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1.
    
The effect of spray dryer processing parameters on the product yield and insecticidal activity of baculovirus was evaluated. Spray-dried samples of a granulovirus (GV) from Pieris rapae (L.) and a multiple nucleopolyhedrovirus (MNPV) from Anagrapha falcifera (Kirby) were prepared using two dryer-atomiser configurations (rotary atomiser and two-fluid spray atomiser), four drying temperatures (50–100°C outlet temperatures) and two encapsulating formulations (lignin and methacrylic acid polymer). The samples were evaluated based on yield and insecticidal activity under laboratory conditions. The two atomising configurations produced similar outlet temperatures for dryer stock feed rates of 4.12 and 20 ml/min when processed using increasing inlet temperatures. The atomiser selection significantly affected the physical properties like the product yield; the microparticles produced with a two-fluid spray atomiser had lower product yields (57.8 ± 18.80% – 74.6 ± 4.26%) when compared with paired samples produced with a rotary-disc atomiser (58.1 ± 7.13% – 82.6 ± 3.12%). Spray drying reduced insecticidal activity of the GV but did not significantly reduce insecticidal activity of the MNPV when compared with samples that were not dried. Among dried samples, the spray dryer processing parameters (atomiser, drying temperatures and formulation) had minimal effect on the insecticidal activity of either baculovirus. The versatility of spray drying for processing baculoviruses was demonstrated by identifying parameters that improve process yield while having minimal impact on insecticidal activity.  相似文献   

2.
    
The identification of effective solar protectants for field application of the codling moth, Cydia pomonella (L.), granulovirus (CpGV) is of interest to improve its efficacy and commercial viability as a biological pesticide. We evaluated several materials as potential adjuvants to protect CpGV from ultraviolet degradation. In laboratory tests with a solar simulator (9.36×106 J/m2), the addition of kaolin clay (Surround® WP at 3 and 6%, w/v), a paraffin wax-based emulsion (SPLAT? at 5%, v/v), and a bark extract trans-cinnamaldehyde combined with a film agent (both at 1%, v/v) did not significantly reduce larval entries or increase larval mortality in irradiated apples that were treated with a commercial CpGV product (Cyd-X). In semi-field tests in an apple orchard, a spray-dried lignin formulation containing CpGV (6.57×1012 OBs/ha) and a lignin-based adjuvant used with Cyd-X (both applied at 4.7–5.6 kg lignin/ha) significantly improved residual activity of CpGV compared with Cyd-X alone applied at the same rate. However, the benefits were short lived and could not be detected after 7 days. In orchard tests, we evaluated two additional refined lignin-products (Lignosulfonate and Vanisperse? CB at 5.61 kg/ha) and two particle film materials (kaolin clay, ‘Cocoon?’, and calcium with boron ‘Eclipse?’) as adjuvants for UV protection of Cyd-X (6.57×1012 OBs/ha) in tests against a dense codling moth infestation. Although all virus treatments were highly effective (causing ≥90% larval mortality), no significant effects of the adjuvant treatments could be detected. In these latter tests, the use of a silicone based wetting agent at 0.025% (v/v) may have been beneficial at increasing mortality among older larvae inside the fruit.  相似文献   

3.
The entomopathogenic fungus, Beauveria bassiana, is highly susceptible to the damaging effects of solar radiation. This study demonstrates protection from simulated solar radiation by coating B. bassiana (GHA) spores with lignin and effects on pathogenicity to Lygus lineolaris (Palisot de Beauvois) adults in direct spray and contact uptake bioassays. Spores were coated with either lignin or cross-linked lignin by spray drying to produce spore coatings of high and low water solubility, respectively. Non-coated spores and the two spore coating treatments were suspended in either water (0.04% Silwet L77) or oil (Orchex 692) to produce six formulations. Rates of loss in spore viability under simulated solar radiation were approximately ten times lower for the three formulations in which spores remained coated in suspension (cross-linked lignin in water, cross-linked lignin in oil, and lignin in oil). However, these three formulations were the least pathogenic. Estimates of LC50 and LC75 values for the most pathogenic formulation (non-coated in oil) were 5 and 12 times lower, respectively, than the least pathogenic formulation (cross-linked lignin in oil), but these differences were not significant. The three lignin-coated formulations that provided the greatest UV protection were also the least pathogenic based on LT values, which were significant. Overall, L. lineolaris mortality was approximately 80 times less when exposed to treated broccoli rather than sprayed directly, based on LC50 values. If the contribution of spore uptake from plant surfaces to L. lineolaris mortality is similarly low under field conditions, then improving persistence may be less important for improving efficacy. However, under control conditions where solar radiation significantly impacts mycoinsecticide efficacy, the improved persistence of lignin coating formulations may outweigh negative effects on pathogenicity.  相似文献   

