High protein, ready-to-eat snack foods.

Field of the Invention

The present invention relates to high protein low fat snack products including crisps and to methods of producing them. In particular the products are dried and flat waferlike products. In one embodiment the product is a dried wafer-like crisp snack product with a high fibre content. Some embodiments may comprise probiotics. Other products may comprise of spores of probiotic microorganisms and nano-sized nutrients dusted onto the exterior of the cooked snack.

Background to the Invention

In recent years it has become the trend for consumers to choose foods that are convenient and tasty and to consume snack food products which represent a "treat" or fit in with a busy lifestyle. Such snack foods tend to be nutritionally unbalanced and they can be high in fat and carbohydrates and low in protein. Snack products that are high in fat (particularly Transfats or hydrogenated fats) and calories contribute to obesity and other chronic diseases such as coronary heart disease etc. The well- informed consumer is therefore developing a need for lower fat but higher protein and higher fibre type snack products which have been shown to increase insulin sensitivity in healthy individuals. For other functional ingredient such as fibre , researchers have found that in general for each 2% increase in dietary fibre there is a 1% decrease in Cardiovascular disease.

Public health authorities and food organizations such as the Food and Agricultural Organization, the World Health Organization, the British Nutrition Foundation and the U.S. National Academy of Sciences recognize resistant starch as a beneficial carbohydrate. Resistant starch (RS) is starch and starch degradation products that escape digestion in the small intestine of healthy individuals. Resistant starch is considered the third type of dietary fiber, as it can deliver some of the benefits of insoluble fiber and some of the benefits of soluble fiber. The WIC program (Women, Infants, Children) includes many foods high in resistant starch. The Joint Food and Agricultural Organization of the United Nations/World Health Organization Expert Consultation on Human Nutrition stated, "One of the major developments in our understanding of the importance of carbohydrates for health in the past twenty years has been the discovery of resistant starch. " Furthermore, resistant starch such as the High Fibre High Amylose Maize starch used in the present invention escapes digestion in the small intestine of healthy individuals. This is used as an insoluble dietary fibre in low moisture foods. It is also utilized as a dietary supplement for its health benefits. Published studies have shown that Type 2 resistant corn helps to improve insulin sensitivity, increases satiety and improves markers of colonic function. It has been suggested that resistant starch contributes to the health benefits of intact whole grains.

High protein snack products are also convenient for athletes and keep-fit enthusiasts, who are trying to follow a healthier lifestyle by following a high protein/ low fat diet. With such a diet, it is difficult to find a snack food product that is not high in fat.

We set out to make a healthy, high protein, low GI, high fibre, low fat, snack with the added health benefits of probiotic bacteria and phytonutrients in a tasty and convenient, customer acceptable format.

Protein

Protein is the building block of all life and is essential for the growth of cells and tissue repair. Muscle mass is made up of proteins and it is also a major macro -nutrient intrinsic to the structure of the brain, nervous system, blood, skin and hair. Protein also helps maintain our acid and fluid base. The human body seeks a stability between protein production (synthesis) and usage (metabolism) for energy and cellular structure. Without regular daily intake of amino acids, the body will reach a net negative protein balance, leading to muscle atrophy (wastage). Studies appear to indicate that as people age, more protein is needed and this may slow down the onset of sarcopenia (the loss of muscle mass and coordination that results from the process of aging).

Cutting back on highly processed carbohydrates and increasing protein improves levels of blood triglycerides and HDL, and so may reduce chances of heart attack, stroke or other form of cardiovascular disease. It may also make you feel full longer, and stave off hunger.

Low Glycemic Index (GI) Carbohydrates

The glycaemic index, or glycaemic index, (GI) provides a measure of how quickly blood sugar levels (i.e. levels of glucose in the blood) rise after eating a particular type of food. The effects that different foods have on blood sugar levels vary considerably. The glycaemic index estimates how much each gram of available carbohydrate (total carbohydrate minus fibre) in a food raises a person's blood glucose level following consumption of the food, relative to consumption of pure glucose. Glucose has a glycaemic index of 100.

More than 20% of the adult population of Britain is obese, with approximately 1000 new cases each day. Added to this, more than one in two people are overweight. It is well established that the risk of developing type-2 diabetes is closely linked to the presence and duration of overweight and obesity.

Once a person is obese for a ten year period their risk of becoming diabetic is 20 times greater. Individuals with BMI of 35.0 more are also approximately 20 times more likely to develop diabetes. Women who were overweight but not obese (i.e. BMI between 25.0 and 29.9) were also significantly more likely than their leaner peers to develop gallstones (R , 1.9), hypertension (RR, 1.7), high cholesterol level (RR, 1.1), and heart disease (RR, 1.4). The results were similar in men. (JAMA July 9, 2001, Vol 161 , No. 13).

The incidence of obesity is increasing in Britain and the US, causing serious health issues. Poor blood sugar control, caused primarily by consuming excessive refined sugars is the main cause of this. By eating low GI carbohydrates, a better blood sugar balance and weight management can be achieved.

