Tandem hydroalkylation and deoxygenation of lignin-derived phenolics to synthesize high-density fuels

Lignin is the most abundant naturally phenolic biomass,and the synthesis of high-performance renewable fuel from lignin has attracted significant attention.We propose the efficient synthesis of high-density fuels using simulated lignin cracked oil in tandem with hydroalkylation and deoxygenation reactions.First,we investigated the reaction pathway for the hydroalkylation of phenol,which competes with the hydrodeoxygenation form cyclohexane.And then,we investigated the effects of metal catalyst types,the loading amount of metallic,acid dosage,and reactant ratio on the reaction results.The phenol hydroalkylation and hydrodeoxygenation were balanced when 180℃ and 5 MPa H_(2)with the alkanes yield of 95%.By extending the substrate to other lignin-derived phenolics and simulated lignin cracked oil,we obtained the polycyclic alkane fuel with high density of 0.918 g·ml^(-1)and calorific value of41.2 MJ·L^(-1).Besides,the fuel has good low-temperature properties(viscosity of 9.3 mm^(2)·s^(-1)at 20℃ and freezing point below-55℃),which is expected to be used as jet fuel.This work provides a promising way for the easy and green production of high-density fuel directly from real lignin oil.

Qualitative and quantitative analysis of characteristic free and bound phenolics in three colored quinoas

Quinoa is a good source of phenolics,which both exist as free and bound forms.In order to mark clear the characteristic free and bound phenolics in different quinoa samples,in this study,characteristic free and bound phenolics in three colored quinoas including WQ(white quinoa),RQ(red quinoa)and BQ(black quinoa)were investigated.Result showed a total of 14 phenolics both acted as free and bound form were analyzed in three colored quinoas(WQ,RQ and BQ).Gallic acid,vanillic acid,epicatechin,p-coumaric acid and quercetin existed both as free and bound forms were common phenolics in quinoas.The highest total free phenolics(238.10 mg/kg)and bound phenolics(3377.75 mg/kg)were presented in WQ and RQ,respectively.It indicated WQ and RQ were respectively good source of free and bound phenolics.Moreover,characteristic free and bound phenolics in three colored quinoas could be well analyzed by principal component analysis(PCA),indicating it was an effective and reliable method in distinguishing three colored quinoas based on their characteristic free and bound phenolics,respectively.

酚酸基纳米金修饰电极检测食品中的亚硝酸盐和亚硫酸盐

基于酚酸良好的还原性和无污染性建立酚酸基纳米金传感体系,以实现亚硝酸盐和亚硫酸盐的灵敏检测。采用不同酚酸还原氯金酸制备纳米金(Gold nanoparticles,AuNPs),通过紫外光谱和交流阻抗法获得还原效果最佳的酚酸为没食子酸(Gallic acid,GA)。利用电沉积法制备GA@AuNPs@Au电极,并由线性扫描伏安法(Linear scanning voltammetry,LSV)表征亚硝酸盐和亚硫酸盐的电化学行为。优化体系条件为:GA浓度1 mmol/L、孵育温度70℃、反应时间60 min、pH6.0磷酸盐缓冲溶液浓度0.15 mol/L。亚硝酸盐和亚硫酸盐浓度在0.001~7 mmol/L范围内与氧化峰电流分别呈良好的线性关系(R2>0.994),检出限分别为0.20μmol/L和0.24μmol/L(S/N=3)。该修饰电极的重现性和稳定性良好,可用于实际样品中亚硝酸盐和亚硫酸盐的同时测定。

