Comparison of electrolized water and multiple chemical sanitizer action against heat-resistant molds (HRM)

Fungi associated with orange juice production and assessment of adhesion ability and resistance to sanitizers

Orange juice is widely consumed worldwide due to its sensory and nutritional characteristics. This beverage is susceptible to contamination by acidic-tolerant microorganisms due to its low pH, especially filamentous fungi and yeasts. To minimize fungal spoilage, companies usually submit juice to thermal treatments; sanitizers are also applied on surfaces to maintain the microbiological quality. This study aimed to identify potential contamination sources in a juice processing line and to verify the susceptibility of isolated yeasts and filamentous fungi to food-grade sanitizers. Also, their ability to form single and binary adherent cells was assessed. The results revealed the presence of fungi in all samplings performed, with the most prominent microorganisms identified as Paecilomyces variotii, P. paravariotii, Pichia kudriavzevii and Wickerhamomyces anomalus. After obtaining results for sanitizer resistance and adhesion ability of the isolates, these were submitted to multivariate analysis using hierarchical cluster analysis (HCA), and two groups were found: one composed mostly of filamentous fungi (16/18) with low adhesion potential and one group formed by yeasts with high adhesion ability and resistance to sanitizers. Microscopy images corroborate those data, demonstrating the importance of yeast cell agglomerates along germinated spores of filamentous fungi and the importance of adhered biomass to protect cells against the sanitizers tested. This study is the first to combine fungi isolated from a beverage processing line and aims to contribute to the current knowledge of fungal adhesion and sanitizer resistance.

Use of dielectric-barrier discharge (DBD) cold plasma for control of bread spoilage fungi

Bread is a greatly consumed bakery product worldwide. Unfortunately, it is an optimal substrate for fungal contamination and deterioration (aw > 0.95), commonly caused by the genera Penicillium, Paecilomyces, and Aspergillus, resulting in significant economic losses. Traditional conservation methods, such as the use of calcium propionate, are rejected by some consumers, leading to investment in alternative methods, such as the use of cold plasma. This study aimed to verify the effectiveness of dielectric-barrier discharge (DBD) cold plasma in inhibiting the growth of bread spoilage fungi. The species Penicillium sumatrense (ML1), Penicillium roqueforti (FML125), Penicillium paneum (FML126), Paecilomyces variotii (FML112), Aspergillus niger (ML2) were used. To assess the effect of plasma on fungi, they were inoculated into swabs, stainless steel coupons, and then small plugs were taken directly from the fungal culture and pan bread slices. All strains were inoculated into swabs and pan bread slices, but only the ML1 strain was used for experiments with coupons and plugs. Regarding the swabs of all strains (System I, 50 W/15 min), in addition to the milder treatments on the plug (System II, 50 W/2.5, 5, 10, and 20 min) and all treatments of ML1 strain coupons (System II, 200 W/15 min, 10 W and 8 W/2.5 and 1.5 min), the cold plasma presented fungistatic properties, delaying mycelial growth from 8 to 30 days and reducing the fungal population by 2.24 log when compared to controls. By analyzing the 200 W treatment with the longest exposure (5, 10, and 20 min) on the plug, plasma showed fungicidal action, completely inactivating mycelial growth. Regarding the pan bread slices, plasma System III, when applied for 45 min, reduced strains FML126 and FML112 by 1 log, FML125 and ML2 by 2 logs, and ML1 by 7 logs, demonstrating potential for use as a control method in the baking industry.

Food spoilage fungi: Main agents, sources and strategies for control

Fungal spoilage poses significant challenges in the global food industry, affecting various types of food products. Certain foods are inherently more susceptible to fungal contamination due to their intrinsic characteristics, as well as both raw materials and the processing environment, particularly the air, serve as major sources of fungal spores. Once a product is contaminated, the ability of fungal species to overcome technological barriers imposed by the industry (such as preservatives, reduced water activity, low pH, storage temperature, and oxygen restriction) will determine the extent of spoilage. Implementing stringent hygiene procedures, focusing on selecting sanitizers with antifungal properties, can help reduce the fungal spore load in the production environment. This, in turn, can limit the number of spores that reach the food, thereby delaying spoilage. This contribution covers the fungi responsible for spoilage of a variety of food types as well as the dynamics involved in the product contamination, physiological adaptations to spoil specific food niches and main control measures, with focus in sanitizers.

