鸡蛋杀菌技术装备研究现状

我国是世界上鸡蛋产量和消费量最大的国家,鲜鸡蛋易受到大肠杆菌、沙门氏菌等致病微生物的污染,从而影响其食用安全性,因此开展鸡蛋杀菌技术研究具有重要意义。针对液态蛋、带壳蛋的杀菌需求,详细介绍了热杀菌技术、紫外杀菌技术、高静压技术和高压脉冲电场技术在鸡蛋杀菌中的应用,包括杀菌原理、杀菌工艺、设备研发、应用现状等,对比分析了各技术的优缺点,并对鸡蛋杀菌技术的发展进行了展望,以期为鸡蛋杀菌技术的改善和设备研发提供一些参考。     

超高压对肉制品的杀菌效果及杀菌机制的研究进展

超高压杀菌是一种新型的非热杀菌技术,通过总结国内外采用超高压技术延长肉制品货架期的研究,分析超高压技术对生鲜肉制品、腌制肉制品、熏制肉制品、卤制肉制品以及烧烤类肉制品的杀菌效果,证明了超高压技术能不同程度地提高这5种肉制品贮藏期的安全性和感官特性。通过总结超高压处理对微生物细胞形态结构的改变,以及对不同微生物酶活性的影响,探究超高压的杀菌机制,为超高压技术在肉制品工业中的进一步应用提供理论依据,也为下一步研究明确了方向。     

超高压均质杀菌技术研究现状

本文论述了超高压均质杀菌技术的国内外研究现状,包括关于杀菌机理的研究、高压均质杀菌对于微生物影响的研究、高压均质杀菌对于产品影响的研究、与其它杀菌方式相结合进行杀菌的研究以及超高压杀菌技术的商业化应用.     

超高压对酱料食品中微生物指标的影响

由于超高压杀菌技术实现了常温或较低温度下杀菌和灭酶,保证了食品的营养成分和感官特性,因此被认为是一种最有潜力和发展前景的食品加工和保藏新技术。广泛的应用于含液体成分的固态食品或液态食品的杀菌。本实验尝试以酱料食品为样本,研究超高压杀菌技术对半固体膏状调味品的微生物卫生指标的影响,探讨非热力抑菌技术在半固体膏状调味品生产的应用。分别对压力、保压时间、温度进行单因素实验,结果为300MPa为最佳压力,20min为最佳保压时间,32℃为最适温度。     

果汁超高压加工技术的研究进展

超高压加工技术是一项具有广阔应用前景的食品冷杀菌新技术.该文综述了超高压加工技术对果汁中微生物、酶和产品品质的影响,以及超高压杀菌设备的现状.在分析各超高压处理效果影响因素的基础上,提出下一步研究的方法与方向,并对其发展前景进行了展望.     

超高压加工技术在牛乳加工中的应用研究概述

超高压加工技术是非热杀菌技术的一种,在牛乳加工中的应用研究是当前热点。本文概述了非热加工技术的概念、发展和特点,特别针对超高压加工技术在牛乳加工中对微生物、乳蛋白和乳脂肪等成分的影响进行了阐述,并简要分析超高压杀菌设备及其在乳品工业的应用现状。超高压杀菌技术在牛乳加工中具有一定的理论依据和实践经验,值得深入研究和商业化推广应用,本文还展望了超高压技术在乳制品工业中的制约因素和应用前景。     

食品超高压杀菌技术

本文主要研究了食品超高压杀菌技术的原理及其最新进展,重点讨论了温度、pH值、水分活度、压力大小和加压时间、施压方式、微生物的种类和特性以及食物本身的组成等因素对超高压杀菌效果的影响。     

超高压杀菌技术在果汁生产中应用的研究进展

超高压杀菌技术是近年来研究较多的冷杀菌技术之一，它能够有效杀灭食品中的微生物，同时减少对食品中营养成分和感官性质的破坏。简要介绍了超高压杀菌技术近年来在果汁生产中的应用，以便对以后的学习研究提供参考。     

超高压杀菌在西式香肠中的应用研究

超高压杀菌是一种新型的冷杀菌技术。通过研究不同压力、时间的超高压杀菌对西式香肠感官质量、微生物变化等方面的影响,确定采用600MPa,5min超高压杀菌,具有较好的杀菌效果,并进行工业化生产。     

