冬瓜奶茶的生产工艺研究

本文研究了以冬瓜、红茶、乳粉和食盐为主要原料制备一种新型奶茶——冬瓜奶茶的生产工艺和最佳参数。单因素试验和正交试验表明:冬瓜汁与茶汤最佳添加比例为50%∶50%、乳粉最佳添加量为5%、食盐最佳添加量为0.4%,同时还需添加0.05%蔗糖酯与0.05%的单甘酯复配而成的稳定剂。在此条件下,冬瓜奶茶呈乳黄色,风味清新,口感细腻,无悬浮物和沉淀。     

百香果水牛乳酸奶的制备工艺研究

本研究以水牛乳为主料,加入百香果汁,制成口味独特、营养价值高的百香果水牛乳酸奶。通过单因素和正交试验确定该酸奶最佳工艺为:百香汁添加量为9%,发酵剂接种量为7%,发酵时间为4.5h,白砂糖添加量为9%,发酵温度为41℃。由此工艺条件制备的百香果水牛乳酸奶口感清新,品质最佳。     

雪菊保健奶茶的研制

选用雪菊、红茶和牛乳生产一种具有提高人体免疫力、降血压血脂、调节人体血糖水平的新型保健奶茶,色泽呈乳黄色,风味清香独特。以产品的色泽、风味、口感和组织状态为指标进行综合评价,通过单因素试验和正交试验,确定了雪菊奶茶的最优生产工艺为雪菊和红茶按1∶1混合,添加雪菊和红茶总重量200倍的纯净水,煮制15min,再添加20%的牛乳、0.4%的食盐、0.05%蔗糖酯与0.05%的单甘酯复配稳定剂。     

盐穗木总生物碱提取工艺研究

目的:利用正交试验设计优选冷浸法提取盐穗木有效成分的工艺条件。方法:以盐酸小檗碱的含量为指标,通过L9(33)正交试验设计,对提取工艺的溶媒浓度、溶媒用量和浸提时间3个因素进行优选,以筛选出盐穗木的最佳提取工艺条件。结果:影响提取的主次因素为:溶媒用量溶媒浓度浸提时间。优选得到的最佳提取工艺条件:75%乙醇提取,物料比为1∶10,浸提3d。结论:该工艺条件不仅提高了醇浸膏得率和总生物碱含量,而且可节省溶剂用量,降低成本。     

桑葚水牛乳酸奶的工艺研究

本试验以水牛奶和桑葚为主原料,研制口感独特、具有高附加值的功能性桑葚水牛乳酸奶。采用正交试验筛选的酸奶最佳工艺参数为：桑葚果浆7%,乳酸菌发酵剂接种量6%,白砂糖3%,发酵时间5h。在此工艺下制备的酸奶口感爽滑,品质最佳。     

杏鲍菇乳酸菌发酵饮料的研制

以杏鲍菇和鲜牛乳为主要原料通过乳酸菌发酵作用研制功能性饮料。单因素试验和正交试验表明杏鲍菇乳酸菌发酵饮料的最佳工艺为:发酵时间6.5h、接种量0.10%、白砂糖添加量8%、杏鲍菇添加量10%,所得产品质地均匀,口感细腻,酸甜可口,兼具杏鲍菇和鲜乳特有的香味。     

巴旦木百合乳饮料的研制

选择巴旦木、百合和牛乳为主要原料,开发研制一种新型乳饮料—巴旦木百合乳饮料,色泽呈乳白色、口感细腻、风味清香、营养丰富。通过单因素试验和正交试验确定该产品的最佳配方为:巴旦木浆30%、百合浆35%、牛乳35%、白糖8%、柠檬酸0.06%。     

葎草叶蛋白提取工艺与含量测定研究

目的:研究葎草叶蛋白的提取工艺及含量测定。方法:采用正交试验法,以浸提温度、浸提时间、浸提液质量分数为实验因素,以叶蛋白得率为指标,优化叶蛋白最佳提取条件,紫外-可见分光光度法测定叶蛋白含量。结果:叶蛋白最佳的提取工艺条件为:浸提液质量分数10%、浸提温度50℃、浸提时间20 min。精密度实验RSD为0.21%,稳定性试验RSD为0.72%,加样回收试验RSD为1.46%。结论:葎草叶蛋白的提取方法简便快捷、精密度较高、稳定性较好、方法可行,叶蛋白得率3.65%。     

