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Chlorophylls a and b, phenolic compounds, carotenoids in total antioxidants from the leaves of eleven varieties of orange and purple sweet potatoes were assessed by spectrophotometry. Using the ABTS method, BF59XCIP1 (43.450 mg ET/g) has the highest antioxidant content ahead of BF59XCIP4, TUSKEGEE-POURPRE CAP VERT and TIB17 (40.969 mg ET/g) and TUSKEGEE-POURPRE (38.161 mg ET/g). The leaves of MOTHER DELIGHT, accumulate much more phenolic compounds (27.37 mg EAG/g) than TIB21 and TIB29 which have an average content of 24.78 mg EAG/g. The lowest levels are observed in TUSKEGEE-POURPRE, BF59XCIP1, TUSKEGEE-POURPRE CAP VERT with an average content of 14.94 mg EAG/g and TUSKEGEE-ORANGE (19.104 mg EAG/g). For Chl b, the extraction solvent accounts for 81.23% of the significant differences observed. Methanol is the best extraction solvent for Chl a (71.93g/100g) and Chl b (56.98g/100g) ahead of the acetone-water system (Chl a 60.81g/100g; Chl b 29.71g/100g). For carotenoids, the extraction solvent (72.5%) has a strong influence in favour of the acetone-water system, which can extract 11,967 g of total carotenoids in 100 g of leaves. [ABSTRACT FROM AUTHOR]

The hexane Soxhlet extraction yields of two new waxes from Borassus aethiopum (rônier) and Mangifera indica fruit (mango) were 1.40 ± 0.08% and 2.51 ± 0.04 % respectively. The kinetics of extraction shows that almost all the waxes are extracted after 4 hours of heating. The respective physico-chemical parameters for wax from Borassus aethiopum and Mangifera indica are: Melting point (78.80 ± 1.09 and 53.23 ± 1.01 °C), Acid value (7.56 ± 0.83 and 17.56 ± 0.46 mg KOH / g), Iodine value (11.68 ± 0.92 and 16.03 ± 0.50 g iodine / 100 g), Saponification value (94.05 ± 0.48 and 158.58 ± 1.03 mg KOH / g), Refractive index (1.515 and 1.475). The chemical composition of the two waxes reveals the majority presence of esters (41.23%), fatty acids (21.28%), fatty alcohols (18.35%) and ketones (09.38%) for Rônier wax and carotenoids (51.35%), esters (19.90%), sterols (14.38%) and fatty acids (08.62%) for Mango wax. On the other hand, stearic acid (39.77%), palmitic acid (26.94%), linoleic acid (16.00%) and palmitoleic acid (12.73%) as well as palmitic (33.96%) and oleic acid (25.16%) and linoleic acid (13.72%) are the major fatty acids of Borassus aethiopum and Mangifera indica respectively. [ABSTRACT FROM AUTHOR]

In birds, the female deposits in her eggs various substances essential for the survival and development of chicks, such as carotenoids. However the amount of maternal carotenoids transferred to eggs may vary in relation to the availability of this resource in the mother's body. The objective of this study was to address this issue in the Yellow-legged Gull (Larus michahellis) nesting in the Gulf of Gabes in southeast Tunisia. Our results first show that at the scale of a brood, the level of yolk carotenoids decreases with egg laying order, which is consistent with the general trend observed in gulls whose reproductive strategy is based on brood reduction. Our results also show that carotenoid level in egg yolk varies between clutches, in parallel with the variation of plasma carotenoid level in the respective females. Indeed, the level of carotenoids in egg yolk is positively correlated with that in the plasma of the corresponding mother, whatever the egg laying order. This result suggests that only females who have a good supply of carotenoids would be able to allocate substantial amounts in their eggs. Inter-clutch variation in the amount of yolk carotenoids would thus reflect differences between females about their ability in obtaining and managing this limited resource. In this regard, we believe that female age seems a key factor in determining its ability to transfer carotenoids in eggs, which needs to be more deeply investigated. [ABSTRACT FROM AUTHOR]

