Browsing by Author "Väisänen, Tiina"

The main objective of the literature review of this Master’s Thesis was to gather information concerning cosmetic products, especially plant based cosmetic ingredients and how they are produced. The part consists of information about cosmetic legislation, safety of cosmetic products and introduction of plant sample materials used in the experimental part. The aim of this Master’s thesis was to isolate plant extracts containing phenolics from three different plant materials (cowberry [Vaccinium vitis-idaea], birch leaf [Betula pendula/pubescens] and flax seed [Linum usitatissimum]) by using accelerated solvent extraction (ASE) with two different extraction solvents (94 % ethanol and 80 % acetone), and supercritical fluid extraction (SFE). The content of total phenolics in the extracts was determined spectrometrically according to the Folin−Ciocalteau procedure and calculated as gallic acid equivalents (GAE). Chlorophyll and carotenoid content of birch leaf extracts were also determined. Antioxidant activity of extracts was tested with emulsion test, where rapeseed oil containing emulsion was oxidized in the presence of plant extracts. Oxidation of the emulsion was monitored for 7 days by determining the content of hydroperoxides in emulsion with a spectrophotometric method. Amount of plant extracts added to emulsions was 100 or 500 μg GAE phenolics per g of oil in emulsion. ASE was suitable for extracting phenolics from all the sample materials. Cowberry and birch leaf extracts contained remarkable amounts of phenolic compounds, but flax seed extracts contained only small amounts of those. Phenolics in flax seed are mainly lignans, which are tightly bound to the hull part of the seed. Thus, it requires extensive pretreatments to extract them. SFE was not suitable method for extracting phenolics from any of the sample materials. Inhibition of oxidation varied between different extracts. Cowberry extract containing 500 μg GAE per g of oil was the most effective extract in inhibiting oxidation in emulsion. Birch leaf extracts inhibited oxidation until day 4. After that the amount of hydroperoxides increased relatively fast. Birch leaf extracts were rich in chlorophylls, which can act as a pro-oxidants. According to the results, cowberry was most optimal raw material of the tested materials for isolating antioxidant containing extracts from plant materials. Both acetone and ethanol were suitable extraction solvents for ASE.