Changes to the composition of colorants caused by the temperature of drying rapeseed
J. Tys 1
A. Sujak 2
More details
Hide details
Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4, P.O. Box 201, 20-290 Lublin 27, Poland
Department of Physics, University of Agriculture, Akademicka 13, 20-033 Lublin, Poland
Massachusetts Institute of Technology, Cambridge, MA, USA
Acceptance date: 2002-06-16
Int. Agrophys. 2002, 16(4): 307–312
The pigment content in both seeds and oil has been an essential indicator of the oil quality, in particular for the cold pressed oil. The chlorophyll content in the seeds depends upon many agents, among which harvesting before full maturity, in case of one-step harvesting and harvesting before technical maturity, in case of two-step harvesting are the most significant ones. The chlorophyll quantity in seeds designed for future processing should not exceed a value of 25 mg kg�1. Where this occurs, a remarkable quantity of chlorophyll pigments will occur both in the seed cover as well as in the oil extracted from non � mature seeds. The high level of chlorophyll content has a negative influence on oil quality (smell) and also oil stability due to its pro-oxidative action. Another indicator of negative chlorophyll influence is the visual darkening of the oil. The high temperature of seed drying and the presence of defective seeds also exert a negative influence on oil colour. Apart from the chlorophyll pigments in rape seeds, carotenoid pigments occur in quite considerable amounts. The presence of carotenoid in the oil is very important mainly due to its antioxidant properties (lipid protection) and vitamin-forming action (dietary purposes). The aim of these studies was the examination of those agents responsible for the pigment content in rapeseed.