共查询到20条相似文献,搜索用时 125 毫秒
1.
以荔枝果皮提取液为材料,研究了光、热、pH值等对荔枝皮色素性能的影响及该色素的耐氧化还原性等。为荔枝果皮色素的保鲜研究提供了理论依据。 相似文献
2.
以壳聚糖为成膜保鲜剂、复配防腐剂山梨酸钾和抗氧化剂抗坏血酸,制成了一种荔枝复合涂膜保鲜剂,考察了其在室温(30~35℃)和低温[(6±1)℃]下对荔枝的保鲜效果。结果表明,与对照相比,无论是室温还是低温贮藏,经由1.0%壳聚糖、0.5%山梨酸钾和1.0%抗坏血酸组成的复合涂膜处理,可以显著抑制荔枝发生褐变,明显降低荔枝果实的失重率,减少可溶性固形物、可滴定酸、维生素C等营养物质的消耗,提高了荔枝的好果率,在室温下可使荔枝在6d内保持100%的好果率,而对照在第2d就只有90%的好果率;低温贮藏20d,对照的好果率仅为20%,而处理组的好果率为100%,低温贮藏30d,处理组的好果率仍高达90%。 相似文献
3.
4.
生物保鲜技术在果蔬贮藏保鲜中的应用 总被引:4,自引:0,他引:4
果蔬贮藏保鲜的发展,具有显著的经济效益和社会效益。生物技术在果蔬贮藏保鲜上的应用是近年新发展起来的具有发展前途的贮藏保鲜方法。本文概述了果蔬贮藏保鲜的原理和技术,同时对生物保鲜技术在果蔬贮藏保鲜中的应用进行了探讨。 相似文献
5.
6.
7.
8.
9.
10.
《精细与专用化学品》2007,15(7):6-6
随着石油能源的日趋紧张,油田化学品的开发对促进采油技术发展的作用也显得越来越重要。为了促进油田化学品工业的发展,提高油田化学品研究、生产及应用的水平,中国精细化工协会于2006年11月在上海召开了全国油田化学品发展研讨会。本次会议在技术交流的基础上,研讨了如何加快我国油田化学品的发展以及需要解决的关键技术等问题。 相似文献
11.
Effect of air drying and freeze drying on polysaccharides of lychee with three cultivars was determined in terms of polysaccharides yield, antioxidant capacity and hypoglycemic action. The results show that Guiwei lychee pulp had the highest crude polysaccharide yield among three lychees. However, Feizixiao lychee had the lowest EC50 concentration and the highest FRAP (Ferric reducing antioxidant power) value. Moreover, Guiwei lychees dried by air drying had the best effect for improving glucose tolerance of normal mice and diabetic mice. Three freeze dried lychees had no significant effect. The effect of air dried Guiwei samples on decreasing TG was the best and it was even better than dapagliflozin group. Only freeze-dried Guiwei lychee could significant decrease the TC content in blood among all lychee samples. In a word, Feizixiao lychees had the best antioxidant capacity and Guiwei lychees had the best hypoglycemic effect. Air drying was better drying method for lychee polysaccharides than freeze drying in this study. 相似文献
12.
Kendra PE Montgomery WS Niogret J Peña JE Capinera JL Brar G Epsky ND Heath RR 《Journal of chemical ecology》2011,37(9):932-942
The redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is an exotic wood-boring insect that vectors the mycopathogen responsible for laurel wilt, a lethal vascular disease
of trees in the Lauraceae. High mortality has occurred in native Persea species in the southeastern U.S., and the vector-pathogen complex poses an imminent threat to the production of commercial
avocado, P. americana, in south Florida. There is a critical need for effective attractants to detect, monitor, and control this invasive pest.
This study combined field tests and laboratory bioassays to evaluate the response of female X. glabratus to host-based volatiles from wood of avocado (cultivars of West Indian, Guatemalan, and Mexican races); from wood of lychee
(Litchi chinensis, a presumed non-host that is high in the sesquiterpene α-copaene, a putative attractant); and to commercial lures containing
manuka and phoebe oils, two reported attractive baits. Volatile collections and GC-MS analyses were performed to quantify
the sesquiterpene content of test substrates. In the field, traps baited with lychee wood captured more beetles than those
with wood from avocado cultivars; traps baited with phoebe oil lures captured more beetles than those with manuka oil lures
(the current monitoring tool). In field and laboratory tests, X. glabratus did not show a preference among avocado races in either attraction or host acceptance (initiation of boring). In choice tests,
lychee was more attractive than avocado initially, but a higher percentage of beetles bored into avocado, suggesting that
lychee emits more powerful olfactory/visual cues, but that avocado contains more of the secondary cues necessary for host
recognition. Emissions of α-copaene, β-caryophyllene, and α-humulene were correlated with field captures, and lychee wood
may be a source of additional semiochemicals for X. glabratus. 相似文献
13.
T. A. Chudinskaya I. V. Nikiforova G. A. Smirnova R. A. Molchanova T. I. Samsonova 《Fibre Chemistry》2011,43(1):18-21
This paper is devoted to a major area of concern and an approach for hygiene and toxicology studies allowing us to estimate
the potential risk to workers from chemicals and to recommend protective measures aimed at preservation of health. We present
tentative safe exposure levels in atmospheric air and maximum permissible concentrations in the workplace for a number of
chemicals, obtained as a result of toxicology animal studies. We demonstrate the capabilities of a method for rapid assessment
in vitro of the general acute toxicity on the AT-05 image analyzer. 相似文献
14.
