转谷氨酰胺酶的性质、制备及在食品加工中的应用

转谷氨酰胺酶是催化蛋白质分子之间交联的一种酶，对蛋白质的成胶能力、热稳定性、持水能力等功能特性有独特的改善作用。目前从微生物Streptoverticillium spp．中分离转谷氨酰胺酶和在食品工业中的实际应用都已经实现，因为从微生物制备可以实现大规模的工业化生产，成本低廉，为转谷氨酰胺酶在工业上的应用奠定了基础。现在转谷氨酰胺酶广泛地应用于海洋食品、面条／面团、奶制品、烘焙食品等食品加工领域，通过温和的酶反应可以明显地改善食品的硬度、弹性、热稳定性和持水能力。主要讨论了转谷氨酰胺酶的性质、分离和在食品加工中的应用。     

TRANSGLUTAMINASE: ITS UTILIZATION IN THE FOOD INDUSTRY

Transglutaminase is an enzyme that forms crosslinks between protein molecules. This crosslinkage has unique effects on protein properties, gelation capability, thermal stability, water-holding capacity, etc. A transglutaminase has been isolated from Streptoverticillium sp., and its practical use in the food industry realized. Transglutaminase is now widely used in seafood, surimi products, meat products, noodles/pasta, dairy products, baked goods, and so on. It has great potential to improve the firmness, elasticity, viscosity, heat stability, and water-holding capacity of prepared foods through the mild enzyme reaction. The overall applications of transglutaminase in the food industry are reviewed.     

Texturisation and modification of vegetable proteins for food applications using microbial transglutaminase

Microbial transglutaminase (MTG) isolated from Streptomyces mobaraensis has been available on a commercial scale for several years. MTG generates inter- and intramolecular cross-links between γ-carboxylamide groups of glutamine residues and ɛ-amino groups of lysine residues in proteins. Due to its great potential to improve various functional properties of proteins, MTG is mainly used to enhance texture, stability, and water binding. Application of MTG for the production of plant protein-based foodstuffs such as tofu, noodles, bread and bakery products, is still limited to raw materials from soybean and wheat. However, with the increasing demand for vegetarian foods, the utilisation of novel proteins as functional ingredients, e.g. from peas, lupins, sesame, and sunflower, seems promising. To open new horizons for MTG application, this review aims at demonstrating the actual potential of MTG in processing foodstuffs based on vegetable proteins. Particular focus was laid on novel plant protein sources suitable for cross-linking with MTG. Furthermore, strategies for improving texture and nutritive value of the proteins are discussed.     

Occurrence of 3-chloro-propane-1,2-diol (3-MCPD) and related compounds in foods: a review

A critical review of the occurrence of 3-chloro-propane-1,2-diol (3-MCPD) in foods not known to contain hydrolysed vegetable proteins is presented. The review covers the properties and chemistry of 3-MCPD and the current methods of analysis in foodstuffs. The results of UK surveys of 3-MCPD occurrence in both retail foods and commercial food ingredients are discussed with particular reference to cereal, meat and dairy products. The possible mechanisms for the formation and decay of 3-MCPD in foods are suggested. The review does not cover the detailed toxicology of 3-MCPD and its occurrence in hydrolysed vegetable proteins, which have been considered elsewhere, nor possible issues such as in-vivo formation.     

Nonthermal pasteurization of liquid foods using high‐intensity pulsed electric fields

Processing foods with high‐intensity pulsed electric fields (PEF) is a new technology to inactivate microorganisms and enzymes with only a small increase in food temperature. The appearance and quality of fresh foods are not altered by the application of PEF, while microbial inactivation is caused by irreversible pore formation and destruction of the semipermeable barrier of the cell membrane. High‐intensity PEF provides an excellent alternative to conventional thermal methods, where the inactivation of the microorganisms implies the loss of valuable nutrients and sensory attributes. This article presents recent advances in the PEF technology, including microbial and enzyme inactivation, generation of pulsed high voltage, processing chambers, and batch and continuous systems, as well as the theory and its application to food pasteurization. PEF technology has the potential to improve economical and efficient use of energy, as well as provide consumers with minimally processed, microbiologically safe, nutritious and freshlike food products.     