牡丹花中不同形态酚类化合物及其抗氧化和α-葡萄糖苷酶抑制活性

对丹凤和香玉两种牡丹花中的游离酚、酯键合态酚、糖苷键合态酚和不溶性结合态酚进行提取,测定不同形态酚类化合物中总酚、总黄酮含量及其主要化合物组成和含量,并对其抗氧化活性和α-葡萄糖苷酶抑制活性进行研究。结果表明,丹凤和香玉牡丹花的游离酚的总酚和总黄酮含量最高,总酚含量分别为31.45、32.64 mg/g,总黄酮含量分别为41.11、40.67 mg/g,其次是酯键合态酚和糖苷键合态酚,不溶性结合态酚含量较低;两种牡丹花游离酚均含有17种成分,其主要成分是白藜芦醇、1,2,3,4,6-O-五没食子酰葡萄糖和大波斯菊苷;酯键合态酚、糖苷键合态酚中主要成分是山柰酚-7-O-β-D-葡萄糖苷和大波斯菊苷。不同形态酚类化合物中游离酚的抗氧化活性最强,丹凤、香玉牡丹花游离酚对1,1-二苯基-2-三硝基苯肼自由基、2,2′-联氮-二(3-乙基苯并噻唑-6-磺酸)阳离子自由基清除能力和铁离子还原能力分别为855.03、367.10、230.54μmol/g和499.06、290.64、196.39μmol/g;丹凤和香玉牡丹花的游离酚对α-葡萄糖苷酶抑制活性最强,半抑制浓度分别为12.15、13.87μg/mL。研究结果对丹凤和香玉多酚利用具有一定的参考价值。

不同加工方式对体外模拟胃肠消化香菇活性物质含量及活性的影响

为研究不同加工方式和处理时间对香菇体外模拟胃肠消化后活性物质含量及体外活性的影响,采用蒸制、煮制、空气炸和烤箱烤制4种方式处理香菇,通过模拟体外胃肠消化后测定消化液中总酚、总黄酮、粗多糖和香菇嘌呤含量及其体外抗氧化、降血脂和降血糖活性,并对消化液的体外活性和活性物质含量相关性进行分析。结果表明,消化前,与蒸制、煮制和空气炸处理相比,烤箱烤制更利于香菇中4种活性物质的保留,其中烤制5 min时总酚、总黄酮和粗多糖的含量和烤制15 min时香菇嘌呤的含量相对较高,分别为(222.13±3.57)mg/g、(4.49±0.06)mg/g、(5.57±0.28)g/100 g和(551.31±3.76)mg/100 g。经体外胃肠消化后,烤箱烤制香菇活性物质释放量相对较高,其次为空气炸。除烤箱烤制香菇总黄酮的释放量随烤制时间延长而降低外,其余活性物质释放量与加工时长无明显相关性。蒸制处理后香菇肠消化液的体外活性相对较高,其中,蒸制20 min的香菇肠消化液1,1-二苯基-2-三硝基苯肼自由基清除率和蒸制10 min的2,2′-联氮-双(3-乙基苯并噻唑啉-6-磺酸)(2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid),ABTS)阳离子自由基清除率最高(P<0.05),分别为(88.74±0.34)%和(50.39±0.07)%;而不同加工方式的香菇肠消化液对α-葡萄糖苷酶抑制率无显著差异(P>0.05);蒸制10 min时肠消化液的胰脂肪酶抑制活性相对较强(P>0.05),为(49.42±2.32)%。相关性分析发现,胃消化液的α-葡萄糖苷酶抑制活性与其总酚(P<0.01)和香菇嘌呤(P<0.05)含量呈显著正相关,ABTS阳离子自由基抑制率与其总酚(P<0.05)和粗多糖(P<0.01)含量呈显著正相关;而肠消化液的胰脂肪酶抑制活性与4种活性物质含量均呈极显著负相关(P<0.01)。综上可以看出烤制更有利于活性物质的保留和消化释放,而蒸制更利于改善香菇肠消化液的体外活性。本研究为香菇科学合理的加工提供了指导。

