Polymethoxy flavones are responsible for the anti-inflammatory activity of citrus fruit peel

In traditional Chinese medicine, dried citrus fruit peels are widely used as remedies to alleviate some respiratory inflammatory syndromes and are considered as potential sources of anti-inflammatory components. Seven citrus fruits were selected for this study. We determined the inhibitory ability of citrus peel extracts on the production of pro-inflammatory mediators, prostaglandin E₂ (PGE₂) and nitric oxide (NO), in lipopolysaccharide (LPS)-activated RAW 264.7 cells. Among the tested citrus peels, Ponkan (Citrus reticulata Blanco) and Tonkan (Citrus tankan Hayata) deserve special attention due to their outstanding inhibitory effect on PGE₂ and NO secretion. We have also examined the composition, flavanone glycosides and polymethoxy flavones. The polymethoxy flavone content, especially nobiletin, appears to correlate well with the anti-inflammatory activities of certain citrus peel extracts. Thus, our results suggest that polymethoxy flavones contribute crucially to the anti-inflammatory activity of citrus peels.     

Power ultrasound for valorization of Citrus limon (cv. Eureka) waste: Effects of maturity stage and drying method on bioactive compounds,antioxidant, and anti-diabetic activity

This study aims to use power ultrasound-assisted extraction (UAE) and maceration (ME) to valorize lemon juice processing residues (flavedo+albedo). Also, the effects of maturity stage (mature vs. immature) and drying method (freeze-drying-FD vs. oven drying-OD) on antioxidant activity, digestive enzymes inhibition, and bioactive compounds (phenolics and flavonoids) were analyzed. Besides. effects of independent parameters were elaborated through principal component analysis (PCA). According to the results, immature lemons exhibited a higher inhibition of α-amylase, α-glucosidase, and lipase by 10, 5, and 46%. Also, replacing OD with FD enhanced the antioxidant activity. HPLC identified hesperidin and sinapic acid as the most abundant bioactive compounds in all extracts and UAE enhanced their concentration by 2.3 and 1.2 times, respectively. Besides, sonication enhanced antioxidant activity and anti-diabetic effects by 1.1–5.6 times. Therefore, replacing mature peels, OD, and ME with immature peels, FD, and UAE can boost the potential health benefits of extracts of lemon processing by-product.     

水蒸馏法提取金桔精油的工艺研究

采用水蒸汽蒸馏法从金桔干燥果皮中提取精油,通过正交实验得到最优条件：干果皮破碎度24目,提取助剂NaCl的质量浓度1%,提取时间2h。实验所得金桔果皮精油为黄色澄清液体,具有新鲜金桔皮的特征香气,其折光率为1.4720-1.4750,气相色谱-质谱（GC-MS）分析显示柠檬烯是金桔果皮精油的主导成分。结果表明金桔精油在外观,色泽,香气,折光率等方面与国际标准接近,品质较好。     

Effects of drying temperature on the flavonoid,phenolic acid and antioxidative capacities of the methanol extract of citrus fruit (Citrus sinensis (L.) Osbeck) peels

There are many active functional compounds in citrus peels, such as flavonoid and phenolic acid. Scientists tried to obtain more bioactive components from citrus peels by various methods. This research investigated the effects of different drying temperatures (50, 60, 70, 80, 90 and 100 °C) on changes in the flavonoid, phenolic acid and antioxidative activities of citrus fruit (Citrus sinensis (L.) Osbeck) peels. The total phenolic and flavonoid contents of drying treated orange peels were decreased by lower drying temperature (50 and 60 °C) and increased by higher drying temperature (70, 80, 90 and 100 °C). Amounts of phenolic compounds in the 100 °C treated sample extract were significantly higher than the amounts in the samples heated at other temperatures (P < 0.05). EC₅₀ values of orange peel extracts by DPPH radical scavenging effects and ABTS^·+ scavenging effects were increased with lower drying temperature and decreased with higher drying temperature, and the values of 100 °C treated sample extract were significantly lower than the samples heated at other temperatures (P < 0.05). However, the chelating Fe^{2 +} activities of samples showed the opposite trend.     

Physico-chemical Properties, Vitamin C Content, and Antimicrobial Properties of Pomegranate Fruit (Punica granatum L.)