Factors That Interfere in the Action of Sanitizers against Ochratoxigenic Fungi Deteriorating Dry-Cured Meat Products

This study verified the factors affecting the antifungal efficacy of sanitizers against ochratoxin A-producing fungi. The fungi Penicillium nordicum, Penicillium verrucosum, and Aspergillus westerdijkiae were exposed to three sanitizers at three concentrations: peracetic acid (0.3, 0.6, 1%), benzalkonium chloride (0.3, 1.2, 2%), and sodium hypochlorite (0.5, 0.75, 1%) at three exposure times (10, 15, and 20 min), three temperatures (10, 25, and 40 °C), and with the presence of organic matter simulating clean (0.3%) and dirty (3%) environments. All the tested conditions influenced the antifungal action of the tested sanitizers. Peracetic acid and benzalkonium chloride were the most effective sanitizers, and sodium hypochlorite was ineffective according to the parameters evaluated. The amount of organic matter reduced the antifungal ability of all sanitizers. The longer exposure time was more effective for inactivating fungi. The temperature acted differently for benzalkonium chloride, which tended to be favored at low temperatures, than for sodium hypochlorite and peracetic acid, which were more effective at higher temperatures. The knowledge of the parameters that influence the action of sanitizers on spoilage fungi is vital in decision-making related to sanitizing processes in the food industry.

Application of Electrolyzed Water in the Food Industry: A Review

Electrolyzed water is a novel disinfectant and cleaner that has been widely utilized in the food sector for several years to ensure that surfaces are sterilized, and that food is safe. It is produced by the electrolysis of a dilute salt solution, and the reaction products include sodium hydroxide (NaOH) and hypochlorous acid. In comparison to conventional cleaning agents, electrolyzed water is economical and eco-friendly, easy to use, and strongly effective. Electrolyzed water is also used in its acidic form, but it is non-corrosive to the human epithelium and other organic matter. The electrolyzed water can be utilized in a diverse range of foods; thus, it is an appropriate choice for synergistic microbial control in the food industry to ensure food safety and quality without damaging the organoleptic parameters of the food. The present review article highlights the latest information on the factors responsible for food spoilage and the antimicrobial potential of electrolyzed water in fresh or processed plant and animal products.

Electrolyzed Water and Its Pharmacological Activities: A Mini-Review

Electrolyzed water (EW) is a new type of cleaning and disinfecting agent obtained by means of electrolysis with a dilute sodium chloride solution. It has low cost and harm to the human body and is also friendly to the environment. The anode produces acidic electrolyzed water (AEW), which is mainly used to inhibit bacterial growth and disinfect. The cathode provides basic electrolyzed water (BEW), which is implemented to promote human health. EW is a powerful multifunctional antibacterial agent with a wide range of applications in the medicine, agriculture, and food industry. Studies in vitro and in vivo show that it has an inhibitory effect on pathogenic bacteria and viruses. Therefore, EW is used to prevent chronic diseases, while it has been found to be effective against various kinds of infectious viruses. Animal experiments and clinical trials clearly showed that it accelerates wound healing, and has positive effects in oral health care, anti-obesity, lowering blood sugar, anti-cancer and anti-infectious viral diseases. This review article summarizes the application of EW in treating bacteria and viruses, the prevention of chronic diseases, and health promotion.

Influence of type, concentration, exposure time, temperature, and presence of organic load on the antifungal efficacy of industrial sanitizers against Aspergillus brasiliensis (ATCC 16404)

Parameters such as type and concentration of the active compound, exposure time, application temperature, and organic load presence influence the antimicrobial action of sanitizers, although there is little data in the literature. Thus, this study aimed to evaluate the antifungal efficacy of different chemical sanitizers under different conditions according to the European Committee for Standardization (CEN). Aspergillus brasiliensis (ATCC 16404) was exposed to four compounds (benzalkonium chloride, iodine, peracetic acid, and sodium hypochlorite) at two different concentrations (minimum and maximum described on the product label), different exposure times (5, 10, and 15 min), temperatures (10, 20, 30, and 40 °C), and the presence or absence of an organic load. All parameters, including the type of sanitizer, influenced the antifungal efficacy of the tested compounds. Peracetic acid and benzalkonium chloride were the best antifungal sanitizers. The efficacy of peracetic acid increased as temperatures rose, although the opposite effect was observed for benzalkonium chloride. Sodium hypochlorite was ineffective under all tested conditions. In general, 5 min of sanitizer exposure is not enough and >10 min are necessary for effective fungal inactivation. The presence of organic load reduced sanitizer efficacy in most of the tested situations, and when comparing the efficacy of each compound in the presence and absence of an organic load, a difference of up to 1.5 log CFU was observed. The lowest concentration recommended on the sanitizer label is ineffective for 99.9% fungal inactivation, even at the highest exposure time (15 min) or under the best conditions of temperature and organic load absence. Knowledge of the influence exerted by these parameters contributes to successful hygiene since the person responsible for the sanitization process in the food facility can select and apply a certain compound in the most favorable conditions for maximum antifungal efficacy.