Dr M. J. Lewis
Dr Lewis has been a member of the academic staff since 1973. In the late 1970s, early 1980s he developed links with Tanzania and in the mid-1990s became coordinator of a British Council Link programme with Thailand. Dr Lewis has over 30 years teaching experience; interests are physical properties of foods, food processing operations, milk and milk processing; heat treatment, evaporation, drying and membranes. His book on Physical Properties of Foods and Food Processing Systems, published in 1987, remains consistently in the top three Google entries in the subject area (5.2 million citations) and his book on heat treatment (co–authored with Neil Heppell), published in 2001 shares a similar distinction (2.4 million citations). His third book on Separation Processes, jointly edited with Alistair Grandison, is still in print.
He has been actively involved with the management of our pilot plant facility and the Process Research Centre (PRC), which is the business development activity that arose from that, for over 25 years.
His current research activities have been studying minerals in milk and their interactions between proteins, especially with regard to calcium and also magnesium and their role in casein micelle stability. Stability aspects that have been studied include ethanol stability, heat stability, involving heat coagulation times, stability to in-container sterilization, stability to UHT sterilization (fouling and deposit formation) and fouling of UF membranes. Rennet coagulation and acid coagulation studies have also been undertaken, as well as partitioning of components between the soluble and the micellar phase. Recent work involves measuring pH and ionic calcium at high temperatures. The work has been extended to include the production and heat treatment of calcium-fortified soy milks. Comparisons have been made of the behaviour of cows milk and goats milk and Jersey milk with Friesian milk and changes in minerals over lactation.
A productive link with professor Hilton Deeth and the University of Queensland has been established. This has lead to funding from DIAL to study factors affecting the heat stability of milk powders.
An accurate method to measure ionic calcium in milk has been developed, which is leading to a better understanding of the properties of calcium fortified beverages and the effects of stabilizers on heat stability and other physicochemical properties of milk.
During 2005, two of Dr Lewis's PhD students received awards for their work at international meetings. Alexandros Tsioulpas won the Manfred Kruger Prize for the best presentation in the Dairy Section of the IFT meeting in New Orleans in July 2005. Leonard Fweja won the prize for the best student poster at the IDF Meeting in Cork in April 2005.
He spent a short sabbatical at the University of Queensland (UQ), with his collaborator Dr Hilton Deeth, funded by a scholarship from the University of Queensland in 2005. This was followed by the award of a "studentship" funded by the Dairy Ingredients Group Australia (DIGA), to study factors affecting the heat stability of milk powder
Lin M-J, Grandison A, Chryssanthou, X, Goodwin C, Tsioulpas A, Koliandris, A and Lewis M (2006), Calcium removal from milk by ion exchange, Milchwissenschaft, 61 (4), 370 -374
Prakash, S.,Datta, N. , Lewis, M J.Deeth, H C (2007) Reducing fouling during UHT treatment of goat's milk, Milchwissenschaft 62,(1), 16-19
Chove B E, Grandison A S and Lewis M J, (2007),Some functional properties of fractionated soy protein isolates obtained by microfiltration, Food Hydrocolloids, 21, 1379-1388
Tsioulpas A, Lewis M J and Grandison A S (2007)Effect of minerals on casein micelle stability, Journal Dairy Research, 74, 167-173.
Tsioulpas A, Lewis M J and Grandison AS (2007) A study of the pH of individual milk samplesInt J Dairy Technol, 60, 96-97
Hallab, R, Kohen, C, Grandison, M A, Lewis M.J. and Grandison A.S. (2007), Assessment of the quality of cottage cheese produced from standard and protein fortified skim milk, Int J of Dairy Technology, 60, 69-73
Fweja, L.W.T., Lewis, M.J. and Grandison, A.S. (2007) Alternative strategies for activation of the natural lactoperoxidase system in cows milk: trials in Tanzania. Journal of Dairy Research 74, 382-387.
Pathomrungsiyounggul, P, Grandison, A .S. and Lewis, M.J. (2007) Effects of calcium chloride and sodium hexametaphosphate oncertain chemical and physical properties of soymilk, Journal of Food Science, 72, 8E428-E434
Tsioulpas A, Lewis M J and Grandison AS (2007) Changes in physical properties of bovine milk from the colostrums period to early lactation, Journal Dairy Sci, 90, 5012-5017
Dr Lewis makes a major contribution to the school's very active enterprise profile and has been actively been involved in Teaching Company Schemes (TCS) and Knowledge Transfer Programmes (KTP).