Sub- and supercritical fluid extraction of functional ingredients from different natural sources: Plants,food-by-products,algae and microalgae: A review

The increasing interest of consumers in functional foods has brought about a rise in demand for functional ingredients obtained using “natural” processes. In this review, new environmentally clean technologies for producing natural food ingredients are discussed. This work provides an updated overview on the principal applications of two clean processes, supercritical fluid extraction and subcritical water extraction, used to isolate natural products from different raw materials, such as plants, food by-products, algae and microalgae. Although the extraction of some compounds with antibacterial, antiviral or antifungical activity is discussed, special attention is paid to the extraction of antioxidant compounds, due to their important role in food preservation and health promotion.     

Purification and partial characterization of antilisterial bacteriocin produced by Pediococcus pentosaceus KJBC11 from Idli batter fermented with Piper betle leaves

Bacteriocins are natural antimicrobial agents mainly act against closely related bacteria and at times unrelated organisms including various food spoilage and pathogenic organisms. Bacteriocins from Lactic Acid Bacteria (LAB) have been widely used for food preservation because of their safety nature. In this study, bacteriocin from Pediococcus pentosaceus KJBC11 was purified with the recovery of 15%, using cell adsorption‐desorption technique, gel permeation chromatography, hydrophobic interaction chromatography, and reversed phase HPLC successively. Molecular weight of bacteriocin KJBC11 was determined to be 4.5 kDa using Tricine SDS‐PAGE. The bacteriocin KJBC11 showed strong inhibitory activity against various Gram‐positive and Gram‐negative pathogens. Bacteriocin KJBC11 activity was not altered when treated with amylase, lipase, and trypsin but inactivated by protease and proteinase enzyme treatment. It was heat stable (100°C, 1 hr) and exhibited strong antimicrobial activity within the pH 3–7. Its mode of action was bactericidal in nature as revealed against Listeria monocytogenes showing leakage of internal contents out of the cell. Bacteriocin KJBC11 could belong to Class IIa‐pediocin like bacteriocins based on its characteristics as well as the presence of pediocin gene in the genome of the isolate KJBC11.

Practical applications

Studies on Lactic Acid Bacteria and bacteriocin have attracted increasing attention for a long time, due to their established role in food fermentation and preservation. The antimicrobial properties of bacteriocin became a trademark approach to achieve food safety and to counter the menace of antibiotic resistant pathogens. This study revealed a potent bacteriocin with wide range of antibacterial activity against various foodborne and clinically important pathogens to have potential application in food preservation and biomedicine.     

大气压冷等离子体在鲜切果蔬保鲜中的应用研究进展

鲜切果蔬因具有新鲜方便、无添加剂和营养价值高等优点而广受消费者喜爱,但是鲜切果蔬在加工和贮藏过程中极易受微生物污染,导致食品品质劣变并缩短货架期.大气压冷等离子体(Atmospheric cold plasma,ACP)是一种新型非热加工技术,广泛应用于食品及生物医药领域.本文综述了ACP对鲜切果蔬表面微生物的灭活效果...     

Preserving quality of fresh-cut products using safe technologies

Food preservation is critical for keeping the global food supply safe and available for consumers. Food scientists study production and processing to develop new technologies that improve the quality and quantity of healthy food products, with the main objective of increasing food production without affecting food quality and environment, while fulfilling consumer expectations. Nowadays consumers want their food to be fresh, nutritious, safe, and attractive, low priced, and ready-to-eat. That is the case of fresh-cut products; however, maintaining the quality of these products is not an easy task, since minimally processed products experience increased ethylene production and respiration rates, with the consequent lost of quality. New effective and inexpensive technologies to safely preserve the quality of fresh-cut products are needed. In the last two decades, food scientists have attempted to solve problems in fresh-cut processing and quality preservation, and rapid advances in scientific knowledge on fresh-cut product preservation have been developed. The present review describes the use of emerging technologies such as ultraviolet irradiation (UV-C), edible coatings, active packaging and natural additives, to preserve the quality of fresh-cut fruits; highlighting the areas in which information is still lacking, and commenting on future trends.     

