锦橙皮膳食纤维抗氧化活性研究

目的:提取锦橙皮膳食纤维,研究其对O2-·、·OH、DPPH·三种自由基的清除作用。方法:采用复合酶法对膳食纤维进行提取,采用邻苯三酚自氧化法和Fronton反应对清除O2-·、·OH、DPPH·的效果进行了研究。结果:对O2-.清除率最高为46.28%,对.OH的IC50为3.27mg/mL,对DPPH.的IC50为5.66mg/mL。综上所述,锦橙皮膳食纤维对三种自由基都具有一定的清除作用。     

Application of high hydrostatic pressure and ultrasound-assisted extractions as a novel approach for pectin and polyphenols recovery from tomato peel waste

In this study, high hydrostatic pressure extraction (HHPE) and ultrasound-assisted extraction (UAE) were used for the improvement of pectin and polyphenol recovery from tomato peel waste.HHPE enhanced pectin recovery by 15% after 45 min of recycling, in comparison with the conventional extraction (CE) for 180 min. Similar mass fractions of anhydrouronic acid, total sugars and total phenols were obtained by using both methods. FTIR and ¹H NMR data confirmed that chemical composition of pectin obtained by HHPE and CE is identical, therefore it was concluded that the faster HHPE method can be used for its further isolation.Although depectinized residues subjected to UAE in 70% ethanol for 15 min contained two times lower values of total phenols (1625.7 mg/100 g) than pectinized samples (3643.9 mg/100 g), their quantities are not negligible, considering the fact that they are generated after HHPE. At the end of UAE, the residues were exploited as a source of fatty acids, among which lauric, palmitic and stearic acids are dominant.In conclusion, by shortening the extraction time using HHPE and UAE, it is possible to efficiently produce two valuable functional ingredients, pectin and polyphenols, and at the same time to reduce peel waste from tomato canning industry, which presents an environmental problem.Industrial relevanceUtilizing HHPE and UAE as novel and emerging technologies, and combining them with traditional ones (Soxhlet) is given the solution for sequential isolation of pectin, polyphenols and fatty acids from tomato peel waste, generated by canning factory.Shortening of extraction time using HHPE and UAE, it is possible to replace the conventional techniques, and achieve efficient production of pectin and polyphenols.Overall, the extraction methodology proposed in this work could provide two valuable benefits, i.e. the producers could find mode for decreasing of disposal costs of waste and consumer would take opportunity that isolated compounds could be reintroduced into food.     

磨皮取油后橙皮的二次利用对精油品质的影响

为了开发利用工业化生产中磨皮取油后的剩余橙皮,提高橙皮精油得率,以伏令夏橙为研究对象,采用水蒸气蒸馏法分别提取机器磨皮所得油水混合物及磨皮后剩余橙皮的精油,计算两者精油得率并比较成分差异,从橘红和橘白中提取的挥发油作为对照。结果显示,剩余的橙皮回收利用可使橙皮精油得率提高11.55%。GC—MS分析发现油水混合物和剩余橙皮提取的精油成分有较大不同。与油水混合物提取的精油相比,剩余皮精油中的酮类化合物、酯类化合物、醇类化合物和脂肪酸相对含量较高,而烃及其衍生物的相对含量较低。试验表明回收利用磨皮后的剩余橙皮可以提高橙皮精油产量,并具有浓郁的香气。     

Investigation of the cholesterol-lowering action of insoluble fibre derived from the peel of Citrus sinensis L. cv. Liucheng

A water-insoluble fibre-rich fraction (WIFF) was isolated from the peel of Citrus sinensis L. cv. Liucheng. The effects of a WIFF-containing diet on lipid and cholesterol absorption in hamsters were investigated and compared with those of a cellulose-containing diet and fibre-free diet, as controls. Results demonstrated that WIFF could significantly (P<0.05) decrease the levels of serum triglyceride, serum total cholesterol, liver total lipids, and liver cholesterol, while it could also significantly (P<0.05) increase the levels of fecal total lipids, fecal cholesterol, and fecal bile acids, as well as the fecal bulk and moisture. The pronounced hypocholesterolemic and hypolipidemic effects of WIFF might be attributed to its ability to enhance cholesterol and bile acids excretion. These results suggest that WIFF could be a potential cholesterol-lowering ingredient in human diets or new formulations of fibre-rich functional foods.     

