Better insight into barley and malt

Methods based on image analysis are flexible, rapid tools enabling both the elevator company and the maltster to monitor and adapt their processes. Thus, image analysis is a suitable technique for integrated chain control in the barley-malt-beer chain. TNO Nutrition and Food Research Institute has assessed a number of image analysis systems for their usefulness in collection and malting of barley.

For the elevator company and the maltster to be able to act in a quality-oriented manner, the homogeneity of batches of barley and malt is essential. Therefore, farmers aim at a healthy crop of a quality as uniform as possible, with a high kernel yield. Many of the preparatory operations preceding sowing and measures taken during cultivation are aimed at those objectives. Subsequently, the elevator company, the next link in the chain, has to make efforts to process the crop received into homogeneous, well maltable batches of the desired size. Unless these conditions are met, the maltster cannot produce the uniform batches of malt requested by the brewer.

To obtain batches of barley with a uniform protein content, separated storage of batches classified by protein content is a realistic option. To this end, protein content of the kernel can be measured about 10 days before harvest [1]. Protein analysis can also be conducted at intake by using the rapid measuring technique near-infrared spectroscopy (NIRS) provided this option does not pose logistic problems during collection. Batches of similar protein content can subsequently be pooled in storage silos.

However, the elevator company and the maltster are in need for more possibilities for monitoring and adapting collection and processing of malting barley in order to be able to eventually produce malt of a quality desired by the brewer. A promising tool in this respect is image analysis which enables to determine external and internal kernel characteristics such as girth, length, width, shape and structure [2, 3]. These characteristics can be quantified on the basis of the images acquired with a suitable recording system. These quantitative data can be used to derive data on properties and quality of a batch of barley.

TNO Nutrition and Food Research Institute has evaluated a number of image analysis systems which can be applied in the barley-malt-beer chain. Some results obtained during collection and malting of barley are presented here.

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