柠檬奶茶加工工艺研究

采用对比试验和正交试验研究了茶汁的浸提工艺、奶茶的加工配方和奶茶的乳化稳定性,确定了柠檬奶茶的加工工艺和配方。结果表明:①柠檬奶茶的加工工艺为:茶叶→浸提→过滤→茶汁→添加柠檬汁、牛奶调配→均质→灌装→灭菌→成品;②茶水浸提液的茶水比为1:75,添加0．5％β—CD,经二次共浸提10min。⑧柠檬奶茶最佳配方为:柠檬汁3％,鲜牛奶60％,茶汁33％,白砂糖3％,蜂蜜1％。④复合稳定剂的添加量是:羧甲基纤维素钠(CMC) 0．04％、蔗糖酯0．12％、黄原胶0．08％。     

颗粒型燕麦牛乳饮品配方及工艺优化

从配方和工艺2 个角度研究颗粒型燕麦牛乳的稳定性,以离心沉淀率、黏度和感官评分作为评价指标。结果表明：对稳定剂进行优化后,得到最佳复配稳定剂配方为结冷胶添加量0.04%、卡拉胶添加量0.020%、羧甲基纤维素钠添加量0.020%、微晶纤维素添加量0.20%;对配料温度、水合时间、均质压力和灌装温度4 个影响体系稳定性的工艺点进行单因素试验,继而设计正交试验,得到最佳参数组合为配料温度50 ℃、水合时间40 min、均质压力30 MPa、灌装温度15 ℃,此条件下产品稳定性最佳,口感良好。     

海南岛红毛丹种质资源DNA指纹图谱构建

分别利用筛选出的多态性高、谱带清晰的8条ISSR标记和18对SRAP标记对海南岛69份红毛丹种质资源进行PCR扩增,8条ISSR引物共检测到425个多态性条带,其中品种(系)特异条带47个,平均位点多态性信息含量(PIC)值为0.928,可鉴别的种质资源数25～67份；18对SRAP引物共检测到894个多态性条带,其中品种(系)特异条带69个,平均位点多态性信息含量(PIC)值为0.936,可区分的种质资源数为17～63份。综合各项指标利用ISSR16和ISSR5引物21个条带用于构建红毛丹种质DNA指纹图谱,该图谱可有效区分69份红毛丹种质资源。同时该DNA指纹图谱还可为下一步红毛丹种质资源鉴定、利用、品种权保护和分子育种等提供了理论依据。     

Evaluation of Oxygen-dependent Immunodefences of the Polymorphonuclear Cells of Some Tropical Ruminants

Activation of polymorphonuclear cells (PMNs) leads to the formation of superoxide, which is in turn dismutated to H₂O₂ by superoxide dismutase (SOD) and is partly responsible for oxygen-dependent microbicidal activity. However, no comparative information is available on the effect of SOD inhibition before PMN activation to allow simulation of the SOD defects that are known to occur in some ruminants. This paper attempts to examine the degranulative and phagocytic responses in buffalo, cattle and goat PMNs exposed to diethyldithiocarbamate, a known SOD inhibitor. The activity of glutathione peroxidase and reductase was increased in the presence of SOD inhibitor. On activation, H₂O₂ production increased significantly (p<0.01), while SOD inhibition before the activation of PMNs caused a significant decline in the production of H₂O₂ (p<0.05) in all the species studied. There was a significant increase (p<0.05) in the phagocytosis of Candida albicans spores by buffalo PMNs activated with opsonized zymosan. Activation of bovine PMNs after exposure to the SOD inhibitor resulted in a significant decline (p<0.05) in phagocytic activity; in the other species, the two values only approached significance. Among the activators, opsonized zymosan caused a significant increase in phagocytic activity as compared to lipopolysaccharide, particularly in the PMNs of buffaloes (p<0.05). Increased fungicidal activity (p<0.05) occurred with opsonized zymosan-activated PMNs of all the species studied. The fungicidal activity was found to decline in PMNs exposed to SOD inhibitor before activation (p<0.05). Interestingly, the phagocytic activity of caprine PMNs was found to be lower than that of PMNs from cattle (p<0.05).     