4.
本研究旨在研制一种基于黄花菜的固体饮料。以黄花菜为主要原料,以感官评分、冲泡性能为指标,采用响应面试验对黄花菜固体饮料的配方和干燥工艺进行优化。试验表明,黄花菜固体饮料配方的响应面优化结果为:食盐添加量0. 01%,麦芽糊精添加量2. 0%,马铃薯全粉添加量1. 0%,奶粉添加量4. 5%,黄花菜与水比值1∶9(m∶v);此配方下研制出的黄花菜固体饮料流动性最佳,表征值为72. 855 mm。喷雾干燥的最佳工艺参数是进风温度为180℃,入料流量为1. 5 mL/min;所得样品的感官评分值为94. 2,流动性表征值为71. 65mm,润湿性表征值为27. 75 min。  相似文献   

5.
The purpose of this research was to develop the taste-masked microspheres of intensely bitter drug ondansetron hydrochloride (OSH) by spray-drying technique. The bitter taste threshold value of OSH was determined. Three different polymers viz. Chitosan, Methocel E15 LV, and Eudragit E100 were used for microsphere formation, and the effect of different polymers and drug–polymer ratios on the taste masking and release properties of microspheres was investigated. The microspheres were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, Drug loading, in vitro bitter taste evaluation, and drug-release properties. The taste masking was absent in methocel microspheres at all the drug–polymer ratios. The Eudragit microspheres depicted taste masking at 1:2 drug–polymer ratio whereas with Chitosan microspheres the taste masking was achieved at 1:1 drug–polymer ratio. The drug release was about 96.85% for eudragit microspheres and 40.07% for Chitosan microspheres in 15 min.  相似文献   

6.
为了建立脑康颗粒的制粒方法,以葛根素含量和制粒情况作为评价指标,采用喷雾干燥——一步制粒联合流化制粒技术对制粒条件进行优化。将经提取、浓缩所得浸膏的2/3进行喷雾干燥,得干燥粉末,并以之为一步制粒的母核,余下1/3量的浸膏作为粘合剂进行一步制粒。结果表明,所得产品质量可控性强,同时该法具有速度快,生产工序简单等优点,可用于进行脑康颗粒的制备。  相似文献   

7.
The basic objectives of this study were to prepare and characterize solid dispersions of poorly water-soluble drug etoricoxib using lipid carriers by spray drying technique. The properties of solid dispersions were studied by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), differential scanning calorimetry (DSC), hotstage microscopy (HSM), radiograph powder diffraction (XRPD), and dissolution studies. The absence of etoricoxib peaks in XRPD profiles of solid dispersions suggests the transformation of crystalline etoricoxib into an amorphous form. In the HSM examination of solid dispersions, the dissolution of drug in the lipid carriers was observed, which was also confirmed by the absence of etoricoxib peak in DSC curves of solid dispersions. The DRIFTS spectra revealed the presence of hydrogen bonding in solid dispersions. The in vitro dissolution rate of solid dispersions as compared with pure etoricoxib, spray-dried etoricoxib, and physical mixtures of drug with lipid carriers. Therefore, the dissolution rate of poorly water-soluble drug etoricoxib can be significantly enhanced by the preparation of solid dispersions using lipid carriers by spray drying technique. Published: October 19, 2005  相似文献   

