广泛靶向代谢组学与转录组学联合分析胰蛋白酶对火龙果中抗氧化酶和饱和脂肪酸的调控

为了进一步研究胰蛋白酶的保鲜机制,探讨火龙果中胰蛋白酶和抗氧化酶的协同机制,根据胰蛋白酶调控火龙果的RNA-seq数据筛选活性氧(reactive oxygen species,ROS)和抗氧化酶相关基因.蛋白质-蛋白质相互作用(protein-protein interaction,PPI)网络分析结果表明,整个RO...     

Simultaneous quantification of major flavonoids in "Bawanghua", the edible flower of Hylocereus undatus using pressurised liquid extraction and high performance liquid chromatography

A pressurised liquid extraction (PLE) and high performance liquid chromatography (HPLC) method was developed for simultaneous quantification of six major flavonoids in edible flower of Hylocereus undatus. In order to achieve the baseline separation of two pairs of isomers, the HPLC conditions were optimised with different kind of reversed phase columns and mobile phase gradient programs. In addition, the solvent concentration, extraction temperature, extraction time and flush cycle for PLE were also optimised. Zorbax SB-C8 (100×2.1 mm, 1.8 μm) column was chosen with acetonitrile and water containing 0.1% trifluoroacetic acid as mobile phase, the six analytes were eluted with baseline separation. The calibration curves showed good linearity (r(2)>0.9994) with LODs and LOQs less than 0.90 and 3.60 ng respectively. The RSDs for intra- and inter-day repeatability was not more than 1.09% and 1.79% respectively. The overall recovery of the assay was 96.9-105.2%. The sample was stable for at least 12 h. The newly established method was successfully applied to quantify six flavonoids in different parts of "Bawanghua", and the commercial samples from different locations.     

火龙果色素的基本性质及结构鉴定

采用液质联用(HPLC/MS)的方法,将色素的不同组分分离,并对分离组分进行结构鉴定.结果表明:火龙果果肉、果皮色素同为甜菜苷类色素,从果肉中分离出4种甜菜苷色素为betanin,2 descarboxy betanin,phyllocactin,2 descarboxy phyllocactin;果皮中分离出2种甜菜苷色素为be tanin,phyllocactin.火龙果中甜菜苷红色素的质量分数分别为676.9mg/kg(以鲜果肉计),97.7mg/kg(以鲜果皮计).     

Physical Evaluation and Hygroscopic Behavior of Dragon Fruit (Hylocereus undatus) Lyophilized Pulp Powder

Relations between moisture content and water activity of foodstuff can be estimated by determining moisture sorption isotherms. This work aimed at investigating the hygroscopic behavior of dragon fruit powder through sorption isotherms, encapsulated with maltodextrin, and analyzing hygroscopicity, density, and caking degree of samples stored in polyethylene wrappings and laminated coverings at 25°C. Dragon fruit powder showed good results regarding hygroscopicity, density, and caking degree for laminated coverings. In order to describe balance of sorption isotherms, the BET model was the most recommended.     

Chemical composition and DSC thermal properties of two species of Hylocereus cacti seed oil: Hylocereus undatus and Hylocereus polyrhizus

Two types of pitaya (Hylocereus cacti) seeds (Hylocereus undatus and Hylocereus polyrhizus) were investigated in this study. The fatty acid, phenolic, tocopherol, and sterol contents of the extracted seed oil were analysed. The results showed that the pitaya seeds contained a high amount of oil (18.33–28.37%). The three major fatty acids in the H. undatus seed oil (WFSO) and H. polyrhizus seed oil (RFSO) were linoleic, oleic, and palmitic acids. The total tocopherol contents in the WFSO and RFSO were 36.70 and 43.50 mg/100 g, respectively. The phytosterol compounds identified in the WFSO and RFSO were cholesterol, campesterol, stigmasterol, and β-sitosterol. Seven phenolic acid compounds were identified in the WFSO and RFSO, namely, gallic, vanillic, syringic, protocatechuic, p-hydroxybenzoic, p-coumaric, and caffeic acids. WFSO and RFSO can be differentiated by their T_off and T_on values in the DSC thermal curves. This study reveals that pitaya seed oil has a high level of functional lipids and can be used as a new source of essential oil.     

Physico-chemical and structural changes of red-fleshed dragon fruit (Hylocereus polyrhizus) during fruit development

BACKGROUND: Determination of physico‐chemical (weight, length, diameter, stomatal density, respiration rate, colour, soluble solids concentration, titratable acidity, chlorophyll and betacyanin content) and structural changes of red‐fleshed dragon fruit (Hylocereus polyrhizus (Weber) Britton & Rose) was carried out from 5 to 35 days after pollination (DAP) in order to explain their growth, development, maturations and ripening stages. RESULTS: Fruit growth of red‐fleshed dragon fruit followed a sigmoid growth pattern. Significant changes in colour were obtained in both peel and pulp as DAP progressed, which were indicated by reductions of L*, C* and h° values as both changed from green to red–violet colour at ripening. Red–violet betacyanin was manifested earlier in pulp at 25 DAP, followed by peel 4–5 days later, and finally both peel and pulp turned full red–violet by 30 DAP. There was a significant increase in soluble solids concentration and titratable acidity with the continuous increase in betacyanin content as DAP progressed. CONCLUSION: The physico‐chemical and betacyanin accumulation of red‐fleshed dragon fruit changed as it developed, matured and ripened which coincided with structural changes. Copyright © 2010 Society of Chemical Industry     

剑花水提取液化学成分清除自由基作用研究

根据颜色反应及沉淀反应初步判断剑花水提取液的化学成分类型,测定其中主要化学成分含量,并进行提取分离,研究各组分对含氧自由基的清除作用。实验结果表明,剑花水提取液中主要含有糖类及甙类、有机酸、鞣质、氨基酸和皂甙,其中多糖及鞣质含量较高;在所研究的浓度范围内,各组分对羟自由基及超氧阴离子自由基有一定的清除作用,其中多糖清除作用较强。     

贵州地区“紫红龙”火龙果采后病原菌分离鉴定

目的 分离鉴定贵州地区“紫红龙”火龙果在采后贮藏期间自然发病的病原菌。方法 “紫红龙”火龙果为试材, 通过涂布平板分离法以及划线纯化, 从贮藏期火龙果中分离、纯化采后病原菌, 并结合形态学观察与rDNA ITS (internal transcribed spacer)序列测定进行准确鉴定。结果 分离出1株真菌, 经鉴定该株病原菌为桃吉尔霉(Gilbertella persicaria)。结论 本研究在贵州地区腐烂的火龙果中首次分离得到G. persicaria, 该菌对红肉火龙果有较强的致病力。