The level of glucose in a person's blood largely determines a person's appetite. When the level drops we feel hungry and if low enough we experience a whole host of symptoms including fat, poor concentration, irritability, nervousness, digestive problems etc. An estimated three in ten people in the US have impaired ability to keep their blood sugar levels even. When eating excessive refined sugars the blood glucose level will rise too high and then drop to low. The result over the years is that they become increasingly fat and lethargic. The best way to achieve optimal blood sugar balance is to control the Glycaemic load in the diet - in summary eat slow release carbohydrates and more fibre. The consumption of excessive refined (high GI) carbohydrates may go some way to explaining why the incidence of obesity is increasing year on year in the States and Britain despite the fact that calorie and fat consumption is declining over the past 15 years. The carbohydrates used in this invention are for this reason slow release or low GI carbohydrates. The glycaemic response of some common foods is shown in Figure 3.

High Fibre

Soluble fibre combines with sugar molecules in food, slowing down the absorption of carbohydrates and therefore helps keep blood sugar levels balanced, control appetite and play a part in weight management. By regulating the gut transit time there is less time for putrefaction to occur and less risk of bowel cancer, diverticular disease etc. Probiotic Bacteria

The proven benefits of probiotic bacteria include the aiding of digestion, lowering of cholesterol, boosting of immunity and increased resistance to infection as well as reducing obesity ) as ongoing research is establishing a relationship between diet, gut micro bacteria and obesity. The vast majority of gut bacteria reside in the Colon - about 100 trillion individual bacteria. In general, probiotic bacterial gut populations decrease with aging. There is a good health case for ingesting viable probiotic bacteria every single day to promote health and prevent disease. For example, it has been established that for people suffering from Crohn's disease - a type of inflammatory bowel disease, much evidence points to an imbalance in the bacteria in the gut. A combination of pre and probiotics may help ease symptoms, but stomach acid kills most bacteria. Allowing probiotic bacteria to transit the stomach and enter the intestines would be desirable.

Phytonutrients (naturally occurring photochemicals), vitamins and trace elements

Phytochemicals or phytonutrients are chemical compounds that occur naturally in plants and are responsible for colour and organoleptic properties, such as the deep purple of blueberries and smell of garlic. The term is generally used to refer to those chemicals that may have biological significance but are not established as essential nutrients. Scientists estimate that there may be as many as 10,000 different phytochemicals having the potential to affect diseases such as cancer, stroke or metabolic syndrome.

Many people in the western world are deficient in essential vitamins and trace elements. Many clinical trials indicate that adequate supplementation can increase health, help reach full intelligence potential, curb undesirable aggression etc.

(Beneton, D and Roberts, G. Effect of vitamins and mineral supplementation on intelligence of school children, Lancet vol 1 (85780, pp.130-3(1988) and Chandra

RK., Effect of vitamins and trace-element supplementation on cognitive function in elderly subjects ^" , Nutrition, vol 17(9),pp.709-12(2001)). Nutrition impacts on all aspects of brain function especially cognition and mood, so good nutrition impacts on general mood and depression. Supplementation by conventional methods may be unacceptable to the individual, absorption into the body may be inefficient, and processing techniques - with particular reference to heating and drying may denature the nutrient.

Heat-expanded and dried snack food products are known, as are heat-expanded crispy, puffed and flat crisp (or chips as they are referred to in the US) snack food products. These are often based on starches or on milk proteins. Typically, such products have a very high fat content and are, therefore, unhealthy. Products based on milk proteins generally have to be extruded in order to produce a puffed product, because a heat- expanded, crispy synthetic cheese product is difficult to achieve.

'Crisps' refer to many different types of snack products in the UK and Ireland, some made from potato, but they may also be made from corn, maize and tapioca. The term "Crisps" is also used in North America to refer to potato snacks made from

reconstituted dried potato flakes and other fillers, such as "Baked Lay's™" and

Pringles™, although Pringles are technically "quick-fried" in oil.

Potato chips are a predominant part of the snack food market in developed countries nations. The global potato chip market generated total revenues of US$16.4 billion in 2005. This accounted for 35.5% of the total savoury snacks market in that year (US$46.1 billion).

Another type of potato chip, notably the Pringles and Lay's Stax™ brands, is made by extruding or pressing a dough made from ground potatoes into the desired shape before frying. This makes chips that are very uniform in size and shape, which allows them to be stacked and packaged in rigid tubes. In the US, the official term for

Pringles is "potato crisps", but they are rarely referred to as such. Conversely Pringles may be termed "potato chips" in Britain, to distinguish them from traditional "crisps". Such products are traditionally oven baked / or extruded in twin screw extruders but all such crisps including low fat varieties involve addition of oils (fats) to the product.

Our previous patent application WO 2012/140195 relates to a process for producing a puffed snack-food product based on milk proteins.

Object of the Invention

It is thus an object of the present invention to provide a method of producing a high fibre, low fat, flat, wafer-like, dried snack food crisp product. The product preferably has a crispy texture.

It is an object of the invention to provide a heat-expanded and dried crispy snack food product with a low glycaemic load. An object is to include 35-40 % high biological value slow release protein including casein (BV =77). By eating low GL carbohydrates with protein rich foods and high fibre, hunger is reduced.

