喷雾干燥与冷冻干燥对鱼油微胶囊品质的影响

Effects of spray-drying and freeze-drying on quality of fish oil microcapsules

为深度开发金枪鱼加工副产物,充分利用金枪鱼油所含营养成分,以壳聚糖为壁材,金枪鱼油为芯材,分别采用喷雾干燥法和冷冻干燥法制备鱼油微胶囊,比较两种制备方法对制得微胶囊品质的影响。结果显示:喷干鱼油微胶囊和冻干鱼油微胶囊的包埋率分别为77.26%、63.86%,但后者对鱼油脂肪酸保护更好;前者挥发性成分共有43种,其中酮类物质相对含量最高,占33.01%;而后者的挥发性成分仅有24种,以酯类为主,占52.29%,且没有检测到典型的腥味物质,这可能是由于冻干过程温度较低,抑制了多不饱和脂肪酸的氧化,更能掩盖鱼油不良风味。贮藏试验显示,两种鱼油微胶囊与鱼油相比,过氧化值的增长速度均显著降低(P<0.05);贮存7d后,两种胶囊的二十二碳六烯酸(DHA)和二十碳五烯酸(EPA)保留率分别为82.22%和85.25%,两种制备方法对DHA和EPA保留率的影响不大(P>0.05)。研究表明,两种鱼油微胶囊制备方法对延缓鱼油氧化和掩蔽不良风味有一定作用,对制备鱼油微胶囊具有一定的参考意义。

To exploit the by-products of tuna processing and make full use of the nutrients from tuna fish oil,microcapsules were prepared by spray-drying and freeze-drying with chitosan as shell material and tuna fish oil as core material.The effects of two preparation methods on the quality of microcapsules made were compared.The results showed that the embedding rates of spray-dried and freeze-dried microcapsules were 77.26% and 63.86% respectively,but the freeze-dried microcapsules can better protect the fatty acids of fish oil.A total of 43 volatile components in spray-dried microcapsules were identified,and ketones were the most,reaching 33.01%.There were a total of 24 volatile components in freeze-dried microcapsules,mainly esters,reaching 52.29%.No typical fishy odor substances were detected,which may be due to the low temperature in the freeze-drying process that inhibited the oxidation of polyunsaturated fatty acids and could cover up the bad flavor of fish oil.During storage,compared with fish oil,the growth rate of peroxide value of the two kinds of fish oil microcapsules was significantly reduced ( P <0.05).The retention rates of DHA and EPA were 82.22% and 85.25% respectively after 7 days,and two preparation methods had little effect on retention rate of DHA and EPA ( P >0.05).The research showed that the two kinds of preparation methods for fish oil microcapsules had certain effect on delaying the oxidation of fish oil and masking bad flavors,and were of reference significance for the preparation of fish oil microcapsules.