茶多酚在鱼糜保鲜中的应用研究

在鱼糜中加入茶多酚进行保鲜试验表明，茶多酚可强烈抑制鱼糜中细菌的生长，抑菌效果与其浓度呈显著正相关；还能抑制鱼糜中ｐＨ值、乳酸及不饱和脂肪酸的上升。鱼糜中加入０．２５～０．５０ｍｇ／ｇ茶多酚，在５℃下保鲜效果明显，保鲜时间可达１３天。添加β－环状糊精，有增加茶多酚保鲜效果的作用。     

Polyphenolic compounds and antioxidant properties in mango fruits

Fruit of eight mango genotypes were evaluated for antioxidant potential by several biochemical assays (DPPH, ABTS, ORAC, FRAP, SASR and MCC) and tested for their polyphenol composition and vitamin C contents. The significance analysis demonstrated that the antioxidant capacity of Tainong 1 fruits were significantly higher than that of other genotypes, which was about 2.1–6.3-fold higher than Guifei assayed in ABTS, DPPH, ORAC and FRAP methods. The total polyphenols and flavonoids contents showed a great variety amongst mango genotypes and highly correlation with the total antioxidant capacity. It is concluded that significant genotypic difference exists in the total antioxidant capacity of mango fruits. Both total polyphenols and flavonoids are major contributors to the total antioxidant capacity in mango fruit.     

滇池流域双龙水库径流区人类活动的沉积物记录

采集滇池以南双龙水库的沉积物柱状样,对不同层的沉积物使用210Pb进行定年;分析了不同年代沉积物的粒度分布特征以及总有机碳(TOC)、总氮(TN)和总磷(TP)的含量;在此基础上,对环境指标与昆明市人口和经济发展数据关系进行了解析。结果表明:1双龙水库沉积物中值粒径的范围分布在4.07~6.90μm,平均值为5.71μm,沉积物中值粒径在1986年后突然减小;2沉积物中TOC、TN以及TP的含量的范围分别是8.78~26.15、1.59~3.26和0.23~0.47 g/kg,均值分别为11.30、2.01和0.33 g/kg。TOC、TN以及TP的含量在1998年之前相对稳定,而在1998年之后有较大程度增长;3利用有机指数和有机氮指标评价双龙水库沉积物污染的变化情况,结果发现两大指标有加速增长的趋势;4通过相关分析发现昆明市国内生产总值(GDP)与双龙水库沉积物有机指数和TOC含量存在较好的相关性。昆明市人口数量与双龙水库沉积物有机指数和TOC含量的相关性也较强。研究结果表明水体生态参数受到社会经济指标的显著影响,人类活动是近几十年影响双龙水库水质的主要因素。     

茶多酚对菜籽色拉油的抗氧化作用研究

在菜籽色拉油中添加ＴＰ,ＶｉｔＥ及ＴＰ＋ＣＡ,对油脂的ＰＯＶ和ＡＶ进行测定,结果表明,三者均有抑制色拉油ＰＯＶ和ＡＶ升高的作用。０．０１％￣０．０４％ＴＰ,０．０１％￣０．０４％ＶｉｔＥ及０．０１％￣０．０４％ＴＰ＋ＣＡ（０．０１％）对油脂ＰＯＶ的降低率依次为２８．４％￣３９．０％,０￣３９．４％及５０．４％￣７１．６％,而对ＡＶ的降低率则依次为０￣１３．５％,５．４％￣１０．８％及３．０％￣７．     

牛至精油对新生犊牛生长发育和血液免疫的影响

选择40头新生犊牛,按出生日期随机分为试验组和对照组,每组各20头,试验组犊牛精料按40g·t~(-1)的比例添加牛至(Origanum vulgare)精油,旨在研究天然添加剂牛至精油对新生犊牛生长发育和血液免疫的影响。从犊牛出生到70日龄,跟踪研究了两组犊牛生长性能和血液免疫指标。结果表明,随着犊牛生长、发育时间的增加,试验组犊牛体重、体高、体长、胸围、腹围、管围、血清总蛋白、免疫球蛋白G、免疫球蛋白A、免疫球蛋白M以及平均采食量均极显著高于对照组(P0.01),且试验组犊牛腹泻次数极显著降低(P0.01)。由此可见,精料中添加牛至精油有促进犊牛生长发育、增强犊牛免疫力、增加犊牛采食量和降低犊牛腹泻发病率的作用。     

Photosynthesis, yield, and chemical composition of Tieguanyin tea plants (Camellia sinensis (L.) O. Kuntze) in response to irrigation treatments

Tieguanyin Oolong tea (Camellia sinensis (L.) O. Kuntze) is a name brand important commodity for Anxi county, Fujian province in China. Four-year-old tea plants at a tea plantation in Anxi were subjected to six different irrigation treatments (i.e. 5, 10, 15, 20, and 25 d irrigation intervals for T₁ to T₅ with a rate of 3.5 kg water per plant, plus a non-irrigated control). After 50 d of irrigation treatments, leaf water potential was −1.70, −2.34, −2.48, −2.89, −3.55, and −4.92 MPa for treatment T₁, T₂, T₃, T₄, T₅, and control, respectively. Leaf biomass yield increased by 32.8%, 21.9%, and 21.3% for T₁, T₂, and T₃, respectively, compared to control. The net photosynthesis (Pn), stomatal conductance (gs) and transpiration (E) decreased with irrigation interval increasing. Tea polyphenol (TP) and free amino acid (AA) decreased when the irrigation intervals were increased, but caffeine (CA) content apparently increased as the irrigation intervals were increased. To balance irrigation water demand and tea yield and quality, it is recommended that the irrigation interval should be set at 10 d with a rate of 3.5 kg water per plant for the optimal production in Anxi, Fujian province of China.     

