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Article

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

by
Sarah Silva
,
Andrieli Stefanello
,
Bibiana Santos
,
Juliana Fracari
,
Graziela Leães
and
Marina Copetti
*
Graduate Program in Food Science and Technology, Federal University of Santa Maria, Santa Maria 97105-900, Brazil
*
Author to whom correspondence should be addressed.
Fermentation 2023, 9(2), 83; https://doi.org/10.3390/fermentation9020083
Submission received: 19 December 2022 / Revised: 12 January 2023 / Accepted: 16 January 2023 / Published: 18 January 2023
(This article belongs to the Special Issue Food Microbiology: Microbial Spoilers in Food)
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Abstract

:
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.

1. Introduction

Fungi play a crucial role in the preparation of meat products. Molds growing on the surface of dry-cured products are often desirable, as they can be considered responsible for developing the specific flavors and aromas of dry-cured meat products due to the lipolytic and proteolytic enzyme activities they produce throughout their growth [1,2,3]. However, some fungi can produce undesirable secondary metabolites, such as mycotoxins, and must be avoided [4].
Ochratoxin A is one of the most relevant mycotoxins and has been considered nephrotoxic, hepatotoxic, neurotoxic, genotoxic, teratogenic, and immunotoxic and is classified by the International Agency for Research on Cancer (IARC) as a possible human carcinogen (group 2B) [5,6]. Ochratoxin A has been described as the major mycotoxin in meat products such as cured and dry-fermented hams [7], including dried meats [8,9,10,11,12,13,14]. Its presence in meat products can be attributed to contamination by raw materials, including spices [15], meat from animals exposed to ochratoxin A in their diet [6,16], and especially by mold growth on the surface of meat products during their maturation [7,8,16,17,18,19], especially under inadequate sanitary conditions in the manufacturing environment [19].
The most common species that can produce ochratoxin A in such products are P. nordicum, A. westerdijkiae, and P. verrucosum. Some P. verrucosum isolates also produce citrinin [20], which has also been reported in meat products [9]. These fungi can grow on the surface of cured meat products during ripening because the ideal conditions for the growth of characteristic fungi, which grow on the surface of meat products, are also suitable for the growth of toxin-producing fungi [8].
The ecology of ochratoxigenic species is also variable. Research has indicated that ochratoxin A production in meat products from temperate climates is due to P. nordicum and P. verrucosum, which present high incidence in most European countries [13,21,22,23,24,25,26,27]. Otherwise, the occurrence of this mycotoxin in salami production from warmer climate countries is related to A. westerdijkiae, which has been reported in Argentina [28,29,30], Italy [8,31], and Brazil [32].
Since the removal of ochratoxin from food is currently not possible, it is necessary to work on preventing the occurrence of potentially ochratoxigenic fungi in food by adopting hygienic practices that aim to eliminate these agents in the food industry environment, this being the most effective way to prevent the consumption of contaminated food [33,34,35,36].
Using chemical sanitizers in food facilities is a common alternative for fungal control. A sanitizer should be selected based on the nature of the practices; the approved use for specific plant areas, equipment, or surfaces to be sanitized; and its effectiveness against pathogenic and spoilage microorganisms [37]. Common sanitizing chemicals used in food-processing plants are peracetic acid, sodium hypochlorite, and benzalkonium chloride [36,37]. Chlorine compounds are widely used sanitizers on equipment in food-processing plants because of their regarded effectiveness against all microbial forms [37,38]. Quaternary ammonium compounds are cationic surfactants used primarily on walls, floors, drains, and aluminum equipment and are considered more effective against fungi than chlorine compounds but are not effective against Gram-negative bacteria [37,38]. Peracetic acid, manufactured by reacting acetic acid with hydrogen peroxide, has a shorter shelf life and is usually more expensive than the above-mentioned agents, although it rapidly gained popularity because of the multitude of its applications, its broad action, and its environmental compatibility [37,38].
Nevertheless, there is limited information about the influence of different conditions, such as temperature, type of product, agent concentration, amount of organic matter in the environment, and time of exposure to the antifungal action of sanitizers; additionally, there is no study directed to spoiling and toxigenic fungi. Given these limitations, this study sought to evaluate the efficacy of three commercial sanitizers commonly used in the food industry against A. westerdijkiae, P. nordicum, and P. verrucusom, which are commonly found in food facilities producing dry-cured meat products. The variables tested were chosen considering relevant characteristics in food facilities’ sanitizing processes, including the concentration and type of sanitizer, exposure time, temperature, and bioburden level.

