Use of Natural Antimicrobial Agents: A Safe Preservation Approach

Microorganism contamination at various stages of food chain is one of the major causes for food spoilage that ultimately leads to food waste, increasing food insecurity issues and substantial economic losses. Various synthetic chemical preservatives are being used to control microbial food spoilage and to extend product shelf life. Researchers and consumers are discouraging the use of synthetic preservatives due to their negative health impacts. Naturally occurring antimicrobials have gained attention among researchers and food manufacturer due to their safety and nontoxic status. Natural preservatives are easy to obtain from plants, animals and microbes. These naturally occurring antimicrobial agents can be isolated from indigenous sources using various advanced techniques. Natural preservatives such as nisin, essential oils, and natamycin have effective potential against spoilage and pathogenic microorganisms. The regulations regarding the use of these naturally occurring preservatives are not well defined in some developing countries. This chapter focuses on source and their potential role, antimicrobial mechanism in food preservation, and current knowledge on the subject

Perspectives in the hurdle techniques in the preservation of a non alcoholic beverage, zobo

The effect of some commonly used chemical preservatives (acetic acid and sodium benzoate), natural plant extracts (clove, garlic, ginger and lime) and pasteurization on the elongation of shelf-life of zobo beverage were investigated by determining total counts and characterization of microorganisms before and during storage at ambient temperature for 14 days. Five bacterial species, namely Staphylococcus aureus, Micrococcus leteus, Micrococcus rosues, Bacillus subtilis and Enterococcus faecalis were predominant isolates. Two fungal species, namely, Saccharomyces cerevisiae and Rhizopus stolonifer were also isolated. Bacillus subtilis and Saccharomyces cerevisiae remained the predominant organisms throughout the storage. The role played by some of the isolates in food spoilage, deterioration and intoxication had been discussed. The microbial population increased for two days as the organisms utilize the nutrients present in the sample. There was a drastic reduction in microbial load as the effects of the preservative became evident, except for the control sample. Antimicrobial activities of the preservatives revealed that samples with chemical preservatives were most effective against bacteria and fungi species, followed by the natural plant extracts samples. Pasteurization confers temporary preservation as its effect was short lived. The phytochemical and antimicrobial activities of the plants used had been reported. Of all the samples, only those treated with chemical preservatives remained organoleptically attractive after preservation for 14 days. The overall reduction in the microbial population could be a concerted effort of the preservatives and exhaustion of nutrients in the zobo drink. The study recommends the use of chemical and natural preservatives to enhance the keeping quality of zobo beverage which conforms to good manufacturing practices globally

Instrumental and sensory characterisation of oleogels for cosmetic use

Oleogels are semisolid systems consisting of an oleogelator (gelling agent) and a lipophilic liquid phase. Despite having some distinct advantages (e.g. absence of preservatives or surfactants), the use of oleogels in cosmetic products is still sporadic. The aim of this study was to compare the effects of different types of oleogelators on instrumental and sensory properties of oleogels made with common emollient types: hydrocarbon, synthetic ester and natural oil

Evaluation of the Antimicrobial Activity of Four Plant Essential Oils against Some Food and Phytopathogens Isolated from Processed Meat Products in Egypt

Synthetic preservatives are widely utilized by the food industry to inhibit the microbial contamination and increase food safety and shelf life. The excessive utilization of synthetic preservatives can have a negative impact on human health and the environment. There is a great interest to find out natural substances as possible food-preservatives. The consumers' preference for food products with natural ingredients prompted food manufacturers to utilize natural-based preservatives in their production. It is worth noting that plant essential oils (EOs) among the natural-based substances have been efficiently used as antimicrobial agents against phyto- and food pathogens. The current study was conducted to evaluate the microbial contamination of three industrial meat products from five governorates in Egypt, identify the predominant bacterial and fungal isolates and determine the antimicrobial efficacy of some EOs (thyme, fennel, anise and marjoram) against the most predominant microbial isolates. A sensory test was also performed to estimate the customer preferences for specific organoleptic aspects of meat products after EOs treatment. Results showed that there is a promising antimicrobial activity of all studied EOs against some microbial isolates in a dose-dependent manner. In particular, thyme EO showed the highest significant antibacterial activity against P. fluorescence and E. coli. Whereas the marjoram EO showed the highest activity against P. aeruginosa. In addition, the sensory test revealed that the treatment with anise and marjoram EOs showed the highest acceptability by the testers and did not show significant differences on the organoleptic properties with respect to control. As overall, the obtained results of the current research are promising and proved feasibility of employing plant EOs as possible preservatives for processed meat products