受阻酚AO-60/天然橡胶复合材料的结构与阻尼性能研究

研究受阻酚AO-60用量对受阻酚AO-60/天然橡胶(NR)复合材料的结构与阻尼性能的影响。结果表明:受阻酚AO-60用量小于50份时,受阻酚AO-60在复合材料中主要形成小型聚集体;随着受阻酚AO-60用量的增大,受阻酚AO-60在复合材料中形成越来越多的大型聚集体;在差示扫描量热分析中,受阻酚AO-60在48和107℃时分别发生无定形态以及晶态转变;在室温下,受阻酚AO-60用量不小于50份的复合材料的损耗因子(tanδ)达到0.2以上,而不加受阻酚AO-60的NR胶料的tanδ仅为0.05;随着受阻酚AO-60用量的增大,复合材料的F_(max)-FL减小,t_(10)和t_(90)明显延长,拉伸强度和撕裂强度减小,受阻酚AO-60用量为50份的复合材料的回弹值最小。综合来看,受阻酚AO-60用量为50份的受阻酚AO-60/NR复合材料的性能最佳。

双缩脲法与福林酚法辨析及应用评价

文章旨在辨析双缩脲法和福林酚法的术语概念,研究改进二者测量血清总蛋白的操作方法,探讨这两种方法检测血清总蛋白含量在教学中的适用性,为临床上对血清总蛋白的检测提供改良思路。通过改进双缩脲法和福林酚法分别对40个健康体检人员的血清进行总蛋白含量测定,并考察标准曲线的精密度、重复性以及加样回收率。结果发现:两种方法检测待测血清样品中总蛋白含量与医院检测结果基本一致。可见,两种方法均适用于血清总蛋白含量的测定。由于双缩脲法检测时间短、操作简单,比福林酚法更适用于实验教学,值得进一步推广。

吐鲁番9个产地无核白葡萄干品质及多酚代谢组分析

以吐鲁番9个产地无核白葡萄干为研究对象,分析比较不同产区间葡萄干品质、抗氧化活性差异,采用超高效液相色谱-串联质谱法测定葡萄干酚类组分和含量。结果表明,平均葡萄干单粒质量和果形指数最大的是连木沁,分别为0.81 g、2.74,平均单粒质量和果形指数最小的是高昌区,分别为0.46 g、2.27。园艺场葡萄干固酸比最高,为29.34,七克台葡萄干固酸比最低,为25.74。连木沁葡萄干a*值最低,ΔE较低,分别为2.56和44.94,表明其葡萄干颜色最绿;园艺场葡萄干a*值较低,ΔE最低,分别为2.94和44.19,这两个产区内葡萄干颜色偏绿且颜色一致性最好。对6个产区无核白葡萄干检测到的518种单体酚进行分类,可分为5大类:黄酮275种,占53.09%;酚酸136种,占26.25%;木脂素和香豆素60种,占11.58%;单宁19种,占3.67%;其他类(茋类)28种,占5.41%。鲁克沁和高昌区、七克台和胜金乡、园艺场和连木沁3组共筛选到246个差异代谢物,分别包含124、144、66个差异代谢物,各有54、92、22个特有差异代谢物,这3组之间有10个共同差异代谢物。上述结果表明,连木沁和园艺场可作为无核白葡萄干的优势产区。

In vitro total phenolics,flavonoids contents and antioxidant activity of essential oil,various organic extracts from the leaves of tropical medicinal plant Tetrastigma from Sabah