2. Materials and Methods

2.1. Microorganisms and Standardization of the Initial Inoculum

The microorganisms used in this study belong to the Laboratory of Mycology in Foods (LAMA) of the Federal University of Santa Maria (southern Brazil), all of them coming from meat products spoiled by them. The strains of A. westerdijkiae (LAMA 346/17 SLM, salami origin), P. nordicum (LAMA 01/21, ham origin), and P. verrucosum (LAMA 49/21, salami origin) were inoculated in tubes containing malt extract agar (MEA) (glucose, 20 g (Neon, São Paulo, Brazil), peptone, 1 g (Himedia, Mumbai, India), and malt extract, 30 g (Bacto™, Maryland USA). After seven days of incubation at 25 °C, the mycelium was scraped off with a sterile disposable loop. Serial dilutions were performed with sterile 0.1% peptone water (peptone, 0.1 g (Himedia, Mumbai, India), distilled water, 1 L) with initial inoculum standardized between 1.5 and 5 × 107 spores/mL for A. westerdijkiae and P. verrucosum and between 1.5 and 5 × 106 spores/mL for P. nordicum using a Neubauer chamber (CRAL/C1010/Brazil).

2.2. Variables Tested

The sanitizers selected are authorized by the National Health Surveillance Agency (ANVISA) for use in the meat products industry, and the concentrations were chosen for the test following the manufacturers’ recommendations. The manufacturer informs on the label the maximum and minimum concentrations recommended for use on surfaces in contact with food, and the intermediate concentration applied in the test was defined by calculating the average maximum and minimum concentrations.
The study conditions, such as exposure time, exposure temperature, sanitizer concentration, presence of organic matter, neutralizing solution, and sanitizing agent, are listed in Table 1. The tests were carried out in duplicate with the different sanitizers, fungi, temperatures, presence of organic matter, and sanitizer concentration.

2.3. Application of Variables in the Test

The in vitro tests applied were conducted according to the proposed model for chemical disinfectants and antiseptics surface test for the evaluation of bactericidal and/or fungicidal activity of chemical disinfectants used in food and industrial areas of the European Committee for Standardization (CEN) [39], with adaptation related to the initial count of conidia according to Bernardi et al. [33] and type of albumin used as an interfering substance (soil).
For each condition tested, 50 μL of the initial inoculum was collected and inoculated onto five sterile stainless-steel discs of 2 cm (three for the effective sensitivity test and two for the control). The presence of organic matter in clean or dirty environments was stimulated by adding 0.3 or 3% albumin, respectively. The disks were taken to the incubator at 35 °C for 40 min for conidia fixation. Next, the disks with the adhered inocula were placed in incubators at the respective test temperatures (10, 25, and 40 °C) for 30 min. The sanitizers were also previously placed in the incubators (3 h before), with their concentrations, for equilibration at the experiment temperatures (10, 25, and 40 °C). Subsequently, 100 μL of each sanitizer was added to the disks, separately in their test concentrations and temperatures, and exposed for 10, 15, or 20 min to evaluate the influence of this variable.
After exposure, the disks were immersed in a neutralizing solution, according to Jaenisch et al. [40]. Then, 5 g of glass beads was added to facilitate the removal of the inoculum adhered to the disks. After 5 min immersed in the neutralizer, serial dilutions were performed in 0.1% peptone water. Next, 1 mL aliquots of the dilutions were added to Petri dishes, and 20 mL of plain malt extract agar (malt extract 30 g/L, agar 15 g/L) was added. The plates were labeled and placed in an incubator at 25 °C for five days; after this period, the colonies were counted, and the results were expressed in logarithms of colony-forming units (log CFU).
To the disks containing microorganisms not exposed to the sanitizers, 100 μL of sterile distilled water was added, following the same protocol, thus obtaining the control. According to European Standard 13697 [39], a sanitizer is only considered effective if there is a reduction greater than 3 log CFU (99.9%) of the fungal population exposed to the sanitizing agent compared to the population of unexposed microorganisms (control).

