Carotenoids peroxide value

Fat-soluble vitamins and related carotenes suffer complete destruction at sterilization doses (G8). As has been mentioned previously, there may be some connection between the peroxide value and bleaching of carotenoid pigments in fats. 

Table II shows that as the number of conjugated double bond increased from 10 to 11, the API of soybean oil increased at the concentrations of 100 and 200 ppm carotenoids. It has been reported that as the number of conjugated double bonds of carotenoids increased, the peroxide values of chlorophyll-sensitized photooxidation of soybean oil decreased significantly 16,17). Therefore, the singlet oxygen quenching ability of carotenoids was dependent on the number of conjugated double bonds of the carotenoids as reported by Lee and Min 16), Jung and Min 17), and Hirayama el al. (23).

The Rancimat method has been used to measure the antioxidant activity of synthetic and natural antioxidants (2-/>2d) and has correlated well with oil stability measured by the Active Oxygen Method (27) and peroxide value measurement (28). Our study showed that using the Rancimat method to study the antiphotooxidative effect of carotenoids on the soybean oil was in agreement with the results using the headspace oxygen depletion method (16) and the peroxide value method (16,JT). 

Canas and Pignata (1998) were able to show that the concentration of pigments and peroxidation products in lichens may be liable to temporal variation as exemplified by carotenoids, chlorophylls, hydroxy-conjugated dienes and MDA in Parmotrema uruguense. Thalli of this lichen from an unpolluted area were transplanted within the unpolluted area and to two other sites subject to different levels of vehicular activity. For most of the quantified parameters, the temporal variation throughout the period of exposure (July-November, 1994) depended on the site of transplantation. The lower content of carotenoids and chlorophyll a and the higher values for the ratio... 

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