Study On The Advanced Utilisation Of Grape Seeds

Grape seed is the byproduct of wine making and which accounts for 5-7% of the raw grape, it contains 14-17% oil in which linoleic acid is up to 68-76% and there are many vitamins in the oil. The extractants of grape seed mainly contents proanthocyanidins(PC), which is known as non-toxic high efficient antioxidants. Proanthocyanidins have strong anti-oxidative and radical scavenging activities and its intensity of this effection is 50 times as that of VE,20 times as that of VC.In this thesis, the author extract grape seed oil with supercritical fluid (CO₂) extraction (SFE) in order to protect the unsaturated fatty acid and proanthocyanidin from destroying and this will be beneficial to the further extraction of proanthocyanidins. The author also tried to protect the bioactivity of proanthocyanidin by microencapsulation. The details of this study is as following:The author studied the conditions of extracting grape seed oil by SFE and the results showed that the water content and the granularity of raw material crushed, together with the extracting pressure, temperature and the flux of CO₂ are the most important affect factors. The most suitable conditions are: the water content of the grape seed should be adjusted to about 4.5% and ground to 40 mesh, the pressure of the extracting kettle is 30Mpa and its temperature is 45℃, the CO₂ flowing rate is 10L/h, the separating kettle pressure is 9-10Mpa and its temperature is 45℃. the yield of extraction is more than 98.53%. The unsaturated fatty acid contents are beyond 90 % , among which the linoleic acid content is 74.42% , the ratio of U/ S is 8, which is good for health.The technology and factors affect the extracting of proanthocyanidin from the reside of grape seed after grape seed oil extraction has been studied. The results showed that the the sequence of the 3 main factors affecting the extraction is the content of acetic acid > temperature of extraction > the content of ethanol, the optimal condition should be: using ethanol solution (ethanol content is 68.3%) with 0.8% acetic acid as extracting agent, the raw material is ground to 40 mesh, the ratio of raw material to extracting agent is 1:8, the temperature of the extraction is 55.5℃and extract 60mins with stirring, then, repeat the above-mentioned operation two times. The efficiency of the proanthocyanidin extracting is up to 98.26%.Microencapsulation of proanthcyanidins with Arabic gum + maltodextrin and EC (Ethylcellulose)+ PEG (Polyethylene Glyeo) is also investigated respectively. When we use Arabic gum + maltodextrin as wall material, the process of microencapsulation is: Arabic gum(40%)and maltodextrin(60%) are mixed, the ratio of core substance(proanthcyanidins) to wall material is 30:70, add all these substance to water and the content of the slurry is 20%, after the homogenization, spray drying was adopted to prepare proanthocyanidins...