Objective:To detect the in vitro total phenolics,flavonoids contents and antioxidant activity of essential oil,various organic extracts from the leaves of tropical medicinal plant Tetrastigma from Sabah.Methods:The dry powder leaves of Tetrastigma were extracted with different organic solvent such as hexane.ethyl acetate,chloroform,butanol and aqueous methanol.The total phenolic and total flavonoids contents of the essential oil and various organic extracts such as hexane,ethyl acetate,chloroform,butanol and aqueous ethanol were determined by Folin-Ciocalteu method and the assayed antioxidant activity was determined in vitro models such as antioxidant capacity by radical scavenging activity usingα,α-diphenyl-β-picrylhydrazyl (DPPH) method.Results:The total phenolic contents of the essential oil and different extracts as gallic acid equivalents were found to be highest in methanol extract(386.22 mg/g) followed by ethyl acetate(190.89 mg/g).chloroform(175.89 mg/g).hexane(173.44 mg/g).and Imtanol extract (131.72 mg/g) and the phenolic contents not detected in essential oil.The antioxidant capacity of the essential oil and different extracts as ascorbic acid standard was in the order of methanol extract】ethyl acetate extract】chloroform】butanol】hexane extract also the antioxidant activity was not detected in essential oil.Conclusions:The findings show that the extent of antioxidant activity of the essential oil and all extracts are in accordance with the amount of phenolics present in that extract.Leaves of Tetrastigma being rich in phenolics may provide a good source of antioxidant.

Correlation Between Antioxidation and the Content of Total Phenolics and Anthocyanin in Black Soybean Accessions

The objective of this study was to investigate the correlations between antioxidations and the contents of the total phenolics and anthocyanin in 127 accessions of black soybean. A T-test, a fast clustering procedure, and a correlation coefficient analysis were used for experimentation. The variation ranges of the total antioxidant capacity （TAC）, the total phenolics, and anthocyanin contents in 127 black soybean accessions were 0.44-3.56, 7.05-74.82, and 0.22-1.87 mg g-l, respectively, displaying significant genotype differences. The major differences in TAC, the total phenolics, and the anthocyanin contents existed among various types of accessions from geographical regions. The differences between the accessions from black and yellow soybeans, spring and autumn, summer and autumn, Dongbeichun and Nanfangchun, Dongbeichun and Nanfangxia, Beifangchun and Nanfangchun, and Beifangchun and Nanfangxia were significant at 0.01 or 0.05 levels, respectively. The general tendency was that the TAC, the total phenolics, and the anthocyanin contents of Beifangchun accessions were higher than that of Dongbeichun ones, while that of Nanfangchun accessions were the worst. 127 black soybean accessions could be clustered into 6 clusters, which consisted of 3, 24, 20, 31, 37, and 12 accessions, respectively. The most significant （P 〈 0.01） correlations existed respectively between the TAC and the total showed that the total substances phenolics content, and the TAC and the anthocyanin content of black soybean. The results phenolics and anthocyanin in black soybean seed coat were the important antioxidation

Identification and characterization of phenolics and terpenoids from ethanolic extracts of Phyllanthus species by HPLC-ESI-QTOF-MS/MS

Phyllanthus species plants are a rich source of phenolics and widely used due to their medicinal properties. A liquid chromatography–tandem mass spectrometry(LC–MS/MS) method was developed using high-pressure liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry(HPLC-ESI-QTOFMS/MS) for the identification and characterization of quercetin, kaempferol, ellagic acid and their derivatives in ethanolic extracts of Phyllanthus species. The chromatographic separation was carried out on Thermo Betasil C_8 column(250 mm×4.5 mm, 5 μm) using 0.1% formic acid in water and 0.1% formic acid in methanol as the mobile phase. The identification of diagnostic fragment ions and optimization of collision energies were carried out using 21 reference standards. Totally 51 compounds were identified which include 21 compounds identified and characterized unambiguously by comparison with their authentic standards and the remaining 30 were tentatively identified and characterized in ethanolic extracts of P. emblica, P. fraternus, P. amarus and P.niruri.

