A rapid non-destructive method for quantification of fungal infection on barley and malt

Description of topic: Barley harvest 2007 in Europe has seen the resurgence of crops highly infected by filamentous fungi. Hence the evaluation of fungal infection on barley and malt kernels by conventional optical measurement methods lacks accuracy and can be tedious. Here we are presenting a new vision system to rapidly perform this task using the VideometerLab®.

This system provides a rapid colour, shape and texture measurement, ideal to analyze kernels surfaces. The principle employed is a high-intensity sphere illuminated by light emitting diodes together with a highresolution black and white camera. The digital image is acquired in less than 10 seconds, over an 18 bands spanning ranging from the ultra-blue (430 nm) to the near-infrared (970 nm) and then analyzed by the VideometerLab® statistical analysis software.

Materials and methods for data collection: Sixty European barley samples from harvest 2004, 2007 and 2008 were collected and screened for their degree of fungal infection using the VideometerLab® equipment. In parallel these samples were analyzed for their Fusarium and hydrophobins content using real-time PCR and/or competitive ELISA.

As reference samples, kernels with low content of Fusarium and hydrophobins were selected and highly infected kernels, artificially inoculated with F. culmorum or F. graminearum, were produced. Results: A good correlation between competitive ELISA tests, real-time PCR experiments and VideometerLab® prediction was found (R2=0.75).

The results obtained indicate that the videometerlab® equipment can accurately evaluate the percentage of global fungal infection in kernels. Discussion: We believe that this system will be able to discriminate between kernels infected from non-infected ones in mixed samples. This system will allow to quantify the level of infection and indirectly the level of fungal mycotoxins in barley and malt crops.

This equipment has the potential of becoming an efficient tool for screening the quality of barley and malt kernels to be used in malteries and breweries.