固定化酶及其在食品中的应用

同定化酶是酶工程的核心，它有利于实现酶的重复使用及产物与酶的分离。本文综述了固定化酶的发展简史、性质和同定方法，介绍了同定化酶中应用的载体。并对该技术在食品工业中的应用进行了重点介绍。     

固定化酶在食品工业中的应用

固定化酶技术是酶工程的核心技术之一,它将酶工程提高到一个新水平.该技术使酶反应的连续生产成为现实,并简化了下游分离纯化步骤,目前已经广泛地应用于食品、发酵、制药等行业,经济效益显著.本文主要介绍了固定化酶的固定方法,总结了近年来在食品行业的应用,最后对其将来的应用进行了展望.     

酶制剂应用于传统大豆发酵食品酿造的探讨

介绍了酶制剂的应用现状、传统大豆发酵食品其产品特色的形成,阐明了日本不批量生产酶法酱油的原因。指出了酶法工艺必须与传统工艺的多酶发酵相结合,才能提高产品质量,降低生产成本,缩短生产周期,提高生产效率,从而取得显著成效。     

臭氧在食品加工中应用的原理和特点

本文回顾了臭氧技术的历史,结合臭氧技术的基础,探讨了臭氧技术在食品加工中应用的原理和特点以及存在的问题,以期加速其在食品工业中的应用。     

超声对改性明胶固定化木瓜蛋白酶活力的影响

本文探讨了超声处理对戊二醛改性明胶包埋的木瓜蛋白酶酶解反应条件以及酶学特性的影响。采用均匀实验的方法优化超声处理固定化木瓜蛋白酶的反应条件。利用偏最小二乘回归法分析均匀实验结果,得到最优条件为:135 k Hz、0.05 W/cm2、20 min、40℃,此条件下实测相对酶活为221.25%,与理论值相对误差为3.58%。超声并没有改变固定化酶的最适p H和最适温度,即超声并不改变固定化酶的酶学特性。      

Quorum-quenching enzymes: Promising bioresources and their opportunities and challenges as alternative bacteriostatic agents in food industry

The problems of spoilage, disease, and biofilm caused by bacterial quorum-sensing (QS) systems have posed a significant challenge to the development of the food industry. Quorum-quenching (QQ) enzymes can block QS by hydrolyzing or modifying the signal molecule, making these enzymes promising new candidates for use as antimicrobials. With many recent studies of QQ enzymes and their potential to target foodborne bacteria, an updated and systematic review is necessary. Thus, the goals of this review were to summarize what is known about the effects of bacterial QS on the food industry; discuss the current understanding of the catalytic mechanisms of QQ enzymes, including lactonase, acylase, and oxidoreductase; and describe strategies for the engineering and evolution of QQ enzymes for practical use. In particular, this review focuses on the latest progress in the application of QQ enzymes in the field of food. Finally, the current challenges limiting the systematic application of QQ enzymes in the food industry are discussed to help guide the future development of these important enzymes.     

Application of enzymes in food processing

Enzymes offer potential for many exciting applications for the improvement of foods. There is still, however, a long way to go in realizing this potential. Economic factors such as achievement of optimum yields and efficient recovery of desired protein are the main deterrents in the use of enzymes. Changing values in society with respect to recombinant DNA and protein engineering technologies and the growing need to explore all alternative food sources may in time make enzyme applications more attractive to the food industry. Research is continuing on the commercially viable enzymes in use today to improve various properties such as thermostabilities, specificities, and catalytic efficiencies. New and unique enzymes continue to be developed for use in enzymatic reactions to produce food ingredients by hydrolysis, synthesis, or biocatalysis. An aggressive approach is needed to open new opportunities for enzyme applications that can benefit the food industry.     

