• Dairy Ingredients in Chocolate

      Keogh, M.K.; O'Kennedy, Brendan; Twomey, Myra; O'Brien, Nora M.; Kennedy, B.; Gorry, C. (Teagasc, 1998-09-01)
      The main objective was to assess and control the contribution of various ingredient components to chocolate behaviour and to optimise ingredients for specific chocolate applications. A key aim, therefore, was to understand the role of composition and particle structure and to produce spray dried powders with a functionality in chocolate as close as possible to roller dried powders. By demonstrating how the powder properties affect chocolate, it should be possible to control the functional properties of the powders to meet any powder or chocolate specification. Novel powder compositions indicated by this work should also be useful to chocolate makers. The ability to make chocolate under test conditions and to assess the role of milk powders or other ingredients has been put in place for the first time in Ireland. Previous knowledge of milk seasonality and of powder technology has provided a basis for understanding variations in milk powder functionality in chocolate. Spray dried powders with mean free fat values of 50 to 94%, particle sizes of 30 to 65 mm and vacuole volumes of 0.0 to 3.9 ml/100g were produced from milks of varying composition but under the same processing conditions. Advances were made in analysing powder structure through microscopy, particle size and occluded air measurement. Valuable new information has been generated on the changes in free fat, solid fat content, particle size and occluded air in powders. Explanations were provided for the first time for the complex effects of these properties on chocolate viscosity and yield value. This information will also make a positive contribution to other projects in the milk powder area. Good contacts have been established with multinational manufacturers and with producers of milk powder for chocolate.
    • Development of a Range of Encapsulated Milk Fat Products

      Keogh, M.K.; O'Kennedy, Brendan; Neville, Denis P.; Kennedy, B.; Gorry, C. (Teagasc, 1998-09-01)
      The aims of this research were to determine the effects of milk composition (fat, whey protein, lactose and salts) and process (homogenisation) factors on the formation of emulsions and microencapsulated powder particles and to relate these to the properties of the powder, especially susceptibility to fat oxidation. The effect of composition, using sodium caseinate and lactose on the production of high fat powders was also studied. Finally, new developments in microencapsulated milk powders were undertaken in collaboration with industry using sodium caseinate and lactose. Overall, the microencapsulation process should provide a technique to extend the shelf-life of sensitive fats and flavours and to produce high fat powders for a range of end-uses. The major components of the emulsions used to make the microencapsulated powders influenced fat globule diameter and stability, but the minor salt components also affected globule size and stability. Free flowing high fat (70%) powders with sodium caseinate and lactose as encapsulants were manufactured using a tall-form Niro spray dryer with fluidised beds. A flavoured ingredient using a by-product flavoured fat as the flavour agent was made using the same encapsulants. Microencapsulated powders were incorporated into baked goods as multi-functional ingredients. They increased loaf volumes and improved handling and processability of the dough, thereby extending the product range for fat and other dairy ingredients used for baking. Microencapsulated 80% fat blends were manufactured for biscuit formulations to overcome the handling problems associated with bulk fats. This sub-project also gave rise to a leading role in a EU FAIR project on the microencapsulation of fish oil for use in functional foods using milk components as the sole encapsulants.