共查询到20条相似文献,搜索用时 734 毫秒
1.
2.
3.
4.
蔬菜是人类摄入类胡萝卜素的重要来源,类胡萝卜素较低的生物可给性极大地限制了其功能的发挥。近年来的研究表明,赋型剂乳液的粒径和蔬菜的加工方式是影响类胡萝卜素生物可给性的重要因素。因此,本实验利用体外模拟消化模型,研究了赋型剂乳液粒径(表面积平均粒径(d3,2)约200、500 nm和10 μm)和菠菜加工方式(生菠菜、热烫菠菜)对菠菜中β-胡萝卜素生物可给性的影响。结果表明:小粒径(d3,2≈200 nm)和中等粒径(d3,2≈500 nm)赋型剂乳液/菠菜混合体系在模拟胃肠道消化过程中的物理特性(粒径和ζ-电位)、微观形态、油脂消化特性和生物可给性无显著差异(P>0.05),但与大粒径(d3,2≈10 μm)赋型剂乳液/菠菜混合体系差异显著(P<0.05);菠菜与小粒径和中等粒径赋型剂乳液共同进行体外模拟消化时,β-胡萝卜素的生物可给性分别为28.78%和28.65%,显著高于大粒径赋型剂乳液/菠菜混合体系(12.80%)(P<0.05);菠菜的加工方式显著影响β-胡萝卜素的生物可给性;与小粒径赋型剂乳液共同进行体外模拟消化时,热烫菠菜中β-胡萝卜素的生物可给性(15.66%)显著低于生菠菜(28.78%)(P<0.05)。综上,调控赋型剂乳液的粒径以及选择合理的方式加工果蔬,对于提高果蔬中β-胡萝卜素的生物可给性具有重要意义。 相似文献
5.
6.
新型聚丙烯酰胺乳液增强剂的合成及应用 总被引:12,自引:1,他引:11
采取乳液聚合法合成了水包水型PAM乳液增强剂,研究了反应条件如反应单体配比、反应时间、引发剂用量等对PAM乳液性能及对草浆成纸增强效果的影响,并与国内常用的增强剂进行了比较. 相似文献
7.
8.
高档涂布白纸板用离型剂 总被引:12,自引:2,他引:10
以石蜡为原料,采用在油中合成造纸离型剂-石蜡乳液。选择复合乳化剂制造出稳定性和分散性良好的石蜡乳液,并讨论了乳化剂用量,乳化水用量,乳化时间,乳化温度,搅拌速度等因素对乳化液稳定性和分散性的影响以及该离型剂在造纸施胶上的试验情况。 相似文献
9.
10.
11.
经分析认为:沿配汽管全程蒸汽加热不均是导致火电厂除氧器投运过程中加热振动的主要原因。通过将配汽管沿程钻孔孔径由小到大分段钻配,同时提高配汽孔总通流面积,成功实现了除氧器均匀配汽强制对流混合换热。实际运行结果表明:该设计有效地解决了除氧器加热振动问题,既提高了除氧器运行中的安全可靠性,又取得了良好的经济效益。 相似文献
12.
13.
造纸过程中泡沫的产生及其对生产和成纸质量的影响越来越受到人们的重视。目前,控制和消除泡沫的方法主要有机械法(如脱气罐等)和化学法(如消泡剂等)。该文简述了造纸过程中泡沫形成的原因.介绍了一种新型水性乳液除气剂在包装纸、箱板纸、新闻纸和文化纸生产中成功应用的情况。 相似文献
14.
中盐皓龙下属天源公司热电厂建有三台Ф9000×9000mm制盐返回冷凝水储桶,用于中转、储存制盐Ⅱ效冷凝返回水。Ⅱ效冷凝返回水通过疏水泵进入除氧器,补充锅炉用水。制盐Ⅱ效冷凝返回水的温度通常在93℃左右,经冷凝水储桶自然降温后,夏季温度降为60℃左右,冬季温度降为50℃左右。从节能降耗方面考虑,对三台冷凝水储桶进行了保温,效果明显。 相似文献
15.
