product was picked into containers manufactured from impermeable plastics material, stable for at least 6 months at -20 ^* C or lower or any other container with similar properties. Preferred packaging procedures include gas flushing after evacuation of the packs to a vacuum of at least 99%. Preferred gases are N ₂ and/or gas mixtures not including C0 ₂ .

The products can be reheated in a domestic or commercial microwave oven in their containers, if the latter are designed for use in a microwave oven. Alternatively the products may be reheated on a plate.

Example 2

INGREDIENTS % by weight High amylose starch 35

Cellulose gum 3

Dried whole egg 10

D-xylose/any reducing sugar 2

Lecithin 5

Buckwheat flour/any flour 20 Wheat flour 20 Enzyme additive 5

100

The enzyme additive for Example 2 comprised the additive of Example 1 with additional Neutrase and beta-glucanase. A similar coating and cooking process was employed.