食品超高压杀菌技术

本文主要研究了食品超高压杀菌技术的原理及其最新进展，重点讨论了温度、pH值、水分活度、压力大小和加压时间、施压方式、微生物的种类和特性以及食物本身的组成等因素对超高压杀菌效果的影响。     

超高压技术在水产品贮藏加工应用中的研究进展

超高压处理技术是当今热门的非热加工技术, 采用冷加工的纯物理方法, 处理方式简单快捷, 它通过常温或低温杀菌灭酶的方式延长水产品货架期, 保障水产品的质量安全, 且仅小幅度改变物料的色泽和香气, 保持食物固有的营养、品质、风味以及新鲜度。本文综述了超高压处理技术的原理, 对水产品中微生物、酶活的作用机制和影响, 以及超高压对水产品营养和物理性质等方面的影响, 结合目前国内外超高压技术在水产领域的应用和研究进展, 指出其存在的问题和未来的发展方向, 以期为该技术的深入研究提供参考。     

不同灭菌工艺对鲜榨柚汁品质及挥发性成分的影响

本文对三种果汁杀菌工艺(热杀菌、UHT杀菌和超高压杀菌)对柚果汁pH、Brix、总酸、维生素C、微生物、感官和香气的影响进行比较。与对照组相比,不同灭菌处理方法对于果汁理化指标并无显著性差异(P<0.05),相对于超高压灭菌,经热杀菌和UHT处理的柚汁的维生素C含量发生显著性降低(P<0.05),这表明超高压处理更利于果汁中维生素C的保存。结合感官评价及GCMS对挥发性成分分析,热处理状态下果汁清香感、柚香感强度出现明显下降,过熟味强度出现明显上升,主要是由于热处理后果汁中醛类、萜烯类成分浓度下降而芳樟醇氧化物浓度增加。该研究结果可为果汁加工提供参考。     

超高压和巴氏杀菌对百香果汁贮藏期品质的影响

本文研究了超高压杀菌(Ultra-High Pressure Sterilization,600 MPa/6 min)和巴氏杀菌(Pasteurization,80℃/30 s)对百香果果汁贮藏期菌落总数、理化指标、抗氧化活性、营养成分及挥发性成分的影响。结果表明:两种处理方式均使百香果汁达到商业无菌的状态,贮藏期结束后,巴氏杀菌和超高压杀菌菌落总数小于100 CFU/mL。巴氏杀菌使果汁总色差显著升高(P<0.05),且始终高于超高压处理,说明超高压杀菌对保持百香果汁色泽更有效。超高压处理对百香果汁可溶性糖、总酸、蛋白质含量无显著性影响(P>0.05)。贮藏期结束后,巴氏杀菌果汁的总酚、维生素C、总黄酮含量显著低于(P<0.05)超高压杀菌处理。巴氏杀菌处理后果汁的挥发性化合物酯类、醇类、酮类、醛类、烯烃类保留率低于超高压处理,且保留率与贮藏期呈负相关。综上,传统巴氏杀菌会降低百香果汁感官品质和营养品质,超高压杀菌对百香果汁品质的保持有显著优势。     

A review on egg pasteurization and disinfection: Traditional and novel processing technologies

Salmonella Enteritidis is a pathogen related to many foodborne outbreaks involving eggs and egg products. Regulations about whether eggs should be pasteurized are very different and inconsistent worldwide. In the United States, eggs are not required to be pasteurized. Hence, less than 3% of the eggs in the country are pasteurized. The standard pasteurization method (57°C, 57.5 min) uses a long thermal process that increases the cost of the product and affects its quality. Foodborne outbreaks can be reduced if eggs are properly pasteurized to inactivate Salmonella spp. However, the technology to pasteurize eggs needs to offer a faster and more reliable method that can be scaled up to industry settings at a low cost and without affecting product quality. Several novel technologies have been tested for eggshell disinfection and egg pasteurization. Some thermal technologies have been evaluated for the pasteurization of eggs. Microwave has limited penetration depth and is a technical challenge for egg pasteurization. However, radio frequency can penetrate eggshells effectively to inactivate Salmonella, considerably reduce processing time, and maintain the quality of the product. Nonthermal technologies such as ultraviolet, pulsed light, cold plasma, ozone, pressure carbon dioxide, electrolyzed water, and natural antimicrobials have been explored for surface cleaning of the intact egg as alternatives without affecting the internal quality. This review presents some of these novel technologies and the current challenges. It discusses the possible combination of factors to achieve the egg's internal pasteurization and the eggshell's disinfection without affecting the quality at a low cost for the consumer.     