8.
Spore survival and moisture content are two important properties of biopesticides, and both are related to field biocontrol efficacy and storage shelf life. In this study, Paenibacillus polymyxa (HY96-2) was spray-dried on both pilot plant and production scales, and the effects of inlet and outlet temperatures on spore survival and moisture content were investigated. The results showed that inlet temperatures ranging from 170 to 230 °C (at an outlet temperature of 80 °C) had no obvious effect on the two properties during pilot scale processing, although an inlet temperature of 230 °C resulted in higher feed speed. When the outlet temperature on the pilot scale was reduced from 100 to 80 °C, no obvious variations in spore survival and moisture content were found, while a further reduction from 80 to 65 °C resulted in a decline in spore survival from 81.0 to 67.0% and an increase in moisture content from 2.3 to 31.7%. These results indicate that both outlet temperature and moisture content have an effect on spore survival. Optimum inlet and outlet temperatures for P. polymyxa processing were 230 °C and 85–90 °C on a production scale. Under these conditions, spore survival and moisture content were 83.5–86.6% and 2.73––4.12%, respectively.  相似文献   

9.
Aim: To ferment buttermilk, a low‐cost by‐product of the manufacture of butter, with a proteolytic strain of Lactobacillus helveticus, to enhance its value by the production of a functional peptide‐enriched powder. Methods and Results: Buttermilk was fermented with Lact. helveticus 209, a strain chosen for its high proteolytic activity. To enhance the release of peptidic fractions, during fermentation pH was kept at 6 by using NaOH, Ca(CO)3 or Ca(OH)2. Cell‐free supernatant was recovered by centrifugation, supplemented or not with maltodextrin and spray‐dried. The profile of peptidic fractions released was studied by RP‐HPLC. The lactose, Na and Ca content was also determined. The powder obtained was administered to BALB/c mice for 5 or 7 consecutive days, resulting in the proliferation of IgA‐producing cells in the small intestine mucosa of the animals. Conclusions: Buttermilk is a suitable substrate for the fermentation with Lact. helveticus 209 and the release of peptide fractions able to be spray‐dried and to modulate the gut mucosa in vivo. Significance and Impact of the Study: A powder enriched with peptides released from buttermilk proteins, with potential applications as a functional food additive, was obtained by spray‐drying. A novel use of buttermilk as substrate for lactic fermentation is reported.  相似文献   

10.
本文采用喷雾干燥法制备高纯α-亚麻酸为芯材、亚麻籽胶为壁材的微胶囊,并以微胶囊化效率和含油率为指标,考察了制备工艺.结果表明,最佳微胶囊原料配方为:芯材与壁材的比例为(m/m)3∶2,料液浓度为5%,进料温度为20℃;最佳喷雾干燥工艺条件:进风温度为180℃,出风温度为80℃,雾化器转速21000 rpm,进料速度为42.01 mL/min.在此工艺条件下亚麻酸的微胶囊化效率为96.18%,含油率为60.09%.  相似文献   

11.
Aims:  This work aims to investigate the survival of Lactobacillus kefir CIDCA 8348, Lactobacillus plantarum CIDCA 83114 and Saccharomyces lipolytica CIDCA 812, all isolated from kefir, during spray drying and subsequent storage.
Methods and Results:  Micro-organisms were grown in De Man, Rogosa, Sharpe (MRS) or yeast medium (YM) medium and harvested in the stationary phase of growth. The thermotolerance in skim milk ( D and Z values), the survival of spray drying at different outlet air temperatures and subsequent storage in different conditions during 150 days were studied. The resistance to the heat treatments was higher in Lact. plantarum compared to Lact. kefir and S. lipolytica . The three micro-organisms studied varied considerably in their ability to survive to spray drying processes . Lactobacillus plantarum showed the highest survival rate for all the tested outlet air temperatures and also to the further storage in the dried state. The survival rates of Lact. kefir and S. lipolytica through drying and subsequent storage in the dried state decreased when the drying outlet air temperatures increased.
Conclusions:  Spray drying is a suitable method to preserve micro-organisms isolated from kefir grains. A high proportion of cells were still viable after 80 days of storage at refrigerated temperatures
Significance and Impact of Study:  It is the first report about spray-dried probiotic strains isolated from kefir grain and contributes to the knowledge about these micro-organisms for their future application in novel dehydrated products.  相似文献   

