• High Pressure Processing of Dairy Foods

      Donnelly, W.J.; Beresford, Tom; Lane, C.N.; Walsh-O'Grady, D.; O'Connor, Paula M.; Fitzgerald, Richard J.; Murphy, P.M.; O'Reilly, Conor; Morgan, S.M.; Ross, R Paul; et al. (Teagasc, 2000-09-01)
      The term High Pressure Processing (HPP) is used to describe the technology whereby products are exposed to very high pressures in the region of 50 - 800 MPa (500 - 8000 Atmospheres). The potential application of HPP in the food industry has gained popularity in recent years, due to developments in the construction of HPP equipment which makes the technology more affordable. Applying HPP to food products results in modifications to interactions between individual components, rates of enzymatic reactions and inactivation of micro-organisms. The first commercial HPP products appeared on the market in 1991 in Japan, where HPP is now being used commercially for products such as jams, sauces, fruit juices, rice cakes and desserts. The pioneering research into the application of HPP to milk dates back to the end of the 19th century. Application of HPP to milk has been shown to modify its gel forming characteristics as well as reducing its microbial load. HPP offers the potential to induce similar effects to those generated by heat on milk protein. Recent reports have also indicated that HPP could accelerate the ripening of cheese. Much of the Irish cheese industry is based on the production of Cheddar cheese, the ripening time for which can vary from 4 - 12 months or more, depending on grade. A substantial portion of the cost associated with Cheddar manufacture is therefore attributed to storage under controlled conditions during ripening. Thus, any technology which may accelerate the ripening of Cheddar cheese while maintaining a balanced flavour and texture is of major economic significance. While food safety is a dominant concern, consumers are increasingly demanding foods that maintain their natural appearance and flavour, while free of chemical preservatives. HPP offers the food industry the possibility of achieving these twin goals as this technology can lead to reduced microbial loads without detrimentally effecting the nutritional or sensory qualities of the product. The development of food ingredients with novel functional properties offers the dairy industry an opportunity to revitalise existing markets and develop new ones. HPP can lead to modifications in the structure of milk components, in particular protein, which may provide interesting possibilities for the development of high value nutritional and functional ingredients. Hence these projects set out to investigate the potential of HPP in the dairy industry and to identify products and processes to which it could be applied.
    • 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.