It is a further object of the invention to provide a continuous production process for producing such a product.

A further object of the invention is to control the level of expansion/shape of the snack to produce a relatively flat, crunchy high protein crisp through the use of low dielectric coatings on the snack prior to microwave heating.

A further object is to provide a simple process for producing a crisped synthetic food product which is tasty and attractive to the consumer.

A further object is to produce a low fat product, rich in nutrients.

A further object of the invention is the use of electrostatics to affix the flavour and increase flavouring dust cover. Increasing flavour pugnacity and intensity can be achieved by affixing nanometre sized flavour particles to the product. Oil/water emulsions or solely water may be used to aid adhesion (traditionally only oil is used). A still further object is to provide a method of coating spores of probiotic bacteria to the surface of the crisp in the final flavouring step. This is with the aim of promoting healthy gut micro flora in the GI tract of the final consumer. The present inventors have demonstrated that spores are sufficiently resilient to reach deep into the small intestine and colon prior to germination.

A further object of the invention is the addition of spores of probiotic bacteria to the flavouring step, with the aim of promoting healthy gut micro flora in the final consumer. We have demonstrated that Spores are sufficiently resilient to reach deep into the small intestine and colon prior to germination.

A further object of the invention is the portioning of the molten product (80°C after mixing) onto a non-stick low dielectric belt, PTFE, silicon or Kevlar belt and rapid chilling of the product using a blast freezer/chillier to enable a continuous production process.

Summary of the Invention

A snack food product is provided comprising a standard recipe of approximately 20% by weight of protein, approximately 17% by weight of a starch, approximately 60% water, the remainder of the volume comprising emulsifiers, preservatives, flavourings and salts (magnesium, potassium and sodium (sea) salts). According to the present invention there is provided a method of making a wafer-like high protein snack product comprising (A) Mixing together water, protein and emulsifying salts at about 50 degrees centigrade,

(B) Heating the mixture to about 70 degrees centigrade and adding starch,

(C) Mixing until all free water is absorbed,

(D) Adding a preservative,

(E) Dispensing the product at 80°C onto a non-stick conveyor belt,

(F) Rapid chilling of the mixture in a continuous process,

(G) Expanding the mixture by heating in a microwave at 800-1100MHz frequency and a power of 10-75kW,

wherein a low-dielectric material/solvent is used to coat the surface of the mixture prior to microwave heating to control the level of expansion of the snack.

The low dielectric material may have a dielectric constant of constant of 1.4-10 K at 5-20°C. The dielectric constant may be between 2- 5k, more suitably between 1.7 and 3.5 K.

Cooking, mixing and forming methods such as pre-heated mixers, twin and single screw mixers and conventional convection ovens may be used in the process.

An electrostatic drum may be used to affix flavour, using an atomised oil/water emulsion or solely water.

The method may further comprise the step of adding spores of probiotic spore- forming bacteria in the flavouring step. The spore-forming bacteria may be selected from Bifidobacteria, Streptococcus, Lactobacillus or Bacillus strains, although other strains could be used. The spores are preferably enterically coated to aid passage through the stomach into the intestines. An enteric coating is a barrier applied to oral medication that controls the location in the digestive system where it is absorbed. Most enteric coatings work by presenting a surface that is stable at the highly acidic pH found in the stomach, but breaks down rapidly at a less acidic (relatively more basic) pH. For example, they will not dissolve in the acidic juices of the stomach (pH ~3), but they will in the alkaline (pH 7-9) environment present in the small intestine. Materials used for enteric coatings include fatty acids, waxes, shellac, plastics, and plant fibres. The method may further comprise the addition of phytonutrients together with the flavourings for coating onto the surface of the crisp. By adding phytonutrients to the exterior of the cooked and formed product they are not denatured via the processing conditions of high heat and high pressure. In addition surface dusting of phytonutrients and vitamins may lead to more rapid absorption transbucally or sublingually which may then be absorbed in the blood through the facial vein.

Variants include controlling the shape of the snack pieces by spraying or immersing in a range of solvents, solutions and gels. We have demonstrated that expansion can be controlled if the above mentioned solutions are of a low dielectric constant 2- 5k (range 1.5-25 K) at 0-10°C prior to microwave drying/cooking. If the dielectric constant of the expansion retarding agent is greater than 1.7k and below 3.5k (range 1.4 to 20 k) then we can achieve a flat, wafer-like end product. This falls off rapidly after dielectric exceeds 5 k.

The microwave used may be a 915MHz microwave with a 75 KW magnetron. Preferably, the microwave used has magnetron waveguide modulator technology (also known as a mode stirrer or polariser). A circular polarising waveguide modulator with side shielding technologies is suitable.

The heating time for expansion in step (G) may be between 10-300 seconds.

The invention also provides a snack food product comprising a standard recipe of approximately 18-38% by weight of protein, approximately 5-30% by weight of a starch, approximately 40-65% water. The product may preferably comprise 20 to 30 % by weight protein and 7 to 18.5 % by weight starch.