环境胁迫调控植物乳杆菌细菌素合成的研究进展

植物乳杆菌作为具有重要经济价值的乳酸菌被广泛应用于食品发酵与保鲜领域,由于其代谢过程中会产生具有广谱抑菌特性、对热稳定且易被蛋白酶水解的细菌素,因此有作为天然食品生物防腐剂的较大应用潜力。研究表明,在发酵过程中菌体的生长和细菌素的合成受多种环境因素如盐胁迫、酸胁迫、氧胁迫及低高温胁迫的影响,但目前环境因素调节信号分子产生以及调控相关基因合成细菌素的具体机制仍然有待研究,另一方面,通用的调控通路还未被发现。因此,本文介绍了植物乳杆菌抵御胁迫的反应机制并详细阐述了环境胁迫下与细菌素合成密切相关的调控基因和重要调控蛋白,为食品发酵加工过程中合理控制发酵条件,促进细菌素合成从而延长食品货架期提供理论依据。     

Physical and nutritional conditions for optimized production of bacteriocins by lactic acid bacteria – A review

ABSTRACT

There has been an increasing debate about the use of synthetic chemical compounds and the consequences of their use in food preservation. In this context, the utilization of some natural compounds produced by bacteria, showing an inhibitory effect against microorganisms associated with food contamination, have gained attention as preservation technology. In order to improve the production and yield costs of bacteriocins, detailed studies are necessary to determine the conditions that allow an optimized production and extraction of bacteriocins from lactic acid bacteria (LAB). In this context, this article aims to discuss the information regarding the main factors that influence bacteriocin production by LAB. The biosynthesis of bacteriocins can be influenced by various culture conditions, such as the composition of the medium, pH, temperature and growth kinetics of the microorganisms. One of the limiting factors for the use of bacteriocins on a large scale in food preservation is the economic factor. In order for the production costs of bacteriocins to be reduced, making them attractive, it is necessary to know the optimum parameters of production, thus maximizing productivity and making costs more attractive.     

Pediocin PA-1, a wide-spectrum bacteriocin from lactic acid bacteria

Pediocin PA-1 is a broad-spectrum lactic acid bacteria bacteriocin that shows a particularly strong activity against Listeria monocytogenes, a foodborne pathogen of special concern among the food industries. This antimicrobial peptide is the most extensively studied class Ila (or pediocin family) bacteriocin, and it has been sufficiently well characterized to be used as a food biopreservative. This review focuses on the progress that have been made in the elucidation of its structure, mode of action, and biosynthesis, and includes an overview of its applications in food systems. The aspects that need further research are also addressed. In the future, protein engineering, genetic engineering and/or chemical synthesis may lead to the development of new antimicrobial peptides with improved properties, based on some features of the pediocin PA-1 molecule.     

Preserving quality of fresh-cut products using safe technologies

Food preservation is critical for keeping the global food supply safe and available for consumers. Food scientists study production and processing to develop new technologies that improve the quality and quantity of healthy food products, with the main objective of increasing food production without affecting food quality and environment, while fulfilling consumer expectations. Nowadays consumers want their food to be fresh, nutritious, safe, and attractive, low priced, and ready-to-eat. That is the case of fresh-cut products; however, maintaining the quality of these products is not an easy task, since minimally processed products experience increased ethylene production and respiration rates, with the consequent lost of quality. New effective and inexpensive technologies to safely preserve the quality of fresh-cut products are needed. In the last two decades, food scientists have attempted to solve problems in fresh-cut processing and quality preservation, and rapid advances in scientific knowledge on fresh-cut product preservation have been developed. The present review describes the use of emerging technologies such as ultraviolet irradiation (UV-C), edible coatings, active packaging and natural additives, to preserve the quality of fresh-cut fruits; highlighting the areas in which information is still lacking, and commenting on future trends.     

细菌素在食品贮藏保鲜中的应用

由微生物污染所引起的食品腐败变质问题是食品工业始终面临的巨大挑战之一。而传统的理化保鲜技术一方面会导致营养成分流失,另一方面对人体健康会造成潜在的威胁。人们一直在寻找一种安全、高效、天然的食品保鲜剂。现代生物技术的发展使得微生物保鲜剂逐渐进入人们的视野并不断地被开发、研究和应用。细菌素是由某些细菌分泌的一种具有抑菌活性的代谢产物。它无毒无抗性,能够在杀死微生物的同时最大程度地保留食品的鲜度和营养价值,可以替代化学防腐剂应用于食品保鲜,作为天然微生物源保鲜剂的一种,近些年受到了广泛关注。因此,本文简要介绍了细菌素的分类、特点,概述了各种类型的细菌素在不同种类食品保鲜方面的应用和研究进展,总结了在保鲜领域中存在的问题和挑战,并对其未来发展趋势提出展望,为细菌素更好地应用于食品工业提供一定的理论依据。     

乳酸链球菌素的研究现状及在食品中的应用

随着科技的进步和人们对食品安全的日益高度重视,传统的化学保鲜剂已经不能满足消费者们对健康的需求,因此科学研究者们将更多的目光转向生物型防腐保鲜剂。细菌素是某些细菌在代谢过程中通过核糖体合成机制产生的一类具有抗菌活性的多肽、蛋白质或蛋白质复合物,具有高效、无毒、无残留、无抗药性及耐高温等优点。乳酸链球菌素是当下研究最彻底、应用最广、通过纯化并实现商业化的细菌素之一,它是由乳酸菌发酵生产的多肽类天然生物抗菌剂,能够抑制或杀死其他细菌。本文综述了乳酸链球菌素的理化特性、抑菌机制、功能应用等方面,以期为后续研究提供参考。     