Pomegranate (Punica granatum L.) fruit is widely used in the food and process industries due to its excellent nutritional and health value and as a raw material for the manufacture of secondary products such as jellies, dyes, and cosmetics. The objectives of this research were to determine the vitamin C content and antimicrobial properties of fresh and dried fractions of fruit peel and arils of locally grown and imported pomegranate in Oman. A significant variation in vitamin C content was found among the five varieties of pomegranate studied, ranging from 52.8 to 72.0 mg/100 g fresh weight (fw) for arils and 76.8 to 118.4 mg/100 g fw for peels. Irrespective of the variety of pomegranate, vitamin C content in the peel was significantly higher than the aril, with differences ranging from 24.4% to 97.0% depending on variety. Fruit fractions showed antimicrobial effects (inhibition zone) on Staphylococcus aureus and Pseudomonas aeruginosa but not Escherichia coli. Sun drying of fruit peel significantly (p ≤ 0.05) enhanced vitamin C retention and antimicrobial effects in comparison with oven drying presumably due to lower rate of moisture removal associated with low temperature drying over longer duration in comparison with short-time high-temperature oven drying.     

我国主要金柑品种果皮中挥发性成分比较

基于顶空固相微萃取-气相色谱-质谱联用技术,比较我国15 个金柑品种果皮中主要挥发性物质的种类和含量差异。15 个金柑品种累计检出195 种挥发性物质,各品种果皮检出组分数变幅为45～78;总含量变化幅度为791.69～27 405.95 μg/g,变异系数为46.46%;包括烃类、醇类、醛类、酮类和酯类;主要成分为柠檬烯、月桂烯、松油烯、萜品烯、异柠檬烯、异松油烯、左旋-α-蒎烯、γ-榄香烯、丁香烯、吉马烯、α-紫穗槐烯、芳樟醇等物质,不同金柑品种间累计特有成分55 种。利用R软件数据统计结合主成分分析,基于挥发性物质对金柑品种进行了统计学分析,结果显示我国金柑挥发性物质种类和含量丰富,差异显著,可以作为区分不同金柑的辅助工具。     

Hypolipidaemic effects and mechanisms of the main component of Opuntia dillenii Haw. polysaccharides in high-fat emulsion-induced hyperlipidaemic rats

The antihyperlipidaemic effects of ODP-Ia, one of the main components of Opuntia dillenii Haw. polysaccharides, were studied. Gavage administration of ODP-Ia was observed to significantly decrease serum lipid levels and to increase serum high-density lipoprotein cholesterol level in hyperlipidaemic rats. Similar suppressive patterns were also seen in hepatic total cholesterol and triglyceride levels. Moreover, the ODP-Ia administration significantly increased serum lecithin:cholesterol acyltransferase activity, increased the production of serum NO, inhibited hepatic HMG-CoA reductase activity, augmented serum and hepatic superoxide dismutase activities and decreased the serum and hepatic malondialdehyde contents in hyperlipidaemic rats. In addition, a histopathological examination revealed that ODP-Ia administration significantly suppressed inflammatory cell infiltration and the expression of VCAM-1. Together, these results indicate that ODP-Ia is a potential natural product for the treatment of hyperlipidaemia-related diseases by improving antioxidant levels, modulating the activities of enzymes involved in cholesterol metabolism, promoting the production of NO and suppressing the expression of VCAM-1, thereby suppressing lipid accumulation and inflammatory cell infiltration.     

Phytocompounds from Vitis kelungensis stem prevent carbon tetrachloride-induced acute liver injury in mice

Vitis thunbergii, Vitis flexuosa, and Vitis kelungensis are three common wild grapes in Taiwan and have been used as a traditional medicine for inflammatory disorders. However, the potential bioactivities of these wild grapes have not been studied to date. In this study, anti-inflammatory activities and hepatoprotective properties of these three wild grapes were assessed by in vitro and in vivo assays, respectively. Results revealed that the methanolic extract of V. kelungensis stem (VKS) strongly suppressed NO production in lipopolysaccharide (LPS)-stimulated murine macrophages. And among all fractions derived from VKS, the EtOAc fraction exhibited the best inhibitory activity. In addition, VKS and its major resveratrol derivatives, (−)-ε-viniferin and 2-(4-hydroxyphenyl)-2,3-dihydrobenzo[b]furan-3,4,6-triol, can prevent CCl₄-induced liver injury and aminotransferase activities in mice, which were comparable to that of silymarin or resveratrol, the natural remedies for liver diseases.     