A particular embodiment for making the product may involve the use of extrusion, whereby a single screw, twin-screw or co-extruder is used, the method comprising

(A) Mixing together of the protein, starches, emulsifying salts and vitamins or micronutrients in a batch mixer,

(B) Addition of water within the extruder and heating to about 70 degrees centigrade,

(C) Mixing under pressure, increasing the temperature to about 140 degrees centigrade towards the end of the barrel,

(D) Addition of liquid flavours if necessary,

(E) Discharge of product through a narrow die,

(F) Cutting to the desired shape and size via a rotary cutter.

The product may further comprise emulsifiers, preservatives and flavourings. The product may further comprise vegetable oils.

The protein source may be selected from rennet casein, acid casein, whey, soya, tofu, rice proteins, pea protein, collagen, wheat proteins, egg albumin, flax seed protein and protein isolates, or combinations thereof. The preferred protein source is rennet casein. Pea protein is particularly preferred. The starch may be selected from the group consisting of maize-derived starches, or cornstarches, including pre-biotic, high amylase starch, Hi-Maize® Resistant Starch, Tapioca, wheat starch, maize-derived potato starch, Pea Starch, flax starches, rice starch, sweet potato, sago and mung bean starches, pepper flour, rice flour, semolina flour, lentil flour, soy flour, corn flour or combinations thereof in both native and modified form. Hi-maize 260, high fibre high amylose maize starch and pea starches are particularly preferred for the above mentioned health and functional benefits.

The ingredient mixture may consist of 10-38% by weight of protein, 5-30%> by weight of starch and 40-65% by weight of water. The protein may be mixed with emulsifying salts prior to the addition of starch.

Additional ingredients may be selected from salt, sodium chloride, trisodium citrate, disodium phosphate, citric acid, sorbic acid, yeasts and garlic may be added to mixture in step (A).

In another embodiment the invention provides a method of making a high protein snack product comprising the step of adding spores of probiotic spore-forming bacteria together with the flavourings. The spore-forming bacteria may be selected from Lactobacillus or Bacillus subtilis. These can be enteric-coated to facilitate even greater penetration into the length of the digestive tract.

In a still further embodiment the invention provides a method of making a high protein snack product comprising use of an electrostatic drum together with an atomised oil/water emulsion or solely water to affix flavourings to the product.

Brief Description of the Drawings

Figures 1.1 and 1.2 illustrate the results of kitchen trials carried out on snack pieces coated prior to microwave-heating with 20% solutions of sorbitol ('Sor 20') and maltodextrin ('MD 20') as well as the conventional coating of sunflower oil ('Oil') and no coating ('Ν'). From the illustrations, it can be seen that sunflower oil is the most effective at preventing 'puffing' of the product and keeping the flat, wafer-like appearance. The sorbitol and maltodextrin solutions were also found to be reasonably effective, while the un-coated sample puffed considerably.

Figure 2 is a schematic diagram of the manufacturing process of the present invention. Figure 3 shows the glycaemic response of some common foods.

Detailed Description of the Drawings

A schematic of the process of the invention is shown in Figure 1. The ingredients are loaded into a mixer cooker (1) which has a forming or ejection head (2). Following mixing and cooking the ingredients are passed along a continuous, low dielectric belt (3) having indentations and shaping dyes. The mix is then passed to a rapid chiller (4) and following chilling the pieces are passed through a low dielectric atomiser (5). They are then passed into a microwave oven (6) with a power of about 1100-800 MHz. The cooked pieces are then coated with flavourings and bacterial spores by an electrostatic applicator (7). The production line includes a continuous weighing and packing system (8).

The snack product is a blend of some or all of the ingredients listed in Table 2. Table 2 Ingredient ranges for the high protein, low fat snack product

The ingredients were mixed using heat and shear to form a molten "mozzarella-like" mass before dispensing chilling into a solid structure for microwave expansion.

Blending and cooking of the raw ingredients was done using a twin-shaft solid flight agitator Blentech DM-10028x mixer (Blentech Corp., Santa Rosa, CA, USA). The cooker is fitted with two augers, which provide a shearing kneading action along with steam-heated jacket and direct steam inlet valves for temperature control. Alternatively, the dry ingredients were pre-mixed in a batch mixer before cooking/hydrating in a co-rotating twin-screw extruder SBX-50 (Baker Perkins Ltd., Peterborough, UK).

Subsequent to microwave cooking and drying, a fine particulate dust flavour mixed with spores of spore-forming probiotic bacteria are electrostatically affixed to the bite sized snack pieces. In addition, neutraceuticals may be added at this stage, together with the flavourings and spores. The nutrients are used in nanometre particle size, as the smaller size allows for easier absorption by the body.

The preferred technology is to adapt static flavour fixing by applying multi dielectric flavour applicators. This involves applying an electrostatic charge to the flavours/probiotics/neutraceuticals and applying an opposite charge to the cooked product pieces. The net result is to achieve a continuous automated manufacturing production line, designed to make commercial, high protein ready-to-eat snacks with over 70% surface coverage (and optional inclusion of probiotics) coverage and less than 5 % dust over run.