Novel approaches to purifying bacteriocin: A review

ABSTRACT

Bacteriocin is a proteinaceous biomolecule produced by bacteria (both Gram-positive and Gram-negative) that exhibits antimicrobial activity against closely related species, and food-borne pathogens. It has recently gained importance and attracted the attention of several researchers looking to produce it from various substrates and bacterial strains. This ushers in a new era of food preservation where the use of bacteriocin in food products will be an alternative to chemical preservatives, and heat treatment which are understood to cause unwanted side effects, and reduce sensory and nutritional quality. However, this new market depends on the success of novel downstream separation schemes from various types of crude feedstocks which are both effective and economic. This review focuses on the downstream separation of bacteriocin from various sources using both conventional and novel techniques. Finally, recommendations for future interesting areas of research that need to be pursued are highlighted.     

Chitosan application for active bio-based films production and potential in the food industry: Review

During the past decade, there was an increasing interest to develop and use bio-based active films which are characterized by antimicrobial and antifungal activities in order to improve food preservation and to reduce the use of chemical preservatives. Biologically active bio-molecules such as chitosan and its derivatives have a significant potential in the food industry in view of contaminations associated with food products and the increasing concerns in relation with the negative environmental impact of conventional packaging materials such as plastics. Chitosan offers real potential for applications in the food industry due to its particular physico-chemical properties, short time biodegradability, biocompatibility with human tissues, antimicrobial an antifungal activities, and non-toxicity. Thus, chitosan-based films have attracted serious attention in food preservation and packaging technology. This is mainly due to a fact that chitosan exhibits high antimicrobial activity against pathogenic and spoilage micro-organisms, including fungi, and both Gram-positive and Gram-negative bacteria. The aim of the present review was to summarize the most important information on chitosan from its bioactivity point of view and to highlight various preparative methods used for chitosan-based active bio-films and their potential for applications in the food preservation and packaging technology.     

Bacteriocins and their Food Applications

Over the last 2 decades, a variety of bacteriocins, produced by bacteria that kill or inhibit the growth of other bacteria, have been identified and characterized biochemically and genetically. This review article focuses on the ecology of bacteriocins, determination of bacteriocin activity, biosynthesis of bacteriocins, and mode of action. Bacteriocin production and modeling are discussed in the article. Nisin is discussed in some detail in this article since it is currently the only purified bacteriocin approved for food use in the U.S. and has been successfully used for several decades as a food preservative in more than 50 countries. For activity spectra and food applications, the review article focuses primarily on class I and class IIa bacteriocins produced by lactic acid bacteria (LAB) given their development as food preservatives.     

植物源精油的抑菌机制及其在食品保鲜包装中的应用进展

随着人们生活水平的不断提高,对饮食结构的要求随之提高,食品安全问题已成为关注焦点之一.而目前在食品生产与包装中使用最广泛的化学防腐剂已不足以满足人们对于安全、健康、绿色的需求.因此,植物源精油的抗菌保鲜方式因其显著的抗菌效果与无毒无残留的特性受到越来越多的关注,其在食品保鲜上的应用已成为研究热点.本文就植物源精油的抑菌...     

乳酸菌细菌素的高效表达方法研究

乳酸菌细菌素作为天然的生物防腐剂,因其高效、无毒等特点而备受关注,但目前只有乳酸链球菌素实现了工业化生产。乳酸菌细菌素产量低是限制其大规模生产的瓶颈之一。从高产菌株筛选、发酵条件调控、基因工程技术、诱导调控和胁迫刺激应答5个方面,综述了提高乳酸菌细菌素产量的方法,期望为提高乳酸菌细菌素产量的研究提供新思路。     

Organic Acids and Meat Preservation: A Review

Despite the application of various preservation methods, many problems are still encountered as a result of food spoilage and food poisoning. There is increasing demand for foods produced with milder treatments, and the movement towards more natural and even certified organic foods has been the fastest growing sector of the food industry over the last decade. The interest in bio-preservation of food systems has necessitated the development of new natural antimicrobial compounds from different origins, and in response to modern consumer trends and food legislation, the food industry is faced with serious challenges. Both conventional and organic modes of production are at risk of contamination, but it is possible that organic food might present a bigger problem. Organic acids have been of considerable value as food preservatives since they are also food ingredients and often naturally produced by microorganisms. However, limited data on their effects in commercial practice are available, and despite regulatory approval, organic acids are not widely accepted in commercial practice, and in particular in meat decontamination.

