4种植物油热氧化同步荧光光谱分析

以亚麻籽油、大豆油、菜籽油与葵花籽油为原料,在不同温度条件下氧化并测定其不同时间的同步荧光光谱,分析同步荧光光谱及荧光物质变化情况。结果表明,4种植物油不同温度下的同步荧光光谱峰变化主要集中在300~415 nm内,且随着加热时间的延长存在波动现象;在50℃和150℃加热氧化条件下,300,330,375,415 nm这4个峰都存在明显的波动现象;二维相关分析表明,这4个峰的荧光强度变化速率不同,不同油变化差异较大;同种油在不同温度下,4个峰的波动情况、相互关系、变化速率均有明显差异。这些峰的变化与油脂氧化过程中荧光物质和油脂氧化程度的变化有关,可以利用同步荧光光谱的变化特性作为监控油脂氧化的依据。     

‘红羽1号’油茶新品种营养成分动态及相关关系分析

为了解‘红羽1号’油茶新品种的营养成分动态及其相关关系，以‘红羽1号’油茶果实近熟期的叶片与果皮、种壳、种仁为材料，测定其还原糖含量、黄酮含量、总酚含量及果皮与叶片中原花青素含量。结果表明，‘红羽1号’油茶中各部位还原糖含量、黄酮含量、总酚含量、原花青素含量具有极显著性差异；在果实近熟期，果实相对成熟，叶片与果皮、种壳、种仁各营养成分动态变化规律明显，但变化幅度不大。叶片原花青素含量与总酚含量间存在显著的线性关系，叶片原花青素含量与黄酮含量和果皮原花青素与总酚含量之间存在显著曲线关系，种壳中总酚含量与黄酮含量极显著正相关。     

Pectic hydrolysates in the diet of silver catfish (Rhamdia quelen): Growth performance,blood and liver biochemistry,histological parameters and intestinal contents

The aim of this study was to investigate the prebiotic potential of pectin hydrolysates that were extracted from agroindustrial waste (apple pomace—AP and passion fruit peel—PFP) and were added to the diet of silver catfish (Rhamdia quelen). A 49‐day biological assay was conducted, and five test diets were evaluated: one diet was a control diet and the other four diets included pectin hydrolysates (2.5 and 5 g/kg). At 49 experimental days, biometric data and biological material were collected to determine the performance, plasma and liver and histological parameters and to evaluate the intestinal contents. The results were analysed by the normality test, which was followed by an analysis of the variance; the treatment means were compared by an orthogonal contrast analysis at a 5% level of significance. The inclusion of 2.5 g/kg apple pomace hydrolysates resulted in a greater production of butyric acid, increased thickness of the muscular layer and higher goblet cell count in the intestine. The inclusion of 5 g/kg apple pomace hydrolysates led to a greater concentration of liver protein. Further studies are needed to increase the knowledge about the use of these additives in the diet of silver catfish and to establish levels that allow greater gains for the species.     

Orange peel fragment improves antioxidant capacity and haematological profile of Nile tilapia subjected to heat/dissolved oxygen‐induced stress

This study evaluated the ability of orange peel fragment (OPF) to act as a functional feedstuff, influencing growth, haematological profile, and antioxidant enzyme activity of Nile tilapia subjected heat/dissolved oxygen‐induced stress (HDOIS). A group of 440 male Nile tilapia (31.7 g ± 0.34) was randomly distributed in 40 250‐L aquaria (11 fish/tank) and fed five practical diets with graded levels of OPF at 0%, 0.2%, 0.4%, 0.6%, and 0.8% for 70 days. The diets were formulated to contain 30% crude protein and 18 MJ/kg crude energy. After the feeding period, growth performance was evaluated and six fish per treatment were sampled for haematological profile and antioxidant enzyme activity, before and after HDOIS. Then, fish were subjected to HDOIS (32°C/2.3 mg/L dissolved oxygen) for three days and the same haematological profile and antioxidant enzyme activity were determined. There was no effect of OPF on the haematological profile, either before or after HDOIS. The polynomial regression model was used to express the relationship between antioxidant enzymes activity and OPF supplementation level. The maximum activity of superoxide dismutase, catalase, and glutathione peroxidase was reached at 0.66%, 0.63%, and 0.68% of OPF respectively. Results of the present study suggest that a dietary supplementation level of 0.63%–0.68% of orange peel fragment was appropriate to maintain Nile tilapia haematological profile and improve its antioxidant capacity under HDOIS.     

怀山药皮对淇河鲫血清生化、免疫指标及组织结构的影响

为探究怀山药皮(Chinese yam peel,YP)对淇河鲫免疫的影响,选取平均体重为(106.76±3.74)g的淇河鲫240尾,随机分为对照组(NC)、0.5%怀山药皮添加组(LYP)、1%怀山药皮添加组(MYP)、2%怀山药皮添加组(HYP)4组,养殖8周,检测实验鱼生长指标、血清生化指标及免疫相关基因的表达情况。结果显示:添加怀山药皮对淇河鲫生长指标没有显著性影响;血液生化指标中谷草转氨酶活性在MYP组显著性降低,碱性磷酸酶的活性显著升高;与NC组相比,怀山药皮添加组肝脏细胞膜与核膜完整性增强,胞质破碎,核溶解、偏移现象减轻;与NC组相比,添加怀山药皮上调了抑炎因子(IL-10)、紧密连接蛋白基因(Claudin-1)、抗氧化基因(CAT和GST)和TLR通路基因(TLR4)mRNA表达量。以上结果表明,饲料中添加怀山药皮,能在一定程度上增强鱼体免疫力。     

The impact of foliar fertilizers on growth and biochemical responses of Thymus vulgaris to salinity stress

