2014 Annual Meeting Abstract - An Example of NIR Calibration Development Limit : Alveographic Criteria on Common Wheat Flour

Poster Presentation
Analytical methods

3-P

An Example of NIR Calibration Development Limit : Alveographic Criteria on Common Wheat Flour
A. DUBAT (1), O. Le Brun (1), N. Boinot (1)
(1) CHOPIN Technologies, Villeneuve la Garenne, France

CHOPIN Alveograph is a standard method used to measure wheat flour rheological behavior, as for example the baking strength (W). In order to save time on analysis process, the possibility to predict such type of parameter using a faster method such as near infrared spectroscopy is of interest for all the cereal industries. It has to be reminded that the flour baking strength (W) is a physical property influenced by protein content. Models allowing wheat classification on W rough estimation are already proposed on most of NIR devices. For wheat flour, the development of calibration for such type of parameter is greatly different because of the possible presence of additives. The aim of this study is to show why additives present in wheat flour limits in the W calibration development on NIR spectroscopy. On 4 industrial flours without additives, 4 improvers (Gluten, ascorbic acid, carob gum and cystein) were added at different concentrations. An ACP analysis of the spectra obtained using an Infraneo NIR Analyzer on all these flours and mixtures flours/additives made, shows that : 1/. The presence of gluten or carob in a flour modify sample spectrum and 2/. The presence of ascorbic acid or cystein in a flour does not modify the spectrum. Certain additives modify W results without impacting the spectral signature this compromises the development of NIR prediction model. In any cases, even if chemiometrics are really powerful, understanding the chemical/rheological reality of any qualitative parameter is important to understand the reality of near infrared prediction models. The W value is not only a function of protein content, but also relies on protein quality and very complex interactions with other flour components. Quality control managers must be informed and consider these information in order to make a choice between accuracy and rapidity.