航天搭载后福橘(Citrus reticulata Blanco)茎尖无性系有丝分裂行为和细胞超微结构的变化

福橘(Citrus reticulata Blanco)茎尖经‘实践八号’育种卫星搭载后,经组织培养获得其再生植株,以此为材料,结合常规压片法与超薄切片技术,研究航天搭载对福橘当代无性系细胞有丝分裂行为及细胞超微结构的影响。结果表明:航天搭载对福橘茎尖具有诱变作用,所得13个诱变无性系中,有丝分裂过程存在不同程度的异常,其中‘08004’无性系植株的有丝分裂畸变率明显高于其他无性系:中期染色体数目异常畸变率为0.34%,落后染色体畸变率为0.69%,微核畸变率为0.86%;并且有丝分裂过程中纺锤体结构发生异常,可见C-形(0.17%)或S-形纺锤体(1.20%),细胞发生多极分裂(1.03%)。绝大多数航天搭载当代无性系的细胞超微结构正常。‘08004’无性系植株叶肉细胞超微结构呈现细胞程序性死亡(PCD)典型特征:细胞核内染色质凝集;叶绿体类囊体结构解体;出现自体吞噬小体;细胞液泡化并发生质壁分离,最终形成凋亡小体。PCD过程中,线粒体保持其结构完整性,直至PCD末期才发生结构变化。

Crc1,6RhaT is involved in the synthesis of hesperidin of the main bioactive substance in the Citrus reticulata ‘Chachi' fruit

Hesperidin is a dihydroflavonoids, accounting for more than 50% of the total flavonoids in Citri Reticulatae Pericarpium(CRP) of traditional Chinese medicine. It is an effective antioxidant and free radical scavenger that has anti-inflammatory, antiviral and hypoglycemic properties.The latest studies reported that hesperidin has a potential for novel coronavirus resistance. However, little is known about the synthesis regulation and accumulation site of hesperidin in plants. In this study, hesperidin synthase gene Crc1,6RhaT was cloned, and the protein can be completely transformed flavanone-7-O-glucoside into hesperidin in vitro and in vivo. Studies on biological characteristics of ovary walls and exocarps showed that the relative expression levels of the Crc1,6RhaT gene and protein decreased gradually with the development of citrus fruits, and the relative content of hesperidin firstly increased, then sequentially decreased. In situ hybridization results further revealed that Crc1,6RhaT transcription was mainly concentrated in the secretory cavity cells, which are revealed to be the site of flavonoid synthesis.Immunocytochemistry localization results showed that the Crc1,6RhaT was mainly located in the endoplasmic reticulum, nucleus and vacuole of secretory cells. We inferred that the Crc1,6RhaT was synthesized in the endoplasmic reticulum, then was transported into the vacuoles through enlarged vesicles at the end of the endoplasmic reticulum. Our results not only revealed that Crc1,6RhaT may be involved in the synthesis of hesperidin of the main bioactive substance in the medicinal plant Citrus reticulata ‘Chachi' fruit, but also provided novel insights into the main subcellular sites of hesperidin biosynthesis in vacuoles.

Manual thinning increases fruit size and sugar content of Citrus reticulata Blanco and affects hormone synthesis and sugar transporter activity

Manual fruit thinning(MFT)in fruit trees has been previously shown to increase fruit size and enhance fruit quality,but the effect of MFT on Ponkan(Citrus reticulata Blanco)and the underlying mechanisms remain poorly understood.In this study,efforts were made to elucidate how MFT influences the fruit quality of Ponkan.The results showed that MFT substantially increased fruit size and elevated fruit total soluble solids in comparison with the fruit from the unthinned trees(used as control).Expression analyses demonstrated that m RNA abundance of three important sugar transporter genes,including CrSUT1,CrSTP1 and CrTMT1,was evidently elevated in the flesh of thinned fruit when compared with those of the control.In addition,MFT prominently up-regulated the transcript levels of various auxin and gibberellin(GA)biosynthesis and signaling genes,including CrYUC6,CrAUX/IAA,CrGA20ox1 and CrGA3ox1.Concurrently,the contents of endogenous IAA and GA3,measured at 90 d after fruit thinning,were notably elevated in the fruit from trees with the thinning treatment relative to the control,although no difference was detected in the two groups before the thinning manipulation.Taken together,these results indicate that manual fruit thinning could greatly improve fruit quality,which may be attributed to promoting fruit expansion due to the increased auxin levels and expediting sugar accumulation through the up-regulation of sugar transporter genes.

