An innovative laser-based optical technology to predict moisture content and color of Bell pepper (Capsicum annuum L.) during drying
- Publication Type
- Contribution to conference
- Authors
- Romano G; Nagle M; Argyropoulos D; Müller J
- Year of publication
- 2011
- Published in
- Proceedings of the 2011 ASABE Annual International Meeting
- Editor
- ASABE Online Technical Library
- Page (from - to)
- 1-9
- Conference name
- 2011 ASABE Annual International Meeting
- Conference location
- Louisville, Kentucky (USA)
- Conference date
- 7-10 August 2011
Bell pepper (Capsicum Annuum L.) is a fruit rich in pigments such as chlorophylls, anthocyanins and carotenoids which is dried to produce spices. The aim of this research was to test the feasibility of laser light for predicting moisture content changes during drying. Green (532 nm) and red light (635 nm) were applied to the pepper tissue at different drying conditions. Detection of discoloration during the drying process using a CCD camera was also investigated by comparing of the RGB color values with CIE L*, a*, b* color coordinates measured by a Minolta Colorimeter. Cross validation analysis showed the highest correlation between laser light at wavelengths of 532 and 635 nm for yellow pepper (R=0.93). On the contrary, the behavior of green and red light in samples with corresponding colors raises questions for the ability to predict moisture content changes. Additional studies are still required to determine the suitability of digital images as an alternative method to the colorimeter for the evaluation of color change during drying of bell pepper. The described optical technology may represent a basis for future in-line quality monitoring of drying processes.