樱桃仁的小鼠饲喂安全性评价

研究中国樱桃仁的饲用安全性,为樱桃仁的综合加工利用提供一定的参考依据。用添加不同量(10%,20%和30%)樱桃仁的饲料饲喂小鼠28 d,以普通饲料饲喂的小鼠为对照组,通过称重法分析小鼠的体重变化和脏器系数、用血细胞分析仪分析小鼠血液组分(白细胞数量、红细胞数量、红细胞压积、平均红细胞体积、血红蛋白浓度、平均血红蛋白浓度、平均血红蛋白含量、血小板计数、血小板压积、平均血小板体积、血小板分布宽度)、用化学分析法分析血液中谷丙转氨酶和谷草转氨酶活性以评价樱桃仁的饲用安全性。结果表明:在饲喂周期内,小鼠无异常症状和体征,除少数指标所测结果与对照组有所差别,大部分指标结果都不存在显著性差异,所有指标测得值均在小鼠正常生理指标范围内,未发现毒害作用,鉴于此,初步可以认为樱桃仁作为饲料添加是安全的。     

Ultrafiltration of Acid Whey in a Spiral-Wound Unit: Effect of Operating Parameters on Membrane Fouling

Membrane fouling by acid (cottage cheese) whey could be minimized by appropriate pH adjustment and removal of insoluble particulates. Acidifying pasteurized whey to pH 2 or 3 followed by conventional centrifugal clarification (e.g. 5000g for 20–30 sec) significantly improved flux over that of unadjusted whey. Neutralizing whey to pH 7 was also just as effective provided resulting insoluble particles could be removed efficiently. Operating at 50°C was slightly more beneficial than 40° or 30°C. High flow rates were beneficial only if transmembrane pressure was below some critical value (about 50 psig or 350 kPa in this case). At pressures higher than this, high flow rates significantly increased fouling rates. After prolonged operating time, neither flow rate nor pressure appeared to have a significant effect, due perhaps to a change in the mode of fouling from surface deposition to pore adsorption.     

含气饮料灌装压盖机新型测控系统

本文分析了含气饮料灌装机的一般测控要求 ,介绍了一种新型的由PLC为主控单元 ,传感器、工控机、触摸屏及执行器件相互关联的测控系统     

Clarification of Apple Juice Using Polymeric Ultrafiltration Membranes: a Comparative Evaluation of Membrane Fouling and Juice Quality

The aim of this study was to evaluate the performance of three different commercial polymeric ultrafiltration (UF) membranes during clarification of raw apple juice, comparatively. The influence of membrane pore size, roughness, and hydrophobicity on flux profile and fouling was investigated. The initial flux was simultaneously decreased at the beginning of the process, and quite steady flux was obtained in the membranes with rougher surface and more hydrophobic nature. As the pore size and hydrophobicity increased, the reversible fouling became the major resistance, while cake formation was more prominent for the membranes with narrower pore size. The overall quality results revealed that the main quality characteristics of the raw juice can be better retained by using the membranes that have higher resistance to fouling.     

用嵌入式工控机实现的饲料厂自控系统

采用美国ＲＴＤ公司的ＰＣ１０４型嵌入式工控机为核心的通用型饲料厂自控系统，其特点是组合灵活、功能强、耗电省、可靠性高、开发周期短、投资不高、适于在饲料行业使用。     

新型饲料添加剂——寡糖的研究进展

本文综述了近十五年来在动物营养领域对寡糖的研究结果。这些内容包括：寡糖在单胃动物消化道内的代谢变化；寡糖作为钆普添加剂对动物生产性能，抗病能力，消化道组织学和微生物生态区系的影响；并着重就寡糖做为肠道内有益寄生菌的营养基质，结合，吸收外源性病原菌，调节机体的免疫系统等机理性研究作了综述。     

陶瓷膜和有机膜超滤处理荔枝汁和膜垢分析及荔枝汁品质研究

应用陶瓷膜和有机膜对荔枝汁进行澄清实验,并进行采用总循环模式(TRM)研究跨膜压力(TMP)和循环流量(Qf)对膜通量(Qp)的影响,确定其各自的最优水平;采用批处理模式(TBM)研究这两个参数最优水平的组合工艺。澄清工艺中：无机陶瓷膜效果优于有机聚醚砜膜,最佳工艺条件为陶瓷膜组件、TMP 0.3MPa、Qf 40L/min。研究在TBM下,膜垢的形成原因,对微分方程--＝k(J－Jlim)J2－n进行拟合,拟合R2为无机膜0.8812和0.8478;有机膜为0.9048,并分析膜垢的形成的模式：有机膜的膜垢主要是层垢(n＝0),无机膜的膜垢形成主要是层垢和部分并在膜垢的综合情况(n＝0,n＝1)。并研究TBM模式下,总糖、总果胶、总蛋白、抗氧化活性等影响果汁品质的物质的动态过程,结果表明：在P＜0.05,无机膜在品质的保持比如总糖、抗氧化活性、总酚的截留滤等方面强于有机膜,其余的品质无显著差异。     