2.4. Statistical Analysis

Tukey’s test was applied to compare means. XLSTAT software version 2019.2.2 (Addinsoft, New York, NY, USA) was used in the statistical analyses, with a significance level of 5%.

3. Results

The results of the inactivation of the A. westerdijkiae, P. nordicum, and P. verrucosum are presented in Figure 1, Figure 2 and Figure 3, which are potential spoilage agents of mature meat products when exposed to peracetic acid, benzalkonium chloride, and sodium hypochlorite sanitizers at different concentrations, exposure times and temperatures, and organic matter concentrations.
From a global perspective, all the factors studied influenced the sanitizers’ actions in inactivating spoilage fungi in meat products to a greater or lesser degree. The type of sanitizer was the primary factor related to higher or lower antifungal activity, with peracetic acid being the best agent for the control of the fungal species studied, and sodium hypochlorite being ineffective in most of the conditions evaluated. The concentration of the active ingredient also deserves attention since the highest concentration stipulated on the product label was the most effective in achieving the necessary antifungal action. However, the intermediate concentration also proved to be effective in some situations. It is important to mention that the level of organic matter reduced the efficacy of all disinfectants studied. This reduction was evident in benzalkonium chloride, regardless of the fungal species. By comparing the fungal species, a difference was observed among the fungus evaluated, emphasizing the low sensitivity of A. westerdjikiae to benzalkonium chloride and lower concentrations of peracetic acid. The temperature influenced the sanitizing action variably since, for peracetic acid and sodium hypochlorite, the greatest inactivation occurred when the temperature was higher, and benzalkonium chloride seemed to have favored action at lower temperatures. Regarding the exposure time, the longer the contact time, the better the antifungal action, usually requiring a minimum of 15 min for adequate action.
The organic matter concentration was a relevant factor influencing the effectiveness of sanitizers, with the highest antifungal activity occurring when the organic matter concentration was 0.3%. An organic matter concentration of 0.3% simulates a clean food industry environment, and 3% a dirty one [39].
Exposure time was also an important parameter because, for all fungi tested, temperatures, and concentrations, the exposure time of the fungus to the sanitizer always obtained better efficacy results at the longer contact times (20 and 15 min). The temperatures also affected the antifungal action of each sanitizer, since high temperatures (e.g., 25 and 40 °C) were favorable for increasing the antifungal action of the peracetic acid and sodium hypochlorite sanitizers.
In general, among the sanitizers evaluated, peracetic acid was the sanitizer with the highest antifungal activity against the spoilage fungi of meat products tested. This sanitizer was effective (inactivation >3 log CFU) at all concentrations and temperatures tested against P. nordicum, P. verrucosum, and A. westerdijkiae in low organic matter conditions (0.3%). Under dirty conditions (3% organic matter), the lowest peracetic acid concentration evaluated (0.3% v/v) was ineffective in fungal inactivation in most situations.
Benzalkonium chloride was the second sanitizer that obtained good results against the fungi mentioned herein. As shown in the results, the inactivation tended to increase as the test temperature was reduced, indicating that the sanitizer was more effective at lower temperatures. When applied at 1.2 and 2% concentrations in the presence of 0.3% organic matter (clean conditions) to P. nordicum, no viable spores were recovered in all parameters tested. When applied to P. verrucosum, no fungal detection occurred at 1.2 and 2% except when the temperature was raised to 40 °C. Under the same conditions described above, the action of the sanitizer on A. westerdijkiae was different since benzalkonium chloride could inactivate the fungus only when the concentration was 2% in 0.3% organic matter after 10 min of exposure at 25 °C, with a certain tolerance of A. westerdijkiae to benzalkonium chloride.
The sanitizer sodium hypochlorite was the sanitizer that, compared with the species evaluated herein, was ineffective for A. westerdijkiae and P. verrucosum, being effective only for inactivating P. nordicum at 25 and 40 °C, with an exposure time of 20 min, presence of organic matter of 0.3%, and a concentration of 1.0% of sanitizer (Figure 2). Figure 1 presents the results of colony counts of A. westerdijkiae after exposure to the sanitizers under different situations. Most of the results showed significant differences among them, indicating that, in general, all parameters interfered with the efficacy of the sanitizers against A. westerdijkiae.
The best performance was of the peracetic acid, which in all parameters of concentration, time, and temperature of exposure in 0.3% of organic matter, resulted in the total inactivation of A. westerdijkiae. Nonetheless, for the concentration of 3.0% organic matter (dirty environment), peracetic acid was ineffective at its lowest use concentration at 10 °C in all exposure times and 25 °C if exposure for only 10 min was adopted.
The worst performance was of sodium hypochlorite, effective only when the maximum recommended concentration (1.0%) was used at the highest temperature tested (40 °C) and for a minimum contact time of 15 min, provided in the presence of low organic matter (0.3%). Regarding benzalkonium chloride, the lowest concentration of the agent tested was ineffective against A. westerdijkiae in all situations, and the agent was strongly influenced by organic matter. The best inactivation results were obtained at the highest contact times and concentrations.
Figure 3 shows the results of the application of sanitizers on the fungus P. verrucosum. In the same way that occurred with the fungus A. westerdijkiae, the sanitizer with the greatest antifungal action was peracetic acid, which had the lowest concentration of 0.3% and was effective in the presence of 0.3% organic matter. When the concentration was 3.0% of organic matter, the antifungal action was reduced, so this agent was considered effective only when the exposure time was 20 min at the concentration of 0.3%. In the following parameters, there was complete fungal inactivation, indicating total inhibition of the fungus P. nordicum.
The action of benzalkonium chloride seemed to be favored at lower temperatures (e.g., 10 and 25 °C). The concentration of organic matter proved to be favorable to fungal survival, and it was observed that the values found were higher when the amount of organic matter was 3%. Figure 2 lists the results for the fungus P. nordicum, which was considered the most sensitive to the sanitizers tested. The results of the action of peracetic acid and benzalkonium chloride were similar to those of fungal species previously presented, although sodium hypochlorite proved to be effective against P. nordicum in specific situations, such as the exposure time of 20 min at 25 and 40 °C, provided that the highest concentration of the agent was used with the low concentration of organic matter.

