Cereals and Bakery Products

Gluten-free breads/low glycaemic breads

The demand for gluten-free products is rising steadily, paralleling the apparent or real increase in coeliac disease and other allergic reactions to wheat gluten. Removal of gluten from flour generates major technical problems for bakers with the result that many gluten-free products currently available on the market are of inferior quality. Previous research has focused on the use of appropriate ingredients (such as starches, gums, protein powders, inulin) and mathematical modelling techniques to improve the quality of gluten-free breads (see more...).

Rapid staling is a major problem in gluten-free breads. Currently, a specially designed, gluten-free maltogenic alpha-amylase enzyme is being assessed in a gluten-free bread formulation. Its effects on shelf-life optimisation (of the gluten-free bread), par baking, freezing and thawing properties of the bread are being studied.

A further study to examine structure formation and ingredient interactions in gluten-free dough and bread is also underway. Preliminary data suggest that NIR and MIR are suitable techniques to track and predict texture changes in gluten-free breads; this capability is of benefit to bakers and those in the supply chain.

Another project involves gluten replacement using a modified dairy protein (casein), i.e. a protein that behaves like gluten. Both casein and gluten form dense chemical gel networks with covalent (disulphide) and co-ordination (with calcium) links. Casein, under the correct conditions of pH and ionic strength can form glutinous masses suitable for elasticity and gas entrapment. This project represents a new approach in this field.
(eimear.gallagher@teagasc.ie)

A new project on low glycaemic (GI) breads was prompted by a Mintel report stating that the increasing demands for low glycaemic breads is here to stay, i.e. low glycaemic-impact foods are no longer a niche market comprising diabetics and people with medically restricted diets. The objective is to formulate bread products which have a nutritious, slowly-digestible status, rich in dietary fibre/resistant starch and functional ingredients. This will diversify the range of available foods with a low glycaemic response to meet rising demands.
(eimear.gallagher@teagasc.ie)

Irish grown wheat varieties and dough rheological tests

Currently, a study involving wheats grown in different locations in Ireland and abroad (e.g. Canada, UK, Greece) is underway. Wheat varieties grown in Department of Agriculture & Food field trials are analysed annually under a routine testing program at Ashtown Food Research Centre to provide data on milling, flour properties and baking characteristics. Traditional methods for wheat quality assessment are slow and no single test can provide all the relevant quality information. The present project is underpinning this work with fundamental science using novel, rapid methodologies. Near infrared spectroscopy is being deployed to collect information on whole grains, flour and the resulting breads. The proteins (low molecular weight, high molecular weight) in the different varieties are being separated and studied. The starch pasting properties are being assessed and rheological tests on the resulting doughs are being developed. Tests such as biaxial extensional viscosity (using uniaxial compression of dough) will be developed as a possible means of predicting baking properties of the dough. Biaxial extensional viscosity is of importance during stretching associated with bubble formation in dough during proofing. It is envisaged that this project will complement the current routine tests and will strengthen the scientific base underpinning this work. (eimear.gallagher@teagasc.ie)

Organic breads and confectionery

Food safety and genetic modification issues have led consumers to opt for organic food as a safer alternative. In a recently completed project (see more...) the effects of commonly used ingredients in baking e.g. organic flours, improvers and fats were assessed. The differences between organic and non-organic flours in terms of compositional and rheological characteristics were small and did not influence baking characteristics. The differences in flour enzyme activity, dough mixing tolerances and crumb lightness/yellowness values did not affect baking quality and acceptability. Organic confectionery flours and ingredients give muffins and Madeira cakes with reduced volumes and a darker crumb appearance. However, staling rate is similar to non-organic confectionery products. (eimear.gallagher@teagasc.ie)

Quality improvement in baked goods through enzyme action

Variations in the quality of flour are the main reason behind inconsistent quality in baked goods and also limit opportunities for novel product manufacture. Remedies have traditionally included the incorporation of flour improving agents but consumers are now resistant to their use. Hemicellulase enzymes are naturally occurring catalysts which alter the physical structure and physico-chemical properties of carbohydrates in wheat flour including changes in water-absorption properties and water distribution between macromolecules in wheat flour dough. This can then affect the organoleptic and functional properties of the bread. During this project, a range of experimental hemicellulase preparations were prepared in the National University of Ireland Galway and examined for their functional effects in bread (white, wholemeal and rye), bread rolls and bread produced using retail (i.e. lower quality) flour. Outcomes from the work indicated that certain hemicellulases can increase loaf volume, improve crumb texture and delay staling in these products. Effects on specific products varied with enzyme preparation and in each case, enzyme effects increased with usage rate up to a maximum after which a decline was observed. Intellectual property issues arising from this work are now being pursued; the release of specific data will be possible once this process is complete. (gerard.downey@teagasc.ie)

Support for bakery industry

This embraces grain testing, milling, flour testing, formulation, product development, dough and batter rheology, test baking (for industry and DAF), packaging, freezing, gas flushing and sensory analysis of baked goods. (eimear.gallagher@teagasc.ie)