Analysis & testing TOUR
by Andrew Wilkinson and Malachi Stone
EXCELLENCE THROUGH KNOWLEDGE AND INVESTIGATION
ust on the outskirts of the Cotswold town of Chipping Campden, set amongst the Cotswold stone buildings, you will find the head offices of Campden BRI. Campden BRI is a dynamic, cutting-edge research organisation, which counts some of the biggest global players in the food and drink industry as its members. It has been supporting the food and drink industry for over 90 years. Boasting a total of 3,000 square metres of labs and 3,500 square metres of pilot plant, the team of 350 staff at Campden BRI provides the food and drink industry with practical scientific, technical and advisory services needed to ensure product safety and quality, as well studying the efficiency of both processes and production. They also train thousands of food and drink specialists each year.
The work carried out by Campden BRI covers four main areas: analysis and testing, knowledge management, research and innovation and operational support.
Analysis and testing
Relevant, reliable and timely analytical results are essential for the food and drink industry. The analysis of food – from the raw materials and ingredients and through processing to the final end product – is an important part of managing food safety, quality and authenticity. Results are the basis for many big decisions. Campden BRI offer a wide range of analyses, including assessing ingredients’ suitability for purpose, and microbiological and contaminant testing, to determining the composition and authenticity of food, foreign body analysis, packaging and sensory analysis. During our tour we were shown Campden BRI’s state of the
DEMO #1 - Flour quality, proving the difference
The technicians at Campden BRI ran a demonstration to show the importance of flour quality. They split us into four groups and allocated a flour from one of four nabim ratings to each group. Groups One and Two got standard white bread flour, though Group One’s was best - an artisanal variety called Centurian, with vitamin C added as an oxidising agent. Group Three were given biscuit flour, while the fourth group were given a low-grade, high-bran formulation of the kind used for animal feed. In each group, the flour and other ingredients were mixed together thoroughly using a spiral mixer. The physical action of mixing aids in the development of the gluten structure, we were told. As the mixing progressed, it became more and more obvious that there was something fundamentally different between the flours - while the higher quality doughs became beautifully stretchy, Group Four’s took a great deal of mixing to get it to stay in one piece. Indeed, by the time it was well enough mixed to move on to kneading, Group One were already putting their loaf to prove. Hand kneading helps spread air through the dough, but industrial bakeries go further: we were shown a machine employing what looked like a chain mail sushi mat to roll the dough. This made doubly sure the air bubbles were small and evenly distributed. The dough was then placed, seam side down, in the tin it would be baked in. To prevent sticking, an emulsifier was used on the tins not butter, as it has a relatively low burning point. The dough was then put in a kind of metal cupboard heated to 40 degrees to speed up the proving process. Once the dough had proved fully, it was removed and given its final touches before baking. Scoring the upper surface with a very sharp knife has a similar effect to scoring a pork joint - it causes it to crisp nicely in the oven. Spraying with a little water likewise aids crust formation, as well as helping in the adherence of any seeds sprinkled on by the baker. The loaf was then placed in a steam-assisted oven to bake for 35 minutes at 220 degrees. The results were very clear. Loaf One was structurally everything you would expect from a supermarket bread: light, resilient and springy. The next two were less so. They were also smaller, not having risen so well during baking. Worst of all was Loaf Four: stunted and somewhat doughy in the middle (it also smelt vaguely of grass). None of this should come as a surprise when you consider the provenance of the flours. Much of a dough’s consistency and that of the resultant loaf is down to the levels of functional protein it contains. Flour One had 11 or 12 percent functional protein; Flours Two and Three had nine or ten percent, and eight or nine percent, respectively. The bran in Flour Four contained a lot of protein, but of the wrong type for forming structures during mixing and baking. Additionally, fragments of bran will also coat gluten particles that are present and block them from linking with each other - an essential process in the formation of effective protein structures in a dough. 42 | September 2016 - Milling and Grain