Oats are available in variety of forms that can be used in formulation of different cereal based consumer products. Unlike other major grains, oats are seldom used as flour. This is due to the high lipid content, which makes oat flour highly adhesive and difficult to handle. Instead, most common wholegrain oat product is oat flakes, which are often used as a raw material in oat baking. Oat flakes, or oat rolls, are prepared form oat groat after the unpalatable hull has been removed.

Flakes are available in different thicknesses that retain their structure differently during baking process and that require different cooking time. Prior the flaking, oat grains can be cut into three to four pieces to yield steel cut grains. These groat parts are sometimes used as such in baking processes without further grinding or flaking.

Oat flour or oat meal is produced by grinding flakes or groats into flour for use as an ingredient in a wide variety of food products. Typically oat starch is partly gelatinized or damaged to overcome problems with product handling.

Oat bran is a dietary fibre and beta-glucan enriched oat fraction that can be used in products aiming towards improved nutritional status. Oat bran is usually separated from endosperm components by sieving or classification processes (Wu and Doehlert, 2002). Traditional oat bran products have beta-glucan content around 8 to 12 %, whereas oat bran concentrates can have remarkably higher beta-glucan content (see attached table). For AACC definition of oat bran please see: http://www.aaccnet.org/definitions/oatbran.asp.

Different bran ingredients are typically available as coarse or fine flour, or as an extrudate with slightly roasted flavour. Concurrently with the production of beta-glucan fraction, an endosperm fraction is recovered as a co-product. This endosperm fraction has a lower dietary fibre and beta-glucan contents than the wholegrain oat products. Such flour can be used in applications where dietary fibre content is not striven.Several special oat fractions are also available for specific usage. Oat oil consists of polar and non-polar fractions. Non-polar oat lipids are comparable to other vegetable oils and it has a nutritionally favourable fatty acids composition and is rich in lipid soluble antioxidant (Peterson and Wood 1997). Polar lipid fraction has a large potential to be used as emulsifier agent and has potential applications also beyond food products (Peterson 2002, Forssell et al. 1998, Erazo-Castrejon et al. 2001).

Two other emerging oat ingredients have recently gained lot of interest:

1) Various oat extracts are available for both food and cosmetic applications. In food applications these are used to provide oat flavour and health benefits without technical limitations evident for other oat products.

2) Due to the fact that many celiac patients have recognised oat as a suitable cereal source there is increasing demand for oat protein concentrates with tailored technological properties (Guan et al. 2006).

References

Erazo-Castrejon, S. V., Doehlert, D. C., D'Appolonia, B. L. (2001) Application of oat oil in breadbaking. Cereal Chem 78, pp. 243-248.

Forssell, P., Shamekh, S., Härkönen, H., Poutanen, K. (1998) Effects of native and enzymically hydrolyzed soya and oat lecithins in starch phase transitions and bread baking. J Sci Food Agric 76, pp. 31-38.

Guan, X., Yao, H., Chen, Z., Shan, L., Zhang, M. (2006) Some functional properties of oat bran protein concentrate modified by trypsin, Food Chem 101, pp. 163-170.

Knuckles, B.E., Chiu, M.M., Betschart, A.A. (1992) β-Glucan-enriched fractions from laboratory-scale dry milling and sieving of barley and oats. Cereal Chem 69, pp. 198-202.

Peterson, D.M. (2002) Oat lipids: composition, separation and applications. Lipid Technology 14, pp. 56-59.

Peterson, D.M., Wood, D. F. (1997) Composition and structure of high-oil oat. J Cereal Sci 26, pp. 121-128.

Wood, P.J., Weisz, J., Fedec, P., Burrows, V.D. (1989) Large-scale preparation and properties of oat fractions enriched in (1→3)(1→4)-β-D-glucan. Cereal Chem 66, pp. 97-103.

Wu, Y.V., Doehlert, D.C. (2002) Enrichment of β-glucan in oat bran by fine grinding and air classification. LWT - Food Sci Technol 35, pp. 30-33.

Oat ingredients and products

Introduction

Although oats have been part of the human diet for centuries, the principal use of oats has been as a feed grain. Their superior nutritional content and ready availability made oats the feed grain of choice until the mid-1900s. However, changes in farming practices, improvements in knowledge regarding animal nutritional requirements, and increased availability of low-cost ingredients that could be blended to provide high-quality feed formulations have caused oat usage as a feed grain to fall dramatically. Additionally, the low nutrient density due to the high hull content has been a significant factor.

In contrast, oat usage in human foods has increased as information on oats' beneficial nutritional properties has come to light. The authorization of the heart health claim for oats in the United States by the FDA is especially significant. Additionally, recent investigations on the health implications of minor oat constituents such as avenathramides have raised hopes that the nutritional benefits of oats in human diets may go well beyond those currently recognized.