农杆菌对蕉柑(Citrusreticulata var.tankan Hayata)胚性细胞的附着研究

农杆菌能够附着蕉柑的胚性细胞。农杆菌对蕉柑胚性细胞的附着曲线表明 ,农杆菌与蕉柑胚性细胞之间的附着是一个动态过程。农杆菌在蕉柑胚性细胞上的附着量受共培养介质中乙酰丁香酮 (As)和表面活性物质影响较小 。

An Efficient Regeneration System for Native Orange (<i>Citrus reticulata</i>) through <i>In-Vitro</i>Culture Technique

Citrus reticulata (Mandarin Orange), commonly known as “Sweet Orange”, is one of the most difficult plants to improve through traditional breeding approaches as it poses various biological limitations that greatly hinder the cultivar improvement. In the present study, using the fresh seed of native orange as explant, an efficient, reproducible, regeneration method was developed through in vitro organogenesis. Mature, healthy and dehusked seeds were treated with Murashige and Skoog, (MS) media containing 3% sucrose, 0.7% agar supplemented with different concentrations and combinations of phytohormones. The highest calli initiation (93.3% ± 0.5%) responses were observed on MS medium supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D) at 3.0 mg/L followed by 2,4-D at 3.5 mg/L (86.7% ± 1.75%) in this experiment. Maximum shoot regeneration (86.7% ± 3.35%) responses were reported using MS medium supplemented with the combination of 6-benzylaminopurine (BAP) at 3.0 mg/L and 1-naphthaleneacetic acid (NAA) at 2.0 mg/L. MS medium supplemented with NAA at 1.0 mg/L showed the best rooting (80% ± 2.89%) response in comparison to (70% ± 5.20%) indole-3-butyric acid (IBA) at 1.0 mg/L. The regenerated plantlets were acclimatized in pots containing sterile garden soil mixture to examine their response in natural conditions.

Effects of Storage and Preservation of Postharvest Gonggan Mandarin(Citrus reticulata)Fruit Immersion in Salicylic Acid Combined with Calcium Chloride

[Objectives]To investigate the effects and mechanism of fruit immersion treatment with salicylic acid(SA),calcium chloride(CaCl_(2))solutions at different concentrations or their combinations on post-harvest preservation of Gonggan Mandarin(Citrus reticulata)fruit.[Methods]13 experiments(2 storage temperatures,3 control treatments,3 concentrations of SA solution,4 concentrations of CaCl_(2) solution and 3 combinations of SA+CaCl_(2) solution for fruit immersion treatment)were conducted for 90 d.Gonggan fruit weight loss rate,rotting rate,disease index,disease type,soluble solids and organic acids content,and the differences in the activity of six enzymes(APX,PPO,CHI,CAT,SOD,PAL)related to fruit disease resistance were detected regularly.[Results]With the increase of storage days,the weight loss rate,rotting rate and disease index increased,the content of soluble solids and organic acids decreased,the activity of APX,PPO,CHI and SOD increased,and the activity of CAT and PAL decreased.However,the increase or decrease of fruit loss at low temperature was the smallest,and the increase or decrease of fruit at natural room temperature was the largest.Gonggan fruit cleaning before storage is an effective preservation and fresh-keeping technology,but its preservation and fresh-keeping effect is far less than that of fruit immersion by SA,CaCl_(2) and SA+CaCl_(2) compound solution.The effect of fruit immersion by SA solution was greater than that of fruit immersion by CaCl_(2) solution;the best concentration of SA alone was 6.0 mmol/L,which was not significantly different from 3.0 mmol/L,but the effect of 9.0 mmol/L decreased;the best concentration of CaCl_(2) alone was 6.0 mmol/L,which was significantly better than 3.0 and 9.0 mmol/L;the optimal concentration combination of SA+CaCl_(2) compound solution for fruit immersion treatment was 6.0 mmol/L SA+3.0 mmol/L CaCl_(2).[Conclusions]The fruit immersion by SA,CaCl_(2) and their compound solutions induced the increase of activity of six enzymes related to disease resistance in Gonggan fruit,and PPO and CHI were judged to be two key enzymes based on response intensity.

