Detection Of Functional Components Of Citrus And Study On Extraction And Stability Of These Functional Components

Citrus is rich in resource in china and it is popular because of its good taste and abundant nutritious.So its furit is used to develop products such as fruit juice drinks.At the same time,studies have shown that citrus peel and flesh contain a series of biologically active components,including flavonoids,limonin analogues,acridone alkaloids,and carotenoids classes,etc.And they have antioxidant,anticancer,anti-inflammatory,anti-aging and many other biological activities.In this thesis,main functional components of the four representative citrus fruit peel and flesh were detected.The extraction of these functional components,impact of various factors on its stability were studied to provide a theoretical basis for further developments.The main results were as follows:1.The main functional components of citrus:flavanone neohesperidoside(naringin),flavanone rutinside(hesperidin)and limonin analogues(limonin and nomilin)exsited in the four types of citrus flesh and peel while two kinds of flavanone aglycones(naringenin and hesperetin)didn't be detected.The contents of flavonoids,naringin,hesperidin,limonin and nomilin in different varieties were different.In the same variety of citrus,the contents of peel and flesh varied widely,but the contents of peel were greater than the contents of flesh in all four types of citrus.Guanxi pomelo orange peel had high level of naringin content,to 29.573 mg/g DW;the peel of mandarin orange,navel orange and tangerine orange had high levels of limonin and nomilin content and they were bitter as food.So they could be developed as special nutrition food,such as capsule;The flesh of four types of citrus had low level of bitter ingredients,so they were good for fresh eating and processing fruit juice.2.Freeze-dried powder of tangerine orange peel was selected as typical experimental material.Ethanol concentration,extraction time,extraction temperature,solid-to-liquid ratio and extraction times as single factor were reseached in the naringin and hesperidin extraction experiments.Extraction rate was used as index,according to the results of single factor experiments,the orthogonal test was desighed,the optimum extraction process of naringin was as follows:ethanol concentration:55%,extraction time:40 min,extracted temperature:60?,solid-to-liquid ratio:1:8,extraction times:2 times,and its extraction rate reached 0.594%,90.4%of total contents;the optimum extraction process of hesperidin was as follows:ethanol concentration:65%,extraction time:40 min,extracted temperature:50 ?,solid-to-liquid ratio:1:6,extraction times:2 times,and its extraction rate reached 1.478%,92.8%of total contents.3.Freeze-dried powder of tangerine orange peel was selected as typical experimental material.Acetone concentration,extraction time,extraction temperature,solid-to-liquid ratio and extraction times as single factor were reseached in the limonin and nomilin extraction experiments.Extraction rate was used as index,according to the results of single factor experiments,the orthogonal test was desighed,the optimum extraction process of limonin were as follows:acetone concentration:60%,extraction time:50 min,extracted temperature:55?,solid-to-liquid ratio:1:6,extraction times:2 times,and its extraction rate reached 0.248%,89.5%of total contents;the optimum extraction process of nomilin was as follows:acetone concentration:80%,extraction time:40 min,extracted temperature:45 ?,solid-to-liquid ratio:1:6,extraction times:2 times,and its extraction rate reached 0.252%,95.8%of total contents.4.Effects of different heat treatment temperature,heat treatment time,pH and light conditions on stability of naringin,hesperidin,naringenin,hesperetin,limonin and nomilin were researched.The results showed that degradation rate of naringin,hesperidin,naringenin,hesperetin,limonin and nomilin increased when heating temperature and time were extended.When they were heated at 100? for 50 min,they lost about 20%.In order to maintain its content and biological activity,they should avoid long time and high temperature heat treatment in developing its related products,especially health care products.In the acidic environment,naringin,hesperidin,naringenin and hesperetin were relatively stable while limonin and nomilin had poor stability.Therefore,naringin,hesperidin,naringenin and hesperetin should be kept in the acidic environment,while limonin and nomilin should avoid acidic environment.In different light conditions,retention rate of naringin,hesperidin,naringenin,hesperetin,limonin and nomilin were as follows:dark>natural light>sunlight.When exposed in sunlight,they lost more than 20%,which naringin lost over 30%.So it was better to keep them in the brown bottle away from light.