February 1, 2015 Thesis Open Access

Shimelis Shumi

Citation Style Language JSON Export

{
  "DOI": "10.20372/nadre:2349", 
  "author": [
    {
      "family": "Shimelis Shumi"
    }
  ], 
  "issued": {
    "date-parts": [
      [
        2015, 
        2, 
        1
      ]
    ]
  }, 
  "abstract": "<p>The study was conducted with the aim of optimizing and characterizing antioxidant activity of<br>\nCamellia sinensis and evaluating its preservative effect on Niger seed and Soybean oils.<br>\nCamellia was prepared by investigating the effect of distilled water concentrations of 100, 150,<br>\nand 200ml, extraction temperature 80, 85 and 90 \u2103 and contact time of 10, 35 and 60 min on its<br>\nantioxidant activity and extract yield. Based on ANOVA analysis, extraction parameters have<br>\nsignificant positive effect (P&lt;0.05) on Camellia antioxidant activity and its extract yield. The<br>\nbest levels of extraction parameters for higher antioxidant activity and extract yield were<br>\ndistilled water concentration of 200ml for 60min at 90 \u2103. As DPPH free radical scavenging<br>\nactivity results shown the highest antioxidant activity of Camellia was 96.1%. On the other hand<br>\nextraction parameters (solvent concentrations, extraction temperature &amp; contact time) were<br>\noptimized. The best extraction conditions were 200ml, 88 \u2103 and 35 min and the results were<br>\nyield (79.850%) and Antioxidant activity (96.9810%). The preservative effect of Camellia was<br>\nalso studied by performing Free Fatty Acids, Peroxide Value/Acid value on Niger seed and<br>\nSoybean oils. In the study, all samples were treated with 0, 1 and 2ml levels of Camellia extract<br>\nand analysis were conducted on weekly basis. Compared to Camellia extract containing Niger<br>\nseed and Soybean oils, control sample showed higher Free Fatty Acid and Peroxide Values in<br>\neach storage weeks.</p>", 
  "title": "Optimization and characterization of antioxidant activity from green tea (Camellia sinensis) and evaluation of its preservative effect", 
  "type": "thesis", 
  "id": "2349"
}