In one embodiment, spores of the Bacillus species were used (specifically B. subtilis and lactobacillus spores). It would however be possible to use spores of any of the strains Bifidobacteria strains including Bifidobacteria Infantis, Bifidobacteria Bifidum, Bifidobacteria Brevis, Bifidobacteria Longum and Bacillus subtilis , Lactobacilli acidophilus , Lactobacilli Salivarius strains Lactobacillus Bulgaricus, Streptococcus Thermophilus, or Lactobacillus Sporogenes. The germinated spores inhibit the growth of pathogens and harmful bacteria that colonise or infect the gut mucosa. Using fibre in the product helps reduce the gut transit time and so transport the probiotic to the colon. It also serves as the food of choice for probiotic bacteria. Approximately 14% fibre may be present in the product.

The probiotic bacteria (principally from the two families of bacteria called the Lactobacillus and Bifidobacteria), including Lactobacilli and Bacillus strains help to balance the gut fiora and prevent pathogens becoming too populous.

It is believed these spores can survive transit through the stomach to colonise and so enhance the normal microbial flora of the further extensions of the gastrointestinal tract, specifically in the small intestine. Unlike vegetative probiotic cells, the probiotic spores will germinate in the extremities of the human gastrointestinal tract with the resultant positive effects of germinating probiotics including aiding in the prevention of colonization of the gut by harmful pathogens. These spore forming probiotic bacteria can be entericlly-coated to facilitate even greater penetration along the length of the digestive tract.

Neither effective drying nor expansion will occur unless the product is sufficiently chilled prior to microwave heating. We have shown that rapid chilling to the desired temperature (<4°C) is sufficient foe effective expansion. This facilitates automation of the production line.

The process involves using Microwave technology for expansion and drying, surface atomisation and or immersion to control final product shape, and rapid cooling to facilitate automation of the line whilst still permitting expansion and drying

Process Summary (i);

1. The ingredients were accurately weighed out and then blended in a twin-auger mixer/cooker (Blentech model no CC-0500, Blentech Corp., Santa Rosa, CA, USA). Initially, the emulsifiers, salts and seasoning are mixed with the water at 50°C for 1 minute. The protein source (added as a powder) is then added and mixed for a further minute before the temperature is increased to 80°C. The starch is then added and mixing continued until all visible water has been absorbed. Finally, a pH regulator is added.

2. The mixture is then ejected from the cooker at approximately 80°C and portioned into 0.2-5 gram pieces and/or continuous strips (1-3 mm wide) which may later be broken to bite size pieces.

3. Shapes may also be formed via a low dielectric conveyor with moulded shapes.

Belt and mould shapes must be made from low dielectric materials, such as PTFE (Teflon), silicone or Kevlar to prevent the product from sticking to the conveyor belt. The conveyor belt surface may be smooth, meshed or dimpled - the latter will facilitate the release of energy from the product during microwave drying and give a rustic look to the final product.

4. Rapid cooling of the product from 80°C to 5°C. The purpose of this is two-fold; it allows us to control the position and shape of the product on the belt prior to entering the microwave and also facilitates a continuous process without the need to wait for the product to cool slowly (if not cooled sufficiently, the product will not dry/expand).

5. Coating of surface of the product with atomised oil/solvent to control the level of expansion during microwave heating. The atomised oil/solvent may simply be sprayed onto the surface of the product pieces or it may be coated in any other manner. We have found that oil and other low Dielectric Fluid materials and mixtures thereof retard expansion. This is of advantage when trying to get a flat shape. If un-coated when exposed to microwave energy, the product expands and 'puffs' violently and sets in a raised shape. When coated with oil/solvent prior to microwave heating, the same violent reaction is observed as the water is rapidly boiled from the product, however the presence of the oil/solvent appears to inhibit the ability of the product to set as quickly and the structure collapses, leading to a flat, crisp-like shape.

6. The product is then passed through an industrial microwave at a frequency of 915MHz (Range 800-1100MHz) and a power of 75kW (range 20-100kW) using single or multiple sets of generators and microwave chambers depending on the required capacity. Preferred additional technology is low frequency, high powered microwave technology with circularly polarizing waveguide modulator and side shielding technologies (Ferrite Inc., Nashua, NH, USA).

7. Upon exiting the microwave, the product enters a flavouring drum where a combination of single or multiple electrostatically charging flavour applicators were used to place a charge on the particulate flavouring and/or probiotic spore forming mix and/or phytonutrients, vitamins and trace elements and an opposite charge on the bite size high protein bites. This coats the flavour and probiotics on all surfaces of the final product. In addition oil solutions, slurries and hydrocolloid solutions may also assist in affixing the flavour/probiotic particles. These include weak gum solutions (Xanthan and guar gums), water, ionized water, weak sugar solutions etc.

8. After flavouring, the product is transferred to automatic weigh and packaging station (schematic of the full process is shown in Figure 2).