Improvement in intestinal function and health by the peel fibre derived from Citrus sinensis L cv Liucheng

The water‐insoluble fibre‐rich fraction (WIFF) was isolated from the peel of Citrus sinensis L cv Liucheng in an economical way. The influences of a WIFF‐containing diet on the intestinal function and health in hamsters were investigated and compared with those of cellulose‐added and fibre‐free diets. Our results showed that the inclusion of WIFF in a fibre‐free diet might result in some significant improvements in serum, intestinal, caecal and faecal parameters, such as elevated serum alkaline phosphatase activity (127%), increased intestinal maltase and sucrase activities (180 and 164% respectively), decreased caecal pH (6.30), reduced caecal and faecal ammonia contents (by 25.4 and 34.1% respectively) and decreased activities of faecal β‐D ‐glucosidase (by 48.1%), β‐D ‐glucuronidase (by 52.9%) and urease (by 81.5%). These results suggested that the incorporation of WIFF in the diet at a level of 50 g kg^?1 might exert a favourable effect on intestinal function and health. Accordingly, WIFF could be exploited as a potential functional ingredient in human diets and also offer industries an opportunity to develop new formulations of fibre‐rich functional foods. Copyright © 2005 Society of Chemical Industry     

响应面法优化超声波辅助提取猕猴桃果皮多酚工艺研究

采用超声波辅助提取猕猴桃果皮多酚,并利用响应面法对多酚提取工艺进行优化。在单因素实验的基础上,采用四因素三水平的响应面实验优化设计,研究超声波功率、提取时间、提取温度、液料比对多酚提取量的影响。结果显示最佳提取工艺条件为:超声波功率384.00 W,提取时间30 min,提取温度65.00℃,液料比23.00 m L/g,多酚提取量的实验值为（28.10±0.38）mg GAE/g,与理论预测值（28.14 mg GAE/g）相差不大。通过体外1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除力测定多酚的抗氧化性,并且得到猕猴桃果皮多酚的EC50值为0.13 mg/m L,说明提取的多酚具有很好的抗氧化性。      

Chemical composition and antimicrobial activities of essential oil from the peel of bingtang sweet orange (Citrus sinensis Osbeck)

The chemical composition of the essential oil obtained from the peel of Bingtang sweet orange ( Citrus sinensis Osbeck) was analysed by gas chromatography and gas chromatography/mass spectrometry (GC/MS). Twenty-seven components were identified. The monoterpenes and sesquiterpene hydrocarbons with 96.03% (w/w) of the total oil were the principal compound groups. Among which, limonene was observed dominant (77.49%), followed by myrcene (6.27%), α-farnesene (3.64%), γ-terpinene (3.34%), α -pinene (1.49%), sabinene (1.29%) and other minor components. Results by disc diffusion method and minimum inhibitory concentration (MIC) determination method showed that the essential oil had a wide spectrum of antimicrobial activities against Staphylococcus aureus , Penicillium chrysogenum , Bacillus subtilis, Escherichia coli and Saccharomyces cerevisiae , with their inhibition zones ranging from 14.57 mm to 23.37 mm and the MIC ranging from 4.66 μL mL⁻¹ to 18.75 μL mL⁻¹.     

Obtaining fruit segments from a traditional orange variety (Citrus sinensis (L.) Osbeck cv. Sangrina) by enzymatic peeling

A process for obtaining fruit segments from a traditional orange of Sangrina variety by enzymatic peeling was optimized. Enzymatic peeling was carried out by fruit infusion under vacuum conditions in a commercial preparation of pectinases and cellulases (Peelzym II). For the optimization of vacuum conditions, the potential enzymatic saturation of albedo was determined. To obtain a final product with good quality, it was necessary to prove the effectiveness of different concentration of Peelzym II for the degradation of the fruit albedo and also the incubation time of the fruits with the enzymatic solution. The best condition to obtain Sangrina segments by enzymatic peeling was 1 ml L⁻¹ of Peelzym II applied at 67 kPa with two vacuum pulses of 2 min and a subsequent period of 40 min in the enzymatic solution at atmospheric pressure. The reuse of the enzyme preparation in an industrial peeling process was also studied. Results show that it is possible to reuse the enzymatic preparation in an industrial peeling process, although a 30% decrease in the pectinase activity occurred after four peeling cycles.     

