Improvement Of Oxidative Stability On Camellia Oil And Studies On Its Antioxidant Components

In this thesis, Camellia oil of different refining stages were extracted by methanol; the loss of antioxidant in refining process were analyzed; by-products occurred in Camellia oil produce were extracted and their antioxidant activity were detected. The one with higher antioxidant activity was concentrated and added in refined Camellia oil. Oxidative stability of Camellia oil after added natural antioxidant was analyzed. Sterol substance in Camellia oil deodoration was extracted. Components and antioxidant activity in crude sterol extract were detected. Crude sterol extract was added to Camellia oil and oxidative stability was analyzed. Finally acid was added in nigre of Camellia refining and polyphenol content and antioxidant activity were calculated. Folin-Ciocalteau, DPPH, FRAP were used as antioxidant detected methods. Schaal oven test was used as a treatment of Camellia oil and peroxides value was detected. Phosphoric acid-sulfuric acid-ferric chloride and GC/MS were used to confirm sterol component and content. Result of this studied will be a great help on refined process improvement, application of byproducts and choice of antioxidants.The results shown that methanol extract of different refined stages had polyphenol substance and antioxidant activity. Especially the virgin Camellia oil, polyphenol content was1.496mg/g and free radical scavenged was63.71%, but linear co-related was not found between polyphenol content and free radical scavenged. This phenomenon shown that polyphenol is one of the most important antioxidant components in Camellia oil, but not the only one. Stainless storage is a better choice than can. Used water as extracting regent to extract the polyphenol substance in Camellia fruit hull,standing time was6hours, solid-liquid ratio was1:25in room temperature, polyphenol content was75.94mg/g. In the condition of extracting temperature65℃, extracting time65min, solid-liquid ratio1:25, polyphenol content was147.63mg/g. Camellia fruit hull, leaves and seed meal extracted in the same condition, polyphenol content were147.63mg/g,65.87mg/g, and54.41mg/g. Camellia fruit hull had a big advantage as a polyphenol resource. Used organic solvent as extracting regent to extract the polyphenol in Camellia fruit hull, ethanol was the best solvent. In the condition of40%ethanol, solid-liquid ratio1:30, standing time15hours, polyphenol content was111.57mg/g. And in the condition of40%ethanol, solid-liquid ratio1:30, extracting temperature55℃, extracting time60minutes, polyphenol content was134.39mg/g. Camellia fruit hull, leaves and seed meal were compared in the same condition, polyphenol content were134.39mg/g,42.90mg/g and25.74mg/g. Both experiments shown Camellia fruit hull was a better source of polyphenol.In order to select the better antioxidant raw material, contrasted Camellia meal and leaves, Camellia fruit hull was rich in polyphenol substances. Polyphenols extracted from fruit hull had superior free radical scavenging ability and reducing capabilities. The extract is added to Camellia oil which can significantly improve the oxidative stability. Fruit hull water extract and antioxidant capacity with increasing concentration of n-butanol extract a range of improved than synthetic antioxidant TBHQ weaker, but significantly better than alpha-tocopherol. Two antioxidants have synergistic effect with citric acid. Camellia fruit hull water extract synergied with the ascorbic acid is particularly prominent.Sterol substances obtained from Camellia oil deodorizer distillate process. Experiments shown that the best process parameters for the extracting temperature of70°C extracting time of150min, saponification concentration of0.6mol/1, raw materials saponification liquid ratio of1:4, in this condition, the the sterol extraction efficiency for106.89mg/g deodorizer distillate. Sterol crude extracted certain radical scavenging capacity,4%sterol crude extract radical scavenging rate of25.19%. Determined by GC/MS, crude extract had0.254mg/ml of stigmasterol and0.14mg/ml of squalene. Crude extract added to the tea oil caused deterioration of the Camellia oil oxidative stability, the need to add a certain amount of antioxidants. Compared to TBHQ, Camellia fruit hull butanol extract antioxidant was more effective in this experiment better.Adding acid Camellia oil off acid the nigre sample polyphenol a certain amount of rise, and there was a certain radical scavenging activity of fully demonstrates the value of Camellia oil deacidification nigre had a certain advantage. However, in the above-mentioned parameters radical scavenging was still low, the specific processing parameters yet to be explored.Data and anylysis of this thesis will help to improve the parameter of refined process of Camellia oil; Optimize antioxidants in Camellia oil to stay in the stock; introduce new anti-oxidants; look for a way to get rid of dependence on traditional synthetic antioxidants; introduce new sterol sources; provide data support to produce sterol substance..