Application of a novel antimicrobial coating on roast beef for inactivation and inhibition of Listeria monocytogenes during storage

Antimicrobial coating with organic acids and essential oil for the enhancement of safety and shelf life of grape tomatoes

This study investigated the antimicrobial efficacy of two coatings against populations of nalidixic acid-resistant Salmonella, Listeria monocytogenes and native microorganisms on whole grape tomatoes. Tomatoes were surface-coated in two chitosan-acid coating solutions. Solution 1 (Chitosan) consisted of 1 % chitosan and 2 % acetic, lactic and levulinic acids. Solution 2 (Chitosan+AIT) consisted of Solution 1 plus 2 % allyl isothiocyanate (AIT). After the treatments, tomatoes were placed in PET containers and stored at 10 °C for 21 days. Chitosan and Chitosan+AIT treatments reduced Salmonella populations from 3.65 to 1.28 and <0.70 log CFU/tomato on day 1, respectively. Both treatments reduced Salmonella populations to undetectable levels (<0.70 log CFU/tomato) from Day 2 through Day 21. Similarly, Chitosan+AIT treatments caused a greater reduction in Listeria populations than Chitosan treatment on day 1, but there were no significant differences between the two treatments after day 2. Chitosan and Chitosan+AIT reduced native bacteria populations to an undetectable level after 2 days and reduced the population of native yeasts & molds to an undetectable level after 1 day. The presence of mold was only observed on control sample after 21 days. Quality analyses showed that samples which were subject to coating treatment maintained their texture and color for 21 days at 10 °C with less water loss compared to the controls. This study suggests that chitosan-acid coating is applicable for extending the shelf-life and enhancing the safety of grape tomatoes.

Prevalence of pathogens harbouring mobile antimicrobial resistance genes and virulence factors in retail beef and mutton

Food safety is always a global issue, due to the increased dissemination of antimicrobial resistance and food poisoning related to foodborne bacterial pathogens. The purpose of this study was to assess the risk of potential foodborne bacteria of beef and mutton in retail stores. A total of 134 samples were collected from 24 local markets in Beijing, including raw and cooked beef or mutton, as well as samples derived from the corresponding environment and human beings. We obtained 674 isolates, of which Klebsiella spp. and Staphylococcus spp. were the dominant bacterial species in the meat samples and the environmental samples, respectively. Additionally, environmental bacteria are common in samples from different sources. Based on the results of antimicrobial sensitivity testing, resistance to tetracycline (with a resistance rate of 47.40%), amoxicillin + clavulanate (47.13%) and erythromycin (28.03%) were the major resistant phenotypes. According to the whole genome analysis, the extended spectrum beta-lactamase genes harboured by two K. pneumoniae strains isolated from cooked and raw beef were located on mobile elements. The major toxin genes of Bacillus cereus and adhesion- or invasion-related virulence factors were also shared among isolates from different sources. These factors pose potential risks to public health and need attention.

Film formation and deposition methods of edible coating on food products: A review

The greatest challenge encountered by the food manufacturer is the loss of quality of food products during storage, which eventually adds to the waste. Edible packaging is known as a potential alternative to protecting food quality and improving shelf life by delaying microbial spoilage and providing moisture and gas barrier properties. Developments in edible packaging and technology have shown promising results in enhancing the shelf life of food products. In 2016, the edible packaging market was valued at $697 million and by 2023 is expected to hit $1097 million growing at a compound annual growth rate (CGAR) of 6.81% from 2017 to 2023 at global level. In global edible packaging markets specific industries including MonoSol LLC, Tate & Lyle Plc, WikiCell Designs Inc., JRF Technology LLC, Safetraces, Inc., BluWrap, Skipping Rocks Lab, Tipa Corp., Watson Inc., and Devro plc have played a key role. Edible packaging can be applied in two forms: (i) edible coating applied directly on the food product or (ii) preformed film wrapped around the food product. The aim of this study is to review different methods of film formation and edible coating depositions. Edible films can be produced using two methods, wet (casting) and dry (extrusion) processes; and methods such as dipping, spraying, fluidized-bed, and panning are used for deposition of edible coatings on the surface of food product. Casting and dipping methods for film formation and coating deposition, respectively, are easy to use and are preferred methods on a lab scale; whereas extrusion and spraying are preferred methods for film formation and coating deposition, respectively, on a commercial scale. This work can help researchers and industries to select an efficient and cost-effective method for the development of edible film/coating for specific application. Further study and evaluation of practical applications of methods of edible packaging should be carried out within the main purpose of keeping food safe with acceptable quality for extended period of time.

Polysaccharide-based component and their relevance in edible film/coating: a review

Purpose

The purpose of this paper is to present an overview of functional properties of the polysaccharide-based component and their application in developing edible film and coating for the food processing sector.

Design/methodology/approach

In this review study, approximately 271 research and review articles focusing on studies related to polysaccharide-based components and their film-forming properties. This article also focused on the application of polysaccharide-based edible film in the food sector.

Findings

From the literature reviewed, polysaccharide components and components-based edible film/coating is the biodegradable and eco-friendly packaging of the materials and directly consumed by the consumer with food. It has been reported that the polysaccharide components have excellent properties such as being nontoxic, antioxidant, antimicrobial, antifungal and with good nutrients. The polysaccharide-based edible film has lipid and gas barrier properties with excellent transparency and mechanical strength. In various studies, researchers worked on the development of polysaccharide-based edible film and coating by incorporating plant based natural antioxidants. This was primarily done for obtaining improved physical and chemical properties of the edible film and coating. In future, the technology of developing polysaccharide-based edible film and coating could be used for extending the shelf life and preserving the quality of fruits and vegetables at a commercial level. There is more need to understand the role of edible packaging and sustainability in the food and environment sector.

Originality/value

Through this review paper, possible applications of polysaccharide-based components and their function property in the formation of the edible film and their effect on fruits, vegetables and other food products are discussed after detailed studies of literature from thesis and journal article.

Innovative technologies for producing and preserving intermediate moisture foods: A review

Intermediate moisture foods (IMF) or semi-dried foods (SDF) have gained more attention worldwide having features very similar to fresh food products, but with a longer shelf life. This review presents the recent developments in novel technologies and methods for the production and preservation of IMF. These include new drying methods, using agents to reduce water-activity, innovative osmotic dehydration technologies, electro-osmotic dewatering, thermal pasteurization, plasma treatments (PT), high pressure processing (HPP), modified atmosphere packaging (MAP), edible coating, active packaging (and energy efficiency, improve quality and extend the shelf life of the final food AP) and hurdle technologies (HT). Innovative methods applied to producing and preserving IMF can enhance both drying products. Yet more systematic research is still needed to bridge knowledge gaps, in particular on inactivation kinetics and mechanisms related to thermal and non-thermal pasteurization technologies for control of pathogens and spoilage micro-organisms in IMF.