采后茶青叶对振动力胁迫的生理响应

摇青是乌龙茶品质形成的关键工序之一，其通过机械胁迫引起各种生物学效应，影响植物体内一系列生理生化变化，被广泛应用于花香红茶、花香白茶、花香绿茶等茶类的加工中以改善品质。为探明青叶响应机械力胁迫的生理变化，以采摘的‘铁观音’品种中开面三、四叶嫩梢为材料，经适度萎凋后进行自然摊放和振动力胁迫处理，研究青叶水分含量、光系统Ⅱ(photosystem Ⅱ,PS Ⅱ)参数、抗氧化酶活力及亚细胞结构的变化规律。结果表明：振动力胁迫30 min内青叶水分含量与自然摊放叶、萎凋叶间无显著差异（P>0.05）,60 min时显著低于自然摊放叶和萎凋叶（P<0.05）。随着振动力胁迫时间延长，青叶青臭气增强，清香减弱；叶绿体和类囊体紧密而清晰的片层结构逐渐松散、变形、收缩、紊乱、瓦解，振动力胁迫处理5 min时淀粉粒数量明显增加，15 min时嗜锇颗粒数量明显增多，出现聚集。振动力胁迫青叶的PS Ⅱ实际光合效率Y(Ⅱ)和光化学猝灭系数qP随处理时间延长总体呈下降趋势，电子传递速率（electron transfer rate,ETR）随处理时间延长呈先降低后升高趋势，5 min和10 min时...     

Special tea products featuring functional components: Health benefits and processing strategies

The functional components in tea confer various potential health benefits to humans. To date, several special tea products featuring functional components (STPFCs) have been successfully developed, such as O-methylated catechin-rich tea, γ-aminobutyric acid-rich tea, low-caffeine tea, and selenium-rich tea products. STPFCs have some unique and enhanced health benefits when compared with conventional tea products, which can meet the specific needs and preferences of different groups and have huge market potential. The processing strategies to improve the health benefits of tea products by regulating the functional component content have been an active area of research in food science. The fresh leaves of some specific tea varieties rich in functional components are used as raw materials, and special processing technologies are employed to prepare STPFCs. Huge progress has been achieved in the research and development of these STPFCs. However, the current status of these STPFCs has not yet been systematically reviewed. Here, studies on STPFCs have been comprehensively reviewed with a focus on their potential health benefits and processing strategies. Additionally, other chemical components with the potential to be developed into special teas and the application of tea functional components in the food industry have been discussed. Finally, suggestions on the promises and challenges for the future study of these STPFCs have been provided. This paper might shed light on the current status of the research and development of these STPFCs. Future studies on STPFCs should focus on screening specific tea varieties, identifying new functional components, evaluating health-promoting effects, improving flavor quality, and elucidating the interactions between functional components.     

冠突散囊菌子囊孢子粗多糖抗氧化活性的比较分析

采用超微粉碎法、超声波法、反复冻融-研磨法,对冠突散囊菌子囊孢子进行破壁处理,探讨不同破壁方法对孢子粗多糖抗氧化活性的影响。结果表明,破壁率由高至低依次为反复冻融-研磨法(93.73%)、超微粉碎法(82.27%)、超声波法(66.54%),粗多糖的提取率分别为2.18%、2.06%、1.84%,均显著高于未破壁孢子(1.15%)。抗氧化试验表明,3种破壁孢子粗多糖均具一定抗氧化活性,且与质量浓度间存在着显著量效关系。以超微粉碎法破壁孢子粗多糖活性为最强,在其质量浓度为2.50 mg/mL时,对DPPH、OH、ABTS~+三种自由基清除能力分别为89.13%、95.22%、80.26%,铁离子还原能力为0.78。反复冻融-研磨组和超声波组粗多糖活性低于超微粉碎组,说明此型号粉碎机低温下的高速剪切作用对冠突散囊菌子囊孢子多糖分子造成的损伤低于超声空化作用与反复冻融,适宜用于冠突散囊菌子囊孢子的破壁。     

