International Research Symposium on Pure and Applied Sciences (IRSPAS)

Permanent URI for this communityhttp://repository.kln.ac.lk/handle/123456789/15650

Browse

Has files: YesSubject: search.filters.subject.Antioxidants

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Incorporation of natural antioxidants from plant extracts in to virgin coconut oil for extension of shelf life
    (4th International Research Symposium on Pure and Applied Sciences, Faculty of Science, University of Kelaniya, Sri Lanka, 2019) Rangani, S. C.; Ranaweera, K. K. D. S.
    Lipid oxidation renders a tremendous impact on the quality deterioration of edible oils. In oils the oxidation leads to loss of flavour, aroma, and overall nutritional value, along with texture degradation. High levels of oxidation products act as cyto-toxic substances that lead to health problems. Synthetic antioxidants are often used to preserve edible oils. Fruits, vegetables and seasoning spices contain high amount of phytochemicals which can be used as natural antioxidants. Objective of this study is to develop natural antioxidants over synthetic antioxidants due to reported health issues. In this study, soxhlet extractions of ten plant varieties were evaluated for their antioxidant properties using DPPH assay and noted Fragaria ananassa (Strawberry) whole fruit, Beta vulgaris (Beet Root) whole fruit with peel, Cinnamom verum (Cinnamon) barks, and Zingiber officinale (Ginger) rhizome with peel contains highest antioxidant activity. The dry crude ethanolic extracts of these four varieties were further evaluated for total phenolics content, total flavonoids content, total antioxidant activities and for their oxidative stability. The oxidative stability was evaluated in comparison with synthetic antioxidant BHT and natural antioxidant vitamin E under accelerated oxidation conditions of 65 ºC for 72 hours, using virgin coconut oil (VCO) as the oxidation substrate. Each and every VCO sample fortified with individual antioxidants and their every possible combination were monitored at each 24 hour intervals. The total phenolics contents evaluated using Folin- Ciocalteu reagent were 0.612, 0.437, 0.429, and 0.068 mg gallic acid /g dry weight in Fragaria ananassa, Zingiber officinale, Cinnamom verum and Beta vulgaris respectively, while total antioxidant activities evaluated using ammonium molibdate assay were 0.828, 0.892, 0.302, and 0.058 mg Trolox /g equivalent (DW) respectively. Highest flavonoids value was reported in Zingiber officinale against 2% AlCl3 solution used. The oil samples fortified with antioxidants subjected to accelerated oxidation was observed with inverse relationships between peroxide value and oxidative stabilities and secondary oxidation products and stability at termination of stage. On the basis of the obtained results, the combination of strawberry, beet root and cinnamon barks and ginger rhizome extracts of 1:1:1:1 ratio and ginger and beet root extract of 1:1 ratio at 1500 ppm could be used as natural antioxidants and might be explored to prevent oxidation of vegetable oils. Therefore, they could be used as preservative ingredients in the oil based food industries.
  • Thumbnail Image
    Item
    A preliminary study of lip moisturizer rich in antioxidants produced using coffee leaf extract
    (Faculty of Science, University of Kelaniya, Sri Lanka, 2016) Gunasinghe, K.G.; Nadeeshani, R.; Jayathilaka, N.
    As the body’s first environmental defense, the skin is exposed to various sources of free radical damage including the sun. In addition, to maintain healthy skin, it is important to maintain the moisture content not only in the deeper dermal and epidermal layers but also at the surface. As such, there are numerous skin moisturizers commercially available specially formulated to not only moisturize the body, face and the lips but also block the harmful rays from the sun to protect the skin surface. The composition of the lip moisturizers available in the market varies from brand to brand. These products often contain castor oil, carnauba wax and chemicals/ preservatives such as propyl paraben, methyl paraben, retinyl palmitate, tocopheryl acetate etc. as well as different agents to block the harmful rays from the sun. Antioxidants can be added to these products to neutralize the free radicals that can cause damage to the skin. Plant polyphenols are known to have high antioxidant activity. In this study, we have formulated a lip moisturizer with aqueous extracts from coffee leaves rich with polyphenols in an effort to develop a product that can neutralize free radical damage on the surface skin. The product was developed using bees wax, vaseline, coffee leaves and water (1: 2: 1: 11.5) with no other additional chemicals to formulate a natural healthy cosmetic. Polyphenols in the water extract was extracted in to methanol by removing the proteins using chloroform. The polyphenol content in the aqueous extract (0.18 ± 0.01 mg/ml) was measured by Folin-Denis assay as Gallic acid equivalent, using water as the control. The antioxidant activity of the extract was measured by DPPH radical scavenging assay. The percentage inhibition of DPPH radical scavenging activity of the aqueous extract of the coffee leaves measured using water as the blank gave 83.46 ± 0.11% of inhibition. Each sample was assayed three times for three biological replicates. The polyphenol content and the percentage inhibition of DPPH radical scavenging activity of the aqueous extracts, extracted from the formulated lip moisturizer were 0.14 ± 0.01 mg/ml and 83.44 ± 0.43% respectively. There is no statistically significant difference in the polyphenol content and the antioxidant activity between the aqueous extracts (p< 0.01). Lip moisturizer produced without the additon of coffee leaf extract was used as the control. According to the DPPH assay 99.97± 0.27% of percentage inhibition of DPPH radical scavenging activity was retained. Therefore, the lip moisturizer formulated with the coffee leaf extract retained the antioxidant properties.