超声协同钙浸渍对樱桃番茄贮藏过程中酚类物质的影响研究

研究超声协同钙浸渍处理对樱桃番茄贮藏过程中酚类物质的含量、结构和抗氧化能力以及相关酶活性的影响。结果表明:超声协同钙浸渍处理有效抑制贮藏期间樱桃番茄果实中多酚氧化酶(polyphenol oxidase,PPO)、过氧化物酶(peroxidase,POD)活性和苯丙氨酸转氨酶(phenylalanine ammonia-lyase,PAL)活性,维持总酚含量,延缓后熟。质谱结果表明,超声协同钙浸渍技术有效抑制贮藏期间樱桃番茄果实主要酚酸的消耗,更好的维持酚类物质的结构特性和抗氧化活性。综上所述,超声协同钙浸渍技术能够有效维持樱桃番茄贮藏期间品质特性,增加果实耐贮藏性。     

Protein Concentrate from Chickpea: Nutritive Value of a Protein Concentrate from Chickpea (Cicer arietinum) Obtained by Ultrafiltration and Its Potential Use in an Infant Formula

A protein concentrate from chickpea (Cicer arietinum) obtained by ultrafiltration for special infant formulas was evaluated for nutritive value with and without methionine supplementation. An infant formula prepared with the concentrate was also evaluated. The Adjusted Protein Efficiency Ratio (A-PER) (official method) values, were 1.86 and 2.14 for the concentrate and concentrate plus methionine, respectively (p < 0.05). Relative Net Protein Ratio (R-NPR) values were 77.4% for the concentrate, and 81.3% of ANRC-casein for the supplemented concentrate. Apparent protein digestibility values were significantly higher concentrates with respect to raw chickpea (p < 0.05). An infant formula based on the concentrate had a R-NPR value of 83.6% that of ANRC-casein, compared to 81.3% in the concentrate, indicating no apparent change in protein quality during processing. The infant formula met Codex Alimentarius Commission Standards (FAO/WHO).     

超声协同钙浸渍对樱桃番茄贮藏过程中 番茄红素和品质特性的影响

通过研究超声协同钙浸渍处理对樱桃番茄贮藏过程中理化品质和番茄红素的影响,阐明了超声协同钙浸渍提高樱桃番茄品质特性的原因.采用质构仪、色差计和高效液相色谱仪研究了樱桃番茄贮藏过程中硬度、色泽和番茄红素含量的变化,同时利用核磁共振技术分析了樱桃番茄贮藏过程中番茄红素结构特性的变化.研究结果表明:超声协同钙浸渍处理可促进钙离...     

Ultrafiltration as a tool to study binding of copper to salivary proteins

Ultrafiltration may be a good methodology to investigate binding of copper to salivary proteins. However under physiological conditions, copper particulates can also be counted as protein-bound, causing an increased estimate. To examine if ultrafiltration can provide a meaningful result to a salivary protein–copper binding study, copper species in ultrafiltration fractions of saliva were identified and compared to those of control (water). A range 20–40% copper was recovered from retentate of water samples at salivary pH, whilst most copper was filtered out at pH 5.5. Saliva samples showed higher copper retention than water samples at same salivary pH. These results demonstrate that copper particulates were retained with protein-bound copper on ultrafiltration membrane, suggesting that estimate of binding should be interpreted with care.     

牛皮胶原蛋白切向超滤工艺参数的优化

如何获得高纯度胶原是实现动物皮胶原高值转化利用的关键。本文研究了将切向超滤技术用于牛皮胶原蛋白的纯化处理,考察了透膜压、切向流量、胶原蛋白浓度和透析倍数对超滤过程的影响。结果表明,对截留量为50kDa的聚醚砜膜优化得到的最佳超滤参数为：透膜压为0．102～0．118MPa,切向流速为57．6L／h,胶原浓度为2mg／mL,透析倍数为6．67,采用该工艺条件可获得较高纯度胶原。     

氧弹燃烧——离子色谱法测定饲料中氟离子含量

建立了氧弹燃烧-离子色谱法测定饲料中氟离子的分析方法。结果表明:用2.5 MPa的氧气压力氧弹燃烧分解样品,然后用离子色谱法测定饲料中氟离子的含量,建立了KOH梯度淋洗程序为10～40mmol/L,流速为1.0 mL/min。氟离子的线性范围为0.5～50 mg/L,饲料中氟的检出限为2.4μg/kg;平均回收率为91.0%～101.7%,相对标准偏差为0.76%～2.97%。本方法具有操作简便,检测干扰小,结果准确可靠的优点。     