J. C. MIERS J. R. WAGNER M-D. NUTTING W. G. SCHULTZ R. BECKER H. J. NEUMANN W. C. DIETRICH D. W. SANSHUCK 《Journal of food science》1971,36(3):400-404
SUMMARY— Mechanically harvested tomatoes were macerated, heated by steam injection to several constant temperatures from 170–240°F and held in a treatment pot from 0-4.6 min at pH levels (adjusted with cont. HCI) ranging from natural down to pH 2.0. Treated macerates were neutralized to original pH with cone NaOH, put through a finisher screen and pumped through a deaerator and chiller. The optimum processing conditions based on highest consistency (efflux-pipet flow time) in seven series of samples were 212°F breaking temperature and a macerate treatment time of 3.3 min at pH 2.75. With the optimum conditions, juice solids yield from VF-145 tomatoes was 4.3% greater and consistency 90% higher than from the natural pH juice. The neutralized acid products could contain 13% less tomato solids and still have a consistency equal to that of the products extracted at natural pH. Dry waste decreased 33% and total wet waste 47%. A 1-day delay before processing caused 9.5% loss in recovered juice solids. Ascorbic acid, reflectance and lycopene data showed no trends due to acid extraction. Water soluble color increased slightly in the acid extractions. 相似文献
16.
17.
目的 探讨肉制品中食品添加剂硝酸盐和亚硝酸盐的标准管理。方法 通过对国际食品法典以及美国、加拿大、欧盟、澳新、日本、韩国和中国肉制品中硝酸盐和亚硝酸盐食品添加剂标准规定的分析,结合风险评估、监测结果和食品中毒事件数据分析的情况,探讨相关标准未来的发展方向。结果 从生产加工过程控制、终产品检测可操作性或进出口口岸检测便利性的角度出发,美国、加拿大、澳新选择制定最大添加量,日本和韩国选择制定最大残留量,欧盟则根据具体食品产品,选择制定最大添加量或最大残留量。我国在食品添加剂标准中采用了添加量和残留量兼顾策略的同时,在污染物限量标准中规定了食品中N-二甲基亚硝胺的限量。膳食暴露评估显示硝酸盐和亚硝酸盐作为食品添加剂对膳食暴露贡献较低,对公众食品安全风险较低。结论 虽然目前标准中保留硝酸盐和亚硝酸盐最大添加量和残留量的做法符合过程控制原则和实际监管需求,但仍建议继续开展关于食品加工工艺改进和替代品的研究,同时也要继续加强对消费者和餐饮业者食品安全教育,减少误食误用引起的食物中毒。 相似文献
18.
19.
现代物流运输技术高速发展,呈现智能化、信息化和高效化的趋势。通过物流运输可满足国内外消费者对鱼类产品多样性的需求,实现渔业资源优化配置。肌肉是鱼体主要食用部分,其品质直接影响产品加工适应性和经济价值。本文将鱼类产品分为鲜活、冰鲜和冷冻三大类,首先概述鱼类物流运输的方式、网络图和特点;其次,从营养价值、组织结构、风味特点、感官品质及物理性质五方面对鱼肌肉品质进行评价,并总结测定方法;最后,论述物流运输过程中温度、时间、包装等主要因素对鱼肌肉品质的影响。 相似文献
20.
An analytical procedure using Fourier transform near infrared (FT-NIR) spectroscopy and chemometrics with multivariate techniques for the rapid determination of the fruit authenticity and for the quantification of the fruit content was developed, based on the cell wall constituents (alcohol-insoluble residue, AIR, and hemicellulose, HC). The contents of rhamnose, fucose, arabinose, xylose, mannose, galactose, and glucose in the hemicellulose fraction of apricots, peaches, and pumpkins determined by gas chromatography were used as references. Furthermore, spectral information was correlated with the fruit content and the gravimetric data obtained from sequential fractionation of the alcohol-insoluble residue. Samples of self-made and commercial apricot and peach fruit preparations, jams, and spreads were included in the investigations. Hemicellulose from 109 samples and AIR from 92 samples was recorded, and principal component regression was used to create calibration models relating chemical and gravimetrical reference values to spectral data. The calibration models provided a good predictability in comparison with the results obtained by reference methods. Good agreement was also obtained for the prediction of the neutral sugar composition of the HC and the fruit content from the AIR. FT-NIR spectroscopy allowed a rapid, accurate and non-destructive assignment of specified fruit from spectral data of the HC fraction and the AIR. Thus, FT-NIR could be applied for investigations on quality control complementing, or even replacing, gas chromatography as the most widespread method for the determination of neutral sugars. Furthermore, preliminary investigation on classification of fruit blends was performed. The probability of belonging to a specific fruit was significantly lowered or precluded for samples with fraudulent admixture like peach or pumpkin to apricot, or pumpkin to peach. 相似文献