Gradient nanoporous phenolics as substrates for high-flux nanofiltration membranes by layer-by-layer assembly of polyelectrolytes

Thin film composite(TFC) membranes represent a highly promising platform for efficient nanofiltration(NF)processes. However, the improvement in permeance is impeded by the substrates with low permeances. Herein,highly permeable gradient phenolic membranes with tight selectivity are used as substrates to prepare TFC membranes with high permeances by the layer-by-layer assembly method. The negatively charged phenolic substrates are alternately assembled with polycation polyethylenimine(PEI) and polyanion poly(acrylic acid)(PAA)as a result of electrostatic interactions, forming thin and compact PEI/PAA layers tightly attached to the substrate surface. Benefiting from the high permeances and tight surface pores of the gradient nanoporous structures of the substrates, the produced PEI/PAA membranes exhibit a permeance up to 506 L? m-2?h-1?MPa-1, which is ~2–10 times higher than that of other membranes with similar rejections. The PEI/PAA membranes are capable of retaining N 96.1% of negatively charged dyes following the mechanism of electrostatic repulsion. We demonstrate that the membranes can also separate positively and neutrally charged dyes from water via other mechanisms.This work opens a new avenue for the design and preparation of high-flux NF membranes, which is also applicable to enhance the permeance of other TFC membranes.

GC-MS analysis,determination of total phenolics,flavonoid content and free radical scavenging activities of various crude extracts of Moringa peregrina(Forssk.) Fiori leaves

Objective:To perform phytochemical screening,estimate total phenolics,flavonoids and to evaluate antioxidant potential of Moringa peregrina(M.peregrina) leaves.Methods:The dried powdered leaves of M.peregrina(150 g) were extracted exhaustively by Soxhlet with ethanol and then fractionated into hexane,chloroform,ethy alacetate and methanol.All the prepared extracts were also analyzed by gas chromatography-mass spectrometry to identify and characterize the chemical compounds present in the crude extracts.Folin- Ciocalteu reagent and aluminium chloride colorimetric methods were used to estimate total phenolic and flavonoid content of extracts.Hydrogen peroxide and 1,1 diphenyl-2-picrylhydrazyl were used to determine in vitro antioxidant activity.Results:Phytochemical analysis of ethanol extract showed presence of major classes of phytochemicals.Gas chromatography-mass spectrometry results revealed presence of 19 phytoconstituents in hexane extract,6 in ethyl acetate and 7 compounds in methanolic extract.Methanol extract was found to contain the highest phenolic content and flavonoids.In vitro antioxidant activities of all crude extracts were significant and comparable with the standard ascorbic acid.Conclusions:Results of this study show that the leaves of M.peregrina are the rich source of phenolic compounds that can play an important role in preventing the progression of many diseases.

The hypoglycemic potential of phenolics from functional foods and their mechanisms

Long-term postprandial hyperglycemia is a primary risk factor for developing chronic metabolic diseases such as obesity,type 2 diabetes,and cardiovascular disease.Chronic hyperglycemia induces the glycation of proteins,oxidative stress,inflammation and increases plasma insulin and lipid concentrations.Insulin resistance is the primary cause of postprandial excursions of blood glucose and lipids.Hyperglycemia can be treated by lowering dietary carbohydrates intake,digestion,and absorption.Various functional foods improve glucose metabolism by increasing insulin sensitivity and inhibitingα-glucosidase in the small intestine.Natural phytochemicals,especially active phenolics are good antioxidants and show anti-inflammatory action and regulate blood glucose.This review aimed to report on hypoglycemic properties of active phenolics from functional foods and their proposed anti-diabetic mechanisms.Nevertheless,further clinical trials are required to confirm the bioavailability,safety,and efficacy of phenolics,especially the dosage and duration of treatment,to avoid adverse effects and give better dietary recommendations.

Phenolics,tannins,flavonoids and anthocyanins contents influenced antioxidant and anticancer activities of Rubus fruits from Western Ghats,India

Rubus fruits are rich in nutrition with a wide range of phytochemical and consumed by humans,but many of its wild varieties are not commercially useful.Phytochemical exploration of these wild fruits could improve the commercial usage of these Rubus species.This study focuses to analyze the phytochemical,antioxidant and cytotoxicity of three wild Rubus ellipticus,R.niveus and R.fairholmianus fruits comparatively,which has not revealed.The in vitro antioxidant studies indicated the ethyl acetate and methanol extracts of studied Rubus species competent in scavenging different stable and generated radical.The correlation and regression analysis also statistically supported the contents in the extracts could act against various radicals.Correlation between phytochemical constituent and radical scavenging activity found to be highly positive.The results acquired from this investigation revealed that they are equally competent and could be recommended as dietary supplements or as nutraceuticals.