Abstract: Phytosterols are natural plant compounds. Phytostanols are derived from phytosterols hydrogenation. Both they inhibit intestinal dietary cholesterol absorption by competition, and they decrease LDL cholesterol by 8-15%, in a dose-dependant manner. They impair carotenoids bioavailability. A very small and variable part of phytosterols and phytostanols is absorbed. No epidemiological data is available for assessing the beneficial of plant sterols intake and cardiovascular risk. In the other hand there are many studies which have shown paradoxically a positive relationship between serum phytosterols concentrations and increase of the coronary heart disease risk. Other studies have established a link between the phytosterols absorption and their plasma and arterial plaque levels. Phytosterols and cholesterol hyperabsorbers subjects would be particularly involved in this unfavourable issue. Phytostanols could have a different effect from that point of view. In animal studies, data are less inconsistent with, in most of the studies, a lesser progression of atheroma lesions, perhaps due to an antiinflammatory effect of phytosterols in atheroma plaque. The place of phytosterols and phytostanols in the therapeutic step for cardiovascular prevention is actually not defined. Many queries are still open. Complementary studies are needed for improving the clinical indications and the efficiency of these compounds. [Copyright &y& Elsevier]

Validation of an HPLC method for carotenoid analysis: application to the determination of the carotenoid content of ten varieties of red potatoes (Ipomea batata). Vitamin A deficiency (VAD) is a major public health problem in developing countries and more than 250 millions children under five are concerned. Three complementary approaches are used to overcome its consequences: prophylactic vitamin A supplementation, vitamin A food fortification and promotion of food containing provitamin A carotenoids. In the framework of the promotion of various types of red potatoes consumption, an HPLC method was validated for carotenoid analysis. Zeaxanthine (ZEA), echinenone (ECHI), lycopene (LYCO), α-carotene (ACAR) and β-carotene (BCAR) were analysed. Good linearity was obtained for all the five carotenoids from 0.25 to 1.5 pmole μl–1. The recovery rates were 100 ± 10 and the precision assessed by the variation coefficients was less than 10%. The analysis of red potatoes show that the Jewel, Narumintang Niger and Caromex Niger types were rich in β-carotene (respectively 1911, 2348, and 2046 μg per 100 g). The Jewel, Narumintang Niger were the most concentrated and homogenous in their carotenoid contents. Others potatoes types (Kolokohogo BF, Lantaogo 2 and Ming Shu Niger) appeared to contain carbobydrate only. To cite this article: I.T. Somé et al., C. R. Chimie 7 (2004). [Copyright &y& Elsevier]

Food-derived anti-oxidants are mainly some vitamins (C, E, carotenoids) and trace-elements (Se, Zn) but also non-nutrients such as flavonoids and other polyphenols. Several epidemiological studies have demonstrated that an anti-oxidant-rich food decreases the risk of cancer, cardiovascular and other chronic diseases. These effects are further demonstrated in various intervention studies the concept and the design of which are considerably evolving towards nutritional prevention and even therapeutic trials. As a consequence, some paradigms in nutrition such as the recommended dietary intakes for some anti-oxidant nutrients need revision because the usually recommended intakes do not cover all the field of biological activity of the concerned nutrient. The optimisation of the dietary intake of anti-oxidants can follow at least three ways that are a healthy diet taken as a whole, functional foods including fortified foods, and food supplements. None of these ways seems to be predominant as far as efficiency is concerned but all converge towards optimised diet and nutritional prevention of diseases that are going to be the scope of many researches in the nutrition field for coming decades. [Copyright &y& Elsevier]

Etiochloroplasts were isolated from wheat leaves (Triticum sativum Lam. cv. Florence Aurore) greened under repeated flashes with intervals of 15 min of darkness. These plastids are unable to evolve oxygen and show a light-induced bleaching of chlorophyll and carotenoids. This bleaching is inhibited by 3-(4-chlorophenyl)-1,1-dimethylurea and partially results from the presence of an active photosystem II. Pigment stabilization can be achieved after giving additional repeated flashes with short intervals of darkness (5 s) to the seedlings; but stabilization is then much lower than that obtained by continuous light when plastids with similar photochemical activity (Hill reaction) are compared. Pigment bleaching in etiochloroplasts is thus not only due to their inability to use water as photosystem II electron donor but results also from other structural or functional deficiencies. [ABSTRACT FROM AUTHOR]