Ribonucleosides: Chemical parameters for controlling the heat treatment of milk

From experimental findings concerning changes in the contents of ribonucleosides - which belong to the group of minor milk constituents - in heat-treated milk it can be concluded that the concentrations of cytidine, guanosine and inosine present in raw milk show a multifold increase in milk which has been subjected to thermization and holder pasteurization, whereas the adenosine level decreases. On the other hand, these enzyme- (e.g. adenosine deaminase, alkaline phosphatase) catalysed changes in the content of unmodified ribonucleosides in milk are not observed in milk samples after short- and long-time pasteurization, high temperature pasteurization, ultra-high heating and sterilization. The changes in milk ribonucleoside contents found in these heating regions are mainly attributable to the catalytic activity of the milk enzymes in the course of the heating-up phase. During short- and long-time-, as well as high temperature pasteurization i.e. in the whole pasteurization region, changes in the nucleoside levels correlating with processing temperature and holding time were not observed since in these heating regions milk enzymes, such as adenosine deaminase and alkaline phosphatase, are inactivated. Hence, in the whole region of pasteurization neither enzyme-induced degradation- and conversion reactions nor thermally induced chemical degradation reactions take place with respect to unmodified ribonucleosides. However, with sterilization values exceeding F₀ = 30 min thermally induced hydrolytic effects are observed in UHT milk samples which lead in particular to an increase in adenosine contents. Comparable observations were made as regards cytidine, guanosine, inosine and adenosine contents in sterilized milk samples. Summing up, it can be concluded that from the viewpoint of dairy technology cytidine, guanosine and mainly inosine can be taken into account as chemical parameters for detecting thermization and, in particular, holder pasteurization. For characterizing heat treatment in the region of pasteurization, high temperature pasteurization, UHT heating and sterilization unmodified ribonucleosides of milk appear to be unsuited. The studies on the Dimroth-rearrangement under heating conditions of thermization and holder pasteurization, as well as short-, long-time- and high-temperature pasteurization, ultra-high heating and sterilization have shown that N⁶-methyladenosine, which is the resulting product of the rearrangement, is suited to be used as chemical parameter for controlling milk heat-treatment under time-temperature conditions with sterilization values (F₀) lying between ≈0.4 and 22 min. N⁶-methyladenosine is, thus, suited to be used as a chemical parameter for detecting heat treatment in the upper range of high temperature pasteurization, the whole range of UHT heating and the lower range of sterilization (as normally applied in dairies). From the viewpoint of dairy technology N⁶-methyladenosine is, thus, suited to be used as a further chemical parameter mainly for characterizing the upper range of UHT heating and the lower range of sterilization of heat-treated milk.     

超高压在冷藏肉类产品贮藏保鲜中的应用研究进展

超高压加工是一个物理过程,对食品中的维生素、色素和风味物质等小分子化合物无明显影响,从而可以较好地保持食品原有的营养。本文旨在探讨超高压技术在冷藏肉类产品贮藏保鲜中的应用现状及前景,分别对超高压在冷藏肉类产品的杀菌、抑酶、抗氧化以及其对冷藏肉类产品颜色、亮度和风味保持方面的应用进行阐述,分析存在的问题,为超高压技术在冷藏肉类产品贮藏保鲜方面的进一步研究提供参考。     

