Discover more sample preparation applications for food analysis in “the sample” vol.43.
Retsch’s “the sample” vol.43 focuses on food analysis: reproducible sample preparation.
Food products are available in a great variety of forms and consistencies and are usually inhomogeneous. To determine nutritional values or detect hazardous substances, for example, homogeneous and representative samples are required to obtain reproducible and meaningful results. Samples, which are often very complex, need to be homogenized and reduced to a suitable particle size prior to analysis. Laboratory mills of different designs are ideally suited for this process.
Most analysis techniques only require a few milligram or gram of sample material which, however, must represent the entire original sample. The composition of the analysis sample may vary, depending from which part of the original sample it was extracted. Cereal bars, for example, consist of a variety of ingredients which all need to be represented in the part sample to ensure correct determination of the nutritional values. This is achieved by thoroughly homogenizing the cereal bars prior to analysis. Basically, the sample preparation process should be adapted to the sample characteristics as well as to the subsequent analysis technique to avoid falsified results. Grinding parameters and accessories should be selected with regard to preserving the sample properties to be analysed. A basic rule is to only grind the sample as fine as necessary and not as fine as possible, as this always generates more effort (energy input, time, heat, wear). The sample preparation process and the required particle size depend on the chosen analysis method. A particle size of 0.5 mm is ideally suited for most digestion and extraction methods.
Read more about the reproducible sample preparation for food testing and other stories in “the sample” vol.43, available for free download below.