Salinity reduces plant biomass and may lead to death when severe. To cope with the negative effects of this stress, plant species present specific physiological or biochemical responses. In this work, we hypothesized that spraying salt-stressed thyme leaves with K⁺ and Ca²⁺ could mitigate the negative effects of salinity on plant growth and metabolism. To test this hypothesis, we grew thyme plants under salinity stress for two and four weeks before applying foliar sprays. Also, to test the effect of stress relief, treated plants were allowed two weeks of recovery after four weeks of salt stress. In general, after two and four weeks of salinity stress, the leaf fresh weight of thyme plants was reduced by 31 and 43%, respectively. Salinity also decreased the relative water content, water, and osmotic potentials and led to ion imbalances and nutrient deficiencies. Salinity altered concentration of some essential oils, but leaf antioxidant contents remained fairly stable, except for a significant increase for plants under NaCl?+?KCl two weeks after treatment. Our results indicated that stressed plants accumulated significantly more soluble sugars and amino acids in comparison with the control. Foliar sprays with KCl and CaCl₂ reversed the negative effects of salinity on plant biomass and induced the accumulations of compatible solutes. Moreover, concentrations of some essential oils and gallic acid increased in sprayed plants, but these effects were dependent on the type and duration of the treatment. Overall, spraying leaves with K⁺ and Ca²⁺ was able to mitigate salinity stress in Thymus vulgaris even during the recovery period.     

Analgesic effect of the mint terpenoid L-carvone in sheep

ObjectiveTo determine whether L-carvone increases the voltage threshold response to a noxious electrical stimulus in sheep.Study designProspective, blinded, randomized, crossover experimental study.AnimalsA group of six healthy adult sheep.MethodsSheep were instrumented with cranial dorsothoracic subcutaneous copper electrodes. A stimulator delivered a 10 ms square-wave stimulus at 50 pps starting at 0.1 V with a 0.2 V second^–1 ramp. The stimulus stopped once two observers who were blinded to treatment noted a behavioral pain response or when a 15 V cut-off was reached. Next, 0.15 mL kg^–1 of either a 50% L-carvone solution or a saline-vehicle control was administered intramuscularly, and electrical threshold responses were measured every 5–15 minutes over a 6 hour period using methods identical to the baseline. One week following the first treatment (L-carvone or control), sheep were studied using identical methods with the second treatment (control or L-carvone). Drug and time effects were evaluated using a two-way repeated measures analysis of variance, and pairwise comparisons were evaluated with Holm-Sidák tests with values of p < 0.05 considered significant.ResultsL-carvone significantly increased voltage threshold responses for most time points up to 75 minutes compared with baseline and with saline control. The last time point with a significantly different response between L-carvone and saline treatments was 5 hours after drug administration. The saline-vehicle control decreased voltage threshold responses at several time points after 3 hours.Conclusions and clinical relevanceIntramuscular L-carvone is analgesic in sheep, although the ethanol-propylene glycol vehicle may cause mild hyperalgesia. This study demonstrates that a food-derived compound can be used to relieve pain in a food-producing animal.     

Effect of different levels of dietary sweet orange (Citrus sinensis) peel extract on humoral immune system responses in broiler chickens

This experiment was conducted to evaluate the effects of different levels of sweet orange (Citrus sinensis) peel extract (SOPE) on humoral immune system responses in broiler chickens. Three hundred 1‐day broilers (Ross‐308) were randomly allocated to treatments varying in supplemental SOPE added in the drinking water. The experimental groups consisted of three treatments fed for 42 days as follows: a control treatment without feed extract, a treatment containing 1000 ppm of SOPE and a treatment containing 1250 ppm of SOPE. All treatments were isocaloric and isonitrogenous. Broilers were vaccinated with Newcastle disease virus (NDV), avian influenza (AI), infectious bursal disease (IBD) and infectious bronchitis virus (IBV) vaccines. Antibody titer response to sheep red blood cells (SRBC) was higher in the group fed 1250 ppm of SOPE (P < 0.05) as well as for immunoglobulin G (IgG) and IgM. Similarly, antibody titer responses to all vaccines were constantly elevated (P < 0.05) by SOPE enrichment in a dose‐dependent manner. Relative weights of spleen and bursa of Fabricius were unaffected by treatments. Dietary SOPE supplementation may improve the immune response and diseases resistance, indicating that it can constitute a useful additive in broiler feeding. Thus, supplying SOPE in rations may help to improve relative immune response in broiler chickens.     

微波辅助提取桔皮中天然抗氧化剂的研究

以桔皮为原料，乙醇为溶剂，在微波功率900W，提取温度75℃条件下，通过单因素试验探讨了乙醇体积分数、浸提时间、料液比对总黄酮提取率的影响，并通过正交试验对桔皮中黄酮类化合物提取工艺进行了研究。结果表明，用微波法从桔皮中提取总黄酮的最佳工艺条件为：乙醇体积分数75％，浸提时间7min，料液比l：30。用此工艺提取的总黄酮得率为12．04％。通过1,1-二苯基-2-苦基肼（DPPH）法测定不同工艺条件下桔皮提取物的抗氧化性能，表明不同工艺的桔皮提取物均有一定的清除DPPH自由基的能力，其清除率与总黄酮的含量有一定的量效关系。     

石榴皮中多酚提取条件的优化

运用正交试验对石榴多酚的乙醇提取条件进行了优化。考察了影响石榴皮中多酚提取效果的4个因素。结果显示,石榴皮中多酚的最佳提取条件为:20%(体积分数)乙醇作溶剂,料液比(g∶mL)1∶20,温度50℃,提取时间1 h,以该优化条件提取时,多酚粗提物的得率44.98%,纯度50.12%,即石榴多酚得率达到22.86%。