Evaluation of thermotherapy against Huanglongbing (citrus greening) in the greenhouse

Huanglongbing （HLB, or citrus greening） is the most destructive disease of citrus, which is associated with Candidatus Liberibacter asiaticus （Las）. Few management options are available, aside from preventive measures such as removing infected plants, planting disease-free seedlings, and managing the insect vector. In this study, we assessed the efficacy of thermotherapy against HLB under controlled greenhouse conditions. A total of 60 two-year-old, graft-infected Citrus reticulata Blanco plants were used. The plants were randomly divided into three groups （45℃, 48℃, and untreated control）, with five plants/replicate （rep） and four reps/treatment. The treated plants were placed in phytotrons for a 4-h treatment session, repeated once per week for three consecutive weeks. Disease remission was observed eight weeks post-treatment. Real-time PCR assays revealed that Las titers in HLB-affected seedlings were significantly reduced in both 45 and 48℃ treatments four weeks after treatment, with the exception of eight plants. In contrast, Las titers in the untreated control plants increased significantly during the same period, with a maximum increase of 28-fold. Except for seven plants, Las titers in the new flushes of treated plants decreased more than 90% eight weeks after treatment. Las titers in mature leaves of treated plants decreased 56 and 60% in average at 45 and 48℃, respectively, eight weeks after treatment. The HLB symptoms and Las titer of seedings were markedly alleviated eight weeks after treatment in both 45 and 48℃ treatments. Our results laid a good foundation for the further development of citrus free-disease seedling cultivation and Huanglongbing control in the field. The whole plants were replaced for scion or branch in previous as the research object in this study, and the expression of Huanglongbing symptoms combined with real-time polymerase chain reaction （PCR） were used to evaluate the effect of heat treatment in the greenhouse.

“Carnauba Citrus”果蜡与“仙亮”果蜡对芦柑保鲜效应的比较

研究了室温条件下澳大利亚果蜡"Carnauba Citrus"与美国"仙亮"果蜡对芦柑保鲜效应的差异,结果表明:2种果蜡均能减少芦柑维生素C和总酸的损耗,降低果实的失重率,但对总可溶性固形物和总糖的影响都不明显;除此之外,"Carnauba Citrus"比"仙亮"更能保持果实外观品质及风味,可有效延长保鲜时间。

Citrus reticulata Blanco (the common mandarin) fruit:An updated review of its bioactive,extraction types,food quality,therapeutic merits,and bio-waste valorization practices to maximize its economic value

Fruits are regarded as the richest dietary sources of polyphenols,carotenoids,terpenoids,and limonoids,making them highly desired prospects for the functional food industry.Citrus waste that remains after fruit processing is also regarded as a valuable source of value-added phytochemicals.A comprehensive analysis of mandarin composition as a determinant of fruit functional properties,health benefits,and valorization into useful products is represented together with the effect of different processes such as light,wax coating,auxin addition,ozone treatment,and ethylene degreening.Such reviewing evidence is an essential precondition for improving the selling market of mandarin and highlighting its waste valorization potential and its incorporation into useful products produced by pharmaceutical industries.In this study,the phytochemical and biological reports presented to emphasize the needed priority for agricultural techniques to provide a certain mandarin product or trait.In addition,the paper summarizes the optimum conditions applied for the updated extraction techniques for phenolic acids,flavonoids,and oils at a commercial scale from mandarin peels and to enhance its global marketing.A brief representation is given towards potential mandarin patents and the valorization of its bio-waste fruits into commercial products of added value.The review can guide researchers to produce future potentially marketed functional food enriched with mandarin extracts and/or bioactives.

