Calendula Oil

J. Serb. Chem. Soc. 70 (1) 115–124 (2005) JSCS – 3254

UDC 633.811+531.3:547.979.8 Original scientific paper

An investigation of influence of solvent on the degradation kinetics of carotenoids in oil extracts of Calendula officinalis
DEJAN BEZBRADICA1,*, JELA MILI]-A[KRABI]2, SLOBODAN D. PETROVI]1# and SLAVICA [ILER-MARINKOVI]1
1Faculty of Tehnology and Metallurgy, Karnegijeva 4, 11000Belgrade (e-mail: dbez@elab.tmf.bg.ac.yu) and 2Faculty of Pharmacy, Vojvode Stepe 450, 11000 Belgrade, Serbia and Montenegro

(Received 3 November 2003, revised 21 May 2004) Abstract: The stability of carotenoids was studied in marigold oil extracts prepared with following solvents: Myritol 312®, paraffin oil, almond oil, olive oil, sunflower oil, grape seed oil, and soybean oil. The concentrationof the carotenoids was determined by spectroscopic measurement at 450 nm. Degradation rate showed a first order dependence on the concentration of carotenoids with a faster first stage (which lasted 35–50 days, depending on the solvent) and a slower second stage. The highest degradation rates were observed in extracts prepared with linoleic acid rich solvents (sunflower oil, soybean oil and grapeseed oil), while the lowest were found in oil with saturated fatty acids (Myritol 312®) and paraffin oil. These results confirm the connection between the degradation of carotenoids and lipid autoxidation, and suggest that the influence of the oil solvents on the stability of oil extracts of Calendula officinalis is a factor that must be considered when selecting a solvent for the production ofmarigold oil extracts. Keywords: Calenula officinalis, oil extract, carotenoids. INTRODUCTION

Marigold (Calendula officinalis) has been used as a folk medicine since ancient times. Extracts of this herb are important ingredients of a number of pharmaceutical preparations for the treatment of poorly healing wounds, burns, cuts, bruises and eczema because of their anti-inflammatory activity andpromotion of the formation of granulation tissue.1 Calendula extracts are also used in cosmetics because of their emollient, protective, antiiritant and antiseptic properties. They are important ingredient of bath preparations, hand care products, sunscreens, products for irritated skins and baby toiletries. Besides cosmetic and medical usage, Calendula flowers have culinary use as substitutes forsaffron in salads and omlettes and as colorants for cheese and butter.2,3
* # Author for correspondence. Serbian Chemical Society active member.

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Marigold has beneficial properties since it contains wide range of bioactive compounds. Carotenoids, especially b-carotene, are very abundant and active. Carotenoids are multifunctional, naturally occurring, red,yellow and orange pigments. They are widely used in pharmaceutical and food industry as natural colorants and as sources of provitamin A. Lately, interest in carotenoids has increased because they function as chain breaking antioxidants, and protect cells and other body components from free radical attack. They also protect the skin from redness and damage following exposure to UV radiation. Theresults of these studies caused an increased usage of supplementary carotenoids in pharmaceutical and cosmetic products, in the form of pure chemicals or various herbal extracts that contain carotenoids. Of these two forms, extracts are less expensive and often more efficient because of the synergistic activity of other compounds with carotenoids. The stability of carotenoids and the kinetics of theirdegradation in various food systems have been extensively studied,4–10 but there is a lack of such investigations for pharmaceutical and cosmetic products. The general conclusion of these studies in the field of food chemistry was that the kinetics of degradation are influenced by factors such as reaction medium, temperature, physical state and type of carotenoid, as well as environmental...