4. Discussion

This study evaluated the impact of different factors on the antifungal action of sanitizers against ochratoxin A-producing fungi reported as spoilage agents of cured meat products. These products are present in the daily diet of most of society, being relevant to conducting research aimed at fungal control to reduce consumers’ exposures to ochratoxin A. For the choice of sanitizers, we considered those available in the market, authorized by regulatory agencies, and used in industrial environments.
Our findings revealed that peracetic acid was the sanitizer with the highest antifungal efficacy and broad action for the three fungi that produce ochratoxin A, being effective even at low concentrations and both at high and low temperatures, thereby corroborating reports of challenges against other food spoilage fungal species where this sanitizer agent was also considered the most effective [33,34,36,41]. Peracetic acid is considered effective in neutral and acid pH and different temperatures, favoring its antifungal action [37,38,42,43], although this compound is less effective at alkaline pH and is partially affected by organic material and has low soil load tolerance [42].
Aspergillus section Circumdati (including A. westerdijkiae) were very sensitive to peracetic acid compared with Aspergillus section Flavi and Nigri toxigenic strains, which were highly tolerant to this sanitizing agent [44]. Nonetheless, a variation in the sensitivity to peracetic acid among A. westerdijkiae strains isolated from meat products was reported [36], with one strain showing tolerance even to the highest concentration challenged. No studies supporting the tolerance acquisition of fungi towards sanitizers were found; however, we believe that because of fungal heterogeneity, repeated exposures to sublethal doses of a sanitizing agent can lead to the selection of a subpopulation of fungi more tolerant to a certain agent. Bacterial resistance to sanitizers in the food industry has also been discussed in the literature [45].
The low antifungal action of sodium hypochlorite at recommended concentrations for sanitizing surfaces in contact with food in food industries with ochratoxigenic fungi deteriorating meat products was only effective in specific situations of low organic matter, long contact time, and high temperatures, as has already been reported elsewhere [32,33,34,35,36,41，44，46]. Because of their efficacy against bacteria and relatively low cost, hypochlorites are widely used in a multitude of sanitization operations [42,47]. Chlorines decrease effectiveness with an increase in pH and reaction with organic material from soils, leading to the formation of harmful by-products [42,48].
When evaluating the interfering factors in the action of sanitizers against the standard fungal species for sanitizing tests, Stefanello et al. [41] observed that sodium hypochlorite was the only sanitizer unable to eliminate 3 log CFU of the exposed population of A. brasiliensis (ATCC 16404) at all concentrations tested, even in the absence of organic load. For A. westerdijkiae, P. nordicum, and P. verrucosum, sodium hypochlorite was less effective than the other sanitizers tested. When testing the antifungal action of sodium hypochlorite in the same concentration reported here against toxigenic Aspergillus strains, Lemos et al. [44] determined the two highest concentrations of this sanitizer to be effective for A. westerdijkiae isolated from cocoa but ineffective against the strain isolated from ham. This compound was ineffective against all the other toxigenic Aspergillus strains studied [44]. Bernardi et al. [35,36] also tested sodium hypochlorite against fungi from bread, cheese, and meat products and found that it was rarely effective against these fungi in concentration for food-contact surface sanitation, and only high agent concentration intended for floor and wall sanitation were effective. Given the results, sodium hypochlorite should be avoided to control filamentous fungi on work surfaces of food facilities.
Benzalkonium chloride, a quaternary ammonium compound, was the second most effective antifungal agent against fungi with the potential to spoil meat products producing ochratoxin A. Quaternary ammonium compounds are cationic surfactants and are more effective against fungi than chlorine compounds, although they are not effective for Gram-negative bacteria, including certain pathogens and spoilage bacteria [37,42,48], limiting their usage in some food plants.
The antifungal action of benzalkonium chloride increased at low temperatures (10 °C), although its efficacy decreased when the organic matter was raised to 3%. These data corroborate Stefanello et al. [41], who reported a higher efficacy of benzalkonium chloride at 10 °C against A. brasiliensis (ATCC 16404). This greater action at low temperatures is favorable, allowing savings with water heating since water can be used directly from the well for this process, in addition to facilitating the cleaning of refrigerated areas (cold chambers, freezing tunnels, coolers, etc.), where temperature increases throughout the process are not desired.