Omics in traditional vegetable fermented foods and beverages

Abstract

For a long time, food microbiota has been studied using traditional microbiological techniques. With the arrival of molecular or culture-independent techniques, a strong understanding of microbiota dynamics has been achieved. However, analyzing the functional role of microbial communities is not an easy task. The application of omics sciences to the study of fermented foods would provide the metabolic and functional understanding of the microbial communities and their impact on the fermented product, including the molecules that define its aroma and flavor, as well as its nutritional properties. Until now, most omics studies have focused on commercial fermented products, such as cheese, wine, bread and beer, but traditional fermented foods have been neglected. Therefore, the information that allows to relate the present microbiota in the food and its properties remains limited. In this review, reports on the applications of omics in the study of traditional fermented foods and beverages are reviewed to propose new ways to analyze the fermentation phenomena.     

Application of microbial transglutaminase in meat foods: A review

Microbial transglutaminase (MTG) is an enzyme isolated from a variant of Streptomyces mobaraensis that forms covalent cross-links between protein molecules. Studies are being conducted since last two decades on utilization of MTG in meat foods to improve their characteristics, such as gelation, water-binding, emulsion stability, purge loss, cooking loss, etc. MTG is one of the important topics of interest in meat processing industry due to its advantages in practical utilization and commercial exploitation. This review will discuss about the overall applications of MTG in manipulating the functional properties of meat and meat products by means of various processes such as restructuring, value addition, etc.     

谷氨酰胺转胺酶的功能性质及其在食品中的应用方法

本主要论述了微生物谷氨酰胺转胺酶的性质,功能及其在食品加工工业以及开发新型食品中的应用。     

TRANSGLUTAMINASE IN DAIRY PRODUCTS: CHEMISTRY, PHYSICS, APPLICATIONS

Literature on the effects of microbial transglutaminase on various dairy‐based systems is discussed. Beginning with a short synopsis on the development of microbial transglutaminase as a functional tool for modifying foods, the principles of reactions catalyzed by transglutaminase and their structural implications, as well as the mechanisms of formation and cleavage of isopeptide bonds are reviewed. After summarizing the present knowledge on the specificity of microbial transglutaminase towards milk proteins, including reactions determined by individual lysine and glutamine residues, emphasis is placed on the effects of enzymatic cross‐linking on physicochemical properties in foods and, particularly, dairy‐based systems. Discussed are implications of cross‐linking on acidified milk gels including yogurt and effects on single milk protein fractions, with respect to several physicochemical properties including rheology and mechanical properties of these systems, but also syneresis, and emulsification behaviour.     

Application in Restructured Fish Products of Transglutaminase Obtained by Strepto verticillum ladakanaum in Media Made from Hydrolysates of Sorghum Straw

ABSTRACT: The efficiency of microbial transglutaminase (MTG), obtained by Streptoverticillum ladakanaum in the fermentation of sorghum straw hydrolysates to increase mechanical properties of restructured fish products, was evaluated. Fish gels were obtained from Mexican flounder ( Cyclopsetta chittendenni ) by (1) adding MTG obtained in the fermentation of sorghum straw hydrolysates (SMTG) at 0.3 units/g; (2) adding commercial MTG (CMTG) at 0.3 units/g; (3) adding 0.4% calcium chloride to activate the endogenous TG; and (4) without additives as control sample. SMTG more efficiently increased the mechanical properties of restructured products and induced a low value of expressible water, similar to the control (6% to 7%). Results demonstrated the feasibility of producing an efficient MTG from agricultural wastes. Keywords: fish, transglutaminase, microbial, restructured, sorghum     

Assessment of the long-term stability of retort pouch foods to support extended duration spaceflight