Cyanide detoxification in cassava for food and feed uses

Cassava (Manihot esculenta Crantz) is an important tropical root crop providing energy to about 500 million people. The presence of the two cyanogenic glycosides, linamarin and lotaustralin, in cassava is a major factor limiting its use as food or feed. Traditional processing techniques practiced in cassava production are known to reduce cyanide in tubers and leaves. Drying is the most ubiquitous processing operation in many tropical countries. Sun drying eliminates more cyanide than oven drying because of the prolonged contact time between linamarase and the glucosides in sun drying. Soaking followed by boiling is better than soaking or boiling alone in removing cyanide. Traditional African food products such as gari and fufu are made by a series of operations such as grating, dewatering, fermenting, and roasting. During the various stages of gari manufacture, 80 to 95% cyanide loss occurs. The best processing method for the use of cassava leaves as human food is pounding the leaves and cooking the mash in water. Fermentation, boiling, and ensiling are efficient techniques for removing cyanide from cassava peels.     

Oven‐dried table olives: textural properties as related to pectic composition

The effects of processing treatments on the microscopic structure, pectic fractions and firmness of ripe olives (Olea europaea L Cassanese variety), processed by the ‘Ferrandina’ method for oven‐dried table olive production, were studied. The process included a first heating step, a salting step and a final oven‐drying process. Scanning electron microscopic observations of olive tissue structure revealed that heat treatment was highly damaging, affecting the intercellular pectic substances and producing cell separation. Epicuticular waxes were barely affected and limited the shrivelling of the fruit during the oven dehydration process. The pectin content was higher in the oven‐dried olives than in the fresh samples. The sodium hydroxide‐soluble fraction was the main pectin fraction in the olive tissues. Its content decreased markedly after the heating step, while it increased after the oven dehydration step. The softening of the olive tissues increased after heat treatment, and a correlation was found between protopectin content and firmness. In oven‐dried olives a firming of the olive tissues was observed due to the de‐esterification of pectin and to its decreased solubility resulting from an increase in cell wall calcium bridging. © 2000 Society of Chemical Industry     

Effect of heat treatments on the essential oils of kumquat (Fortunella margarita Swingle)

Kumquats (Fortunella margarita Swingle) cultivated in Taiwan are eaten raw or made into candied fruit or fruit tea. For the experiments described in this paper, essential oils were obtained from kumquat peels or whole fruit by cold pressing, steam distillation or heating in water at 90 °C for 15 min followed by steam distillation. The volatile components contained in the essential oils were identified by direct injection (DI) or headspace-solid phase microextraction (HS-SPME) coupled with gas chromatography (GC). A total of 43 compounds were identified, of which 37 were verified by DI/GC and 31 by HS-SPME/GC. Hot water heating increased the yields of essential oils from both peels and whole fruit. The principal constituents of the oils were similar except for the minor compounds, including linalool, terpinen-4-ol and α-terpineol, the levels of which increased after steam distillation. The whole fruit also contained higher levels of terpene alcohols.     

Evaluation of Drying Methods with Respect to Drying Kinetics,Mineral Content,and Color Characteristics of Savory Leaves

Sun, oven (50 °C), and microwave oven (700 W) drying of savory leaves (Satureja thymbra L.) were carried out to monitor the drying kinetics, changes in mineral content, and color degradation of the product. Oven and microwave oven drying shortened the drying time over than approximately 70% and 99% when compared to the sun and oven drying methods, respectively. Fresh and dried savory leaves had high amounts of K (8875.2–28468.0 mg/kg), Ca (3681.6–9852.03 mg/kg), Mg (1388.0–3102.0 mg/kg), and P (2313.2–5045.8 mg/kg) minerals. K, Ca, P, and Mg were the most abundant elements in savory samples. Mineral content of oven-dried savory were higher than the sun and microwave dried samples. Midilli and Küçük model was shown to give a good fit to the sun and oven drying. The Midilli and Küçük, modified page and page models exhibited high coefficient of determination (R ² ) values ranging between 0.9995 and 0.9997, to the experimental microwave oven drying data of savory. Microwave oven drying revealed optimum color values. Oven drying resulted in a considerable decrease in color quality of savory.     

