Probiotic meat products and human nutrition

Raw cured and ripened meat products have been traditionally manufactured using the fermentation of native or added carbohydrates by lactic acid bacteria found in meat or in its environment. The commercial application of probiotic microorganisms in dry fermented meat products is not yet common. Probiotic bacterial strains that can be used in the manufacturing of dry fermented meat products should be capable of surviving in conditions found in fermented products; furthermore, they should dominate other microorganisms found in the finished product. The initial number of microorganisms in sausage filling or on the surface of ham or loin cannot be reduced as in milk pasteurization, for example. Therefore, the choice of appropriate microorganisms is important. Probiotic meat products are a relatively new and not very well recognized field of meat industry, but the most important issue is to find a compromise between technological aspects, safety, quality and health-beneficial effects of food. Therefore, the object of this review is on the one hand to analyze technological possibilities and quality parameters of probiotic meat products, and on the other hand to discuss risks and benefits of probiotic meat used in human nutrition.     

Survival and therapeutic potential of probiotic organisms with reference to Lactobacillus acidophilus and Bifidobacterium spp

The present paper provides an overview on the use of probiotic organisms as live supplements, with particular emphasis on Lactobacillus acidophilus and Bifidobacterium spp. The therapeutic potential of these bacteria in fermented dairy products is dependent on their survival during manufacture and storage. Probiotic bacteria are increasingly used in food and pharmaceutical applications to balance disturbed intestinal microflora and related dysfunction of the human gastrointestinal tract. Lactobacillus acidophilus and Bifidobacterium spp. have been reported to be beneficial probiotic organisms that provide excellent therapeutic benefits. The biological activity of probiotic bacteria is due in part to their ability to attach to enterocytes. This inhibits the binding of enteric pathogens by a process of competitive exclusion. Attachment of probiotic bacteria to cell surface receptors of enterocytes also initiates signalling events that result in the synthesis of cytokines. Probiotic bacteria also exert an influence on commensal micro-organisms by the production of lactic acid and bacteriocins. These substances inhibit growth of pathogens and also alter the ecological balance of enteric commensals. Production of butyric acid by some probiotic bacteria affects the turnover of enterocytes and neutralizes the activity of dietary carcinogens, such as nitrosamines, that are generated by the metabolic activity of commensal bacteria in subjects consuming a high-protein diet. Therefore, inclusion of probiotic bacteria in fermented dairy products enhances their value as better therapeutic functional foods. However, insufficient viability and survival of these bacteria remain a problem in commercial food products. By selecting better functional probiotic strains and adopting improved methods to enhance survival, including the use of appropriate prebiotics and the optimal combination of probiotics and prebiotics (synbiotics), an increased delivery of viable bacteria in fermented products to the consumers can be achieved.     

Post-genomics of lactic acid bacteria and other food-grade bacteria to discover gut functionality

Recent years have seen an explosion in the number of complete or almost complete genomic sequences of lactic acid bacteria and other food-grade bacteria that are used in functional foods to increase the health of the consumer. These have been instrumental in the development of functional, comparative and other post-genomics approaches that provide the possibility to detect, unravel and understand their functionality in the human intestinal tract. In conjunction with other high-throughput approaches, these advances can be exploited in the functional food innovation cycle for developing new or designed probiotic and other bacterial products that impact gut health.     

Application of Saccharomyces cerevisiae var. boulardii in food processing: a review

Probiotics are increasingly being added to food in order to develop products with health‐promoting properties. Particularly, Saccharomyces cereviceae var. boulardii yeast is recently being investigated like a starting‐culture for development of functional and probiotic foods. Although the literature is abundant on the beneficial effects of S. boulardii on health, slight information is available on the effects of supplementing this probiotic to food systems. The aim of this paper is to examine the applications of S. boulardii to different food matrices and its implication in food processing (stability, sensorial properties and other technological implications) and the concomitant effects on nutrition and health.     

Application of Microencapsulated Synbiotics in Fruit-Based Beverages

In the last years, demand for functional products containing both prebiotics and probiotics (known as synbiotic) has increased, which stimulated their incorporation into other food matrices than milk-based ones. Synbiotics improve gut functionality as well as respond to the increasing demand of consumers who have become aware of the health benefits of a proper diet. The most important criterion for preserving consumer acceptance in such products is maintaining the minimum viability and activity of probiotics from the beginning of production to the end of shelf-life. For their viability, fixation and multiplying within the host, several solutions have been proposed including the fortification with prebiotics and microencapsulation of prebiotics along with probiotics. The challenge of microencapsulation is to protect the probiotic cells in foods that are not usually considered their vehicle, such as fruit matrices. It is generally known that different prebiotics may exert different degrees of protection on the entrapped bacteria cells. For food products, such as fruit beverages, few works exist that investigate the functionality of synbiotic microcapsules in protecting the survivability of probiotic cells during processing and storage. This article provides an overview of this novel trend based on a review of relevant literature. The article summarizes the synbiotic concept, challenges for synbiotic formulation in fruit beverages, and future perspectives.