12.
对黑米花青苷浸膏进行喷雾干燥的响应面实验。喷雾干燥的特点是干燥迅速,颗粒均匀,可以大范围使用,可加工的物料多样,操作简单稳定,适合工业化生产。响应曲面设计方法是利用合理的试验设计并通过实验得到一定数据,采用多元二次回归方程来拟合因素与响应值之间的函数关系,通过对回归方程的分析来寻求最优工艺参数,是解决多变量问题的一种统计方法。采用此方法优选黑米花青苷浸膏的喷雾干燥工艺。以喷雾干燥过程的出粉率、干粉中黑米花青苷的含量为指标,考察进风口温度、浸膏比重、蠕动泵泵速,对黑米花青苷浸膏喷雾干燥工艺的影响。结果表明,在进风口温度154.04 ℃ ,浸膏比重1.05,蠕动泵泵速10 r/min的条件下得到黑米花青苷粉末成粉率为38.08%,粉末中花青苷含量为112.758 mg/g。该优选工艺参数可为黑米花青苷的工业化生产提供实验依据。  相似文献   

13.
AIMS: To obtain beta-carotene-rich dry cell preparation from mutant 32 of Rhodotorula glutinis and determination of its pigment stability. METHODS AND RESULTS: The mutant 32 of R. glutinis was grown in a 14 l stirred tank fermenter. Cell mass was concentrated 10-fold by cross-flow microfiltration and then spray dried. Butylated hydroxy toluene (BHT) and d-tocopherol were used as protecting agents. A two-level, three-variable, factorial optimization was performed to achieve moisture-free, non-viable and beta-carotene-rich feed additive. CONCLUSIONS: The beta-carotene and cell mass in stirred tank fermenter were found to be 54 +/- 5 mg l-1 and 12.8 +/- 2 g l-1, respectively. In the presence of BHT, 97 +/- 3% (w/w) beta-carotene was recovered for all the inlet temperatures studied. The best beta-carotene and yeast powder recoveries were obtained at 160 degrees C, 11.6% (w/v) cell mass concentration and 1 g l-1 BHT. The pigments inside dried yeast powder were stable in dark and cold condition for at least 10 weeks. The purified beta-carotene got almost totally denatured, under similar conditions of storage, within 76 h. SIGNIFICANCE AND IMPACT OF THE STUDY: Spray dried and stable preparation of beta-carotene-rich yeast, R. glutinis can provide alternative source of beta-carotene for use in animal nutrition.  相似文献   

14.
Drug delivery systems that are based on pectin have been studied for colon specific delivery using the specific activity of colon microflora. The aim of this study was to design a novel method of manufacturing pectin microspheres without oils and surfactants and to investigate the potential use of the pectin microsphere as an oral colon-specific drug carrier. The pectin microspheres were successfully formed using the spray drying method and crosslinking with calcium chloride. From the crosslinked pectin microspheres, indomethancin (IND) release was more supressed than its release from non-crosslinked microspheres. In a low pH (pH 1.4) environment, the pectin microspheres released IND at an amount of about 18±2% of the total loaded weight for 24h while the release rate of IND was stimulated at neutral pH (pH 7.4). IND release from the pectin microspheres was increased by the addition of pectinase. The results clearly demonstrate that the pectin microspheres that were prepared by the spray drying and crosslinking methods are potential carriers for colon-specific drug deliveries.  相似文献   

15.
随着生物技术的飞速发展,疫苗在预防和控制传染病方面的作用越发显著,广泛的疫苗接种对全球健康至关重要。然而,在中等及低收入国家,要提高疫苗接种覆盖率还存在重大挑战。由于液体疫苗存在易分解、热稳定性差、冷链配送成本高昂等不足,限制了疫苗在这些地区的分发和接种,使一些传染性疾病在偏远地区得不到有效控制。为了保证疫苗的稳定性和有效性,冷冻干燥(freeze-drying,FD)技术成为疫苗制备和保藏的关键技术之一。从冷冻干燥技术的原理、影响因素、FD技术在不同类型疫苗中的研究以及未来发展趋势等方面进行了全面、系统的综述,以期为疫苗研究和疫苗产业化的进一步发展提供有益的信息和思路。  相似文献   

16.
    
