Application of one injection of prostaglandin F2α in the five-day Co-Synch + CIDR protocol for estrous synchronization and resynchronization of dairy heifers

The objective was to determine if the 5-d Co-Synch + CIDR (controlled internal drug releasing insert) protocol can be used in dairy heifers for a synchronized timed artificial insemination (TAI) with one injection of PGF_2α for first and second services. In experiment 1, heifers were assigned randomly to receive 1 (n = 295) or 2 (n = 298) injections of PGF_2α in the 5-d Co-Synch + CIDR protocol. Corpus luteum (CL) regression was measured in one replicate (n = 218). No difference in pregnancy per TAI (P/TAI; 46.1 and 48.6%) or CL regression (86.9 and 92.8%) was detected for 1 versus 2 injections of PGF_2α, respectively. In experiment 2, nonpregnant heifers (n = 86) were assigned to a resynchronized 5-d Co-Synch + CIDR with 1 PGF_2α/TAI or insemination at detected estrus. There was no difference in P/TAI (52.2 and 55%) between groups. In experiment 3, nonpregnant heifers (n = 110) were assigned randomly to receive a CIDR (n = 54) or no CIDR insert (n = 56) in the 5-d Co-Synch protocol for resynchronization of TAI. Pregnancy per TAI was lower without the CIDR device (39.3 vs. 51.8%). In a commercial field evaluation, 416 heifers were synchronized for the first and resynchronized TAI with the 5-d Co-Synch + CIDR protocol with 1 injection of PGF_2α. Pregnancy per TAI on d 60 was 58.2 and 47.5% for first and second TAI, respectively; there was a sire effect to the second TAI. In conclusion, the 5-d Co-Synch + CIDR protocol with 1 injection of PGF_2α is an effective reproductive management program for first and second TAI in dairy heifers.     

CO2-Footprints for Food of Animal Origin – Present Stage and Open Questions

The environmental assessment of human activities is presently a hot topic. It is not only important from an ecological perspective, but also from the view of efficient utilization of limited natural resources such as fuel, land area, water und phosphorus. The environmental impact of food of animal origin is currently quantified by so-called CO_2eq-footprints. To define CO_2eq-footprints, emissions arising along the food chain will be calculated according to their greenhouse potentials (carbon dioxide = 1 eq; methane ≈ 23 eq, laughing gas ≈ 300 eq). For the primary production of milk, meat and eggs, emissions during crop production, transportation, the storing and processing of feeds, animal keeping, enteric losses and excrement management can be mentioned as examples.     

CO2浸渍发酵法研究进展

作为一种特殊的酿酒工艺,CO2浸渍法为酿制新型葡萄酒提供了新的思路。综述了CO2浸渍过程中化学成分和微生物群落的变化以及影响因素,并对CO2浸渍法的应用前景进行了展望。     

超临界CO2萃取玉米黄色素

本文研究了用超临界CO     

TiO2纤维在光催化还原CO2中的应用

以二氧化碳(CO₂)为代表的温室气体可以利用催化剂在太阳光的作用下转化为可回收产物。TiO₂化学性能稳定、毒性低且生物友好，是制备高效光催化剂的备选原料之一。本文对TiO₂催化机理、主要成形工艺和相关改性处理方法进行介绍，并分析材料内部电子运动、光生电子空穴分离和光子吸收效率，探究其对以TiO₂为主体的纳米纤维光催化效率的影响。通过分析对比，为TiO₂纤维结构的设计和对应CO₂产物的还原研究提供思路。     