Controlling expansion/shape

We have determined that the shape of the snack pieces can be controlled by spraying or immersing in a range of solvents, solutions and gels. We have demonstrated that expansion can be controlled if the above mentioned solutions are of a low dielectric constant 2- 5k (range 1.4-10 K) at 5-20°C prior to microwave drying and cooking. If the dielectric constant of the expansion retarding agent is greater than 1.7k and below 3.5k (range 1.4-10 k) it is possible to achieve a flat wafer-like end product. This ability falls off rapidly after dielectric exceeds 5 k. These include but not limited to Functional Milk Protein gel supplied by Aria Foods DK, liquid whey/milk protein mixture, hydrocolloids, gums and gels (e.g. carageenan, guar gum, pectin) maltodextrin, sorbitol, xylitol and solutions thereof, as well as a range of oils and fats (e.g. sunflower oil, rapeseed oil, canola oil). Retardation of expansion generally increased for most sample gels and solutions with lower temperatures and lower dielectric constant at the microwave frequencies between 900 and 2450 MHz in tested samples.

The Dielectric Constant or permittivity - ε - is a dimensionless constant that indicates how easily a material can be polarized by imposition of an electric field on an insulating material. The constant is "the ratio between the actual material ability to carry an alternating current to the ability of vacuum to carry the current. "

Dielectric constant may be expressed as:- s = s _s /so (1)

Where;

ε = the dielectric constant

¾ = the static permittivity of the material

so = vacuum permittivity

The Dielectric Constant of common liquids and fluids are indicated in the table below. The Dielectric Constant is in general influenced by temperature, moisture levels, electrical frequency and thickness of the material.

Dielectric Constant

Fluid Temperature (°F)

- £ -

Acetic Acid 68 6.2

Acetone 77 20.7

Air (at STP, for 0.9 MHz)) 1.00058986 ± 0.00000050

Alcohol, ethyl (ethanol) 77 24.3

Alcohol, methyl (methanol) 68 33.1

Alcohol, propyl 68 21.8

Ammonia (aqua) 68 16.5

Castor Oil 60 4.7

Cotton seed oil 3.1

Ethylene glycol 68 37.0

Glycerine 47-68

Glycerol 77 42.5

Linoleic Acid 32 2.6-2.9

Linseed Oil 55 3.4 Dielectric Constant

Fluid Temperature (°F)

- £ -

Olive Oil 3.1

Oxygen -315 1.51

Palmitic Acid 160 2.3

Pentane 68 1.8

Stearic Acid 160 2.3

Vacuum (by definition) 1

Water 68 80.4

Xylenol 62 3.9

Deionised Water 70 15

Carbonated Water 70 80

Vegetable Oil 100 3.96

Vegetable Oil 230 3.25

Grapeseed Oil 60 2.9

Following microwave cooking and drying, low dielectric substrates sprayed onto the product will allow the product to expand but prevent a starch matrix setting whilst expanded, thus leading to a flat shape. This is most effective with food grade substances of a dielectric constant 2- 4.5, at a temperature of 2-10 Celsius.

Expansion trials

Expansion trials were carried out with 20% solutions of sorbitol and maltodextrin coated externally on the product prior to expansion and compared with the standard oil-coating, as well as no coating at all. Results are illustrated in figures 1.1 and 1.2. The uncoated product was most expanded, with the oil coated product the least expanded. While the sorbitol and maltodextrin solutions did not perform as well as the oil, they did prevent expansion to an acceptable extent. We then trialled a range of further products including gums and gels, maltodextrin, functional milk proteins and xylitol at 2% to 20% solutions, in addition to a range of oils and low dielectric hydrocolloids. Hi amylose starch such as we use requires high temperatures to form gelatization. As the boiling water violently leaves the microwaved product, it expands and remains in an expanded state - the starch forming a tough matrix. However when we spray on atomized vegetable oil, atomized oil: water mix at a ratio of up to 50:50 at and or low dielectric atomized food grade fluids we found that the matrix collapses and reforms as the substrate cools. This appears to be due to disruption of the chemical cross bonds which re-form on cooling. High density solutions consisting of low dielectric solvents of between 2 and 5 k materials not containing a strong mobile electric charges at low temperatures (2- 10 Celsius ) allowed the least amount of expansion .

Electrostatic Flavour

Flavour addition in snack foods generally uses a flavouring drum whereby the product is tumbled with the flavour and the flavour sticks to the product. With fried snack foods, the flavour is added after frying, so the residual fat on the surface helps the flavour to adhere to the product.

With low-fat products, there is little or no fat in the snack, so another method of flavour application is required. Therefore, the flavour is affixed using an electrostatic flavouring drum and applying the opposite charge to the base product The drum has two electrostatic heads, one at the front of the drum (where the snack enters) and one at the back end of the drum (where the flavour enters). The electrostatic heads put opposite charges on the product and the flavour so that they are attracted to each other resulting in a very consistent coverage. To ensure sufficient flavour coverage, it was thought that oil needed to be coated on the snack using an atomiser. However, after testing, we were able to produce better results with oil in water emulsions at optimal OikWater 40:60 mix(range 20% oil to 80% water, by weight) as well as a range of other solutions (including water on its own). Thus oil to water emulsions of 30:70, 50:50 and 70: 30 will also be suitable for use in the process.

The addition of health-promoting spore-forming probiotic bacteria in the surface flavour is also novel.

