Investigations on the Effect of Ozone as a Disinfectant of Egg Surfaces

The feasibility of gaseous ozone to reduce the number of microorganisms on the shell surface, of Salmonella Enteritidis (S.E.) in particular, of avian hatching eggs was investigated. Shell eggs were externally contaminated with S.E. to contain either 10²–10⁴ or 10⁵–10⁶ cfu/shell. Subsequently, the eggs were exposed to several ozone concentrations ranging from 0.5% to 5% wt/wt in combination with two relative humidities (< 30, > 70%) at room temperature. Exposure times varied between 20 minutes and 24 hours. A complete inactivation of 10²–10⁴cfu S.E./egg shell was reached by using an ozone concentration of 1% (wt/wt) for 120 min. Considering higher concentrations of S.E. on the shell ozone treatment caused approximately a 6 log₁₀ reduction. This demonstrates that gaseous ozonation is suitable for applications in hatcheries provided that high-power ozone generators are available. The parameters should be verified in large ozone cabinets.     

Microbial Responses after Disinfectant Change to Ozone in a Full-Scale Distribution System

Ozone is a promising alternative disinfectant when the concentration of organic carbon is high in the source water. The microbial responses to primary disinfectant change from monochloramine to ozone in a full-scale distribution system were investigated. Several water quality parameters including heterotrophic bacteria and a new parameter, growth potential (GP), were determined from the finished water and at three different distribution system locations before and after switching to ozone for a period of 12 months. The GP assesses the potential of the water to sustain growth of bacteria. The literature suggests that ozonation will result in a higher biodegradable organic carbon concentration and will therefore stimulate bacterial growth. Biodegradable organic carbon concentration (BDOC) and HPC increased but GP decreased after ozonation during the study period. In order to exclude seasonal effects, the data from the same seasons of the previous year were compared in the statistical analyses. Our findings showed that among the water quality parameters, HPC, disinfectant dose and total organic carbon (TOC) concentration showed statistically significant differences between the two years (paired t-test, p<0.05). When ozone was used as primary disinfectant the TOC was 1.5 times higher than when chloarmine was used, but the HPC and disinfectant dose were lower. Thus the switch of the primary disinfectant to ozone did not increase bacterial growth. At the lower dose, the disinfectant dose was effective enough to control bacterial regrowth in the distribution system during the study period.     

喷雾干燥法生产麦胚粉的工艺研究

文章以产品的溶解时间为主要指标,通过单因素及正交优化试验,研究了压力式喷雾干燥法生产麦胚粉的工艺以及喷雾压力、进风温度、物料浓度等工艺参数对冲调性能的影响.试验表明,当喷雾压力为0.9 MPa,进风温度180 ℃、料液浓度25%时,所得的麦胚产晶具有较好的冲调性.     

Comparison of the Effects of Ozone,UV and Combined Ozone/UV Treatment on the Color and Microbial Counts of Wheat Flour

The effects of direct ozone treatment, UV treatment and combined ozone/UV treatment on the color and microbiological count of milled wheat flour were compared. The changes in color and microbiological properties during a 19-week storage period were also examined. Each of the treatments significantly reduced the microbial count of the flour and resulted in whiter flour. The results showed that only the combined treatment furnished flour suitable for consumption. The effect of the combined treatment was similar to, but more pronounced than that of ozone treatment. Changes in the quality of the dough were observable, similar by as in response to other oxidizing agents.     

Effects of Atmospheric Chemical and Climate Change on Tropospheric Ozone

Changes in atmospheric levels of certain pollutants (CH₄, CO, NO_X, nonmethane hydrocarbons) have the potential to affect tropospheric O₃ formation and the abundance of the free radical OH on a global scale. Perturbations to stratospheric O₃ and climate (temperature and moisture) also can influence tropospheric O3 and OH. We have used a tropospheric photochemical model with projections of CO, NO_X, and CH₄ to predict tropospheric ozone and OH changes from 1980-2030. The calculations simulate the background chemistry of various global regions and assume that increases in CH₄ and CO will continue at current rates. Predicted changes in tropospheric O₃ and OH are different in urban and nonurban areas, and in marine and continental regions.

Generally, increasing levels of CH₄ and CO at constant NO_X levels will increase O₃ and suppress OH. A rough estimate of possible global changes shows tropospheric O3 increasing ?10% from 1980 to 2030 and OH decreasing ?10% during that period. When calculations are performed assuming that stratospheric ozone depletion and climate warming occur at anticipated rates during the same period, tropospheric O₃ enhancement and OH loss in nonurban areas are both reduced relative to changes assuming that only CH₄ and CO emissions change.

