|
Abstract: Moisture content is an important quality criterion of fresh mushrooms. Oven-drying and freeze-drying are the time consuming and laborious methods that are presently used to determine moisture content. In principle near infrared spectroscopy (NIRS) offers a fast and user-friendly alternative. We therefore studied the potential of NIRS for moisture determination of fresh mushrooms. In general measurement of moisture content in fruits and vegetables is relatively simple if the product is either homogeneous or ground. This study shows that when measuring intact individual mushrooms with diffuse reflectance spectroscopy, problems occur due to their internal non-homogeneous moisture distribution. Another problem is caused by the large variation of the moisture content of individual mushrooms of the same batch. We used transmission spectroscopy in the wavelength region 800- 1100 nm, having the advantage that information is collected not only from the surface but also from the interior of the mushroom. The results show that transmittance spectroscopy may allow quantitative determination of moisture or dry matter content (% DM) of fresh mushrooms in a non-destructive way. Using normalised second derivative spectra the measurement is independent of the mushroom size and of polystyrene, which is often used for packaging. The commercially available NIR instruments are at present not suitable for quality control of large volumes of mushrooms; a new type of instrument must be developed with a high intensity light source and more sensitive detectors.
Full text download: ISMS subscribers
ISHS members & pay-per-view
Translate:
   |