不同青贮玉米品种抗病性评价

对10个青贮玉米品种自然发病情况进行调查,并采用病级分类方法对抗病性分类。结果表明:对锈病表现抗性和中抗的品种有3个和5个,分别占供试品种的30%和50%;对大斑病表现抗性和中抗的品种有4个和5个,分别占供试品种的40%和50%;对褐斑病表现抗性和中抗的品种有6个和3个,分别占供试品种的60%和30%;对小斑病表现抗性和中抗的品种有6个和3个,分别占供试品种的60%和30%。多数品种对青贮玉米4种病害抗性表现较好,可从青贮玉米供试材料中选用优良抗病材料用于四川地区种植。     

Effect of dietary stable isotopic ratios of carbon and nitrogen on the extent of their incorporation into tissues of rats

This study was conducted to investigate the effect of different dietary ratios of ¹³ C to ¹² C or ¹⁵ N to ¹⁴ N on their relative incorporation into tissues. Eighty male rats were used in two 21-day feeding trials in which they were fed diets with either high δ¹³C levels (δ¹³C = −13.89‰ and δ¹⁵N = 2.37‰ in experiment 1 and δ¹³C = −19.34‰ and δ¹⁵N = 4.73‰ in experiment 2) or low δ¹³C levels (δ¹³C = −17.90‰ and δ¹⁵N = 3.08‰ in experiment 1 and δ¹³C = −21.76‰ and δ¹⁵N = 0.53‰ in experiment 2), meanwhile, the dietary δ¹⁵N levels were designed to two ranks. Blood, liver, adipose and muscle tissues were collected on day 0, 3, 7, 14, and 21 for determination of ¹³ C, ¹² C, ¹⁵ N and ¹⁴ N isotopes. Rat growth rate, antioxidant capacity and metabolic parameters were also assessed. The results indicate that adipose tissue tend to deplete ¹³ C before the stable isotopic ratios achieved final equilibrium. Therefore, feeds with different isotopic signatures had different incorporation rates into tissues. Low dietary ¹³ C levels decreased tissue δ¹³C values whereas high dietary ¹³ C levels did not alter tissue δ¹³C values during the 21-d experiment. Blood δ¹⁵N values were a reliable parameter in assessing the relative contribution of dietary nitrogen to tissues. This study revealed a relationship between dietary isotopic signatures and their incorporation rates into rat tissues. However, more studies are needed to illustrate the mechanism through which dietary isotopic ratios influence the extent of isotopic incorporation into the tissues.     

Pharmacokinetics of three formulations of vitacoxib in horses

The pharmacokinetic properties of three formulations of vitacoxib were investigated in horses. To describe plasma concentrations and characterize the pharmacokinetics, 6 healthy adult Chinese Mongolian horses were administered a single dose of 0.1 mg/kg bodyweight intravenous (i.v.), oral paste, or oral tablet vitacoxib in a 3-way, randomized, parallel design. Blood samples were collected prior to and at various times up to 72 hr postadministration. Plasma vitacoxib concentrations were quantified using UPLC-MS/MS, and pharmacokinetic parameters were calculated using noncompartmental analysis. No complications resulting from the vitacoxib administration were noted on subsequent administrations, and all procedures were tolerated well by the horses throughout the study. The elimination half-life (T_1/2λz) was 4.24 ± 1.98 hr (i.v.), 8.77 ± 0.91 hr (oral paste), and 8.12 ± 4.24 hr (oral tablet), respectively. Maximum plasma concentration (C_max) was 28.61 ± 9.29 ng/ml (oral paste) and 19.64 ± 9.26 ng/ml (oral tablet), respectively. Area under the concentration-versus-time curve (AUC_last) was 336 ± 229 ng hr/ml (i.v.), 221 ± 94 ng hr/ml (oral paste), and 203 ± 139 ng hr/ml, respectively. The results showed statistically significant differences between the 2 oral vitacoxib groups in T_max value. T_1/2λz (hr), AUC_last (ng hr/ml), and MRT (hr) were significantly different between i.v. and oral groups. The longer half-life observed following oral administration was consistent with the flip-flop phenomenon.     