Regional changes in surface-level O₃, OH and the water-soluble oxidant H₂O₂ are estimated for the year 2030. Increases in CO and CH₄ suppress OH and enhance O₃ and H₂O₂ in nonpolluted (low NO_X) areas. In urban environments (background NO_X > 1 ppbv), increases in CO and CH₄ add significantly to all three oxidants, O₃, OH and H₂O₂. Changes in and near urban areas may be of greatest magnitude, but the high levels of OH (and H₂O₂) found in the tropics indicate that perturbations in that region could dominate future global oxidant changes.     

Extraction and Demulsification of Oil From Wheat Germ,Barley Germ,and Rice Bran Using an Aqueous Enzymatic Method

An aqueous enzymatic method was developed to extract oil from wheat germ. Wheat germ pretreatment, effect of various industrial enzymes, pH, wheat germ to water ratio, reaction time and effect of various methods of demulsification, were investigated. Pretreatment at 180 °C in a conventional oven for 4 min reduced the moisture 12.8–2.2 % and significantly increased the oil yield. Adding a combination of protease (Fermgen) and cellulase (Spezyme CP) resulted in a 72 % yield of emulsified oil from wheat germ (both commercial and laboratory milled wheat germ). Using the same oil extraction conditions optimized for wheat germ, yields of 51 and 39 % emulsified oil were obtained from barley germ (laboratory milled), and rice bran, respectively. Three physical demulsification methods (heating, freeze-thawing, and pH adjustment) and enzymatic methods (Protex 6L, Protex 7L, Alcalase, Fermgen, Lysomax and G-zyme 999) were compared. After demulsification with Protex 6L, free oil yields of 63.8 and 59.5 % were obtained with commercial wheat germ and with laboratory milled wheat germ, respectively. Using the same demulsification conditions optimized for wheat germ, yields of 45.7 % emulsified oil and 35 % free oil were obtained for barley germ and rice bran, respectively.     

Antioxidant Activities and Phenolic Compositions of Wheat Germ as Affected by the Roasting Process

Wheat germ is a good source for wheat germ oil, and it is a by‐product with highly concentrated nutrients from the wheat flour‐milling industries. In the present study, raw wheat germ was firstly heat‐treated at 180 °C for 20 min in a fluidized bed dryer, and further roasted at 180 °C for different periods of time. Roasting influence on total phenolic content (TPC), antioxidant activities, and phenolic compositions of wheat germ were evaluated. The roasting process significantly increased the TPC and antioxidant activities including free radical scavenging against DPPH and ABTS radicals, FRAP, and ORAC. In particular, the wheat germ roasted at 180 °C for 20 min showed higher antioxidant activity than those roasted at 180 °C for 5 and 10 min. Three major phenolic acids, namely, ferulic, chlorogenic, and caffeic acid, and four main flavonoids, namely, schaftoside and its isomers or adduct of sinapic acid were identified by HPLC. In general, the content of individual phenolic compounds decreased with prolongation of the roasting time except for ferulic acid. The results suggest that the antioxidant activities of wheat germ can be enhanced by roasting, and the enhancement effect might be partially attributed to the formation of Maillard reaction products (MRP).     

Effect of Moisture and Heat Treatment of Corn Germ on Oil Quality

The changes in the quality of crude corn oil caused by moisture and two different thermal pretreatments (oven heating and steam heating) of wet‐milled corn germ were evaluated and compared with those of untreated oil. Increasing the moisture content of the corn germ from 8 to 25% before oil extraction increased the acid value (AV) (3.02–4.01 mg KOH g^?1), peroxide value (PV) (0.52–1.05 meq kg^?1), and the red value (7.3–8.7) and decreased the content of total tocopherols by 37% and that of γ‐tocopherols by 31%. Oven heating tended to decrease the AV and PV while steam heating significantly increased the total and individual tocopherol contents (P < 0.05). The different moisture contents and thermal pretreatments of corn germ caused no significant differences in the fatty acid composition and the contents of total and individual phytosterols of the crude oils. The γ‐tocopherol contents were found to be highly correlated with the red values (the corresponding R² reached 0.9977 and 0.9089 for moisture and heat pretreatments, respectively).     

The Chemical Reactions of Ozone and Their Role in Developing Improved Analytical Methods

Most methods for the determination of ozone have been developed by utilizing, with or without odifications, existing methods for chlorine determination. The problem with this approach is that ozone chemistry is very different from chlorine chemistry. We believe that a detailed understanding of the mechanism of ozone decomposition and the chemistry of the by-products is essential in order to develop selective methods forozone. This paper briefly describes the ozone decomposition mechanism and introduces the concept of an “Ideal Method. The indigo method is examined as an “Ideal method” and the automation of this method by Flow Injection is discussed.     

