Content of chlorophylls and carotenes in rapeseed oil

Abstract

The content of the green components in crude rapeseed oil, namely chlorophylls A and B, as well as the products of their decomposition pheophytins A and B, were determined by means of the spectrophotometric method of analysis.No chlorophyll A was found in any of the analyzed samples but the content of pheophytin A was quite high and amounted to from 17.99 to 25.65 ppm. Because of the fact that the oils were investigated 5 to 6 months after their extraction, the results obtained are not unexpected, bearing in mind that chlorophyll contained in oil easily changes into pheophytin.No chlorophyll B was found in some of the samples, investigated and in the remaining samples from 0.14 to 1.79 ppm was found. This can be explained by the hypothesis of slower change of chlorophyll B into pheophytin B.The content of pheophytin B in the investigated samples was between 0.52 and 6.15 ppm. This confirms the results obtained by Mingot (3). With old oils, the results of determining such components, whose content approaches nil in the sample, are less precise because of the influence of the oil which was used as a blank.The content of carotenes in crude rapeseed oils was also determined by the spectrophotometric method after isolating them by means of the column chromatography on Al2O3.In spite of the small amount of carotenes determined in rapeseed oils, a correlation can be observed between the quantity of chlorophylls and carotenes. It has been found that the higher the chlorophyll content, the higher also the carotene content, even if very slight in some cases, in all the investigated oils either extracted or pressed.

Pigments in Greek virgin olive oils: occurrence and levels

“…The Pheo α content was greater than the initial value owing to transformation of Chl α. In contrast, Chl b was still present, possibly owing to its slower transformation rate to Pheo b according to Niewiadomski et al 29 The almost exclusive presence of Pheo α in an oil may be partially related to the time elapsed between sampling and analysis owing to the free fatty acids liberated from the oil itself 30. In processed foods, chlorophyll degradation may also follow another pathway, which involves cleavage of the phytol chain to form chlorophyllide and, subsequently, pheophorbide as a result of chemical hydrolysis and enzymic cleavage by chlorophyllase 31.…”

Effects of processing and storage on chlorophyll derivatives in commercially extracted canola oil

“…The genetic term "chlorophyll" is generally used to refer to all green pigments in canola seed, oil or meal. Several studies have determined that pressed oils tend to contain fewer chlorophyll pigments than solvent-extracted oils (11)(12)(13). Seed quality also affected the chlorophylYpheophytin composition, with moldy, heated or otherwise damaged seeds containing more pheophytins (10).…”

Behavior of chlorophyll derivatives in canola oil processing

“…These derivatives must be removed by adsorbents, such as activated earth (AE) or activated carbon (AC), in the bleaching process. There have been recent reports (6)(7)(8)(9)(10)(11)(12)(13)(14)(15) on the occurrence of chlorophyll derivatives in canola seed and canola oil. Analytical methods for these derivatives have rapidly improved (12,15).…”