| Camellia oleifera Abel is particular to China, which together with Chamaerops excels, Olea europaea and Elaeis guineensis is called one of the four kinds of woody edible oil in the world. Camellia oleifera Abel has a long history of cultivation. Camellia flowers as one of the by-products, not only an important basis for the formation of camellia fruit production, and focus the nutrients in the camellia. There are lots of camellia flowers with high value of reaearch, development and utilization. However, current research about camellia flowers nutritional quality is still not perfect and lack of systematicness, it's products development is at the blank stage.Chosen camellia flowers as raw materials, there nutritional quality and activity were analyzed. On the other hand, deep discuss camellia flowers product development process, so as to provide theoretical guidance for the further application. The main contents and results are as follows:(1) Study on the nutritional components of camellia flowers.Main nutrient indexes of flowers of Camellia chekiangoleosa Hu, Camellia reticulate, Camellia semiserrata and Camellia oleifera were determined. The results show that all varieties of camellia flowers exist significant differences between nutrient content. The comprehensive evaluation of nutritional properties was C.chekiangoleosa Hu flower>C. semiserrata flower>C. reticulate flower>C. oleifera flower.Camellia chekiangoleosa Hu flower was the best to be chosen to research deeply. Analyzed three kinds of factors, including growth period, organs parts and planting altitude. Results are as follows, the camellia flowers that open in the early period had the best nutritional value, next was in blooming period, but the buds had the lowest score. The nutritional value of each organ parts of camellia flowers was petal>stamen>pollen>receptacle. Petals had the highest content of polysaccharide, anthocyanins, total sugar and catechins, were 274.45 mg/g, 1.57 mg/g, 348.54 mg/g and 29.75 mg/g, respectively. Pollen had the highest content of polyphenols and amino acids, were 180.74 mg/g and 5.48 mg/g, respectively. Each nutrient content of camellia flowers which cuativation in the high altitude is significantly higher than the growth of the low altitude, especially the flavonoids content is about 2.5 times higher.(2) Study on the antioxidant activity of camellia flowers.Comparison of C.chekiangoleosa Hu flowers and C.oleifera flowers extract in vitro antioxidant capacity, It turned out that the C.chekiangoleosa Hu flowers had a strong ferric ion reducing antioxidant power and strong scavenging capacity against free radicals. Correlation analysis showed that the correlations between antioxidant components and activites were good(R > 0.850), especially that between polyphenol content and DPPH· scavenging activity in C.chekiangoleosa Hu flowers(R=0.996), polysaccharide content and reducing capacity in C.oleifera flowers(R=0.992).And on this basis, optimization of extraction conditions for polyphenols from camellia flowers. Response surface analysis methodology(RSM) was used for optimizing. By comparison, ethanol solution was the most effective in extracting. The effects of three factors of ethanol concentration, extraction temperature and time on the extraction of polyphenols were investigated to determine the appropriate ranges for central composite design. Results were 60%, 70 ? and 50 min, respectively. Based on results of single-factor experiments, the total polyphenol content and IC50 of scavenging activity on DPPH free radical as the response values. Through optimization, the optimal extraction conditions were as folloes: ethanol concentration 56.6%, extraction temperature 68.8 ? and time 51.6min for camellia flowers polyphenols content(62.92 mg/g); ethanol concentration 58.4%, extraction temperature 68.5 ? and time 50.7 min for DPPH· scavenging activity(IC50=501.277?g/m L). The results shows that the same optimal conditions could be used to get camellia flower extract with higher polyphenols content and better antioxidant activity.(3) Study on the camellia flowers product development technology.(1) Tea processing technology of camellia flower.Effects of three factors of drying temperature, de-enzyme ways and rolling processing on nutrient composition content and sensory quality of camellia flowers were determined. It showed that take direct hot-air drying, the higher the temperature, the worse the nutritional quality, but higher temperature is helpful to enhance the sensory quality. In different de-enzyme ways, the order of nutritional quality was microwave heating in 80 W>microwave(300 W)>steaming>microwave(500 W)>microwave(750 W). Compared with the direct drying, enzyme inactivation by microwave or steam were more advantageous to sensory quality. In addition, through different rolling processing, nutritional quality and sensory quality were outstanding.(2) Brewing process of camellia flower.Brewed with different temperature, time and water quality, discuss the effect of extraction and sensory evaluation of camellia flower in different conditions. Results showed that the concentration of polyphenol, amino acid, total sugar and caffeine in infusion were increased with the rise of temperature and the extension of time. At same temperature, the small molecular substances dissolve out more easily, and the concentration of soluble substances with brewing time was in line with the logarithmic curve regression model. On the other hand, water quality has great influence, especially for polyphenols and amino acids. According to the results of sensory evaluation, there are correlations between the color, aroma, taste, and leaves of infusions and each component content in infusions, conform to the multivariate linear regression equation. In conclusion, the camellia flower infusion had the best sensory quality with temperature 100 ?, time 15 min and purified water. |
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