When present in higher concentration in the tests performed, the organic matter increased the survival of all tested fungal species regardless of the sanitizer considered, indicating that the cleaning and removal of organic matter in food facilities are crucial because organic matter is a determining factor of sanitizer action. This study corroborates the statement of Stefanello et al. [41], who reported that in order to improve the sanitizer action, it is crucial to proceed with an effective cleaning step before the sanitization procedure since the presence of organic load reduced the efficacy of most sanitizers [37,42,48]. In this sense, the ineffective hygienic control regarding removing organic matter from the environment and the lack of care in selecting raw materials favor the development and proliferation of fungal microbiota with the potential for meat product deterioration [49].
Even with a reduction in efficacy in the presence of 3.0% organic matter, peracetic acid remained effective. The literature has reported this compound as partially affected by organic material but with low tolerance to soil load [42]. In previous studies, peracetic acid was affected by the presence of organic matter [41]. Despite quaternary ammonium compounds being considered stable against reaction with organic matter [48] and with high tolerance to soil load [42], Stefanello et al. [41] reported that the antifungal efficacy of benzalkonium chloride decreased in the presence of organic load, as observed here.
Regarding the differences observed among the species evaluated in this study, where A. westerdijkiae was the most tolerant compared to P. verrucosum and P. nordicum, Bernardi et al. [35] reported the importance of knowing the sensitivity of the strains present in the environment or the harmful agents from a specific food plant for selecting the most appropriate sanitizer and the best concentration to be applied for effective fungal control. A high tolerance of fungal strains isolated from processed meat products to the sanitizers used in food industries was reported, even when the highest sanitizer concentration was considered [36]. The same study revealed that the lowest concentration specified on the product label was the closest to the one adopted in the hygiene routine of meat industries [36,47]. According to our data, the lowest concentration recommended by the manufacturer in most cases was ineffective against the ochratoxigenic species related to the spoilage of dry-cured meat products.
By considering the various factors tested, we cannot fail to point out that most chemical cleaning products (cleaning and sanitizing) have a residual toxicity rate, which is why specific care must be taken in their application, handling, and storage, and the use of individual protection equipment, careful and abundant washing so as not to have residues of the chemical products applied [37,42]. Unlike peracetic acid and benzalkonium chloride, sodium hypochlorite irritates the skin; however, both sodium hypochlorite and peracetic acid do not have residual antimicrobial activity, which occurs with benzalkonium chloride [42]. Another relevant factor in the application of chemical products is their stability and the damage they can cause to the surface of the equipment, as after a corrosive lesion it can lead to the accumulation of organic matter and thus favor the insertion of a microbial biofilm in the equipment, making it difficult to sanitize [35,37,42]. Sodium hypochlorite is the most corrosive among the studied agents, followed by peracetic acid; benzalkonium chloride is not corrosive [42].
Implementing a sanitization and hygiene plan for the industry must be considered a crucial step in food facilities. One must have a critical view to raise crucial points, such as the region of the food facility, and the ambient temperature that can cause the proliferation of fungi (e.g., A. westerdijkiae) at higher and also milder temperatures (e.g., P. verrucosum and P. nordicum). Another critical point in the hygiene plan of a food facility should be the efficient removal of organic matter remaining after the industrial process and the use of appropriate resources, including spatulas, mops, and movements that provide greater removal of organic matter present. Training for employees responsible for cleaning and sanitizing must occur routinely, observing the concentration of the sanitizer utilized that must be within the standards allowed by law, and the concentration adopted must always be effective to the company’s goal. The choice of the sanitizer is vital to achieving effective sanitization because some active principles are more effective for certain fungi. The exposure time is another step of great interference because the shorter the contact time of the sanitizer, the lower its effectiveness, so the contact time must always be necessary to eliminate toxigenic fungi and the total effectiveness of the sanitizer.