The process may also include fixing probiotic bacterial spores to the snack, that carry all the way to the small intestine and/or fixing encapsulated vitamins and phytoneutrients. In a healthy person the gut flora is composed of 85% so called good bacteria or probiotic (fermentation flora) and 15% of pathogenic organisms (putrefaction flora). The main beneficial functions of the good bacteria include.

- To create a barrier to prevent pathogenic organisms or incompletely digested foods from the intestines entering into the bloodstream.

- To provide immunity for the recipient: they are the basic pillar of immunity.

- To improve absorption of nutrients.

- To synthesize some vitamins: B complex and vitamin K.

- To keep under control the flora of putrefaction flora (harmful). When the balance 85% - 15% of the intestinal flora is broken, putrefaction flora take control of the intestines, in particular by the fungus Candida Albicans - that have the capacity to grow and expand very quickly when control by good bacteria is lost. Not only will the fungus expand, but any good bacteria will not develop well. There will be increasingly more harmful organisms, and increasingly fewer good bacteria. Trials have linked increased bloating, allergies, intestinal parasites, food intolerances, Crohn's disease, irritable bowel syndrome, and even cancer with harmful gut bacteria. In addition, lack of beneficial bacteria (probiotic) decreases the body's ability to absorb nutrients from food - which may lead to chronic fatigue syndrome. All this strongly affects the patient's mental and emotional balance: depression, anxiety, emotional sensitivity and insomnia may develop.

Lactobacilli acidophilus and Salivaius strains are permanent residents of the human alimentary canal which may also used to populate the gut flora. The same can be said of non-resident probiotic bacteria such as Lactobacillus Bulgaricus, Streptococcus Thermophilus, Lactobacillus Sporogenes strains. We chose to focus on Bifidobacterium strains (including Bifidobacteria Brevis, B. Infantis, B. Longum, ) and Bacillus coagulans strains which are not only permanent residents of the human alimentary canal but also spore forming, so when entericly-coated, they populated deeper levels of the human gut including the colon.

Bacillus coagulans has been added by the European Food Safety Authority to their Qualified Presumption of Safety (QPS) list. In humans there are many references to use of this bacterium- including improving abdominal pain and bloating in Irritable Bowel Syndrome patients and increasing immune response to viral challenge. One strain of this bacterium has also been assessed for safety as a food ingredient. Spores are activated in the acidic environment of the stomach and begin germinating and proliferating in the intestine. The electrostatic technique for applying nutrients, spores etc. works by applying a static charge to the enteric capsulated probiotic spores, flavour and /or phytonutrients powder. As the enteric coated probiotic spores, flavours and /or phytonutrient dusts are 'negatively' charged, they adhere automatically to the 'positive' base product, creating a true wraparound effect. Alternatively we can reverse the polar charge- this would be to open the cells for easy adsorption of nano nutrients. To ensure enough ingested probiotic bacteria make it through the stomach and into the small, large intestine and colon an adult would require 100 million to a billion viable bacteria daily.

Bacteria would not traditionally be dusted onto a snack product as the production process involves cooking and drying which would kill the viable bacteria. In addition dusting on a probiotic would be largely inefficient because of poor coverage and high powder wastage .The more traditional way to consume probiotics is via live vegetative cell-containing fermented dairy products. Many people are lactose intolerant, specifically around 90 percent of the Chinese adult population is thought to be lactose intolerant (lactose -the sugar found in milk and milk products including yogurts) and up to 20 % of adult European population, which means they have low levels of the enzyme required to digest lactose. This means that they cannot consume milk or yogurt based probiotics. By applying an electrical charge to the spore probiotic flavour mix and the opposite charge to the base crisp, the net result is that it dramatically improves spore powder and flavouring coverage.

Table: the electrostatic dust applicator compared to conventional drum flavour / powder applicators

Coverage can further be increased via applying a fine atomized mist from fluids which have low electrical conductivity. Fluids with less than 50 picosiemens per meter, where picosiemens per meter is a measure of electrical conductivity, are considered low electrical conductivity fluids. We found the optimum range was up to 50 picoseconds per metre, preferably 20 50 picosiemens per meter. We further found that mixtures of low electrical conductivity fluids also worked to enhance the electrostatic effect and assist in transporting the electrostatically charged Probiotic / Flavoured dust to the high protein /high fibre base material.

Glycerol 25 0.064

Spores of Bifidobacteria (Brevis, Infantis, Longum Bifidum) and Bacillus species are used commercially as probiotics and competitive exclusion agents assisting to regulate intestinal microbial homeostasis via the inhibition of pathogens and harmful bacteria that colonize and/or infect the gut mucosa -(such as campylobacteria, Salmonella , Staphlococci, etc .)

Probiotics are typically used in yoghurts or fermented drinks, or as tablets. The present invention is unusual in that it seeks to provide probiotics on a dry coated product, which was not expected to work. It has the advantage that probiotics can be delivered to people who are lactose intolerant, don't like yoghurt or are reluctant to take tablets. We set out to mix the spores with the electrostatically charged flavour. Tests were conducted to ensure the spores germinated in the gastrointestinal tract. We chose spores as they are dormant life forms which can exist in a desiccated and dehydrated state indefinitely. Survival during passage through the gastrointestinal tract is generally considered a key feature for probiotics to preserve their expected health-promoting effects. It was hoped the majority would travel through the stomach and become active and germinate and colonise the small intestine, We primarily used spore forming probiotics Bifidobacteria (Brevis, Infantis, Longum, Bifidum) and Bacillus subtilis strains, rather than the vegetative cells, for example Lactobacillus - type probiotics, (-as these are do not form spores and their live vegetative cells may be destroyed in the stomach ,a harsh environment for germination with its-stomach acids and bile salts.)

