HYPERSPECTRAL IMAGING EVALUATION OF THE FRESHNESS OF MUSHROOMS (AGARICUS BISPORUS)

Hyperspectral imaging (HSI) is a non-destructive analytical tool that can be used for sensing multiple attributes of foods. This thesis evaluates the application of HSI for measuring the freshness of the mushroom Agaricus bisporus (A. bisporus) in comparison with traditional seed methods. Three separate experiments were performed with 135 mushroom samples stored either in packed or unpacked conditions for 11 days. The overall results suggest that the HSI spectral region between 400 and 1000 nm is suitable for the inspection of mushroom freshness. Two distinguishing variables that aligned with physicochemical and microbiological analysis were recognized. Moisture loss was the main reason for mushroom deterioration during the first three days of storage while polysaccharide degradation and slime growth was the main factor by day six. However, there is no significant difference between packed and unpacked conditions. In HSI, the first region [530-700 nm] was used to calculate the Shelf-Life Index 1 associated with moisture content, color, and texture changes, while the second region [750 – 900 nm] was used to calculate the Shelf-Life Index 2 (or Slimy Index) associated with the slime secretion by microorganisms. The first index decreased faster until day four and reached a plateau afterward, while the slimy Index peaked at day six and then decreased. This study could be helpful for real-time monitoring of the quality of A. bisporus using spectral imaging techniques