食品安全标准在食品安全管理实践中的应用

食品安全标准是食品安全执法的重要依据,在执法实践中得到广泛应用,但在实际工作中,标准应用依然存在一些问题。本文在介绍我国食品安全标准体系的基础上,探讨了我国食品安全标准的法律地位,分析了食品安全标准在食品安全行政执法、刑事司法、检验检测等管理事务中的实际应用,剖析了标准实际应用中存在的标准间指标不协调、标准宣贯不到位、标准使用不准确等问题,并从完善标准体系、加强标准宣贯、强化制定与应用衔接等方面提出了加强标准应用的对策与建议。     

论食品安全消费者信任的重构:以食品经营者规制为视角

食品的信用品特征形成食品经营者和消费者之间信息的不对称,并成为食品安全社会信任缺乏的根本原因。但是,为保障食品行业的发展和维护消费者权益,必须通过强化监管和责任承担等构筑食品安全的消费者信任。     

Rethinking the measurement of food security: from first principles to best practice

While food security measurement has been substantially expanded in recent decades, there persists significant dissatisfaction with existing measurement systems, especially in the wake of the ongoing food and financial crises. In this paper we first set out a list of criteria that an ideal food security measurement system should satisfy. In addition to standard issues of cross-sectional validity, our criteria include inter-temporal validity (the ability to gauge trends and shocks), and nutritional relevance. Using a mixture of literature review and fresh empirical analysis, we then benchmark four types of indicators (calories, poverty, dietary diversity and subjective indicators) against these criteria as a means of systematically identifying their relative strengths and weaknesses, and comparing overall performance. We conclude that, overall, dietary diversity indicators are the best performing class of indicators: they are powerful predictors of economic status and malnutrition (both stunting and wasting), sensitive to shocks, and relatively cheap to measure. Our concluding section therefore also outlines possible steps for scaling up the measurement of dietary diversity (and other indicators) through a mixture of increased funding, greater inter-agency coordination and technological (ICT) innovations that will reduce the cost of high frequency food security measurement.     

无致敏原食品产业分析

无致敏原(包括无麸质、牛奶、坚果和鸡蛋等致敏原中的一种或者几种)食品能极大满足过敏人群的需要,具有非常巨大的市场需求。介绍了无致敏原食品的发展状况,揭示了我国无致敏原食品产业发展存在的问题,提出了发展我国无致敏原食品产业的对策。      

Short communication: Effect of active food packaging materials on fluid milk quality and shelf life

Active packaging, in which active agents are embedded into or on the surface of food packaging materials, can enhance the nutritive value, economics, and stability of food, as well as enable in-package processing. In one embodiment of active food packaging, lactase was covalently immobilized onto packaging films for in-package lactose hydrolysis. In prior work, lactase was covalently bound to low-density polyethylene using polyethyleneimine and glutaraldehyde cross-linkers to form the packaging film. Because of the potential contaminants of proteases, lipases, and spoilage organisms in typical enzyme preparations, the goal of the current work was to determine the effect of immobilized-lactase active packaging technology on unanticipated side effects, such as shortened shelf-life and reduced product quality. Results suggested no evidence of lipase or protease activity on the active packaging films, indicating that such active packaging films could enable in-package lactose hydrolysis without adversely affecting product quality in terms of dairy protein or lipid stability. Storage stability studies indicated that lactase did not migrate from the film over a 49-d period, and that dry storage resulted in 13.41% retained activity, whereas wet storage conditions enabled retention of 62.52% activity. Results of a standard plate count indicated that the film modification reagents introduced minor microbial contamination; however, the microbial population remained under the 20,000 cfu/mL limit through the manufacturer’s suggested 14-d storage period for all film samples. This suggests that commercially produced immobilized lactase active packaging should use purified cross-linkers and enzymes. Characterization of unanticipated effects of active packaging on food quality reported here is important in demonstrating the commercial potential of such technologies.     