     

Functional bacterial cultures for dairy applications: Towards improving safety,quality, nutritional and health benefit aspects

Traditionally, fermentation was used to preserve the shelf life of food. Currently, in addition to favouring food preservation, well standardized and controlled industrial processes are also aimed at improving the functional characteristics of the final product. In this regard, starter cultures have become an essential cornerstone of food production. The selection of robust microorganisms, well adapted to the food environment, has been followed by the development of microbial consortia that provide some functional characteristics, beyond their acidifying capacity, achieving safer, high-quality foods with improved nutritional and health-promoting properties. In addition to starters, adjunct cultures and probiotics, which normally do not have a relevant role in fermentation, are added to the food in order to provide some beneficial characteristics. This review focuses on highlighting the functional characteristics of food starters, as well as adjunct and probiotic cultures (mainly lactic acid bacteria and bifidobacteria), with a specific focus on the synthesis of metabolites for preservation and safety aspects (e.g. bacteriocins), organoleptic properties (e.g. exopolysaccharides), nutritional (e.g. vitamins) and health improvement (e.g. neuroactive molecules). Literature reporting the application of these functional cultures in the manufacture of foods, mainly those related to dairy production, such as cheeses and fermented milks, has also been updated.     

Probiotics: an overview of beneficial effects

Food products fermented by lactic acid bacteria have long been used for their proposed health promoting properties. In recent years, selected probiotic strains have been thoroughly investigated for specific health effects. Properties like relief of lactose intolerance symptoms and shortening of rotavirus diarrhoea are now widely accepted for selected probiotics. Some areas, such as the treatment and prevention of atopy hold great promise. However, many proposed health effects still need additional investigation. In particular the potential benefits for the healthy consumer, the main market for probiotic products, requires more attention. Also, the potential use of probiotics outside the gastrointestinal tract deserves to be explored further. Results from well conducted clinical studies will expand and increase the acceptance of probiotics for the treatment and prevention of selected diseases.     

阿克苏地区传统酸乳中乳酸菌筛选及安全性初步评价

为挖掘新疆传统发酵乳制品中的优质乳酸菌资源,获得具有良好益生特性及食用安全性的乳酸菌菌株,对新疆阿克苏地区托木尔峰自然保护区周围村镇传统酸乳进行了样品采集、乳酸菌的分离、筛选及菌株生长特性、抗氧化活性和抑菌等功能特性的分析,并进行溶血性和有害代谢物质等食用安全性检测.16S rRNA测序结果显示,8份代表样品共获得12...     

Bringing a probiotic-containing functional food to the market: microbiological, product, regulatory and labeling issues

Properly formulated probiotic-containing foods offer consumers a low risk, low cost dietary component that has the potential to promote health in a variety of ways. Several such products are available commercially, although markets in Japan and Europe are more developed than in the USA. Once healthful attributes of a probiotic product have been identified, there remain microbiological, product, regulatory and labeling issues to be addressed prior to marketing. Microbiological and product issues include safety, effective scale-up for manufacturing, definition of probiotic activity, probiotic stability in the product over the course of product manufacture, shelf-life and consumption, definition of effective dose and target population(s), and development of quality assurance approaches. Examples of probiotic-containing foods are given. Regulatory and labeling issues are complicated because they differ for each country, but are likewise critical because they provide the means for c ommunication of the product benefits to the consumer. The regulatory climate worldwide appears to be one of caution about overstating the benefits of such products but at the same time not preventing corporate commitment to marketing.     

Dairy propionibacteria as probiotics: recent evidences

Nowdays there is evidence that dairy propionibacteria display probiotic properties, which as yet have been underestimated. The aim of this paper is to review the recent highlights of data representing the probiotic potential of dairy propionibacteria, studied both by general selection criteria (useful for all probiotic potentials), and by more specific and innovative approach. Dairy propionibacteria show a robust nature, that makes them able to overcome technological hurdles, allowing their future use in various fermented probiotic foods. In addition to the general selection criteria for probiotics in areas such as food safety, technological and digestive stress tolerance, many potential health benefits have been recently described for dairy propionibacteria, including, production of several active molecules and adhesion capability, that can mean a steady action in modulation of microbiota and of metabolic activity in the gut; their impact on intestinal inflammation, modulation of the immune system, potential modulation of risk factors for cancer development modulation of intestinal absorption.     