Chemical Composition, Phenolics, Anthocyanins Concentration and Antioxidant Activity of Ten Wild Edible Plants

Plants were collected and prepared for chemical analysis, total phenolics, anthocyanins concentrations, and free radical scavenging activity. Results showed that, protein concentration of Malva parviflora (22.9%) was the highest among the plants. Ruta chalepensis had high levels of fat and carbohydrates (4.2% and 51.7%, respectively), but had the lowest level of ash (8.7%). Mineral concentrations varied and found to have appreciable amounts of Ca, Na, K, Cu, Fe, Mg, Mn, Zn and P. Total phenolic ranged from 163.1 (Tetragonolobus palaestinus) to 1328.8 mg GAE/100g (Ruta chalepensis). Anthocyanins ranged between 18.1 (Gundelia tournefortii) and 100.1 mg/100g (Rumex acetosella). These plants differed in free radical scavenging activity. It was concluded that these plants could be considered as natural sources for antioxidants and valuable natural resources as a new addition to the diet of inhabitants.

Role of phenolics as antioxidants,biomolecule protectors and as anti-diabetic factors-Evaluation on bark and empty pods of Acacia auriculiformis

Objective:To search for an efficient and inexpensive source of phytoconstituents with antioxidant potential and health promoting traits from bark and empty pods of Acacia auriculiformis （A.auriculiformis）.Methods:Samples of bark and empty pod extracts were analyzed for bioactives（phenolics,flavonoids and proanthocyanidins） and subjected to free radical scavenging activity on DPPH*,ABTS?,OH?,O2*,and NO along with the determination of reducing power, iron chelating activity and peroxidation inhibition.Defensive action of extracts on biomolecules and cell membranes were evaluated by DNA nicking assay and haemolysis inhibition assay respectively,α-amylase andα-glucosidase inhibitory potentials were also determined. Results:All the bioactives analyzed were higher in bark（B） than empty pods（EP）[TPC:B （574.51±16.11）;EP（96.80±3.45） mg GAE/g.TFC:B（94.71±7.65）;EP（24（?）87±20.45） mg RE/g. Proanthocyanidins:B（2.81±0.31）;EP（1.25±0.01） mg LE/100 g DM]except flavonoids.Both the extracts showed higher quenching capacity on DPPH and ABTS（DPPH:B（0.21±0.01）;EP（1.51±0.17） g extract/g DPPH.ABTS:B（111 519.14±79 340.91）;EP（80 232.55±32 894.12） mmol TE/g） with the FRAP of B（84 515.63±3 350.69） and EP（47 940.79±1 257.60） mmol Fe（（?））/g.Iron chelation was not observed.In addition,they showed lower quenching activity on OH?（B（48.95±1.72）;EP（34.94±1.62）%） and equivalent quenching on O2?（B（53.47±3.92）;EP（24.41±2.61）%）,NO（B（49.04±5.04）; EP（51.00±5.13）%）,peroxidation inhibition（B（67.50±5.50）;EP（55.l±2.3）%） and antihaemolytic potential（B（87.60±6.84）%） towards authentic antioxidant standards.Interestingly,Empty pod extracts are devoid of antihaemolytic activity.Both the extracts showed dose dependent DNA protection.Besides this,bark and empty pod extracts exhibited dual inhibiting potential againstα-amylase andα-glucosidase enzymes.Conclusions:On summarization,it insinuated that both bark and empty pods can be used for the preparation of antioxidant/nutraceutical supplements and in anti-diabetic formulations.