超声对包埋-交联法固定化木瓜蛋白酶催化活性的影响

研究超声对包埋-交联法固定化木瓜蛋白酶催化活性的影响。将醋酸纤维素铺制成膜,包埋木瓜蛋白酶;以戊二醛为交联剂,进行交联反应,制得固定化木瓜蛋白酶。分别研究超声频率、超声功率和超声时间对固定化酶活性的影响,再由均匀试验得到超声强化固定化木瓜蛋白酶催化活性的最优条件。经均匀试验确定最优超声条件为135kHz、0.05W/cm2、25min,相对酶活力为197.22%。验证实验证明最优的超声条件下测得固定化木瓜蛋白酶的相对酶活力为182.68%,相对标准偏差为7.37%,没有显著差异。     

食品加工中超声波生物学效应的研究进展

伴随科技的发展,超声波技术已经用于各行各业。近年来,超声波技术的生物学效应在食品方面也得到了应用。食品加工中的超声波生物学效应研究主要集中在超声波对微生物的促生长、超声波杀菌、菌种诱变以及对酶学的影响等方面。因此,本文对食品加工中超声波生物学效应的研究进展进行了概要阐述,并对今后超声波的生物学效应在食品加工的应用研究提出了建议。      

酶解法脱除食品过敏原

阐述了食品脱除过敏原的必要性。介绍了食品过敏原及食品过敏机制,重点综述了近几年酶解法在食品脱除过敏原中的应用研究,并针对当前酶解法在食品脱敏中出现的问题提出了几点建议。     

Microencapsulation of active ingredients in functional foods: From research stage to commercial food products

BackgroundTwelves categories of active ingredients have been recognised to enhance human health. They are to some extent susceptible to certain conditions such as heat, light and low pH. To reduce their susceptibility and achieve controlled release at the target site, various microencapsulation strategies have been introduced.Scope and approachIn this review, the chemical structures, physicochemical properties and beneficial effects of the active components are summarised. Different encapsulation techniques and tailored shell materials have been investigated to optimise the functional properties of microcapsules. Several encapsulated constituents (e.g., amino acids) have been successfully incorporated into food products while others such as lactic acid bacteria are mostly used in the free format. Encapsulating some of these active ingredients will extend their ability to withstand process conditions such as heat and shear, and prolong their shelf stability.Key findings and conclusionsThe functional properties of a microcapsule are encapsulation efficiency, size, morphology, stability, and release characteristics. Several microencapsulation strategies include the use of double emulsions, hybrid wall materials and crosslinkers, increasing intermolecular attraction between shell and core, physical shielding of shell materials, and the addition of certain ions. Other approaches such as the use of hardening agents, nanoencapsulation, or secondary core materials, and the choice of shell materials possessing specific interactions with the core may be used to achieve targeted release of active ingredients. The physicochemical properties of shell materials influence where the active ingredients will be released in vivo. A suitable microencapsulation strategy of active ingredients will therefore expand their applications in the functional foods industry.     

酶技术在食品加工中应用研究进展

酶技术是一种绿色安全高效的生物技术,对食品工业的技术革新和水平提高具有重要的作用。食品加工过程涉及许多复杂的理化变化,受热时营养素、颜色、质构、风味等方面容易受到破坏,这就为酶技术的应用提供了必要。目前,酶技术已经广泛应用于乳制品工业、肉制品工业、焙烤工业、饮料和果汁工业、淀粉和糖工业、油脂工业及安全检测等食品领域。本文主要从改善食品加工工艺、提高食品品质、提高食品安全性、增强食品质量控制等方面介绍了酶技术在食品加工中的应用进展,并对酶技术在食品行业中的发展作了展望。     

浅谈我国食品酶制剂的应用现状

综述了食品酶制剂在食品工业中的应用概况,并对其未来的发展方向做了展望。     

First investigation on ultrasound-assisted preparation of food products: sensory and physicochemical characteristics

This paper presents a comparison between manufactured food products using conventional and ultrasound-assisted procedures. Three different foam-type products, chocolate Genoise, basic sponge cake, and chocolate mousse were prepared using both methods with subsequent evaluation of the samples using both sensory and physicochemical methods. Ultrasound-assisted preparations were considered superior according to the sensory analysis, and physicochemical data confirmed this finding. This approach of applying an emerging piece of equipment, with potential industrial application to assist food preparation, consists of a new technique that could be of great interest for the development of not only other food products created by molecular gastronomy but also for practical work carried out by students.