Effect of drying methods on the phenolic constituents of meadowsweet (Filipendula ulmaria) and willow (Salix alba)

The objective of this study was to investigate the effect of drying conditions on the phenolic constituents and colour of extracts of organically grown white willow and meadowsweet for incorporation into a functional beverage with potential anti-inflammatory properties. The herbs were freeze-dried, air-dried, oven or tray-dried at 30 or 70 °C. The drying kinetics of the herbs was first determined. Both drying temperature and method had a significant effect (p ≤ 0.05) on the drying rate, the samples tray-dried had a faster drying rate than those oven-dried. Results show that for meadowsweet and willow, freeze-drying and oven or tray drying at 30 °C had no significant effect on the phenolic constituents (e.g. total phenols, salicylates, quercetin) or the colour of the extracts in comparison to traditional air-drying. Although increasing the drying temperature to 70 °C resulted in an increase in the drying rate of both herbs it also led to the loss of some phenolic compounds. Also, the extracts from both herbs dried at 70 °C were significantly (p ≤ 0.05) redder than the other drying methods. Therefore, tray drying these herbs at low temperatures may reduce drying time without having a significant effect on the phenolic content and colour of the extracts.     

Tomato peel drying and carotenoids stability of the extracts

Tomato peels were firstly dried by different methods (hot air, freeze‐drying, and fluidized bed drying) to evaluate the recovery of lycopene, β‐carotene and DPPH radical scavenging activity. Comparison of the results showed that hot air drying at 50 °C was a suitable method and alternative to freeze‐drying to preserve carotenoids compounds and antioxidant activity in tomato peels. Then, ethanol/ethyl acetate (1:1) extracts from tomato peel, previously dried at 50 °C by hot air, were submitted to heat (100 °C) and light treatment (1000 lumen) to evaluate their stability as natural food dyes. Heating of the extracts caused a progressive reduction of total carotenoids, up to about 30% after 250 min of treatment, whereas the colour at the end of heat treatment showed small changes, with an overall colour difference (?E) equal to 7. Fluorescent lighting treatment showed an almost total degradation of carotenoids in the extracts after 48 h combined with a fading colour.     

Phenethyl isothiocyanate suppresses nitric oxide production via inhibition of phosphoinositide 3‐kinase/Akt‐induced IFN‐γ secretion in LPS‐activated peritoneal macrophages

Phenethyl isothiocyanate (PEITC), a constituent of many cruciferous vegetables, is well known to have versatile physiological activities, including chemopreventive effects. On the other hand, its anti‐inflammatory effects are poorly reported. Nitric oxide (NO) is associated with a wide variety of inflammatory diseases. In this study, we investigated the effects of PEITC on NO production in LPS‐activated peritoneal macrophages from ICR mice. The signaling pathway of LPS‐induced NO production was examined using neutralizing antibodies [anti‐interferon (IFN)‐γ and anti‐interleukin (IL‐12)] and specific protein kinase inhibitors, as well as others. The activity of PEITC toward NOx production was assessed in mice that received LPS via intraperitoneal administration. The neutralizing antibody of anti‐IFN‐γ, but not anti‐IL‐12, suppressed LPS‐induced NO production by 90%. LY294002, a specific inhibitor of phosphoinositide‐3‐kinase, suppressed Akt and IFN‐γ mRNA expression up‐regulated by LPS, whereas PEITC exhibited a similar inhibition profile. Furthermore, oral administration of PEITC significantly suppressed the serum concentration of NOx in ICR mice. Our results suggest that PEITC suppresses LPS‐induced NO production via inhibition of Akt activation and the resultant decrease in expression of IFN‐γ. This is one of the first reports to demonstrate a marked anti‐inflammatory effect of PEITC following its oral administration.     