Molecular Characterization and Expression Analysis of S1 self-incompatibility Locus-linked Pollen 3.15 Gene in Citrus reticulata

Gametophytic self-incompatibility （GSI） is controlled by a highly polymorphic locus called the S-locus, which is an important factor that can result in seedless fruit in Citrus. The S 1 self-incompatibility locus-linked pollen 3.15 gene （S1-3.15） belongs to a type of S locus gene. The role of S1-3.15 in the SI reaction of Citrus has not yet been reported. In this study, full-length sequences of cDNA and DNA encoding the S1-3.15 gene, referred to as CrS1-3.15 , were isolated from ‘Wuzishatangju’ （Self-incompatibility, SI） and ‘Shatangju’ （Self-compatibility, SC） . The predicted amino acid sequences of CrS1-3.15 between ‘Wuzishatangju’ and ‘Shatangju’ differ by only three amino acids. Compared to ‘Wuzishatangju’, three bases were substituted in the genomic DNA of CrS1-3.15 from ‘Shatangju’. Southern blot results showed that one copy of CrS1-3.15 existed in the genomic DNA of both ‘Wuzishatangju’ and ‘Shatangju’. The expression level of the CrS1-3.15 gene in the ovaries of ‘Shatangju’ was approximately 60-fold higher than that in the ovaries of ‘Wuzishatangju’. When ‘Wuzishatangju’ was cross-pollinated, the expression of CrS1-3.15 was upregulated in the ovaries at 3d, and the highest expression levels were detected in the ovaries at 6d after cross-pollination of ‘Wuzishatangju’ × ‘Shatangju’. To obtain the CrS1-3.15 protein, the full-length cDNA of CrS1-3.15 genes from ‘Wuzishatangju’ and ‘Shatangju’ was successfully expressed in Pichia pastoris. Pollen germination frequency of ‘Wuzishatangju’ was inhibited significantly with increasing CrS1-3.15 protein concentrations from SI ‘Wuzishatangju’.

沃柑混倍体新种质的鉴定及评价

【目的】鉴定和评价沃柑变异材料,为利用提供依据。【方法】采用流式细胞仪、石蜡切片和扫描电镜方法进行倍性和叶片显微结构鉴定,比较形态特征和果实品质。【结果】变异材料为二、四混倍体(2x+4x),倍性细胞比例为2x∶4x=39.1∶60.9;混倍体的叶片长、宽、周长和面积比二倍体显著增加14.75%、31.01%、19.38%和46.09%,叶形指数显著减小12.61%;两者均为两性花,花瓣数、花瓣颜色、花丝离合状态和花柱状态相同,花瓣长度和宽度均显著大于二倍体;种子均为单胚类型,单粒质量、横径和纵径较二倍体分别显著增加30.77%、8.12%和26.64%;单果质量、纵径、横径、果形指数、果皮厚度和果实硬度比二倍体分别显著增加29.67%、13.38%、8.57%、3.85%、38.31%和16.37%,单果种子数显著减少61.68%;可溶性固形物和可滴定酸含量无显著差异,可食率显著降低,出汁率高,维生素C含量显著增加39.70%;叶片、下表皮、栅栏组织和海绵组织厚度较二倍体分别显著增加19.75%、10.10%、9.38%和43.92%,气孔长度和密度分别显著减小7.36%和15.76%,气孔宽度显著增加5.09%。【结论】鉴定获得了沃柑二、四混倍体新种质,与二倍体在形态特征、果实品质及叶片显微结构等方面存在较大差异。