The majority of probiotic bacteria reside in the human colon - outnumbering host cells by 10 to 1. Gabriella Casuala, Simon Cutting, and S. M. Woodward (2001) have shown that spores of Baccillus subtilis do appear to have the potential to suppress all aspects of Escherichia coli 078:K80 infection in a 1 -day-old-chick model (1). In addition, Hoa, T. T., L. H. Due, R. Isticato, L. Baccigalupi, E. Ricca, P. H. Van, and S. M. Cutting (2001) analysed spore counts in the faeces of mice administered spore suspensions and shown that it is possible that spores could germinate in the gastrointestinal tract (2).

Using a sensitive RT-PCR assay, Gabriella Casula and Simon M. Cutting of the School of Biological Sciences, Royal Holloway University of London developed a molecular method to demonstrate that bacterial spores can germinate in the small intestine of mice. Their results showed that vegetative cells were detected in the small intestine. It has also been shown that, following dosing of mice with spores, counts can be detected in the faeces.

Example 1

In the present study, nine healthy volunteers whose mean age was 36.3 years were fed 50g of our spore laden probiotic product twice a day for 1 week. Subsequent trials were then performed with nine test subjects. These volunteers were required to abstain from consumption of any type of probiotic including yogurt and fresh dairy products for 10 days before the beginning of the trials.

The faecal matter was pasteurized (70°C for 30 seconds) and homogenized to ensure no subsequent germination occurred. This step was taken as excreted spores may be able to germinate and hence cell division would occur.

Faecal samples, which were obtained at the beginning of each trial (zero time) and after 2 and 6 days, were stored for a maximum of 12 h at 3 to7°C. A lg sample of faecal material was decimally diluted in sterile saline and plated onto skim milk medium and the indole test used to determine the presence of Baccillis species. The plates were incubated at 44°C for 48 hours. The spore-laden probiotic product resulted in germinated cells and some Bacillus species spores were found in the stools, suggesting that they can survive transit in the gastrointestinal tract. The results are shown in Table 1.

Table 1 Concentrations of viable Bacillus subiilis Spores of subjects who consumed probiotic spore and flavouring dust mix.

Concn (logio CFU/g feces)

Trial Subject ^^^^^— ^^^^^

Day 2 Day 6

1 ND ^e 2.5

2 2.4 3.3

3 ND 1.6

4 ND 1.3

5 2.2 3.9

6 ND 3.0

7 4.1 3.9

8 ND 3.0

9 1.1 2.8 ^a Subjects whose stools did not contain viable spores strains were not included.

Example 2

Day 1 - Six volunteers fasted overnight for eight hours before giving a blood sample. These were then sent for analysis.

Day 4 - Three days later the same procedure was followed. Six volunteers fasted overnight for eight hours before giving a blood sample this time after eating 50 grams of dusted protein snack according to the invention, as part of the last meal 8 hrs previously. Day 9 - Five days on the same procedure was followed. Six volunteers fasted overnight for eight hours before giving a blood sample this time after ingesting vitamin tablets 8 hrs previously. Vitamin B6 .10 mg tablets - Boots Own Label. Boots Co PLC. Nottingham England.

Average results - Table 3

We set out to produce a novel and customer acceptable method to ingest probiotic bacteria and thus facilitate consumers benefiting from novel sources of probiotic bacteria, especially spore forming strains and, in addition, demonstrate that viable probiotic bacteria can be retrieved from faeces of healthy individuals within a few days of ingestion.

Further to this, we wish to add lower particle size health promoting phytoneutrients and herbs to the dust flavour mix. The size of the particle dominates the intensity of the herb and spice flavours, how quickly they are tasted and their flavour intensity. Smaller particle sizes (15-200nm) lead to increased intensity of the flavour. This is due to the increase in surface area exposed to the taste buds.

In addition we added nano phytonutrients including Carotenoids, Ellagic acid, Flavonoids, Resveratrol, Glucosinolates and Phytoestrogens.

In nano-sized form the phytonutrients are more absorbable in the mouth thus giving consumers a novel way of injecting health beneficial nutrients and ingesting an overall healthier product.

The words "comprises/comprising" and the words "having/including" when used herein with reference to the present invention are used to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.

References

1/ Higgins JA, Brand Miller JC, Denyer GS (March 1996). "Development of insulin resistance in the rat is dependent on the rate of glucose absorption from the diet". J. Nutr. 126

2/ J.H. Cummings, G.T. Macfarlane, H.N. Englyst. "Prebiotic digestion and fermentation" Am J Clin Nutr 2001;73(2 suppl): 415S-20S.PubMedl 1157351