To determine the suitability of retort processed foods to support long-duration spaceflight, a series of 36-mo accelerated shelf life studies were performed on 13 representative retort pouch products. Combined sensory evaluations, physical properties assessments, and nutritional analyses were employed to determine shelf life endpoints for these foods, which were either observed during the analysis or extrapolated via mathematical projection. Data obtained through analysis of these 13 products were later used to estimate the shelf life values of all retort-processed spaceflight foods. In general, the major determinants of shelf life appear to be the development of off-flavor and off-color in products over time. These changes were assumed to be the result of Maillard and oxidation reactions, which can be initiated or accelerated as a result of the retort process and product formulation. Meat products and other vegetable entrées are projected to maintain their quality the longest, between 2 and 8 y, without refrigeration. Fruit and dessert products (1.5 to 5 y), dairy products (2.5 to 3.25 y), and starches, vegetable, and soup products (1 to 4 y) follow. Aside from considerable losses in B and C vitamin content, nutritional value of most products was maintained throughout shelf life. Fortification of storage-labile vitamins was proposed as a countermeasure to ensure long-term nutritive value of these products. The use of nonthermal sterilization technologies was also recommended, as a means to improve initial quality of these products and extend their shelf life for use in long-duration missions. Data obtained also emphasize the importance of low temperature storage in maintaining product quality. PRACTICAL APPLICATION: Retort sterilized pouch products are garnering increased commercial acceptance, largely due to their improved convenience and quality over metal-canned products. Assessment of the long-term stability of these products with ambient storage can identify potential areas for improvement, and ultimately increase consumer satisfaction with these technologies.     

谷氨酰胺转胺酶在面制品中的应用

简要回顾谷氨酰胺转胺酶的发展历史,描述其理化性质和作用机理。详细阐述谷氨酰胺转胺酶在面条、烘焙食品等面制品中的应用,并展望其在食品中广阔的应用前景。     

Trends in microbial control techniques for poultry products

Fresh poultry meat and poultry products are highly perishable foods and high potential sources of human infection due to the presence of several foodborne pathogens. Focusing on the microbial control of poultry products, the food industry generally implements numerous preventive measures based on the Hazard Analysis and Critical Control Points (HACCP) food safety management system certification together with technological steps, such as refrigeration coupled to modified atmosphere packaging that are able to control identified potential microbial hazards during food processing. However, in recent years, to meet the demand of consumers for minimally processed, high-quality, and additive-free foods, technologies are emerging associated with nonthermal microbial inactivation, such as high hydrostatic pressure, irradiation, and natural alternatives, such as biopreservation or the incorporation of natural preservatives in packaging materials. These technologies are discussed throughout this article, emphasizing their pros and cons regarding the control of poultry microbiota and their effects on poultry sensory properties. The discussion for each of the preservation techniques mentioned will be provided with as much detail as the data and studies provided in the literature for poultry meat and products allow. These new approaches, on their own, have proved to be effective against a wide range of microorganisms in poultry meat. However, since some of these emergent technologies still do not have full consumer's acceptability and, taking into consideration the hurdle technology concept for poultry processing, it is suggested that they will be used as combined treatments or, more frequently, in combination with modified atmosphere packaging.     

Reviewing the effects of vacuum frying on frying medium and fried foods properties

Vacuum frying (VF) is a process developed at a pressure lower than atmospheric pressure, in which lower temperatures are employed to remove moisture from the food and reduce the oil content in the final product. Diverse studies have been published for VF or assisted with microwave and ultrasound, facing the challenges of accomplishing the physical and sensory properties appreciated in fried products. The studied matrices under VF include mainly vegetable origin foods (apple, banana, carrot, donuts, kiwi, mushroom, pea, pear, potato and sweet potato) and some animal origin products (chicken nuggets, fish fillets and surimi products). This review aimed to show recent and relevant findings of the application of VF, analysing both the effects on the frying medium and the impact on the fried foods. The inclusion of microwave and ultrasound technologies aids in the obtention of high-quality products in terms of sensory and textural attributes, oil content as well as reduced oil degradation. This technique may provide safer and stable fried foods with lower oil content aiding in improving the diet of consumers and reducing production costs.     

The use of transglutaminase in dairy products

Modification of proteins by enzymes such as transglutaminase (TG) has recently become of great interest to food scientists. TG (EC 2.3.2.13) catalyses the post-translational modification of proteins by transamidation of available glutamine residues by the formation of covalent cross-links between glutamine and lysine residues in proteins. It is suggested that TG is a useful tool for the production of dairy products. In this review, properties of TG and its possible use in the manufacture of dairy products are discussed. Aspects covered include reactions catalysed by the enzyme and properties of modified proteins of selected milk proteins and products.     