不同配比陈皮-蜜橘皮茶汤品质分析

为了解陈皮、蜜橘皮以及两者不同配比合煎所得茶汤的汤色、风味感官以及活性成分等品质变化规律,以10年新会陈皮、温州蜜橘皮为研究对象,采用高效液相色谱法测定茶汤中的主要黄酮类化合物,顶空固相微萃取结合气相色谱-质谱联用技术测定其挥发性成分。结果表明,陈皮茶汤的感官评价综合得分、总黄酮、川陈皮素、橘皮素、总酚含量和抗氧化能力(DPPH法、ABTS法、FRAP法)均显著高于蜜橘皮茶汤,而蜜橘皮茶汤的橙皮苷和香蜂草苷含量显著高于陈皮茶汤;陈皮茶汤的主要挥发性成分是2-(甲氨基)苯甲酸甲酯、(-)-4-萜品醇、百里醌等,蜜橘皮茶汤的主要挥发性成分是(1 R,5 R)-rel-香芹醇、4-乙烯基-2-甲氧基苯酚、芳樟醇等;陈皮-蜜橘皮的不同质量比(5∶5、3∶7、2∶8、1∶9)茶汤中,随着陈皮比例的下降,除橙皮苷和香蜂草苷含量之外,其余相应的活性成分含量和抗氧化能力均随之降低,其中5∶5能够全面地凸显两者的优点。该研究明确了新会陈皮、温州蜜橘皮以及两者不同配比茶汤的品质变化规律,为陈皮、蜜橘皮的综合利用及精深加工提供理论基础。

陈皮精油对脂多糖诱导的RAW264.7细胞炎症的干预作用

基于脂多糖(lipopolysaccharide,LPS)诱导的RAW264.7细胞模型研究陈皮精油抗炎作用。通过Griess法检测一氧化氮(nitric oxide,NO)分泌水平,采用Real-time PCR法检测细胞中肿瘤坏死因子(tumor necrosis factorα,TNF-α)、白细胞介素6(interleukin-6,IL-6)、白细胞介素1β(interleukin-1β,IL-1β)和诱导型一氧化氮合酶(inducible nitric oxide synthase,iNOS)、环氧化酶2(cyclooxygenase 2,COX-2)mRNA的表达水平。结果显示,陈皮精油显著降低LPS诱导的RAW264.7细胞释放NO的含量,抑制iNOS、COX-2、IL-1β、IL-6和TNF-αmRNA的表达。综上所述,陈皮精油通过抑制炎症因子的分泌和表达,有效缓解由LPS诱导RAW264.7细胞炎症反应。

基于模糊建模解析不同产地沃柑果实感官品质差异

【目的】果实感官品质是决定果品市场竞争力最重要的因素,建立科学的柑橘果实综合感官品质评价方法,明确不同产地柑橘果实感官品质差异,探究消费者偏好性,筛选与柑橘感官属性密切相关的代谢产物,为柑橘育种、实际生产及市场销售提供理论支撑和数字化方法。【方法】以具有品质差异的9个产区沃柑果实为试验材料,首先组织评价员对样品各感官属性及权重进行评价,利用模糊数学得出不同感官属性的权重排名,并对不同产地样品的综合感官品质进行排序及分组;同时,检测常规理化指标,并通过气相色谱质谱联用仪(gas chromatography-massspectrometry,GC-MS)和高效液相色谱(high performance liquid chromatography,HPLC)分析与果实风味相关的可溶性糖、有机酸、氨基酸、类黄酮等代谢产物;进而利用OPLS-DA分析不同组间样品的主要差异代谢物,并通过皮尔逊相关性分析将样品各感官属性与相关代谢物质数据进行关联;最终获得可反映沃柑风味品质的重要代谢标志物。【结果】沃柑感官属性权重排名为果肉甜度>果肉酸度>果肉化渣性>果实色泽>果实香气>果实外形;常规指标固酸比不适合用于沃柑果实样品内在品质优劣的精准分级。因此,基于综合感官品质差异,9个产地沃柑样品被划分为两组,高感官品质组沃柑样品综合得分均高于60分,低感官品质组综合得分均低于60分。OPLS-DA分析表明,3种主要差异代谢产物可在风味上显著区分高、低感官品质组沃柑样品,这些物质分别为L-谷氨酸、橙皮苷和L-缬氨酸。皮尔逊相关性分析表明,α-酮戊二酸、L-谷氨酸和橙皮苷含量与沃柑综合感官品质、甜度和酸度得分多呈显著负相关。【结论】模糊数学可用于沃柑果实综合品质评价,消费者对沃柑的果肉甜度和酸度更为关注,L-谷氨酸和橙皮苷对沃柑果实品质差异的形成具有重要作用。

