The problem and its context
In the manufacture of wafers for assembly into multi-component, chocolate biscuits (see Fig 3.4) problems were being experienced with blocking of the flow of the wafer batter through the depositor which often resulted in incomplete sheets coming from the wafer irons. The recipe contained oil and lecithin but variations in their levels, individually or collectively, failed to reduce the develop-ment of the gummy material or to improve the completeness of the sheet. Changes in flour supply had no significant effect on the problem.
The analysis
In the manufacture of wafers it is important to avoid the formation of gluten in the batter. There are a number of factors which will influence the formation or not of gluten including the solid content of the batter, the type of flour being used and the levels of oil in the recipe. The mixing process used will also have an influence on potential gluten formation.
Even though the viscosity of the batter is low, gluten strands can form in the batter during mixing and these long strands can be broken up as the batter is pumped around the plant and the tumbling action of the batter-circulation system can cause small gluten balls to form. The presence of coarse filters in the pipe work may remove some of the larger fragments of gluten but the ones which are smaller than the sieving mesh can pass through and block the depositor. The gluten ‘balls’ are distinctive in having a light brown colour as they contain reduced levels of starch.
The gluten-forming proteins in flour used in the preparation of the batter are the primary source of the gluten balls but lowering the level of flour protein or using a flour with different protein qualities does not necessarily reduce the problems of gluten ball formation.
Similarly, increasing the level of oil which may be seen as a gluten-inhibiting ingredient may have no significant effect on the problem.
A major contributor to gluten formation in batters of this type comes from the shear created during the pumping operations. High shear is created whenever the batter is squeezed through narrow gaps and the work that is done on the batter at such points is a significant contributor to gluten formation, just as work done on bread dough during mixing promotes gluten formation. If the batter is held for any length of time before depositing (whether planned or accidental) the common practice is to re-circulate the batter and thereby increase the likelihood of gluten formation because of the extra work being done on the batter.
The causes of the problem and its solution Re-circulation of the batter is undoubtedly a significant contributor to this problem. In addition to the development of gluten strands, the extra work being done on the batter causes the temperature of the batter to rise and this increases the potential for gluten formation. The elevated temperature and any prolonged processing times before depositing can encourage microbial activity and a lowering of the batter pH changes which also exacerbate gluten formation.
The solution is to limit gluten formation as much as possible at all stages of the wafer manufacturing process. In particular, cold water (less 20◦C) should be used for the initial mixing and the flour should
be added gradually to the water while the mixer is running. Mixing times should be kept as short as possible (less than 6 min) and higher mixing speeds should be used where possible. The aim during mix-ing should be to quickly disperse and hydrate the mix-ingredients with minimal gluten formation. Reducing batter re-circulation times is also helpful.
References
Bell, L.N. (2007) Moisture effects on food’s chemical stability, in Water Activity in Foods (eds. G.V. Barbosa-Canovas, A.J. Fontana Jr, S.J. Schmidt and T.P.
Labuza). Blackwell Publishing, Oxford, UK, pp. 173–98.
Bent, A.J. (1997) Cakemaking processes, in The Technology of Cakemaking, 6th edn (ed. A.J. Bent). Blackie Academic & Professional, London, UK, pp. 251–74.
Bent, A.J. (2007) Speciality fermented goods, in Technology of Breadmak-ing, 2nd edn (eds. S.P. Cauvain and L.S. Young). Springer, New York, pp. 245–74.
Catterall, P. and Cauvain, S. (2007) Flour milling, in Technology of Breadmaking, 2nd edn (eds. S.P. Cauvain and L.S. Young). Blackie Academic & Professional, London, UK, pp. 296–329.
Cauvain, S.P. (1995) Putting Pastry under the Microscope. Baking Industry Europe, 68–9.
Cauvain, S.P. (2001) The production of laminated bakery products. CCFRA Review No. 25, CCFRA, Chipping Campden, UK.
Cauvain, S.P. and Cyster, J.A. (1996) Sponge cake technology. CCFRA Review No. 2, CCFRA, Chipping Campden, UK.
Cauvain, S.P., Hodge, D.G., Muir, D.D. and Dodds, N.J. (1976) Improvements in and relating to treatment of Grain. British Patent No. 1 444 173, HMSO, London, UK.
Cauvain, S.P. and Muir, D.D. (1974) High-ratio yellow cakes: The effect of flour particle size. FMBRA Report No. 61, CCFRA, Chipping Campden, UK.
Cauvain, S.P. and Screen, A.E. (1990a) Sugars, sweeteners and low-sweetness bulking agents. FMBRA Bulletin No. 2, CCFRA, Chipping Campden, UK, pp.
62–9.
Cauvain, S.P. and Screen, A.E. (1990b) Effects of some ingredients on cake tex-ture. FMBRA Report No. 142, CCFRA, Chipping Campden, UK.
Cauvain, S.P. and Telloke, G.W. (1993) Danish pastries and croissants. FMBRA Report No. 153, CCFRA, Chipping Campden, UK.