传统与未来的碰撞：食品发酵工程技术与应用进展

随着生物技术的飞速发展,作为食品生物工程的主要组成部分,食品发酵工程技术不断升级,在传统发酵食品的菌种、发酵过程、产品品质得到改善的同时,生物制造的功能食品组分、未来食品等新型产品也应运而生。首先概述了由生物技术和信息技术的进步带来的食品发酵研究手段与生产方式的多层面变革,并重点阐释了利用食品合成生物学设计构建细胞工厂的思路和方法,以及食品生物工程在微生物分析、过程工程和分离工程方面的智能化进程。其次,介绍了现代食品生物工程技术在改善传统发酵食品品质及安全性、生产功能食品组分、添加剂和酶制剂、创制未来食品和开发新型益生食品方面的应用进展。最后,对全球和我国食品发酵产业面临的挑战和未来发展趋势进行了总结和展望,以期为食品发酵的技术革新和工业化应用提供参考。     

Usefulness of epifluorescence for quantitative analysis of lactobacilli in probiotic feed

AIMS: Enumeration of total, active or viable probiotic micro-organisms from liquid or solid commercial feedstuffs was studied during processing and storage. METHODS AND RESULTS: After sample preparation, an epifluorescence microscopy technique and a plating method were investigated comparatively. It was shown that (i) on the day of manufacture, active or viable bacteria were in equivalent amounts and that viable numbers then decreased, depending on the different processing and storage factors enhancing ABNC production, (ii) the amount of total and active lactobacilli remained close and quite stable for months at a high level (>10(8) active fluorescent units). CONCLUSIONS: Processing and storage promoted ABNC cells in the products tested. Consequently, both techniques should be used to evaluate the viable-dead-active status of bacteria for which functional properties are claimed. SIGNIFICANCE AND IMPACT OF THE STUDY: Enumeration of the whole probiotic bacterial population should be take into account for guidelines and labelling since non-viable bacteria could have a probiotic effect.     

Safety and probiotic functionality of isolated goat milk lactic acid bacteria

Purpose

Lactic acid bacteria (LAB) are traditionally employed in the food industry. LAB strains from goat milk may also present probiotic potential, and it is fundamental to study the safety and functionality aspects which are desirable for their use in food. The objective of this study was to verify the probiotic potential of lactic bacteria isolated from goat milk.

Methods

The presence of safety-related virulence factors (hemolytic activity, gelatinase production, coagulase, and sensitivity to antibiotics) as well as functionality (exopolysaccharide (EPS) production, proteolytic activity, autoaggregation, gas production, survival in the gastrointestinal tract, and antimicrobial activity against bacteria that impair oral health) were determined.

Result

The selected LAB strains are safe against the evaluated parameters and have characteristics of possible probiotic candidates. Especially L. plantarum (DF60Mi) and Lactococcus lactis (DF04Mi) have potential to be added to foods because they have better resistance to simulated gastrointestinal conditions. In addition, they are isolated with already proven antimicrobial activity against Listeria monocytogenes, an important food-borne pathogen. DF60Mi was able to produce EPS (exopolysaccharides). LS2 and DF4Mi strains, both Lactococcus lactis subsp. lactis, demonstrated antimicrobial activity against S. mutans ATCC 25175, a recurrent microorganism in oral pathologies, mainly caries.

Conclusion

This study provides subsidies for future exploration of the potentialities of these LAB strains for both the development of new functional foods and for application in oral health.

     

Towards understanding molecular modes of probiotic action

The possibility that certain microorganisms might be beneficial to human health is highlighted by the numerous consumer products containing probiotic bacteria. Probiotics are typically administered in food that, following entry into the gastro-intestinal tract, results in measurable health-promoting effects. Although there is a growing list of health benefits provided by the consumption of probiotics, their precise mechanisms of action remain largely unknown. Recent molecular- and genomics-based studies are starting to provide insight into the ways probiotic bacteria sense and adapt to the gastro-intestinal tract environment. Complementary approaches using host cell in vitro systems together with animal models and human volunteers are revealing specific intestinal cell responses to probiotics. These studies should ultimately disclose the molecular mechanisms and pinpoint the bacterial and host effector molecules and pathways by which probiotics are able to modulate human health.     