加工工艺对茶树花品质及抗氧化活性的影响

以‘黄金桂’品种茶树的鲜花为原料,研究锅式杀青烘干、微波杀青烘干、真空冷冻干燥对茶树花中水浸出物、茶多酚、游离氨基酸、儿茶素组分、生物碱含量及对1,1-二苯基-2-三硝基苯肼自由基清除能力的影响。结果表明,冷冻干燥处理的茶树花茶中茶多酚、游离氨基酸、表没食子儿茶素、表儿茶素、表没食子儿茶素没食子酸酯、表儿茶素没食子酸酯、甲基化表儿茶素没食子酸酯含量以及儿茶素总量显著高于锅式杀青烘干和微波杀青烘干(P<0.05);没食子酸含量最低;水浸出物、茶没食子素和咖啡碱含量与锅式杀青烘干和微波杀青烘干差异不显著(P>0.05)。这3种工艺中,真空冷冻干燥工艺最有利于多酚类化合物的保留,因此成品茶具有最强的抗氧化活性;微波杀青烘干其次,锅式炒青烘干的抗氧化活性最低。感官分析表明,锅式杀青烘干、微波杀青烘干工艺由于经过热脱水处理,所制得的茶树花茶具有玉米香;滋味均有麻涩感,其中冷冻干燥处理的茶树花茶涩味最明显,不同工艺处理下感官风味不同。综上,可将茶树花茶开发为功能性饮品。     

导热油加热技术在单板干燥机上的应用

通过BG134辊筒式单板干燥机热耗量计算、导热油炉选择、供热管线布置和换热器设计,介绍导热油加热技术在辊筒式单板干燥机上的应用,为胶合板生产技术改造和增产节能提供参考。     

Drying of olive pomace by a combined microwave‐fan assisted convection oven

The drying rate curves in terms of moisture content versus time for olive oil pomace have been experimentally obtained using microwave and combined microwave‐convection oven. The effects of microwave power (350, 490, 700 W( thickness (6, 9, 14 mm) and temperature (100, 160, 225°C) have been investigated. It has been found that the effects of power output and thickness are negligible in microwave oven, whereas the drying rate increases with temperature increase in combined microwave‐convection oven. The diffusion model fitted well to the drying curve of experimental data obtained for olive pomace at the studied conditions of drying.     

Immunomodulatory effects of feruloylated oligosaccharides from rice bran

Feruloylated oligosaccharides (FOs), the ferulic acid ester of oligosaccharides, can be released either by the enzymatic or mild acid hydrolysis of arabinoxylans present in cereal bran, and are usually considered as natural antioxidants. However, no related research is available to explain their immunomodulatory effects. This report elucidated their immunomodulatory effects through the variations of pro-inflammatory mediators in vitro. FOs were obtained from the mild acid hydrolysis of rice bran. We found that FOs (0.1–100 μg/ml) induced tumour necrosis factor alpha (TNF-α), IL-1β, IL-6, nitric oxide (NO) and PGE₂ production in unstimulated macrophages, RAW264.7 cells. Furthermore, pre- and post-treated FOs (0.1–100 μg/ml) dose-dependently suppressed TNF-α, IL-1β, IL-6 and NO production, and induced IL-10 production in lipopolysaccharide (LPS)-stimulated RAW264.7 cells without exerting cytotoxicity. As a result anti-inflammatory and therapeutic activities were revealed. It is noteworthy that prostaglandin E₂ (PGE₂) production was significantly suppressed at an FO level of 100 μg/ml. The in vitro assessment of inflammatory mediators should be useful in further characterising the effects of FOs on immunomodulation. Moreover, it will create the economical value of rice bran, which has long been considered as conventional agricultural wastes.     

Antioxidant and anti-inflammatory properties of Dichondra repens Forst. and its reference compounds

Dichondra repens (DR) is the main constituent in herbal beverages and consumed daily as a nutrition supplement for the liver in Taiwan. This study investigated the antioxidant and anti-inflammatory effects of D. repens ethanol extract (EDR) and its reference compounds ex vivo and in vivo. Fingerprint chromatograms (from HPLC) indicated that EDR contained vanillin, umbelliferone and scopoletin. EDR was evaluated for its antioxidant effects and LPS-induced NO production in RAW 264.7 cells. EDR decreased the LPS-induced NO production and expressions of iNOS and COX-2 in RAW 264.7 cells. In vivo anti-inflammatory activities of EDR were assessed in mouse paw oedema, induced by λ-carrageenan (Carr). We investigate the antioxidant mechanism of EDR via studies of the activities of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) in the liver and the levels of malondialdehyde (MDA) and nitrite oxide (NO) in the oedematous paw. Serum NO and TNF-α were also measured. EDR exerts anti-inflammatory effects by suppressing TNF-α, NO, and might be related to the decrement of the level of MDA in the oedema paw via increasing the activities of CAT, SOD and GPx in the liver. The results show that EDR might be a natural antioxidant and anti-inflammatory agent.