5. Conclusions

Peracetic acid was the most effective sanitizer against potential fungal species of dried cured meat products and ochratoxin A producers; it should be the sanitizer of choice for sanitizing these environments. Notably, its antifungal activity increases at higher temperatures. Benzalkonium chloride showed promising results at high concentrations and for long exposure times, with an apparent increase in activity at lower temperatures. Sodium hypochlorite showed low antifungal activity under all conditions tested in this study and should be avoided when the goal is fungal inactivation in food-processing surfaces. The antifungal action of all sanitizers is greater at longer exposure times, with the best results starting at 15 min. The occurrence of considerable reduction in the antifungal action of all the sanitizers evaluated when in the presence of bioburden simulating a dirty environment shows that food facilities must follow a rigorous cleaning step with effective removal of organic matter to obtain good results in the sanitization step. Therefore, we conclude that all tested variables, namely, time, temperature, organic matter concentration, sanitizer concentration, and active principle, should be considered critical in the food industry to eliminate toxigenic fungi, such as P. nordicum, P. verrucosum, and A. westerdijkiae.
As Supplementary Material, Tables S1–S3 detail the statistical results of the tested variables.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/fermentation9020083/s1, Table S1: Aspergillus westerdijkiae colonies recovered after exposure to different concentrations of sanitizing agents at different temperatures and concentrations of organic matter. Table S2: Colonies of Penicillium verrucosum recovered after exposure to different concentrations of sanitizing agents at different temperatures and concentrations of organic matter. Table S3: Recovered colonies of Penicillium nordicum after exposure to different concentrations of sanitizing agents at different temperatures and concentrations of organic matter.

Author Contributions

Conceptualization, S.S. and M.C.; methodology, A.S. and M.C.; software, B.S.; formal analysis, S.S.; A.S.; J.F. and G.L.; writing—original draft preparation, S.S.; writing—review and editing, M.C.; supervision, A.S.; M.C.; project administration, M.C.; funding acquisition, M.C. All authors have read and agreed to the published version of the manuscript.

Funding

This study was supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) (Process 428454/2018-6), a research grant for M.V.C. (Process 303570/2019-9), and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) through graduate grants (Financial code 001).

Conflicts of Interest

The authors declare no conflict of interest.