Total phenolics and flavonoids and total antioxidant capacity in pistachio (Pistachia vera L.) nuts in relation to cultivars and storage conditions

The effects of cultivar, drying and storage conditions on total phenolics (TP), total flavonoids (TF) and total antioxidant capacity (TAC), measured with ferric reducing antioxidant power (FRAP) and radical scavenging capacity (2,2-diphenyl-1-picrylhydrazyl or DPPH) assays, of in-shell and unpeeled kernels of ripe pistachios were investigated. Drying was carried out at 45 °C for 34 h to approximately 5% moisture in kernels and storage of dried nuts in packaging atmosphere of dry air or N₂ at 1 °C or 20 °C for 6 or 12 months. At harvest, each cultivar showed its highest values for each measured variable and TP ranged from 16.2 to 7.9 mg gallic acid equiv. g⁻¹ d.w., TF from 7.2 to 3 mg catechin equiv. g⁻¹ d.w., FRAP from 132.5 to 58.8 μmol Trolox equiv. g⁻¹ d.w., and DPPH from 122.6 to 45.7 μmol Trolox equiv. g⁻¹ d.w. Drying resulted in losses in all cultivars that averaged approximately 14.2%, 14.1%, 11.9% and 12.2% for TP, TF, FRAP and DPPH, respectively, while during 12-month storage the corresponding losses in dried kernels averaged approximately 24.7%, 21.8%, 30.3% and 32.4%. Decreases in all measured variables were advanced by storage time, but prevented by low temperature and packaging in N₂ atmosphere. Among the studied cultivars, Pontikis, Aegina, Bronte and Cerasola showed higher values of TP, TF and TAC than Sirora, Kerman, Joley and Mumtaz in all cases, while Pontikis the highest in most cases. The effects of cultivar, time, temperature and packaging atmosphere during storage were all significant on TP, TF, FRAP and DPPH. Strong correlations were also found among the measured variables.     

茶叶对糖尿病的预防作用及其机理研究进展

随着人们生活水平的提高和饮食结构的变化,糖尿病的患病呈流行趋势,发病率逐年上升,预防和治疗糖尿病成为热门话题。现代科学证明茶叶作为健康饮品的同时对人体健康具有多方面的保健功效。本文回顾了茶叶在糖尿病预防方面已取得研究进展,综述了茶叶与糖尿病预防的相关流行病学和人体临床研究结果,并对茶叶预防糖尿病的机制进行了梳理。     

规模化浅海养殖水域沉积作用的初步研究

从2001年9月到2002年7月底分5个阶段,使用沉积物捕获器在桑沟湾养殖海区的扇贝区、牡蛎区和海带区进行自然沉积作用的研究。通过对收集的沉积物进行分析,估算该养殖海区的总氮和总磷由海水到海底的通量。估算结果显示,该海区颗粒物质的年平均沉积速率为278.8g/(m2·d),而每克颗粒物质则携带了190.4μg总氮、472.5μg总磷和0.103g有机物质沉入海底。沉积物的总氮和总磷含量显示了较明显的季节性变化。总氮的峰值出现在5月(春季),最低值出现在12月(冬季)。而总磷含量在12月显著高于5月和7月时段。分析表明,下沉的颗粒物质的氮磷摩尔比为0.67～2,而底泥的氮磷摩尔比为0.025～2。研究结果为桑沟湾沿岸海域氮磷营养盐的通量建模提供了重要参数,并为养殖水域环境容量的研究提供了依据。     

Marine Antimicrobial Peptide TP4 Exerts Anticancer Effects on Human Synovial Sarcoma Cells via Calcium Overload,Reactive Oxygen Species Production and Mitochondrial Hyperpolarization

Synovial sarcoma is a rare but aggressive soft-tissue sarcoma associated with translocation t(X;18). Metastasis occurs in approximately 50% of all patients, and curative outcomes are difficult to achieve in this group. Since the efficacies of current therapeutic approaches for metastatic synovial sarcoma remain limited, new therapeutic agents are urgently needed. Tilapia piscidin 4 (TP4), a marine antimicrobial peptide, is known to exhibit multiple biological functions, including anti-bacterial, wound-healing, immunomodulatory, and anticancer activities. In the present study, we assessed the anticancer activity of TP4 in human synovial sarcoma cells and determined the underlying mechanisms. We first demonstrated that TP4 can induce necrotic cell death in human synovial sarcoma AsKa-SS and SW982 cells lines. In addition, we saw that TP4 initiates reactive oxygen species (ROS) production and downregulates antioxidant proteins, such as uncoupling protein-2, superoxide dismutase (SOD)-1, and SOD-2. Moreover, TP4-induced mitochondrial hyperpolarization is followed by elevation of mitochondrial ROS. Calcium overload is also triggered by TP4, and cell death can be attenuated by a necrosis inhibitor, ROS scavenger or calcium chelator. In our experiments, TP4 displayed strong anticancer activity in human synovial sarcoma cells by disrupting oxidative status, promoting mitochondrial hyperpolarization and causing calcium overload.