Monodemethylated polymethoxyflavones from sweet orange (Citrus sinensis) peel Inhibit growth of human lung cancer cells by apoptosis

Polymethoxyflavones (PMFs) are almost exclusively found in the Citrus genus, particularly in the peels of sweet orange (Citrus sinensis L. Osbeck) and mandarin (C. reticulate Blanco). We studied the effects of two major PMFs, namely, nobiletin and 3,5,6,7,8,3′,4′‐heptamethoxyflavone (HMF), and two major monodemethylated PMFs, namely 5‐hydroxy‐3,7,8,3′,4′‐pentamethoxyflavone (5HPMF), and 5‐hydroxy‐3,6,7,8,3′,4′‐hexamethoxyflavone (5HHMF), on the growth of human lung cancer H1299, H441, and H460 cells. Monodemethylated PMFs were much more potent in growth inhibition of lung cancer cells than their permethoxylated counterpart PMFs. In H1299 cells, cell cycle analyses further revealed that monodemethylated PMFs caused significant increase in sub‐G0/G1 phase, suggesting possible role of apoptosis in the growth inhibition observed, whereas the permethoxylated counterpart PMFs did not affect cell cycle distribution at same concentrations tested. These results strongly suggested that the phenolic group is essential for the growth inhibitory activity of monodemethylated PMFs. Further studies in H1299 cells demonstrated that monodemethylated PMFs downregulated oncogenic proteins, such as iNOS, COX‐2, Mcl‐1, and K‐ras, as well as induced apoptosis evidenced by activation of caspase‐3 and cleavage of PARP. Our results provide rationale to develop orange peel extract enriched with monodemethylated PMFs into value‐added nutraceutical products for cancer prevention.     

采后橘油诱导及振动胁迫对贮藏期锦橙果皮油胞病的影响

以果皮塌陷指数和变色指数为测定指标,研究橘油及振动胁迫处理对锦橙果皮油胞病的影响。结果表明：随橘油体积分数增大果皮油胞病逐渐加重,并以100%橘油处理对锦橙果皮油胞病的诱导效果最明显;锦橙果皮油胞病发病程度随着振动胁迫强度增大而加重,其中500r/min的诱导效果最显著。另外,在橘油和振动胁迫处理后的果实在不同温度下贮藏时,发现20℃贮藏的锦橙果皮油胞病最为严重,0℃冷害温度也能加剧果实油胞病的发生,5℃贮藏的锦橙果皮油胞病最轻微。研究结果为进一步研究柑橘油胞病的发生机理及防控措施提供理论依据。     

超声辅助法提取平榛榛仁多酚的工艺研究

榛子营养成分丰富且口味独特广受大众喜爱,有着"坚果之王"的美誉。为提高榛子的综合利用程度以及潜应用价值的深度开发,本文以平榛为原料利用超声辅助法在单因素实验的基础上进行正交试验,探索超声功率、乙醇浓度、料液比和提取时间对榛仁多酚提取量的影响。结果表明,榛仁多酚的最佳提取条件为;超声功率240W,乙醇浓度为65%(V/V),料液比1∶60(g/mL),超声时间100min,得到最高多酚提取量0.43mg/g。试验表明,通过正交对榛子多酚提取工艺进行优化,可以提高提取效率而且具有较好的稳定性。     

Preparative separation of polymethoxylated flavones from Ponkan (Citrus reticulata Blanco cv. Ponkan) peel by high-speed countercurrent chromatography and their antifungal activities against Aspergillus niger