咪鲜胺和百可得对南丰蜜橘保鲜效果的协同效应

为探究咪鲜胺和百可得复配浸果对南丰蜜橘的保鲜效果,本研究采用咪鲜胺(P)、百可得(B)及“咪鲜胺+百可得”(PB)处理南丰蜜橘,以清水浸泡为对照(CK),分别在室温贮藏(R)及4℃冷藏(C)下,每隔7 d测定南丰蜜橘的腐烂率、失重率及内在品质指标。结果表明,与CK相比,贮藏期内P、B及PB处理后的腐烂率及失重率均显著降低,室温贮藏下腐烂率分别平均降低10.8、7.9及12.4个百分点,失重率分别平均降低8.1、6.3及7.2个百分点;而冷藏下腐烂率分别平均降低3.5、1.8及4.5个百分点,失重率分别平均降低4.0、1.1及5.2个百分点。室温下经P与B处理后,维生素C及可溶性固形物含量总体高于CK及PB处理;可溶性总糖含量、糖酸比及固酸比均表现为P处理最高、B处理较低,PB及CK处理介于二者之间;可滴定酸含量与可溶性总糖含量、糖酸比及固酸比的变化规律相反。冷藏条件下经P、B及PB处理后,内在品质指标的总体变化规律不明显。综上,室温贮藏或冷藏下单一使用咪鲜胺或百可得均能显著提升采后保鲜效果,二者结合使用可协同延长货架期,其中室温下单一使用咪鲜胺果品更佳,而冷藏下药剂处理对果品无不利影响。本研究为咪鲜胺和百可得的保鲜机理及南丰蜜橘采后保鲜研究提供了理论支持。

广西壮族自治区柑橘园杂草物种多样性及其影响因素

以广西壮族自治区南宁市、柳州市和桂林市44个柑橘园为代表,系统地调查了广西壮族自治区柑橘产区的杂草群落结构,结果显示广西柑橘产区柑橘园共有杂草68种,隶属于37个科、65个属。根据物种重要值,确定广西柑橘产区重要值大于1%的杂草为优势杂草,其种类包括马唐、鬼针草、牛筋草、鸭跖草、阔叶丰花草、稗、喜旱莲子草、龙葵、藿香蓟、凹头苋、铁苋菜、酢浆草、狗尾草、碎米莎草、小心叶薯、酸模叶蓼、墨苜蓿、积雪草、狗牙根、乌蔹莓和竹节菜等,其中鬼针草、牛筋草、稗和喜旱莲子草等是广西柑橘产区内发生危害较为严重的恶性杂草。并通过CCA分析发现广西柑橘产区杂草群落结构主要受到年平均降水量、年平均气温、经度、纬度以及海拔等环境因子的影响。本研究明确了广西壮族自治区柑橘产区杂草群落结构及发生现状,对指导柑橘园杂草科学防控具有重要意义。

湖南省16种柑橘陈皮加工适宜性分析

为探究湖南16个柑橘品种的陈皮加工适宜性,建立陈皮加工品质综合评价方法,采用UPLC法、比色法、GC-MS法对16种柑橘果皮主要功能成分、抗氧化能力和挥发性香气成分等果皮营养品质进行比较。采用主成分分析方法综合评价果皮品质,同时分析16种柑橘的陈皮加工品质。结果显示,16种柑橘果皮的主要功能成分含量和抗氧化能力具有显著差异。其中,温州蜜柑总酚(28.91 mg/g DW)、总黄酮(17.61 mg/g DW)、橙皮苷(98.64 mg/g DW)、辛弗林(12.71 mg/g DW)含量最高,椪柑中甜橙黄酮(2.29 mg/g DW)、川陈皮素(5.26 mg/g DW)、橘皮素(6.20 mg/g DW)、挥发油(8.95%)含量最高。克里曼丁红橘的DPPH自由基清除能力最强(30.81μmol Trolox/g DW)、油良的ABTS自由基清除能力最强(43.27μmol Trolox/g DW),辛女椪柑的FRAP铁离子还原力(47.46μmol Trolox/g DW)和综合抗氧化活性(96.52%)最强。从16种柑橘果皮中共检出81种挥发性香气成分,不同样品中含有多种独有的挥发性香气成分。柑橘果皮的主体香气成分为芳樟醇、β-月桂烯、D-柠檬烯。通过主成分分析提取5个主成分,累积方差贡献率达88.824%,结果显示主要功能成分对陈皮的加工综合品质影响最大,其次是抗氧化能力和香气成分。椪柑、温州蜜柑的果皮营养品质综合得分最高。通过K-means聚类分析,将16种柑橘陈皮加工特性分为适宜和不适宜,温州蜜柑、椪柑的加工品质最好。研究结果可为寻找既适宜加工又具有高生物活性的陈皮原料提供参考。