Effects of GnRH treatment on initiation of pulses of LH,LH release,and subsequent concentrations of progesterone

Progesterone is essential for establishment and maintenance of pregnancy. One proposed method to increase progesterone is administering GnRH at insemination. However, this method has resulted in conflicting results. Therefore, 2 experiments were conducted to evaluate how administering GnRH at insemination affected pulses of luteinizing hormone (LH) and subsequent progesterone. In Experiment 1, cows were allotted to 2 treatments: (1) GnRH (100 μg) given approximately 12 h after initiation of estrus (n = 5); and (2) Control (n = 5). Blood samples were collected at 15-min intervals for 6 h at 12 (blood sampling period 1), 26 (blood sampling period 2), 40 (blood sampling period 3), 54 (blood sampling period 4), and 68 (blood sampling period 5) h after onset of estrus. Daily blood samples were collected for 17 d. In Experiment 2, cows were allotted into 2 treatments: GnRH administered 10 to 11 h (n = 10) or 14 to 15 h (n = 10) after onset of estrus. Daily blood samples were collected for 17 d. Cows treated with GnRH tended (P ≤ 0.075) to have greater LH release during blood sampling period 1, tended (P = 0.095) to have fewer pulses during blood sampling period 2, tended (P = 0.067) to have greater concentrations of progesterone, and had an earlier (P = 0.05) increase in progesterone than control cows. Cows treated with GnRH 10 to 11 h after onset of estrus had greater (P = 0.01) progesterone and an earlier (P = 0.04) increase in progesterone than cows treated 14 to 15 h. In conclusion, timing of GnRH treatment following onset of estrus influenced pulses of LH and subsequent progesterone.     

Determination of optimal dietary selenium levels by full expression of selenoproteins in various tissues of broilers from 1 to 21 d of age

The current NRC dietary selenium (Se) requirement (0.15 mg/kg) of broilers is primarily based on growth performance data reported in 1986. Our study aimed to determine optimal dietary Se levels of broilers fed a practical corn-soybean meal diet for the full expression of selenoproteins in various tissues. A total of 384 one-d-old male broilers (n = 8 replicates/diet) were fed a basal corn-soybean meal diet or the basal diet supplemented with 0.1, 0.2, 0.3, 0.4 or 0.5 mg Se/kg in the form of Na₂SeO₃ for 21 d. Regression analysis was conducted to evaluate the optimal dietary Se levels using broken-line, quadratic or asymptotic models. The activity of glutathione peroxidase (GPX) in the plasma, liver, kidney and pancreas, iodothyronine deiodinase (DIO) in the plasma, liver and pancreas, and thioredoxin reductase (Txnrd) in the liver and pancreas, the mRNA levels of Gpx1, Gpx4, Dio1, selenoprotein (Seleno) h, Selenop and Selenou in the liver, Gpx4, Dio1, Txnrd1, Txnrd2, Selenoh, Selenop and Selenou in the kidney, and Gpx1, Gpx4, Selenoh and Selenou in the pancreas, and the protein levels of GPX4 in the liver and kidney of broilers were influenced (P < 0.05) by added Se levels, and increased quadratically (P < 0.05) with the increase of added Se levels. The estimates of optimal dietary Se levels were 0.07 to 0.36 mg/kg based on the fitted broken-line, quadratic or asymptotic models (P < 0.001) of the aforementioned selenoprotein expression in the plasma, liver and kidney, and 0.09 to 0.46 mg/kg based on the fitted broken-line models (P < 0.001) of the aforementioned selenoprotein expression in the pancreas. The results indicate that the optimal dietary Se levels would be 0.36 mg/kg to support the full expression of selenoproteins in the plasma, liver and kidney, and 0.46 mg/kg to support the full expression of selenoproteins in the pancreas of broilers fed a practical corn-soybean meal diet from 1 to 21 d of age.     