Three polymethoxylated flavones (PMFs) including nobiletin (NOB), tangeretin (TAN) and 5-demethylnobiletin (5-DN) were separated from Ponkan (Citrus reticulata Blanco cv. Ponkan) peel by high-speed countercurrent chromatography (HSCCC) with a two-phase solvent system composed of n-hexane–ethyl acetate–methanol–water (1:0.8:1:1, v:v:v:v). A total of 6.4?mg of NOB, 20.2?mg of TAN and 2.8?mg of 5-DN with the purity of 97.7, 99.05 and 95.9?%, respectively, were obtained in one-step separation from 70?mg of crude extracts. Their chemical structures were identified by HPLC/ESI–MS and ¹H and ¹³C-NMR. The antifungal activities of the three compounds against Aspergillus niger were evaluated by using a microbroth dilution assay. 5-DN displayed the best inhibitory effect, while NOB showed the lowest potency, with respective minimal inhibitory concentration (MIC) values of 0.1 and 0.8?mg/mL, which indicated that the inhibition against A. niger could be affected by the structural difference in PMFs.     

干燥条件对茶枝柑果皮黄酮和精油成分的影响

采用HPLC对日晒和不同温度热风干燥下的茶枝柑果皮中的黄酮进行定性和定量分析,同时利用GC-MS检测分析了其精油成分及相对含量。结果表明,36、40、45和50℃干燥条件下的茶枝柑果皮的主要黄酮类化合物的含量与日晒相比有显著差异,42℃热风干燥与日晒相比则无显著差异。不同热风干燥条件下茶枝柑果皮精油的总离子流图基本一致,但是精油成分的总含量均显著高于日晒,此外精油成分的种类、数目、相对含量也存在一定的差异性,42℃热风干燥下的精油成分与日晒最为接近。结论:从保证茶枝柑果皮品质和节约能源提高生产效率的角度出发,42℃热风干燥是有利于保存茶枝柑果皮黄酮和精油成分的较佳干燥方式。      

Antibacterial activity of grapefruit (Citrus paradisi) peel extracts

Citrus paradisi peels were successively extracted with hexane, chloroform, acetone and methanol using a Soxhlet extractor for 8 h each. Thin layer chromatography (TLC) of hexane and chloroform extracts showed three spots with different concentrations; hence both the extracts were mixed and fractionated into alcohol soluble and insoluble fractions. Naringin was isolated from acetone and methanol extracts by column chromatography and its structure was confirmed by ¹H and ¹³C NMR spectroscopic studies. Antibacterial activity of these fractions was evaluated against different bacteria. The alcohol soluble fraction was found to possess maximum activity followed by hexane extract. Extracts were more effective against Gram-positive than Gram-negative bacteria.     

超声波辅助提取黄秋葵多酚和多糖的工艺研究

以黄秋葵为原料,对超声波辅助水提黄秋葵多酚和多糖的提取工艺进行了研究。通过单因素确定超声时间、超声温度、料液比和超声功率对黄秋葵多酚和多糖的影响,并在单因素实验的基础上利用正交实验确定最佳工艺条件。结果表明多酚和多糖的最佳提取条件为超声时间90min,超声温度45℃,料液比1∶45,超声功率84W。在此条件下,黄秋葵多酚和多糖的含量分别为4.207、2.671mg/g。      

锦橙皮渣膳食纤维微粉化及其功能特性分析

以锦橙果汁加工副产物锦橙皮渣为原料制备锦橙皮渣膳食纤维,通过普通粉碎和球磨法微细化处理,得到不同粒径大小的锦橙皮渣膳食纤维微粉和超微粉,测定其理化性质和重金属离子结合力,并利用激光粒度仪、红外光谱、X射线衍射、热分析、扫描电镜对不同锦橙皮渣膳食纤维粉进行粒径测定和结构观察,探究超微粉碎对锦橙皮渣膳食纤维理化性质、微观结构及重金属离子吸附能力的影响。结果表明,球磨微细化处理后膳食纤维的粒径减小;粉体的持水性、持油性、溶胀性、重金属离子结合力显著升高（P＜0.05）,色泽变浅。本实验为锦橙皮渣的综合利用以及作为一种潜在食品添加剂资源提供理论参考。