Evaluation of Standards and Interfering Compounds in the Determination of Phenolics by Folin-Ciocalteu Assay Method for Effective Bioprocessing of Biomass

Folin Ciocalteu (F-C) assay is the most widely used and convenient method to determine the total phenolics content in foods, herbs, and other plant extracts. Different phenolics standards such as gallic acid, ferulic acid, chlorogenic acid, catechol, and vanillic acid have been used for calibration curves in this assay method. Comparison of these standards, in single or combination of two or more, for more accurate determination of phenolics has not been reported so far. This study tested five single phenolics and seven combinations of mixed phenolic standards to evaluate the optimal standards for F-C method. The different standards were tested to calculate the phenolic content in three known test solutions. We also evaluated interference effect of various compounds in phenolics estimation by F-C method that is usually present in the lignocellulosic biomass-derived sugar solution, and in food products along with phenolics. Finally, the optimal standards with five phenolics were used for the determination of phenolics in alkali pretreated biomass extract. The results indicated that gallic acid was the best standard among the single phenolic compounds and five phenolic compounds solution was the best standard among the mixed phenolic solutions. The presence of glucose, HMF, furfural, and vitamin-B12 did not interfere in phenolic determination;whereas ascorbic acid, tyrosine, formic acid, and acetic acid strongly interfered the results. The results also showed that biomass pelleting process did not affect the generation of phenolics in alkali pretreatment extract.

Enzymes inhibitory property,antioxidant activity and phenolics profile of raw and roasted red sorghum grains in vitro

Whole grain cereals are important dietary sources for management of metabolic diseases due to the bioactive components they contain.Hence,this study investigated enzymes(pancreatic lipase,-amylase,-glucosidase,xanthine oxidase and angiotensin 1-converting enzyme)inhibitory property,antioxidant activity and phenolics profile of raw and roasted red sorghum(Sorghum bicolor)grains in vitro.Extracts of flours of raw and roasted(150◦C and 180◦C,for 20 min)grains were assayed for enzymes inhibitory and antioxidant activities using spectrophotometric methods;while their phenolic constituents were characterized using HPLC-DAD.The raw grains exhibited strong enzymes inhibitory and antioxidant activities,and contained phenolic acids(gallic,chlorogenic,caffeic,ellagic and p-coumaric acids)and flavonoids(quercetin,luteolin and apigenin).However,whereas the enzymes inhibitory activity and levels of the phenolic compounds in the grains decreased significantly(p<0.05)with increasing roasting temperature,the antioxidant activity increased.Hence,roasting at high temperature may not be recommended for the optimum retention of the enzymes inhibitory property and phenolic compounds of red sorghum grains.

Studies on Changes of Phenolics in the Apple Fruit Peel in Response to Light Intensity

Fruits from 9-year-old apple trees (Malus domestic Borkh. cv. Fuji) were wrapped by two-layerbag in middle of June, and bags were removed in middle of September. The bag-removed treatmentwas performed in following three ways: once-removing all inner and outer bags; twice-removingbag (removing inner bag 3 d after removing outer bag); dipping 5 s in 1 mM salicylic acid (SA)after once-removing all bags. Changes of phenolic compounds in fruit peel in response to lightenvironment were studied before or after removing bag. The results showed that the baggedtreatment could significantly decrease the contents of UV (ultraviolet)absorbing compounds,rutin and anthocyanins of the fruit peel, but increased chlorogenic acid level. After removalof bag, the level of SA and quercetin in the fruit peel appeared peak 1 d after bag-removed,except that quercetin was decreased in SA-treated fruits. UV absorbing compounds, anthocyaninsand rutin were kept increasing all along after the removal of bag, except that chlorogenic acidwas decreased during being retained inner bag in the treatment of twice removing bag. Thepositive correlations existed between changes of UV absorbing compounds and changes ofanthocyanins or rutin. It was suggested that light played an important role in phenolicsmetabolism.