麦芽油衍生物在化妆品中的应用

介绍了麦芽油衍生物的特性,结构及其在化妆品配方中的应用。     

Comparison of Ozone Efficiency for Manganese Oxidation Between Raw and Settled Water

Ozone was tested at the Moores Bridges WTP as a replacement for chlorine for oxidizing dissolved manganese. Two points of ozone application were tested, raw and settled water. Dissolved manganese appeared to be much more readily oxidized with a lower ozone dose when ozone was applied to the settled water than when it was applied the raw water. Apparently the TOC concentration of the water affected ozone's ability to oxidize manganese by exerting an ozone demand which must be overcome. Because of the results of the pilot testing, a decision was made to ozonate settled water rather than raw water to oxidize the manganese.     

The Effect of Salts on Ozone Oxidation Processes

Much research on ozone oxidation is performed using model wastewaters, containing a number of organic compounds to be degraded. In some cases they contain low concentrations of inorganic buffers to stabilize the pH during the experiments. In practical applications, however, salts and detergents may be present as well. The effect of such compounds on the process has to be investigated to prevent unexpected results in pilot- or full-scale applications. To quantify these effects, experiments have been performed on model waste waters in the absence and the presence of high concentrations of several inorganic salts. The oxidation selectivity in these experiments was interpreted using Hammett free-energy relationships. The effect of the different salt concentrations on the oxidation selectivity when considering reactions in the bulk of the liquid was seen to be small. This implicates the design of an ozone-based oxidation system can often be based on literature or calculated data regarding reaction rates. However, the effect of increased salt concentrations on ozone solubility and bubble size distribution may have implications for the reactor design, as these factors affect the mass transfer efficiency.     

Possibility of Improvement on Ozone Production by Using the Back-Corona Effect

Electrostatic precipitators’ problems and experimental results in point-to-plane or wire-to-cylinder systems indicate that the presence of a thin layer of porous dielectric material on the electrodes increases the discharge current for the same applied potential. This socalled Back-Corona effect, which generally reduces the sparking potential, depends on the active electrode polarity; nature, and thickness and porosity of the insulating layer; and position on the active or passive electrode of the deposited particles or insulating layer. In laboratory experiments in a point-to-plane device, with a dielectric porous layer on the plane, the current may be many times higher than its “normal” value (clean electrodes). In a DC negative wire-to-cylinder system, where the ozone concentration depends quasi directly on the discharge current, it appears possible to increase the ozone production, for the same running conditions (gas flow, electrical circuit, etc.).     

The Effect of Ozone on Cold Water Coagulation

The application of pre-coagulation ozone in drinking water treatment to provide primary disinfection, has an impact on coagulation and flocculation, and needs to be evaluated further for cold water temperatures, especially when accompanied by episodes of high alkalinity and dissolved organic carbon (DOC). Ozone application to raw water, prior to the addition of coagulants and coagulant aides, was shown to reduce coagulant and coagulant aide doses, and improve settled and filtered water turbidity. The impact on particle count was also noticeable, filtered water particle count was reduced after the application of pre-coagulation ozonation. Pilot-scale experiments were conducted at the Walkerton Clean Water Centre, Walkerton, Ontario, Canada, to investigate the effect of pre-coagulation ozonation, on filtered water turbidity, particle count, and filter performance, during periods when water temperatures could be lower than 5°C.     

以小麦秸杆为原料生产乙二醇的可行性探索

以小麦秸杆为原料生产乙二醇的可行性探索。通过系统分析和实验,各方面都得到很好的结果,预处理产率为99.5%、发酵产率为93.60%、秆转化总产率为29.50%;并且得到的乙二醇质量达到国家标准水平,属于合格产品。以小麦秸杆为原料生产乙二醇也是可行的。     

Effect of Ozone on Fruit Quality and Fungicide Residue Degradation in Apples during Cold Storage

ABSTRACT

The potential of the ozone-enriched atmosphere for the improvement of the shelf life of apples of Gloster variety (Malus domestica) in cold storage was investigated. The storage experiment was conducted for 84 days. During that period, ozone at the concentration of 1 ppm was dosed every 12 hours for 1 minute. However, the exposure to ozone at such a concentration was unsuccessful in terms of inhibition of fungal disease development. Furthermore, the captan level in apples was reduced; therefore, they were more susceptible to fungal disease. On the other hand, the tests of the physical properties showed that utilization of ozone slowed down the ripening of apples; therefore, extending their shelf life provided that they were not infected.     

Oxidation by UV and Ozone of Organic Contaminants Dissolved in Deionized and Raw Mains Water

Organic contaminants dissolved in deionized pretreated and raw mains water were reacted with ultraviolet light and ozone. Ozone first was used for partial oxidation followed by ozone combined with ultraviolet radiation to produce total oxidation. The reduction of TOC level and direct oxidation of halogenated compounds were measured throughout the treatment process. The rate of TOC reduction was compared for ozone injected upstream and inside the reactor.