Cauvain, S.P. and Young, L.S (2001a) Baking problems solved. Woodhead Pub-lishing, Cambridge, UK, p. 73.
Cauvain, S.P. and Young, L.S (2001b) Baking problems solved. Woodhead Pub-lishing, Cambridge, UK, p. 154.
Cauvain, S.P. and Young, L.S. (2006) Baked Products: Science, Technology and Prac-tice. Blackwell Publishing, Oxford, UK.
Dobraszczyk, B.J. (1997) Development of a new dough inflation system to eval-uate doughs. Cereal Foods World, 42, 516–19.
Doe, C.A.F and Russo, J.V.B. (1968) Flour treatment process. British Patent No.
1 110 711, HMSO, London, UK.
Faridi, H. (1990) Application of rheology in cookie and cracker industry, in Dough Rheology and Baked Product Texture (eds. H. Faridi and J.M. Faubion).
Van Nostrand Reinhold, New York, pp. 363–84.
Gaines, C.S. (1982) Influence of dough absorption level and time on stickiness and consistency in sugar-snap cookie doughs. Cereal Chemistry, 59, 404–7.
Hodge, D.G. and James, C.D. (1981) Pastry technology: Factors affecting the consistency of short paste. FMBRA Report No. 96, CCFRA, Chipping Camp-den, UK.
Kent-Jones, D.W. and Mitchell, E.F. (1962) The Practice and Science of Breadmaking, 3rd edn. The Northern Publishing Company, Liverpool, UK.
Knight, R.A., Mears, K. and Robb, J. (1967) Puff pastry: A test bakery inves-tigation of a shortened process of manufacture using the ‘English’ method.
FMBRA Report No. 2, CCFRA, Chipping Campden, UK.
Manley, D. (2000) Technology of Biscuits, Crackers and Cookies, 3rd edn. Woodhead Publishing, Cambridge, UK.
Mears, K. and Wade, P. (1969) The manufacture of meat pies: Some factors affecting the properties of boiling water paste. FMBRA Report No. 26, CCFRA, Chipping Campden, UK.
Menjivar, J.A. (1990) Fundamental aspects of dough rheology, in Dough Rheology and Baked Product Texture (eds. H. Faridi and J.M. Faubion). Van Nostrand Reinhold, New York, pp. 1–28.
Miller, A.R. (1985) The use of a penetrometer to measure consistency of short doughs, in Fundamentals of Dough Rheology (ed. H. Faridi). American Asso-ciation of Cereal Chemists, St Paul, MN, pp. 117–32.
Morgenstern, M.P., Newberry, M.P. and Hoist, S.E. (1996) Extensional properties of dough sheets. Cereal Chemistry, 73, 478–82.
Oliver, G., Thacker, D. and Wheeler, R.J. (1995) Semi-sweet biscuits. 1: The influ-ence of sodium metabisulphite on dough rheology and baking performance.
Journal of the Science of Food and Agriculture, 69, 141–50.
Pritchard, P.E., Emery, A.H. and Stevens, D.J. (1975) The influence of ingredients on the properties of wafer sheets. FMBRA Report No. 66, CCFRA, Chipping Campden, UK.
Robb, J. (October 1968) Effect of work input in different mixers on Madeira cake. FMBRA Bulletin No. 5, CCFRA, Chipping Campden, UK, pp. 340–45.
Robb, J. (1984) The practical implication of baking powder reaction rates. FM-BRA Bulletin No. 6, December, CCFRA, Chipping Campden, UK, pp. 215–24.
Shekara, S.C., Haridas Roa P. and Shurpalekar, S.R. (1986) Studies on the con-sistency of biscuit doughs using a ‘Research’ water absorption meter. Journal of Food Science & Technology, 23, 208–12.
Street, C.A. (1991) Flour Confectionery Manufacture. Blackie Academic & Profes-sional, London, UK.
Taylor, S.L. (October 1984) The mixing of short paste. FMBRA Bulletin No. 5, CCFRA, Chipping Campden, UK, pp. 200–9.
Telloke, G.W. (1984) The mixing of cake batters. FMBRA Report No. 114, CCFRA, Chipping Campden, UK.
Telloke, G.W. (1986) Chlorination of cake flour. FMBRA Report No. 131, CCFRA, Chipping Campden, UK.
Telloke, G.W. (1991) Puff pastry: I. Process and dough ingredient variables.
FMBRA Report No. 144, CCFRA, Chipping Campden, UK.
Thacker, D. (1997) Pastries, in The Technology of Cakemaking (ed. A.J. Bent).
Blackie Academic & Professional, London, UK, pp. 239–50.
Young, L.S., Davies, P.R and Cauvain, S.P. (1998) Cakes – getting the balance right, in Proceedings of ES98, the 18th Annual International Conference of the British Computer Society Specialist Group on Expert Systems (eds. R. Milne, A. Macintosh, and M. Bramer). Springer, London, UK, pp. 42–55.