Foods: Yoghurt

Microorganisms have been identified and exploited for more than a century. The Babylonians and Sumerians used yeast to prepare alcohol. There is a great history beyond fermentation processes, which explains the applications of microbial processes that resulted in the production of food and beverages. In the mid-nineteenth century, Louis Pasteur understood the role of microorganisms in fermented food, wine, alcohols, beverages, cheese, milk, yoghurt and other dairy products, fuels, and fine chemical industries. He identified many microbial processes and discovered the first principal role of fermentation, which was that microbes required substrate to produce primary and secondary metabolites, and end products. 

Food Diary products (cheese, yoghurts, etc.) Non-sterile... 

Kumar, K. and Mishra, H. N. (2004). Mango soy fortified set yoghurt Effect of stabilizer addition on physicochemical, sensory and textural properties. Food Chem. 87, 501-507. 

Migration of ethylbenzene Ifom polystyrene into various foods has been reported. The following ethylbenzene levels were found sour milk beverages, < 2.5-6 pg/L noodle soup, 15-21 pg/L noodle curry, 89-153 pg/kg and wantan soup 9-28 pg/L (ECETOC, 1986). Migration of ethylbenzene Ifom polystyrene containers into dairy products resulted in concentrations of ethylbenzene ranging from 2 to 4 pg/kg in yoghurt and 4 pg/kg for chocolate dessert (Ehret-Henry et al, 1994). 

M Biasolo, A Bertazzo, C Costa, A Beghetto, G Allegri. Determination of nonprotein tryptophan in yoghurts by selective fluorescence and HPLC. Food Chem 52 87-92, 1995. 

Biotechnology involves making use of microorganisms or their components, such as enzymes, for the benefit of humans to produce, for example, foods such as yoghurt and bread. One of the oldest biotechnologies is that of fermentation. It involves a series of biochemical reactions brought about by micro-organisms or enzymes. 

The key issue with a number of modifications that have been made to (3-lactoglobulin is their performance as food ingredients, especially when added to complex formulations (Lee et al., 1994). As a model system, yoghurt is simple and could be improved by reducing whey syneresis. Since the double... 

Nerin, C., Rubio, C., Cacho, J., Salafranca, J., 1998, Parts-per-trillion determination of sytrene in yoghurt by purge-and-trap GC with mass spectrometry detection. Food Add. Contam. 15, 3, 346-354. 

Wu, H., Hulbert, G.J., Mount, J.R. 2001. Effects of ultrasound on milk homogenization and fermentation with yoghurt starter. Innov. Food Sci. Emerg. Technol. 1, 211-218. 

Gels are of central importance for most semisolid food products. A gel can contain more than 99% water and still retain the characteristics of a solid. The network structure will determine whether the water will be firmly held or whether the gel will behave more like a sponge, where water is easily squeezed out. The gel structure will also have a major impaet on the texture as well as diffusion of water and soluble compounds. Many food matrixes are based on colloidal gels such as yoghurts, cheeses, many desserts, sausages etc (see also Chapters 19 and 20). In whole foods, there is often a combination of colloidal structures and fragments of biological tissues or gel structures in combination with particles, emulsion and foam structures. This level of complexity of composite food structures will not be dealt with here. 

Sultana, K., Godward, G., Reynolds, N., Animugaswamy, R., Peiris, P., and Kailasapathy, K. (2000). Encapsulation of probiotic bacteria with alginate-starch and evaluation of survival in simulated gastrointestinal conditions and in yoghurt. Int. J. Food Microbiol. 62,47 55. 

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