Whey Protein-Based Gel as a Model Material for Studying Initial Cleaning Mechanisms of Milk Fouling

The dissolution kinetics and mechanical properties of whey protein concentrate (WPC) gels were investigated as part of a general study on cleaning mechanisms of milk fouling. The dissolution results showed that the WPC gel is a suitable model material to simulate milk fouling and the dissolution process is a major factor controlling the cleaning process. The hardness, elastic modulus, and fracture load of the WPC gels decreased significantly when they were treated with alkaline solution, indicating that certain physical and chemical changes occurred in these treated gels; as a result, different dissolution rates were observed. The results obtained in this article provide a good foundation for further studies on the cleaning mechanisms of milk fouling using WPC gels.     

Ineffective Cleaning of Polysulfone Ultrafiltration Membrane Systems and Corrosion by Bisulfite Used as a Sanitizer

Bisulfite solution was used to sanitize polysulphone ultrafiltration membranes. The ultrafiltration system consisted of a 380-L jacketed vat with agitator, prefilter, centrifugal pump, and two polysulphone ultrafiltration membranes in parallel with valves and pressure gauges before and after the membranes. The system was soiled by recycling 380 L of sweet whey (40°C) for 2.0 h followed by concentrating (by diverting permeate steam to drain) whey for .5 h. The cleaning cycle consisted of acid cleaner (.5 h, 40°C) followed by enzyme cleaner (10.0 h, 40°C) and rinsing (2.0 h, 40°C). A .2% sodium metabisulfite solution was circulated for 5 min and the ultrafiltration unit left idle overnight. Swabs and rinse water samples were taken immediately after soiling, after cleaning, and the next morning to check sanitizing. Samples were plated on plate count agar and potato glucose agar (acidified with tartaric acid to pH 3.5) to determine numbers of bacteria, yeasts, and molds. Effectiveness of bisulfite was pH dependent. At pH 4.7, bisulfite solution was ineffective in controlling microorganisms and at pH 3.5, bisulfite was microstatic. Compared with trials with Antibac B (30 ppm Cl), bisulfite (pH 3.5) was similar for controlling bacteria, yeasts, and molds. Extensive corrosion of stainless steel housings was apparent following long-term contact (2 wk) with bisulfite solution. Laboratory trials using stainless steel fittings, plates, and rubber gaskets found that extensive corrosion and pitting of stainless steel and leaching of gaskets by bisulfite solution required several conditions: low pH, exposure to bisulfite vapors, use of 304 type stainless steel, and oxygen. Intermittent or continuous exposure to acidic bisulfite vapors resulted in corrosion. Antibac B (30 ppm Cl) did not show similar corrosion or leaching effects.     

Fermentation of a High Concentrate Diet as Affected by Ruminal pH and Digesta Flow

Continuous culture fermentations were conducted to determine the effect of pH and digesta flow rates on fermentation of a 65% grain, 35% forage ration by rumen microorganisms. The pH selected were 5.8, 6.2, 6.6, and 7.0. Imposed on each pH in a randomized complete block design were digesta flow rates of 30/4, 26/8, 22/12, and 18/16, where the first number represents solids retention time (hour) and the second the liquid dilution rate (percent/hour).Digestibility of organic matter, neutral detergent fiber, and nitrogen was significantly depressed at pH 5.8, increased markedly at pH 6.2, and increased only slightly at pH 7.0. Digestibility of total nonstructural carbohydrate averaged 91.4% and was not affected by digesta flow rate or pH.Production of total volatile fatty acid was highest at pH 6.2 and 6.6. Overall means for acetate production increased, but propionate and butyrate production decreased as pH was increased from 5.8 to 6.2 with little response to further pH increases.Microbial efficiency decreased with increasing pH but increased 36% as digesta flow rate increased. The percentage of the microbial population associated with effluent neutral detergent fiber was decreased when pH was reduced below 6.2, which reflects the pattern seen for fiber digestion.     

Ultrafiltration of Milk on French Farms and in the Making of a New Specialty Cheese Industry

Ultrafiltration and thermization of milk on dairy farms in France have been under study since 1979. More recently five dairy farms in Brittany have been routinely producing 2:1 whole milk retentate for Emmental and St. Paulin cheese making. The milk processed is ultrafiltered at 35°C and thermized at 72°C for 15 s in an Ultratherm unit. Cheese quality generally appears satisfactory.In Eastern France a new specialty cheese industry has been started utilizing 4.5:1 whole milk retentate produced by ultrafiltration conducted at 40°C. The specialty cheese attains its characteristic white surface from Penicillium album mold. It has a bland, nutty flavor and very soft, smooth texture. A surface bluing phenomenon occurs after 14 d.