Lychee high sugar content is the biggest disadvantage in drying processes which limits the production of dried lychee for snacks. Purple sweet potato was blended with lychee to develop new snacks using microwave drying techniques. Optimal ingredients proportion and drying conditions were evaluated in terms of their influences on product's organoleptic properties (crispness and mouth feel) and quality attribute. The results showed that addition of 4% potato starch to paste mixture improved the crispness of dried chips. Also, the optimum ratio between purple sweet potato and lychee to produce desirable snacks was found to be 7:3 (W:W). In case of the drying parameters, the high power density resulted in shorter drying time and chips with improved nutrients. Generally speaking the method employed for the drying operation produced no browning throughout the experiments. Therefore, this research has a good future for industrial application. 相似文献
15.
荔枝核主要含酸性化合物,挥发油,碳水化合物等化学成分,其主要药效有降血糖,调血脂,抑制乙型肝炎病毒表面抗原(HBsAg)等,干燥对荔枝种的发芽率,活力指数和湿度会产生影响,荔枝种应在80%NO2/20%O2的条件下贮藏。 相似文献
16.
工业锅炉锅内水处理药剂现状与发展 总被引:3,自引:0,他引:3
工业锅炉通过锅内加药处理来防腐防垢是一种主要的水处理方式,锅内水处理质量的好坏直接影响其安全运行和使用寿命。作者在对我国目前工业锅炉水处理现状及药剂现状进行分析的基础上,重点论述了工业锅炉锅内水处理药剂的应用与发展,对广泛使用的各种无机阻垢剂、有机胶体、有机阻垢剂、无机除氧剂、有机除氧剂以及新开发使用的药剂的使用范围、优缺点等都作了比较分析,并且对蒸汽冷凝水系统防腐蚀药剂进行了探讨,最后对工业锅炉水处理药剂未来的发展方向作了展望。 相似文献
17.
Novel polymer blends were prepared from a mixture of 2 wt % konjac glucomannan and 4 wt % quaternized poly(4‐vinyl‐N‐butyl) pyridine (QPVP) in aqueous solution and dried at room temperature for 72 h. Their structure and properties were studied by infrared, wide‐angle X‐ray diffraction, scanning electron microscopy, thermogravimetric analysis, and differential scanning calorimetry. Thermal stability in the dry state was reduced with increasing content of QPVP. Compared with QPVP film, the tensile strength of the films was improved in the dry state. The maximum value of 12.74% tensile break elongation was reached when the content of QPVP was 30%. Structural analysis indicated that clear phase separation was observed when the content of QPVP was only 50%. Results from the filmcoating preservation experiments with lychee showed that this blend film had water‐holding ability. The fruit weight loss rate and rot rate both decreased in various degrees. The potential uses of these novel polymer films could be as preservative films. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1868–1875, 2004 相似文献
18.
The effect of ozone on the reduction of chlorpyrifos residue in lychee cv. Chakapat (Litchi chinensis Sonn.) was studied. Lychee fruits were dipped in the solution of chlorpyrifos at a concentration of 10 mg L?1 for 10 min. Then, they were exposed to ozone gas (O3) at concentrations of 80, 160, 200, 240 mg L?1 and dipped in ozone-containing water, at concentrations of 2.2, 2.4, 3.4 and 3.2 mg. L?1 for 10, 20, 30 and 60 min, respectively. Both ozone gas and ozone-containing water reduced pesticide residue in lychee, but exposure to ozone gas for 60 min was most effective. When lychee fruits were stored at 25 °C for 6 days, both processes did not show significant differences in weight loss, total soluble solids (TSS) and titratable acidity (TA). However, ozone-containing water decreased the eating quality of lychees after storage, compared with the ozone-fumigated groups. 相似文献
19.
Three designs for the internal release of sealants, adhesives, and waterproofing chemicals into concrete to reduce permeability 总被引:4,自引:0,他引:4
Various types of hazardous wastes need engineered barriers to prevent outflow. Concrete is a brittle and porous material, which changes dramatically over its lifetime. In order to design waste barriers using any type of concrete, the most effective intervention occurs at the time when it is needed during the life of the material and at the location undergoing distress. Internally placed encapsulators containing sealants, adhesives, and waterproofing are designed to release these chemicals where and when they are needed. Optimizing for durability requires an understanding of the timing and location of release. In all of the cases, brittle fibers containing adhesives or sealants release the chemicals where and when the matrix cracks, causing the fiber to crack and release chemicals. Research from over a decade is presented with special emphasis on permeability, cracking, and data and results from field tests. 相似文献
20.
Volker Pilz 《化学,工程师,技术》1988,60(6):452-463
Safe storage of chemicals. Stored chemicals can be a health risk, combustible, unstable, or explosive. It is consequently necessary to prevent such substances and their reaction products from damaging the environment or endangering people as a result of their release, decomposition, fire, or explosion. Storage conditions must therefore always be appropriate for the properties of the substances. This paper starts by outlining the basic principles of safe storage, namely minimization of potential hazards, avoidance of potential causes of danger and containing of any possible effects. Examples illustrate how the properties of the substances are taken into account in practice. 相似文献