Applications of nonthermal plasma technology on safety and quality of dried food ingredients

Cold plasma technology is an efficient, environmental-friendly, economic and noninvasive technology; and in recent years these advantages placed this novel technology at the centre of diverse studies for food industry applications. Dried food ingredients including spices, herbs, powders and seeds are an important part of the human diet; and the growing demands of consumers for higher quality and safe food products have led to increased research into alternative decontamination methods. Numerous studies have investigated the effect of nonthermal plasma on dried food ingredients for food safety and quality purposes. This review provides critical review on potential of cold plasma for disinfection of dried food surfaces (spices, herbs and seeds), improvement of functional and rheological properties of dried ingredients (powders, proteins and starches). The review further highlights the benefits of plasma treatment for enhancement of seeds performance and germination yield which could be applied in agricultural sector in near future. Different studies applying plasma technology for control of pathogens and spoilage micro-organisms and modification of food quality and germination of dried food products followed by benefits and current challenges are presented. However, more systemic research needs to be addressed for successful adoption of this technology in food industry.     

Probiotics from an industrial perspective

Probiotic products have gained popularity with consumers that expect that the products they consume are healthy and help them maintain health. Hence, the need and preferences of the consumers are translated into a product format concept. Probiotics have been used for a long time as natural components in supplements and functional foods, mainly in fermented dairy products. Most of the strains used as probiotics belong to the genera Lactobacillus and Bifidobacterium. By definition, a strain has to have documented health benefits, in order to be called a probiotic. Although each bacterial strain is unique, there are some points that are essential when selecting a probiotic regarding the genetic stability, survival, and technical properties of a strain. Proper components, food matrices and production processes need to be selected since the matrices may affect the viability of the strain in the product and the intestine. Survival in the product is considered a requirement for the beneficial effects of probiotics.     

Microencapsulation of probiotic bacteria: technology and potential applications

In the recent past, there has been an explosion of probiotic health-based products. Many reports indicated that there is poor survival of probiotic bacteria in these products. Further, the survival of these bacteria in the human gastro-intestinal system is questionable. Providing probiotic living cells with a physical barrier against adverse environmental conditions is therefore an approach currently receiving considerable interest. The technology of micro-encapsulation of probiotic bacterial cells evolved from the immobilised cell culture technology used in the biotechnological industry. Several methods of micro-encapsulation of probiotic bacteria have been reported and include spray drying, extrusion, emulsion and phase separation. None of these reported methods however, has resulted in the large numbers of shelf-stable, viable probiotic bacterial cells necessary for use in industry for development of new probiotic products. The most commonly reported micro-encapsulation procedure is based on the calcium-alginate gel capsule formation. Kappa-carrageenan, gellan gum, gelatin and starch are also used as excipients for the micro-encapsulation of probiotic bacteria. The currently available equipment for micro-encapsulation is not able to generate large quantities of uniform sized micro or nano capsules. There is a need to design and develop equipment that will be able to generate precise and uniform micro or nano capsules in large quantities for industrial applications. The reported food vehicles for delivery of encapsulated probiotic bacteria are yoghurt, cheese, ice cream and mayonnaise. Studies need to be done on the application of micro-encapsulation of probiotic bacteria in other food systems. The number of probiotic supplements will increase in the future. More studies, however, need to be conducted on the efficacy of micro-encapsulation to deliver probiotic bacteria and their controlled or targeted release in the gastrointestinal tract.     

Kefir micro-organisms: their role in grain assembly and health properties of fermented milk

Kefir is a homemade viscous and slightly effervescent beverage obtained by milk fermentation with kefir grains, which are built up by a complex community of lactic acid and acetic acid bacteria and yeasts confined in a matrix of proteins and polysaccharides. The present review summarizes the role of kefir micro-organisms in grain assembly and in the beneficial properties attributed to kefir. The use of both culture-dependent and independent methods has made possible to determine the micro-organisms that constitute this ecosystem. Kefir consumption has been associated with a wide range of functional and probiotic properties that could be attributed to the micro-organisms present in kefir and/or to the metabolites synthetized by them during milk fermentation. In this context, the role of micro-organisms in kefir health promoting properties is discussed with particular attention to the contribution of yeast as well as bioactive metabolites such as lactic and acetic acid, exopolysaccharides and bioactive peptides. Even though many advances on the knowledge of this ancient fermented milk have been made, further studies are necessary to elucidate the complex nature of the kefir ecosystem.     

The Relevance of the Distribution of Micro-organisms Within Batches of Food to the Control of Microbiological Hazards from Foods

The distribution of micro-organisms within batches of food is identified as log-normal and this distribution has practical implications in the control of microbial hazards in foods. These implications are explained as effects upon counting procedures, changes in levels through processes, detection of low levels of micro-organisms, the use of indicator groups, presence/absence tests, consumer safety calculations, and sample unit size analysed.