福州单瓣茉莉和双瓣茉莉不同器官的广泛靶向代谢组学分析

以福州单瓣茉莉和双瓣茉莉的花器官和叶片作为材料，采用超高效液相色谱-串联质谱技术并结合多元统计分析方法，测定并比较2种茉莉花及其器官的代谢物。结果表明：福州单瓣茉莉和双瓣茉莉的花器官和叶片中共鉴定出935种代谢物，包括氨基酸及其衍生物、酚酸类、核苷酸及其衍生物、黄酮类、木脂素和香豆素、鞣质、生物碱、萜类、有机酸、脂质、糖及醇类、维生素等13类。福州单瓣茉莉与双瓣茉莉的花器官和叶片中分别筛选出348种和337种差异代谢物，主要差异代谢物均以酚酸类、黄酮类、脂质、糖及醇类为主。双瓣茉莉的叶片含有丰富的黄酮类化合物，且黄酮和黄酮醇的生物合成旺盛使其积累更多的烟花苷、木犀草苷、槲皮苷、异槲皮苷、芦丁、紫云英苷、阿福豆苷等具有生物活性和药理活性的物质。福州单瓣茉莉的花器官和叶片中的特有代谢物以脂质类为主，双瓣茉莉的花器官和叶片中特有代谢物种类丰富且均多于福州单瓣茉莉。本研究从品种到器官的层面得到2种茉莉花代谢特征及其主要活性物质，对开发茉莉花资源具有一定指导意义。     

A comprehensive review of polyphenol oxidase in tea (Camellia sinensis): Physiological characteristics,oxidation manufacturing,and biosynthesis of functional constituents

Polyphenol oxidase (PPO) is a metalloenzyme with a type III copper core that is abundant in nature. As one of the most essential enzymes in the tea plant (Camellia sinensis), the further regulation of PPO is critical for enhancing defensive responses, cultivating high-quality germplasm resources of tea plants, and producing tea products that are both functional and sensory qualities. Due to their physiological and pharmacological values, the constituents from the oxidative polymerization of PPO in tea manufacturing may serve as functional foods to prevent and treat chronic non-communicable diseases. However, current knowledge of the utilization of PPO in the tea industry is only available from scattered sources, and a more comprehensive study is required to reveal the relationship between PPO and tea obviously. A more comprehensive review of the role of PPO in tea was reported for the first time, as its classification, catalytic mechanism, and utilization in modulating tea flavors, compositions, and nutrition, along with the relationships between PPO-mediated enzymatic reactions and the formation of functional constituents in tea, and the techniques for the modification and application of PPO based on modern enzymology and synthetic biology are summarized and suggested in this article.     

花椒调味油加工过程中品质变化分析

为确定花椒调味油加工过程中的关键控制点，于花椒调味油生产企业现场取样，对浸提前(大豆油)、加热(180℃大豆油)、浸提24 h、浸提72 h、板框过滤、澄清、成品等7个工序间油样的基本理化指标(色泽、酸值、过氧化值、脂肪酸组成及含量、酰胺类化合物含量)及挥发性风味物质进行监测。结果表明：加工过程中随着花椒色素的溶出a^*值总体呈下降趋势，酸值整体呈上升趋势，过氧化值在整个加工过程中呈波动趋势，酰胺类化合物含量呈先平缓后下降趋势，脂肪酸组成基本无差异；大豆油中检出8种挥发性风味物质，花椒调味油中检出13种挥发性风味物质，大豆油中以醛类化合物为主，花椒调味油中以醇类和烯烃类化合物为主，花椒调味油加工过程中各样品间气味差异较明显，在浸提及澄清过程中芳樟醇及柠檬烯等花椒调味油的重要呈味物质有一定程度损失，板框过滤对花椒调味油整体风味影响不大。由此可知，原料选择、浸提时间、过滤及澄清等工序为花椒调味油加工过程中关键控制点。     

Overexpression of a sugarcane<i> ScCaM</i> gene negatively regulates salinity and drought stress responses in transgenic <i>Arabidopsis thaliana</i>

Calmodulin (CaM) proteins play a key role in signal transduction under various stresses. In the present study, the effects of a sugarcane ScCaM gene (NCBI accession number: GQ246454) on drought and salt stress tolerance in transgenic Arabidopsis thaliana and Escherichia coli cells were evaluated. The results demonstrated a significant negative role of ScCaM in the drought and salt stress tolerance of transgenic lines of A. thaliana, as indicated by the phenotypes. In addition, the expression of AtP5CS and AtRD29A, two genes tightly related to stress resistance, was significantly lower in the overexpression lines than in the wild type. The growth of E. coli BL21 cells expressing ScCaM showed weaker tolerance under mannitol and NaCl stress. Taken together, this study revealed that the ScCaM gene plays a negative regulatory role in both mannitol and NaCl stresses, and it possibly exerts protective mechanisms common in both prokaryotes and eukaryotes under stress conditions.