Temperature-dependent dynamics of bovine casein micelles in the range 10–40 °C

Milk is a complex colloidal system that responds to changes in temperature imposed during processing. Whilst much has been learned about the effects of temperature on milk, little is known about the dynamic response of casein micelles to changes in temperature. In this study, a comprehensive physico-chemical study of casein micelles in skim milk was performed between 10 and 40 °C. When fully equilibrated, the amount of soluble casein, soluble calcium and the pH of skim milk all decreased as a function of increasing temperature, whilst the hydration and volume fraction of the casein micelles decreased. The effect of temperature on casein micelle size, as determined by dynamic light scattering and differential centrifugation, was less straightforward. Real-time measurements of turbidity and pH were used to investigate the dynamics of the system during warming and cooling of milk in the range 10–40 °C. Changes in pH are indicative of changes to the mineral system and the turbidity is a measure of alterations to the casein micelles. The pH and turbidity showed that alterations to both the casein micelles and the mineral system occurred very rapidly on warming. However, whilst mineral re-equilibration occurred very rapidly on cooling, changes to the casein micelle structure continued after 40 min of measurement, returning to equilibrium after 16 h equilibration. Casein micelle structure and the mineral system of milk were both dependent on temperature in the range 10–40 °C. The dynamic response of the mineral system to changes in temperature appeared almost instantaneous whereas equilibration of casein was considerably slower, particularly upon cooling.     

超临界CO2萃取花生油工艺研究

研究了低温下花生油的超临界萃取技术,采用单因素实验研究萃取压力、萃取温度、花生粉碎粒度、CO2气体流量等因素对花生油萃取率的影响,采用均匀实验方法确立花生油超临界萃取的最佳工艺条件.结果表明,萃取的最佳工艺条件为:萃取压力39 MPa,萃取温度59℃,物料粉碎度20目,气体流量30 kg/h,萃取时间为2 h.在此条件下,花生油萃取率可达95%以上,花生油品质较好,清香味纯正,花生粕的蛋白活性保持率可达93%以上.     

超临界CO2萃取枸杞油研究

应用超临界CO     

超临界CO2流体染色的研究进展

介绍了超临界CO2(Supercritical CO2,SC-CO2)流体染色的发展历史、染色原理,详述了超临界CO2染色的工艺流程和国内外研究进展,简述了超临界CO2流体染色的应用前景。     

Effects of high-temperature treatment (⩾100 °C) on Alaska Pollock (Theragra chalcogramma) surimi gels

Surimi gels from Alaska Pollock were obtained by heating and maintaining their central temperature at 100 ± 1 °C, 105 ± 1 °C, 110 ± 1 °C, 115 ± 1 °C and 120 ± 1 °C for 10 min respectively under a certain pressure (0.12 MPa). With temperature increasing, both the breaking force and gel strength decreased significantly (P < 0.05) while the deformation decreased with a much smaller gradient. The ionic bonds and the hydrophobic interactions declined with a drastic rate while the hydrogen bonds and the disulfide bonds took on an increasing trend on the whole. NMR spin–spin relaxation (T₂) measurements showed that most of the water in the gels is movable water, the peak of T₂₂ became lower and the relaxation time of T₂₂ became longer with treating temperature increasing. SDS–PAGE showed that high-temperature treatment decreased the content of myosin heavy chain (MHC) entirely and significantly decreased the content of actin. SEM showed that the gel treated with 100 ± 1 °C showed a uniform network structure with strong frames.     

Characterisation of volatile components of Pinotage wines using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC × GC–TOFMS)

As part of the ongoing research into the chemical composition of the uniquely South African wine cultivar Pinotage, the volatile composition of nine young wines of this cultivar was investigated using comprehensive two-dimensional gas chromatography (GC × GC) in combination with time-of-flight mass spectrometry (TOFMS). Headspace solid phase micro-extraction (HS-SPME) using a carboxen/polydimethylsiloxane (CAR/PDMS) fibre was used to extract the volatile compounds from the wine matrix. Extracts were analysed using an in-house developed GC × GC system equipped with a single jet, liquid nitrogen-based cryogenic modulator. In the current study, 206 compounds previously reported in wine and related matrices have been detected in nine Pinotage wines. Positive identification for 48 compounds was performed using authentic standards, while tentative identification of 158 compounds was based on deconvoluted mass spectra and comparison of linear retention indices (LRI) with literature values. Identified compounds included esters, alcohols, aldehydes, ketones, acids, acetals, furans and lactones, sulphur compounds, nitrogen compounds, terpenes, hydrocarbons, volatile phenols and pyrans. Volatile compounds potentially capable of influencing wine aroma are highlighted. Many of the compounds were common to all 9 wines, although volatile components unique to specific samples were also observed. The results represent the most detailed characterisation of volatile constituents of this cultivar reported to date.     