酱腌菜防腐技术的研究进展

酱腌菜是受大众喜欢的传统食品,近年来随着新工艺、新品种的出现,人们也加强了对其防腐技术的研究以期延长产品的货架期。本文对目前酱腌菜防腐技术研究进展情况进行了综述,包括热杀菌技术如巴氏杀菌、微波杀菌,非热杀菌技术如超高压杀菌、臭氧杀菌、辐照杀菌、低温等离子体杀菌、高密度二氧化碳杀菌,真空包装或充气包装技术,添加化学防腐剂或添加来源于微生物、植物或动物的天然防腐剂等。生产企业可根据产品特点选择一种或多种防腐技术满足防腐要求。新型非热杀菌技术以及天然防腐剂虽然能够提高产品品质并具有更好的安全性,但目前应用并不广泛,建议酱腌菜生产企业进一步加强对新型杀菌技术以及天然防腐剂的应用研究,不断满足人们对产品健康、安全的需求。     

Physical properties of egg whites and whole eggs relevant to microwave pasteurization

Microwave pasteurization is a novel thermal processing technology in which non-uniform heating may be a major challenge. In this study, the suitability of using egg whites (EWs) and whole eggs (WEs) as model foods to evaluate the heating uniformity and to determine the cold and hot spots during microwave pasteurization was investigated. The samples were prepared from mixtures of water with commercial EW or WE powders at different solid concentrations (20%, 25%, 27.5%, and 30%) and salt contents (0, 50, 100, and 200 mM). Critical physical properties for desirable model food systems include appropriate dielectric properties, gelation temperatures, gel strengths, and water holding capacities (WHCs). The gelation temperature of liquid EW and WE were 70 and 80 °C; both fell in the pasteurization temperature range. At 915 MHz, the dielectric constants of liquid EW and WE samples and their heat induced gels decreased with solid concentration while the loss factor was not affected. Loss factors of liquid EW and WE samples increased linearly with salt addition, which could be explained by the linear increase of electrical conductivities by adding salt. The strength and WHC of heat induced EW and WE gels increased linearly with solid concentration, while salt addition had no significant effect. The results demonstrated the suitability of using EW and WE as model foods to determine the heating uniformity during microwave pasteurization process.     

超高压处理对黑果枸杞汁贮藏及品质特性的影响

为开发黑果枸杞汁加工新技术,采用超高压处理(300、400、500 MPa/10 min)和巴氏杀菌(75℃,15 min)处理,分析处理前后及贮藏期(4和37℃,40 d)的微生物、活性成分、关键内源酶及抗氧化活性等品质的变化。结果表明,200 MPa以上高压处理和巴氏杀菌均能有效杀灭酵母菌和霉菌,300 MPa以上高压处理能使菌落总数降低到1个对数以下;300 MPa高压处理能使过氧化物酶(Peroxidase,POD)活性减少17.81 U/mL,但不能使多酚氧化酶(Polyphenol oxidase,PPO)酶活性显著降低;400 MPa以上及巴氏杀菌均能使POD酶和PPO酶活性降低至0.5 U/mL;超高压处理分别为300、400、500 MPa条件下,总酚含量分别为87.10、87.11、86.92 mg/100 g、总多糖含量分别为61.54、61.04、60.97 mg/mL、花青素含量分别为2.62、2.56、2.58 mg/mL;超高压处理的黑果枸杞汁对DPPH自由基清除率分别为86.82%、87.40%、86.60%,均高于巴氏杀菌处理的82.17%;超高压处理组对亚铁离子的还原能力分别为15.74、16.15、15.95 μg/100 mL DW,处理后直至贮藏结束,高压处理各活性物质均高于巴氏处理。超高压处理在有效灭活微生物、钝化酶的同时,极大程度保护活性物质不被破坏并保证了黑果枸杞汁的抗氧化能力,使得黑果枸杞汁得到了良好的贮藏品质。     

Effect of Processing on the Quality of Pineapple Juice

Pineapple processing plays an important role in juice preservation. Because the quality of the pineapple juice is affected by the processing technology applied, the effects of pasteurization and other preservation methods on the overall juice quality were discussed. During juice processing, microorganisms are destroyed and chemical changes occur. To optimize processing conditions, knowledge of the kinetics of these reactions is needed, but as of yet, data on the degradation of the amino acids and vitamin C and the change in sugar contents during pineapple juice pasteurization are scanty. Furthermore, the kinetics of hydroxymethylfurfural production should be investigated by a precise technique such as high-performance liquid chromatography.