บทคัดย่องานวิจัย

หมวดหมู่ : ฐานข้อมูลงานวิจัย

Non-destructive assessment of pigments in apple fruit and carrot by laser-induced fluorescence spectroscopy (LIFS) measured at different time-gate positions

Wulf J.S.; Geyer M.; Nicolai B. and Zude M.

5th International Postharvest Symposium . Volume of Abstract . Verona, Italy 6-11 June 2004, p.118

2004

บทคัดย่อ

Non-destructive assessment of pigments in apple fruit and carrot by laser-induced fluorescence spectroscopy (LIFS) measured at different time-gate positions During recent years consumers and producers request to objectively determine quality of horticultural products along the entire supply chain has been increased. In this context innovative, optical techniques would provide the opportunity to examine qualitatively and quantitatively changes in compound contents of single fruits and vegetables. Commercial methods used up to now are mostly destructive, which renders further utilizations or long-term investigations of the products impossible.

In the present study laser-induced fluorescence spectroscopy (LIFS) was applied o­n apple fruit and carrot for determining changes in pigment contents such as chlorophyll, carotenoids and polyphenols. The Laser Fluoroscopy (LF301 Lambda, I.O.M., Germany) used was equipped with a fibre-optic probe and a nitrogen laser emitting short pulses at 337 nm to trigger fluorescence recorded in a wavelength range from 350 nm to 820 nm.

The application of LIFS was aimed to point out the possibilities of this method for a non-destructive, rapid and objective screening of fruit and vegetable qualitative compounds along the supply chain. Data processing was carried out by derivative spectroscopy to analyse appearances and disappearances of peaks in the spectra and variances in the fluorescence intensities due to changes in fruit pigment contents. Furthermore, according to the specific lifetime of fluorescence molecules the spectra were taken with time-resolved readings to separate overlaid signals. It was found that specific fluorescence intensity maxima appearing in the blue-green wavelength range can be attributed to variances in carotenoid and polyphenol contents. Additionally chlorophyll degradation due to mechanical impact such as bruise became visible in the red fluorescence of apple fruit.

These results show the potential usage of LIFS for a rapid and non-destructively monitoring of fruit and vegetable quality.