潮州柑果皮多糖对凝固型酸奶冷藏期品质的影响

以潮州柑果皮多糖为原料,通过评价凝固型酸奶的理化和感官特性,探讨潮州柑果皮多糖添加量对酸奶冷藏过程中品质的影响。研究结果表明:在7 d的冷藏期内,添加潮州柑果皮多糖可提高酸奶的可溶性固形物含量、黏度、持水力和悬浮稳定性,降低酸奶的乳清析出率;当多糖添加量为2.0%时,酸奶的综合品质最佳。冷藏第7天,添加2.0%多糖的酸奶pH值为4.12,可滴定酸度为96.61°T;相比对照组,可溶性固形物含量、黏度、持水力和悬浮稳定性分别提高了9.08%、40.59%、25.41%和145.83%,乳清析出率降低了55.37%。另外,相比其他组,添加1.5%和2.0%潮州柑果皮多糖的酸奶感官评分更高。因此,潮州柑果皮多糖可作为一种天然稳定剂可用于提高冷藏期凝固型酸奶品质。

橘叶化学成分及其抗炎活性研究

目的研究橘Citrus reticulata Blanco叶化学成分及其抗炎活性。方法橘叶85%乙醇提取物采用硅胶、D101大孔树脂、MCI、ODS、Sephadex LH-20进行分离纯化,根据理化性质及波谱数据鉴定所得化合物的结构。采用Griess法测定化合物对脂多糖诱导RAW 264.7细胞产生NO的抑制活性。建立角叉菜胶致小鼠足肿胀炎症模型,检测IL-1β、TNF-α水平。结果从中分离得到12个化合物,分别鉴定为川陈皮素(1)、橘红素(2)、5-去甲川陈皮素(3)、5,4′-二羟基-6,7,8,3′-四甲氧基黄酮(4)、5-羟基-7,8,3′,4′-四甲氧基黄酮(5)、3,5,6,7,8,3′,4′-七甲氧基黄酮(6)、橙皮素(7)、5-羟基-6,7,3′,4′-四甲氧基黄酮(8)、β-香树脂醇(9)、豆甾-5-烯-3β-醇(10)、对羟基苯甲醛(11)、香草醛(12)。化合物1~4、6~7、10、12对脂多糖诱导RAW 264.7细胞释放NO有较强抑制活性,IC_(50)值分别为(25.21±2.10)、(37.77±0.50)、(38.19±1.58)、(21.89±1.73)、(43.81±1.18)、(47.98±2.55)、(41.23±1.11)、(43.80±1.43)μmol/mL。化合物2~3可降低IL-1β、TNF-α水平(P<0.05,P<0.01)。结论化合物6~7、9为首次从该植物中分离得到。化合物1~4、8有较强的体外抗炎活性,化合物2~3有明显的体内抗炎活性。

陈皮多糖提取工艺及其抗氧化活性研究

该研究以广陈皮为原料,利用超声波辅助提取法提取陈皮多糖,采用单因素试验优化陈皮多糖提取工艺并对其抗氧化活性进行研究,建立以葡萄糖为标准品,采用苯酚-硫酸法测定广陈皮多糖含量的定量分析方法。采用正交试验以多糖得率为指标优化工艺参数:料液比为1∶45(g/mL),提取时间为10 min,超声功率为350 W,提取温度为65℃,在此条件下,陈皮多糖得率高达40.06%。结果表明,广陈皮多糖对1,1-二苯基-2-三硝基苯肼自由基(DPPH·)的最大清除率为85.19%,对羟基自由基(·OH)的最大清除率为63.42%。