食用菌等生鲜食品液态N2和CO2深冷冻结技术

介绍了食用菌等生鲜食品速冻技术的最新研究进展与应用情况,就速冻食用菌等生鲜食品加工技术的方法、设备、冻结与冻藏工艺进行综述,并对食用菌等生鲜食品的开发利用前景进行了展望。     

红提葡萄低O2和高CO2处理效果研究

以红提葡萄为试验材料,研究(0±0.2)℃,2.5%O2+5%CO2、2.5%O2+10%CO2、2.5%O2+15%CO2和8%、10%、12%O2条件下气体处理效果。结果表明:CO2对红提葡萄有明显的抑菌作用,(0±0.2)℃处理50d,2.5%O2协同5%、10%、15%CO2处理比单纯低8%、10%、12%O2处理效果好,腐烂率低,硬度变化小;2.5%O2,5%～10%CO2可以取得较好的保鲜效果;2.5%O2+15%CO2处理50d未见高CO2伤害症状,表明新疆产红提葡萄耐高CO2能力强;单纯低O2贮藏时,O2含量在±2%范围变化时就会对果肉硬度、果胶酶活力、PPO活力及SSC产生显著性影响(P<0.05)。     

GC-MS分析荔枝核超临界CO2萃取物

采用超临界CO2萃取荔枝核,并用气相色谱-质谱联用仪对荔枝核萃取物的挥发性成分进行分析。结果表明:超临界CO2萃取荔枝核的萃取率为4.26%,气相色谱-质谱联用鉴定出67种化合物,主要为甾醇类、萜类、不饱和脂肪酸、棕榈酸、脂肪酸酯、VE,相对含量分别为31.3%、25.7%、12.03%、9.63%、7.53%、7.21%。     

清酒罐CO2平衡系统的运用

本文主要针对清酒罐CO₂平衡系统的使用进行交流与探讨。1 CO₂使用分析CO₂在啤酒生产过程中用途很广,主要用于酒液容器备压、脱氧水制备等。啤酒中CO₂含量和罐压、温度的关系为:CO₂（%,m/m）=0.298+4p-0.008t,其中:p—罐压（表压MPa）;t—啤酒温度（℃）当罐体压力达到0.05MPa、酒液温度为-1℃时,酒液中的CO₂含量达到0.50%（m/m）,因此发     

超临界CO2萃取凤眼草挥发油化学成分

为了研究凤眼草挥发油的化学成分,本文采用超临界CO2萃取技术从凤眼草中提取挥发油,并用GC-MS法采用最佳分析条件对化学成分进行鉴定,用峰面积归一法测定各化合物在挥发油中的相对百分含量;通过研究,鉴定出42种化合物,其峰面积相对含量约占挥发油总量的92.91%。凤眼草挥发油的主要组分为邻苯二甲酸异丁辛酯(7.05%),棕榈酸(8.74%),(Z,Z)-9,12-十八碳二烯酸(20.47%),(Z)-9,17-十八碳二烯醛(15.14%),22,23-二氢豆甾醇(14.09%),3,5,6,7,8,8a-六氢-4-8a-二甲基-6-[1-甲乙烯基]-2(1H)萘酮(6.86%),α-香树脂醇(2.04%),羽扇烯酮(3.53%)等。     

超临界CO2萃取茯苓皮中三萜类成分

以茯苓皮为原料,建立超临界CO2萃取茯苓皮中总三萜类化合物的最佳工艺条件。采用超临界CO2萃取技术和有机溶剂提取法对比。设计正交试验考察夹带剂(95%乙醇)用量、萃取压强、萃取温度和萃取时间对萃取率的影响。超临界萃取最佳工艺条件为夹带剂用量按每克茯苓皮2.0mL、压强35MPa、温度65℃、时间60min,总三萜化合物萃取率为2.06%;有机溶剂提取法得总三萜化合物萃取率1.39%。优选出的萃取工艺稳定可靠、简便易行,较有机溶剂提取法萃取率高出48.2%。