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Fermentation 09 00083 g001 550
Figure 1. Antifungal action of different sanitizers, namely, (A) sodium hypochlorite, (B) benzalkonium chloride, and (C) peracetic acid, against Aspergillus westerdijkiae (LAMA 346/17) at different concentrations, exposure times (0, 10, 15, and 20 min, in different color shadows), temperatures (10, 25, and 40 °C), and organic matter concentrations (0.3 and 3.0%).
Figure 1. Antifungal action of different sanitizers, namely, (A) sodium hypochlorite, (B) benzalkonium chloride, and (C) peracetic acid, against Aspergillus westerdijkiae (LAMA 346/17) at different concentrations, exposure times (0, 10, 15, and 20 min, in different color shadows), temperatures (10, 25, and 40 °C), and organic matter concentrations (0.3 and 3.0%).
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Figure 2. Antifungal action of different sanitizers, namely, (A) sodium hypochlorite, (B) benzalkonium chloride, and (C) peracetic acid, against Penicillium nordicum (LAMA 01/21) at different concentrations, exposure times (0, 10, 15, and 20 min, in different color shadows), temperatures (10, 25, and 40 °C), and concentrations of organic matter (0.3 and 3.0%).
Figure 2. Antifungal action of different sanitizers, namely, (A) sodium hypochlorite, (B) benzalkonium chloride, and (C) peracetic acid, against Penicillium nordicum (LAMA 01/21) at different concentrations, exposure times (0, 10, 15, and 20 min, in different color shadows), temperatures (10, 25, and 40 °C), and concentrations of organic matter (0.3 and 3.0%).
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Figure 3. Antifungal action of different sanitizers, namely, (A) sodium hypochlorite, (B) benzalkonium chloride, and (C) peracetic acid, against Penicillium verrucosum (LAMA 49/21) at different concentrations, exposure times (0, 10, 15, and 20 min, in different color shadows), temperatures (10, 25, and 40 °C), and concentrations of organic matter (0.3 and 3.0%).
Figure 3. Antifungal action of different sanitizers, namely, (A) sodium hypochlorite, (B) benzalkonium chloride, and (C) peracetic acid, against Penicillium verrucosum (LAMA 49/21) at different concentrations, exposure times (0, 10, 15, and 20 min, in different color shadows), temperatures (10, 25, and 40 °C), and concentrations of organic matter (0.3 and 3.0%).
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Table
Table 1. Variables considered for the study of factors interfering with the antifungal activity of sanitizers.
Table 1. Variables considered for the study of factors interfering with the antifungal activity of sanitizers.
SanitizersConcentration
(%)		Temperature
(°C)		Exposure Time (min)Organic Matter (%)Neutralizers
Benzalkonium chloride0.3, 1.2, 210, 25, 4010, 15, 200.3, 3Nutrient broth with 0.5% Tween 80 and 1% tryptone
Peracetic acid0.3, 0.6, 110, 25, 4010, 15, 200.3, 3Nutrient broth with 0.6% sodium sulfate
Sodium hypochlorite0.5, 0.75, 110, 25, 4010, 15, 200.3, 3Nutrient broth with 0.6% sodium sulfate
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Silva, S.; Stefanello, A.; Santos, B.; Fracari, J.; Leães, G.; Copetti, M. Factors That Interfere in the Action of Sanitizers against Ochratoxigenic Fungi Deteriorating Dry-Cured Meat Products. Fermentation 2023, 9, 83. https://doi.org/10.3390/fermentation9020083

AMA Style

Silva S, Stefanello A, Santos B, Fracari J, Leães G, Copetti M. Factors That Interfere in the Action of Sanitizers against Ochratoxigenic Fungi Deteriorating Dry-Cured Meat Products. Fermentation. 2023; 9(2):83. https://doi.org/10.3390/fermentation9020083

Chicago/Turabian Style

Silva, Sarah, Andrieli Stefanello, Bibiana Santos, Juliana Fracari, Graziela Leães, and Marina Copetti. 2023. "Factors That Interfere in the Action of Sanitizers against Ochratoxigenic Fungi Deteriorating Dry-Cured Meat Products" Fermentation 9, no. 2: 83. https://doi.org/10.3390/fermentation9020083

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