Visualization of β-carotene and starch granules in plant cells using CARS and SHG microscopy
Journal article, 2010

Information on the content and bioavailability of provitamin A carotenoids, such as beta-carotene, in plant foods is of great interest due to the widespread vitamin A deficiency in developing countries. While the amount of beta-carotene can readily be quantified with analytical techniques, there is limited information on beta-carotene morphology in native plant materials. Here, we introduce nonlinear microscopy for three-dimensional, label-free imaging of carotenoids in fresh and thermally treated plant tissues, providing quantitative information at single-aggregate level and detailed insight into their distribution. Carotenoids in orange-fleshed sweet potato (OFSP), carrot, and mango were visualized by coherent anti-Stokes Raman scattering (CARS) microscopy and, in the case of OFSP, related to the plant-matrix morphology by simultaneous second-harmonic generation (SHG) microscopy of starch granules. Sizes, shapes, densities, and location of different types of carotenoid bodies were quantified. While OFSP and carrot showed heterogeneous rod-shaped bodies with high carotenoid densities indicated by higher CARS signals, the carotenoid-filled lipid droplets in mango appeared as homogeneous low-density aggregates of rounded shape. In addition, beta-carotene densities and morphologies in OFSP were studied after thermal processing, showing that the bodies remain intact despite significant changes of the surrounding starch granules.

coherent anti-Stokes Raman scattering

carotenoids

microscopy

plant cells

second-harmonic generation

Author

Christian Brackmann

Chalmers, Chemical and Biological Engineering, Molecular Imaging

Anton Bengtsson

Chalmers, Chemical and Biological Engineering, Life Sciences, Food and Nutrition Science

Marie Alminger

Chalmers, Chemical and Biological Engineering, Life Sciences, Food and Nutrition Science

Ulf Svanberg

Chalmers, Chemical and Biological Engineering, Life Sciences, Food and Nutrition Science

Annika Enejder

Chalmers, Chemical and Biological Engineering, Molecular Imaging

Journal of Raman Spectroscopy

0377-0486 (ISSN) 1097-4555 (eISSN)

Vol. 42 4 586-592

Subject Categories

Food Science

Areas of Advance

Life Science Engineering (2010-2018)

DOI

10.1002/jrs.2778

More information

Created

10/8/2017