Compatible solutes constitute a diverse class of low-molecular-mass organic molecules that are accumulated in high intracellular concentrations in response to the external stress of hyperosmolality or high temperature. Many of these compounds like α, α-trehalose are well known for their stabilizing effect on protein structure and could lead to development of more stable protein formulations. Negatively charged solutes like mannosylglycerate (R-2-O-α-D -mannopyranosyl-glycerate) are widespread among (hyper)thermophilic microorganisms and are thought to be exceptionally potent stabilizers of proteins under high-temperature denaturation conditions. To further inquire into the role of compound charge for protective function, we have compared two naturally occurring and structurally related solutes, glucosylglycerol (2-O-α-D -glucopyranosyl-sn-glycerol) and glucosylglycerate (R-2-O-α-D -glucopyranosyl-glycerate), as stabilizers of different enzymes undergoing inactivation through elevated temperature or freeze drying, and benchmarked their effects against that of α,α-trehalose. Glucosylglycerate in concentrations of ≥0.1 M was the most effective in preventing thermally induced loss of enzyme activity of lactate dehydrogenase, mannitol dehydrogenase, starch phosphorylase, and xylose reductase. α,α-Trehalose could usually be replaced by glucosylglycerol without compromising enzyme stability. Glucosylglycerol and glucosylglycerate afforded substantial (eightfold) protection to mannitol dehydrogenase during freeze drying.  相似文献   

17.
Biopharmaceutical proteins are often formulated and freeze dried in agents that protect them from deleterious reactions that can compromise activity and authenticity. Although such approaches are widely used, a detailed understanding of the molecular mechanisms of protein stabilization in low water content amorphous glasses is lacking. Further, whilst deterioration chemistries are well described in dilute solution, relatively little is known about the extent and mechanisms by which protein integrity is compromised in the glassy state. Here we have investigated the relationship between protein modification and rate thereof, with variation of pH, carbohydrate excipient, temperature and the glass transition temperature using a model protein, lysozyme. Mass spectrometry analysis and peptide mapping confirm that protein modifications do occur in the glassy state in a time‐, temperature‐, and carbohydrate excipient‐dependent manner. There were clear trends between the buffer pH and the primary modification detected (glycation). Most importantly, there were differences in the apparent reactivities of the lysine residues in the glass compared with those previously determined in solution, and therefore, the well‐characterized solution reactivity of this reaction cannot be used to predict likely sites of modification in the glassy state. These findings have implications for (i) the selection and combinations of formulation components, particularly with regard to glycation in the glassy state, and (ii) the design of procedures and methodologies for the improvement of protein stability in the glassy state. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009  相似文献   

18.
Construction of baculovirus recombinants   总被引:3,自引:0,他引:3  
Kitts PA 《Cytotechnology》1996,20(1-3):111-123
  相似文献   

19.
ABSTRACT

The aims of this study were to compare the effectiveness of different drying methods and to investigate the effects of adding a series of individual protectant such as skim milk, sucrose, maltodextrin, and corn starch for preserving Lactobacillus acidophilus FTDC 3081 cells during spray and freeze-drying and storage at different temperatures. Results showed a remarkable high survival rate of 70–80% immediately after spray- and freeze-drying in which the cell viability retained at the range of 109 to 1010 CFU/mL. After a month of storage, maltodextrin showed higher protective ability on both spray- and freeze-dried cells as compared to other protective agents at 4°C, 25°C, and 40°C. A complete loss in viability of spray-dried L. acidophilus FTDC 3081 was observed after a month at 40°C in the absence of protective agent.  相似文献   

20.
目的:利用喷雾干燥工艺制备芽孢杆菌dhs-330-021菌粉,并研究菌粉的活性及稳定性。方法:以脱脂乳、海藻糖、β-环糊精和谷氨酸钠为保护剂,采用喷雾干燥(条件为:进口温度100℃,出口温度50~60℃,进样速度2~4mL/min)制备芽孢杆菌菌粉,以喷干存活率和菌粉活菌数为指标,选择最佳制备条件。结果:获得喷干保护剂配方为脱脂乳10.0%、海藻糖6.0%、β-环糊精13.0%、谷氨酸钠15.0%,喷干存活率为65.9%,菌粉活菌数为1.38×109CFU/g,存放180 d后菌粉活菌数为1.03×10~9CFU/g。结论:喷雾干燥工艺可以用于芽孢杆菌dhs-330-021菌粉的制备,获得的菌粉稳定性较好。  相似文献   

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