鱼油在食品领域中的应用技术综述

对鱼油在食品领域中的应用技术进行综述。由于具有独特的营养功能,鱼油的应用十分广泛。中国居民目前对二十碳五烯酸(EPA)和二十二碳六烯酸(DHA)摄入不足,因而鱼油在食品中的应用十分必要。目前市场上已有多种鱼油应用于各类食品中。在应用过程中,鱼油的氧化稳定性问题一直是研究热点,选择不同的添加形式(纯鱼油、乳状液和微胶囊)并采用某些新工艺可有效提高氧化稳定性。鱼油应用于食品在技术和商业方面的发展前景均十分广阔。     

支链脂肪酸的食源性分析及活性机理研究进展

支链脂肪酸是一种具有特殊支链结构的饱和脂肪酸,在自然界中广泛存在。与直链脂肪酸相比具有低熔点、低冻点、氧化稳定性和热稳定性好等独特的理化性质以及抗癌、抗炎和降脂等生理活性,使其具有优异的应用特性,有较高的市场价值。本文主要阐述了支链脂肪酸在母乳、畜产品、鱼类制品及其他食品中的分布特点,并对支链脂肪酸抗炎、抗癌、防治缺血及再灌注损伤、降脂的功能活性机理及应用研究进展进行了综述,以期为支链脂肪酸在功能性食品及特殊医学用途配方食品中的应用提供理论参考。     

Application of bacteriocins in vegetable food biopreservation

Bacteriocins are generally recognized as "natural" compounds able to influence the safety and quality of foods. In the past years, a lot of works have been aimed to the detection, purification and characterisation of bacteriocins, as well as to their use in food preservation strategies. A list of review articles dealing with the application of bacteriocins to the protection of foods of animal origin is also available in literature, but it lacks for a summary on the utilization of bacteriocins in vegetable foods. These biopreservatives can be used in a number of ways in food systems and this paper mainly focuses on the state-of-the-art application of bacteriocins from lactic acid bacteria (LAB) to promote the microbial stability of both fermented and non-fermented vegetable food products using bacteriocinogenic strains as starter cultures, protective cultures or co-cultures and the employment of pure bacteriocins as food additives. In addition, applications of bacteriocins from non-LAB are also reviewed. The scopes of future directions of research are summarised.     

The effect of transglutaminase from Streptomyces sp. CBMAI 837 on the gelation of acidified sodium caseinate

The influence of the transglutaminase (TG) from a newly isolated Brazilian Streptomyces sp. CBMAI 837 and sodium caseinate concentration (4% and 8%, w/w) on acid-gel properties was studied. Standard gels with and without commercial transglutaminase samples were tested in parallel. The mechanical properties of the samples (stress and strain at rupture and elasticity modulus) were evaluated using uniaxial compression measurements. Texture parameters showed that the commercial TG gels had greater values of elasticity modulus, while addition of the Streptomyces sp. CBMAI 837 TG to the gel led to the formation of less elastic, but more deformable gels. The electrophoresis results showed that the commercial TG enzyme in this system promoted higher molecular mass protein polymers than the enzyme from Streptomyces sp. CBMAI 837. Microscopy and water-holding capacity (WHC) observations showed that all the gel characteristics could be associated with specific interactions promoted by each TG tested.     

Dietary fibre composition,antioxidant capacity and physico-chemical properties of a fibre-rich product from cocoa (Theobroma cacao L.)

The proximate composition and dietary fibre (DF) content of a fibre-rich product obtained from cocoa were studied. This product contained 60.54% (dry matter basis) of DF, made of mainly insoluble fibre although with appreciable amounts of soluble dietary fibre (10.09% d.m.). The presence of associated polyphenolic compounds (1.32% and 4.46% of soluble polyphenols and condensed tannins, respectively) provides this fibre material with intrinsic antioxidant capacity as determined by the FRAP and TEAC methods. Hydration properties (swelling and water holding capacity) and the glucose retardation index of cocoa fibre were similar to other natural commercial insoluble fibres. The antioxidant capacity of this fibre-rich cocoa powder and its physico-chemical properties render it a suitable product to be used in the preparation of low-calorie, high-fibre foods.