Influence of fibre and betaine on development of the gastrointestinal tract of broilers between hatch and 14 d of age

An experiment was designed to determine the influence of fibre and betaine on the development of the intestine, liver and pancreas of broilers from hatch to 14 d of age. A total of 250-day-old Cobb 500 male broilers were allocated to 16 cages with 15 broilers each. Treatments were arranged in a 2 × 4 factorial design, consisting of 2 feed formulations (low and high fibre diets) and 4 levels of betaine (0, 1, 3 or 5 kg/t). At hatch, 10 birds in total were euthanised, and samples of the liver, pancreas, yolk sac and intestine were collected for reference of the analysed parameters before the start of the trial. On d 4, 9 and 14, 5 birds per cage (10 birds per treatment) were selected, euthanised and treated as the same as the birds at hatch. Villus height and width and crypt depth were determined on the duodenum samples, and absorptive area was calculated. The number of enterocytes in mitosis at the villus was determined by a positive reaction to antibody for Ki67 protein, and fused villus was evaluated visually. The relative weight of the yolk sac reduced (P < 0.05) as birds aged while the intestine and liver reached a maximum (P < 0.05) at around d 4 and the pancreas at d 9. Birds fed the high fibre diet had greater feed intake, lower relative weight of the pancreas and higher villus (P < 0.05) than birds fed the low fibre diet. Villus width increased (P < 0.05) at 4 d of age, and this was associated with fused villus. Betaine inclusion reduced (P < 0.05) villus width, increased (P < 0.05) villus size and absorptive area, and reduced (P < 0.05) the number of enterocytes with positive reaction for the antibody Ki-67. Betaine inclusion reduced the width and increased the absorptive area and the villus height of the duodenum of birds up to 14 d of age. The higher fibre diet increased feed intake and villus height, yet reduced pancreas relative weight, while not affecting body weight gain. This response was possibly due to a dilution effect of the fibre, reducing nutrient absorption and consequently stimulating villus growth to improve absorption rates.     

Accuracy of Potassium Supplementation of Fluids Administered Intravenously

Background

Potassium (K⁺) supplementation of isotonic crystalloid fluids in daily fluid therapy is commonly performed, yet its accuracy in veterinary medicine is undetermined.

Objective

To investigate the accuracy of K⁺ supplementation in isotonic crystalloid fluids.

Animals

None.

Methods

Observational study. 210 bags of fluid supplemented with KCl being administered to hospitalized dogs and cats intravenously (IV) were sampled over a 3‐month period. Measured K⁺ concentration ([K⁺]) was compared to the intended [K⁺] of the bag. In a second experiment, 60 stock fluid bags were supplemented to achieve a concentration of 20 mmol/L K⁺, mixed well and [K⁺] was measured. In another 12 bags of 0.9% NaCl, K⁺ was added without mixing the bag, and [K⁺] of the delivered fluid was measured at regular time points during constant rate infusion.

Results

The measured [K⁺] was significantly higher than intended [K⁺] (mean difference 9.0 mmol/L, range 6.5 to >280 mmol/L, P < .0001). In 28% of clinical samples measured [K⁺] was ≥5 mmol/L different than intended [K⁺]. With adequate mixing, K⁺ supplementation of fluids can be accurate with the mean difference between measured and intended [K⁺] of 0.7 (95% CI −0.32 to 1.7) mmol/L. When not mixed, K⁺ supplementation of 20 mmol/L can lead to very high [K⁺] of delivered fluid (up to 1410 mmol/L).

Conclusions and Clinical Importance

Inadequate mixing following K⁺ supplementation of fluid bags can lead to potentially life threatening IV infused [K⁺]. Standard protocols for K⁺ supplementation should be established to ensure adequate mixing.     

The effect of low levels of dietary cobalt on the chemiluminescence response of polymorphonuclear leukocytes of goats

Twenty ten-week-old newly weaned male Batinah goats were randomly assigned to a control (n = 10) and a treated (n = 10) group and were fed a diet containing 0.1 mg/kg DM cobalt (Co). Goats in the treated group received bi-monthly subcutaneous injections of 2000 μg of hydroxycobalamin. The phagocytic function of the polymorphonuclear leukocytes (PMN) were tested using a luminol-dependent chemiluminescence assay with opsonized zymosan as the phagocytic target. One month after the onset of the experiment PMN from the control group exhibited a significantly (p < 0.05) lower CL response, which continued for the second month. The results of the present study demonstrated that low levels of dietary cobalt leads to an early impairment of phagocytic function. This may at least in part, be an explanation as to why at the field level in Oman young goats fed diets containing low levels of Co appear to be more susceptible to infections.