Food uses

Oat products are used as ingredients in a wide variety of bread and baked products. These ingredients provide unique flavour and moisture retention characteristics, as well as enhancing the nutritional benefits of these products. It has been demonstrated that oat flour stabilized the fat component in breads. For the production of bread the baker can use different types of oat fractions, rolled oat, oat flour, whole oat and oat bran.

In conventional wheat bread processing, up to 10-20 % of wheat flour can be easily replaced with oat flakes. Even higher amounts of oats can be used by adapting optimized baking technologies (Flander et al. 2007). Thus it is possible to provide physiologically effective quantities of oat beta-glucan in oat bread. A special attention should be paid on to the fact that beta-glucan can be depolymerised during baking procedure due to action of endogenous enzyme activities (Åman et al. 2004).

Oat flour is a major component of infant foods. In many instances, this is a baby's first introduction to solid foods. Oat flour is also a major constituent in granola bars, South American beverage products, and pancake mixes. Additionally, oatmeal is used as a thickening agent in soups, sauces, and gravies and as a meat extender.

Cold cereals or ready-to-eat (RTE) products represent the other major use for oat products. The high fat and fibre content of oats limits the utilization of oats in this application, but a number of economically important products have been successfully introduced into the markets.

Examples of Innovative oat products

Oatly (CeBa Food AB, Lund, www.oatly.com) is a range of dairy product made of oats instead of milk. The products are milk- and soya-free, and most of them are entirely vegetable-based. Oat kernels and water are mixed and ground and a patented mix of natural enzymes is added. This gives a milk-like consistency, and some of the insoluble fibres are withdrawn while leaving the water-soluble fibre in the product. Finally, the mixture is homogenised to make the product smooth and even.Oatly products can be used in the same way as traditional dairy products such as milk and cream.

Oatrim (ConAgra, www.conagrafoods.com, Quaker Oats, www.quakeroats.com, Rôhne-Poulenc); Fat replacer with 5 % β-glucan and partly hydrolysed starch. Preparation of Oatrim involves the conversion of starch in oat flour or bran into amylodextrins by enzymatic hydrolysis. Oatrim consists primarily of amylodextrins and soluble fibre (β-glucan usually at 5 - 10 % by weight) with low amounts of lipids, proteins and minerals. Oatrim can be used in most foods as a powder or gel.

In OatWell® oat bran, β-glucans are present in high contents due to a careful stabilization process of oat bran. CreaNutrition / Swedish oat fibre (www.oatingredients.com) develops, produces and sells OatWell® oat bran products rich in ß-glucan, up to 22 %. Cereals with added OatWell® oat bran can be used as fortification in breakfast mueslis or designed as RTE cereals.

Primaliv^TM (Skåne mejerier, Malmö, Sweden, www.skanemejerier.com); Primaliv^TM consists of a cup of 200 ml is delivering 4 grams of OatWell® β-glucans, equivalent to the amount in three plates of oat-porridge. In 2002, Skånemejerier's PrimaLiv became the first product in Sweden to be approved and marked in compliance of the new rules of the food industry for health statements.

YOSA® (Bioferme, Finland, www.bioferme.fi). YOSA® is a, non-dairy oat product made from oat and oat bran. The oats are fermented with a combination of probiotic bacteria (inc. Bifidobacterium lactis BB-12^TM and Lactobacillus acidophilus LA-5^TM). These probiotics have scientifically proven benefits that can help regulate your digestive system. YOSA® has been granted the Heart Symbol the Finnish Heart Association and the Finnish Diabetes Association.

Provena (Raisio, Finalnd, www.provena.fi). Provena® is a line a various oat products that are certified to have an extreme low level of contamination with other cereals. Thus this product line is suitable coeliac disease patients who can tolerate oats.

Conclusions

New product development has the opportunity to expand oat utilization in the human diet. Oats have primarily been used as a component of breakfast. Development of oat products that serve as a side dish or main dish for other eating occasions could dramatically expand oat usage and the opportunities for consumers to increase their consumption of "oat soluble fibre." As usual, challenges are plentiful, for changing eating habits is "easier said than done."

References

Flander, L., Salmenkallio-Marttila, M., Suortti, T., Autio, K. (2007) Optimization of ingredients and baking process for improved wholemeal oat bread quality. LWT - Food Sci Technol 40, pp. 860-870.

Åman, P., Rimsten, L.,  Andersson, R. (2004) Molecular Weight Distribution of beta-Glucan in Oat-Based Foods. Cereal Chem 81, pp. 356-360.