Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6399784 | Food Research International | 2011 | 7 Pages |
Abstract
Blanched blueberries were dipped in sucrose and fructose + glucose osmotic solutions for 24 h, and the osmotic exchanges were determined by mass balances (water loss, solid gain, sugar intake, changes in total phenolics and anthocyanins); NIR spectra were collected in order to study modifications due to the osmotic treatments. Untreated and infused berries were subsequently air-dried at 70 °C to final moisture content of 10-14%. During drying chemical, nutritional and structural changes were monitored and NIR spectra were acquired on whole berries, using an optic probe working in diffuse reflectance. Spectral data were standardized, transformed into first derivative and processed by Principal Component Analysis. Results show that NIR spectroscopy was able to follow the osmotic and the air-drying processes and to discriminate untreated and osmo-dehydrated berries. Spectral differences reflect the main molecular modifications associated with water absorption bands due to OH stretch + OH bending and sugar absorption bands due to CH stretch + CH bending and OH stretch + OH bending. In order to investigate the variation of main constituents (sugars and water) involved in the osmo-dehydration process, two-dimensional correlation analysis of spectral data was also carried out.
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Food Science
Authors
Nicoletta Sinelli, Ernestina Casiraghi, Stefania Barzaghi, Ada Brambilla, Gabriella Giovanelli,