Susceptibility of microorganisms to the most currently used preservatives has been decreasing, and there is concern that decontamination with organic acids could result in the emergence of acid-tolerant food-borne pathogens, evolving to overcome the protective barrier of the human gastric stomach. In the evaluation and integration of new processing/preservation treatments, research objectives would have to include the identification of specific targets of organic acids—understanding the molecular mechanisms that confer high level resistance and analysing pathogen response to antimicrobials. This article provides an overview of various studies done on organic acids as preservatives and highlights aspects such as application, antimicrobial action, and future prospects. Other important issues, such as the application of functional genomics in developing new preservation methods, resistance development, and conventional laboratory procedures are also discussed.     

Class IIa bacteriocins from lactic acid bacteria: antibacterial activity and food preservation

In the last decade, a variety of ribosomally synthesized antimicrobial peptides, or bacteriocins, produced by lactic acid bacteria have been identified and characterized. As a result of these studies, insight has been gained into various fundamental aspects of biology and biochemistry such as bacteriocin processing and secretion, mechanisms of cell immunity, and structure-function relationships. In parallel, there has been a growing awareness that bacteriocins may be developed into useful antimicrobial food additives. Class IIa bacteriocins can be considered as the major subgroup of bacteriocins from lactic acid bacteria, not only because of their large number, but also because of their significant biological activities and potential applications. The present review provides an overview of the knowledge available for class IIa bacteriocins and discusses common features and recent findings concerning these substances. The activity and potential food applications of class IIa bacteriocins are a major focus of this review.     

Non-thermal technologies and its current and future application in the food industry: a review

In recent years, consumers have been demanding convenient and healthy foods which have ‘fresh-like’ characteristics while still being safe and a long shelf-life. These requirements are hard to achieve using existing traditional thermal food processing technologies and the innovative new food process and preservation technologies based on thermal processing systems are needed. However, non-thermal technologies in food processing do not generate high temperature and use short treatment times. This means that the nutritional components of foodstuffs are better retained, and the sensory properties of foods are less changed compared with traditional thermal processing. The aim of this review was to present non-thermal technologies applications and its mechanism in food industry in recently, and to explore the potential application prospects of combining non-thermal treatments applied in food industry because it not only could overcomes the drawback of single technology, but also can enhances the processing efficiency at lower treatment intensity.     

Organic Acids and Meat Preservation: A Review

Despite the application of various preservation methods, many problems are still encountered as a result of food spoilage and food poisoning. There is increasing demand for foods produced with milder treatments, and the movement towards more natural and even certified organic foods has been the fastest growing sector of the food industry over the last decade. The interest in bio-preservation of food systems has necessitated the development of new natural antimicrobial compounds from different origins, and in response to modern consumer trends and food legislation, the food industry is faced with serious challenges. Both conventional and organic modes of production are at risk of contamination, but it is possible that organic food might present a bigger problem. Organic acids have been of considerable value as food preservatives since they are also food ingredients and often naturally produced by microorganisms. However, limited data on their effects in commercial practice are available, and despite regulatory approval, organic acids are not widely accepted in commercial practice, and in particular in meat decontamination.

Susceptibility of microorganisms to the most currently used preservatives has been decreasing, and there is concern that decontamination with organic acids could result in the emergence of acid-tolerant food-borne pathogens, evolving to overcome the protective barrier of the human gastric stomach. In the evaluation and integration of new processing/preservation treatments, research objectives would have to include the identification of specific targets of organic acids—understanding the molecular mechanisms that confer high level resistance and analysing pathogen response to antimicrobials. This article provides an overview of various studies done on organic acids as preservatives and highlights aspects such as application, antimicrobial action, and future prospects. Other important issues, such as the application of functional genomics in developing new preservation methods, resistance development, and conventional laboratory procedures are also discussed.     

Integration of Emerging Biomedical Technologies in Meat Processing to Improve Meat Safety and Quality

Modern‐day processing of meat products involves a series of complex procedures designed to ensure the quality and safety of the meat for consumers. As the size of abattoirs increases, the logistical problems associated with large‐capacity animal processing can affect the sanitation of the facility and the meat products, potentially increasing transmission of infectious diseases. Additionally, spoilage of food from improper processing and storage increases the global economic and ecological burden of meat production. Advances in biomedical and materials science have allowed for the development of innovative new antibacterial technologies that have broad applications in the medical industry. Additionally, new approaches in tissue engineering and nondestructive cooling of biological specimens could significantly improve organ transplantation and tissue grafting. These same strategies may be even more effective in the preservation and protection of meat as animal carcasses are easier to manipulate and do not have the same stringent requirements of care as living patients. This review presents potential applications of emerging biomedical technologies in the food industry to improve meat safety and quality. Future research directions investigating these new technologies and their usefulness in the meat processing chain along with regulatory, logistical, and consumer perception issues will also be discussed.