• Effect of Milk Composition on the Quality of Fresh Fermented Dairy Products

      Wilkinson, M.G.; Guinee, Timothy P.; Fenelon, Mark (Teagasc, 2000-09-01)
      The rheology of yogurts or fresh fermented products generally describes and measures the texture of the product and includes such terms as viscosity and firmness of the gel while syneresis refers to the tendency of the yogurt to whey-off during storage. The importance of rheology and susceptibility to syneresis of fermented milk products is that they both have major impacts on consumer perceptions of the final product quality. Indeed, variation in the quality of yogurt products can lead the consumer to experience either an over-thin watery or an over-thick stodgy texture or a product which has a high level of free whey. It is obvious that the seasonal milk supply in Ireland compounds the particular difficulties associated with achieving a consistency in the quality of yogurts or other fresh fermented products. Importantly, both the rheology and syneresis of yogurts are markedly influenced by milk composition, processing treatments and the addition of hydrocolloids. Therefore, this project was undertaken so as to develop a laboratory fermented milks model system which allows the evaluation of the effects of variation of milk components, individually or in combination, on the rheological and syneretic properties of fermented milk products such as yogurt. In particular, the effects of varying total protein, casein-to-whey protein ratio, and fat content were studied as these variations reflect both the differences in milk composition due to lactational/seasonal effects and those due to process variations such as milk heat treatment.
    • Enzyme Modified Cheese Flavour Ingredients

      Wilkinson, M.G.; Kilcawley, Kieran; Mulholland, E.; Department of Agriculture, Food and the Marine, Ireland (Teagasc, 01/09/2000)
      Enzyme-modified cheeses (EMCs) are defined as concentrated cheese flavours produced enzymatically from cheeses of various ages and are principally used as an ingredient in processed foods, where they provide a cost-effective alternative to natural cheese. They can be used as the sole source of cheese flavour to intensify an existing cheese taste, or to impart a specific cheese character to a more bland product. Their main applications are in processed cheese, analogue cheese, cheese spreads, snack foods, soups, sauces, biscuits, dips and pet foods. Their main advantages over other cheese flavour ingredients are: low production costs, consistency, high flavour intensity, diverse flavour range, extended shelf- life, low storage costs and increased functionality. EMCs are generated utilising the same flavour pathways that occur in natural cheese ripening i.e. proteolysis, lipolysis and glycolysis. They are not as easy to differentiate as natural cheeses, as they are characterised by flavour and aroma alone as texture is not a factor in EMC production. The relationship of the flavour of EMCs to the flavour of the corresponding natural cheese remains unclear. This is especially true for Cheddar EMC which is commercially available in a range of Cheddar flavours . Despite the fact that a wide range of commercial EMCs are available, there is very little detailed information available regarding their properties or the specific production processes used. The main objective of this research was to build a knowledge base on EMC products and to utilise this to develop a biotechnological process for the production of improved enzyme modified cheeses for use as flavour ingredients. The strategy was to establish quantitative relationships between the compositional, proteolytic and lipolytic parameters and the sensory characteristics of EMCs. This data would then be used to develop a predictive model for flavour development in EMC production and the subsequent generation of an optimised EMC process enabling the generation of a range of cheese flavours from single or multiple substrates.
    • Establishment of Enabling Technology for Manufacture of Selected Types of Continental and Speciality Cheeses

      Wilkinson, M.G.; Sheehan, Diarmuid (JJ); Guinee, Timothy P.; Cogan, Tim (Teagasc, 1998-09-01)
      The objectives in the project were the development of the science and technology for speciality cheese manufacture, identification and overcoming of the technical constraints to the manufacture of soft speciality cheeses in Ireland and the development of Moorepark Technology Limited (MTL) pilot plant as an integrated, flexible pre-commercial manufacturing platform with which to evaluate the market for speciality cheese.
    • Model System for the Production of Enzyme Modified Cheese (EMC) Flavours.

      Kilcawley, Kieran; Beresford, Tom; Lee, B.; Wilkinson, M.G.; Department of Agriculture, Food and the Marine, Ireland; Irish Dairy Levy Research Trust (Teagasc, 01/04/2002)
      Natural cheese flavour ingredients, in the form of enzyme modified cheeses (EMCs), are widely used in the convenience food industry and can provide high volume added opportunities for the cheese industry. Many EMCs are produced using commercial enzyme preparations and previous studies have indicated that they contain side activities in addition to their stated main activity (see DPRC Report No.10). Therefore, it is critical that the exact enzyme complement of these preparations are known before they can be used to produce EMC of specific requirements on a consistent basis. The scientific basis of rapid enzyme mediated flavour formation in the production of EMCs is not fully understood. Consequently this knowledge gap is a major obstacle in the development of high value cheese flavour ingredients. Hence, a major objective of this project was to deepen the scientific understanding of flavour formation with a view to the production of natural enzyme-mediated dairy flavour ingredients with commercial potential. The ultimate aim was to develop the technology to produce customised high value dairy flavour ingredients in an optimised process.
    • Novel and Speciality Cheeses - Broadening the National Cheese Base

      Sheehan, Diarmuid (JJ); Wilkinson, M.G.; Beresford, Tom; Meehan, Hilary; Cowan, Cathal; Delahunty, Conor; McSweeney, Paul L. H.; Kelly, Alan L. (Teagasc, 2002-04-01)
      The Irish dairy industry is considered vulnerable to the price pressures of the commodity market, on which it is highly dependent. Hence, a broadening of the product base, would reduce exposure to this market while offering the potential of exploiting the lucrative added value market. This involves risks and challenges. The cheese market in particular continues to grow and investment in innovative products have in some cases been highly successful. However, a number of obstacles confront Irish cheese manufacturers. These include: seasonality of milk supply, strong tradition of Cheddar production, knowledge gaps in industrial-scale specialty cheese manufacture, and a reticence to commit significant investment, particularly in plant. To address some of these obstacles a project was undertaken with the overall objective of developing a range of cheeses with novel flavour, texture and appearance which were complementary to existing manufacturing plant and technologies. The project was built on the knowledge, skills base and flexible cheese manufacturing plant developed in a previous study (see DPRC Report No. 9), and had the following specific objectives: * assess consumer preferences, * develop a range of novel cheeses capable of being manufactured wholly, or in part, on existing plant, * determine the effects of manipulation of process variables on novel hybrid composition and ripening, * assess market potential and consumer reaction to selected cheeses, * determine the relationships between cheese composition and sensory characteristics, and * present product options to Irish industry.