Use of Spectroscopic Techniques to Monitor Changes in Food Quality during Application of Natural Preservatives: A Review

Consumer demand for food of high quality has driven research for alternative methods of food preservation on the one hand, and the development of new and rapid quality assessment techniques on the other hand. Recently, there has been a growing need and interest in healthier food products, which has led to an increased interest in natural preservatives, such as essential oils, plant extracts, and edible films and coatings. Several studies have shown the potential of using biopreservation, natural antimicrobials, and antioxidant agents in place of other processing and preservation techniques (e.g., thermal and non-thermal treatments, freezing, or synthetic chemicals). Changes in food quality induced by the application of natural preservatives have been commonly evaluated using a range of traditional methods, including microbiology, sensory, and physicochemical measurements. Several spectroscopic techniques have been proposed as promising alternatives to the traditional time- consuming and destructive methods. This review will provide an overview of recent studies and highlight the potential of spectroscopic techniques to evaluate quality changes in food products following the application of natural preservatives

Antioxidants of natural plant origins: from sources to food industry applications

ReviewIn recent years, great interest has been focused on using natural antioxidants in food products, due to studies indicating possible adverse effects that may be related to the consumption of synthetic antioxidants. A variety of plant materials are known to be natural sources of antioxidants, such as herbs, spices, seeds, fruits and vegetables. The interest in these natural components is not only due to their biological value, but also to their economic impact, as most of them may be extracted from food by-products and under-exploited plant species. This article provides an overview of current knowledge on natural antioxidants: their sources, extraction methods and stabilization processes. In addition, recent studies on their applications in the food industry are also addressed; namely, as preservatives in different food products and in active films for packaging purposes and edible coatingsinfo:eu-repo/semantics/publishedVersio

EVALUATION OF NATURAL ANTIMICROBIAL PHENOLIC COMPOUNDS AGAINST FOODBORNE PATHOGENS

Raw and processed foods are vulnerable to contamination during their production, distribution and sale. Thus, a wide variety of chemical preservatives are used in the food industry to prevent the growth of food spoilage and pathogenic bacteria. However, health and economic concerns have led to an intensive search for natural alternatives, such as plant extracts, that can safely be used as substitutes for synthetic antimicrobials and preservatives to partially or completely inhibit the growth of bacteria. This study evaluated the antimicrobial effects of natural phenolic compounds extracted from vegetables, fruits, herbs and spices. The main objective was to determine the lowest concentration of phenolics to inhibit the visible growth of the pathogenic bacteria which is defined as the minimum inhibitory concentration (MIC). Some of the most common Gram-positive and Gram-negative foodborne pathogens were treated with several natural phenolic compounds. Concentrations of 5, 10, 15, and 20 ppm (pH 5-6) of each compound were evaluated by broth micro-dilution method and the MICs were determined by using official density (OD) assay. The results demonstrated that the phenolic compounds have varying antimicrobial activities against foodborne pathogens. Natural sources of phenolic compounds contain major antibacterial components and have great potential to be used as natural antimicrobials and food preservatives

Bioprotective properties of Dragon's blood resin: In vitro evaluation of antioxidant activity and antimicrobial activity

Abstract Background Food preservation is basically done to preserve the natural characteristics and appearance of the food and to increase the shelf life of food. Food preservatives in use are natural, chemical and artificial. Keeping in mind the adverse effects of synthetic food preservatives, there is a need to identify natural food preservatives. The aims of this study were to evaluate in vitro antioxidant and antimicrobial activities of Dragon's blood resin obtained from Dracaena cinnabari Balf f., with a view to develop safer food preservatives. Methods In this study, three solvents of varying polarity were used to extract and separate the medium and high polarity compounds from the non-polar compounds of the Dragon's blood resin. The extracts were evaluated for their antimicrobial activity against the food borne pathogens. The antioxidant activities of the extracts were assessed using DPPH and ABTS radical scavenging, FRAP, metal chelating and reducing power assays. Total phenolics, flavonoids and flavonols of extracts were also estimated using the standard methods. Results Phytochemical analysis of extracts revealed high phenolic content in CH2Cl2 extract of resin. Free radical scavenging of CH2Cl2 extract was found to be highest which is in good correlation with its total phenolic content. All test microorganisms were also inhibited by CH2Cl2 extract. Conclusions Our result provide evidence that CH2Cl2 extract is a potential source of natural antioxidant compounds and exhibited good inhibitory activity against various food borne pathogens. Thus, CH2Cl2 extract of Dragon's blood resin could be considered as possible source of food preservative.</p