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Ozone gas (O3) is a promising alternative for fungal inactivation in agricultural commodities. This study aimed to (i) investigate the influence of airflow on the saturation of popcorn kernels with ozone gas, (ii) evaluate its effectiveness in controlling Aspergillus flavus, and (iii) analyze the quality of ozonated grains. Samples of 3.0 kg of kernels were exposed to oxygen (control) or ozone at specific flow rates of 0.15 or 1.00 m3 min−1 t−1, with an input ozone concentration of 16.0 mg L−1 for 0, 6, 12, 24, 36, or 48 h. Quality parameters assessed included expansion volume, water content, electrical conductivity, and color. At 0.15 m3 min−1 t−1, ozone consumption and saturation time were lower, with an 80% reduction in A. flavus infection after 6 h. This flow rate did not affect grain expansion or water content. Conversely, at 1.0 m3 min−1 t−1, reductions in water content and expansion were observed with extended exposure. Electrical conductivity increased in both treatments, more significantly at the lower flow rate. In conclusion, ozonation at 0.15 m3 min−1 t−1 effectively inactivated A. flavus without compromising grain quality. [ABSTRACT FROM AUTHOR]

Wastewater generated from agricultural activities and food production is a source of environmental pollution, and its treatment is a challenging technological issue. Ozone gas (O3), and the possibility of associating it with hydrogen peroxide (H2O2), has the potential to remove persistent organic compounds in effluents. In the present work, wastewater from industrial potato processing was characterized, and its treatment with ozone combined with hydrogen peroxide was assessed. The inlet ozone concentration and the flow rate were 84.5 mg L−1 and 62.5 mL min−1, respectively. The promising conditions of temperature, pH, and H2O2/O3 proportion were determined to reduce the chemical oxygen demand, turbidity, and color, according to a central composite rotatable design. The H2O2/O3 proportions were 0.1, 0.3, 0.5, and 0.6. Additionally, the response variables were evaluated as a function of the ozone and hydrogen peroxide treatment time for up to 24 h. The conditions obtained for treating wastewater from industrial potato processing were the following: temperature = 25°C; pH = 3.0, and H2O2/O3 proportion = 0.1. For the water quality parameters adopted, the combination of ozone and hydrogen peroxide was effective at removing color and turbidity. The chemical oxygen demand, color, and turbidity reduction stabilized after 1.16 h, with cumulative applied dosages of ozone and hydrogen peroxide equal to 380 mg L−1 and 35 mg L−1, respectively. [ABSTRACT FROM AUTHOR]

BACKGROUND: The application of allyl isothiocyanate (AITC) has been proposed as an alternative to control stored‐grain insects. However, AITC is a compound with a low diffusion coefficient, making its distribution throughout the grain mass difficult. Therefore, the objective of the present study was to evaluate the effectiveness of AITC applied in systems with or without recirculation for controlling Sitophilus zeamais (Mots. 1855) (Coleoptera: Curculionidae), Rhyzopertha dominica (Fabr.) (Coleoptera: Bostrichidae), and Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) infesting a corn grain mass. The assays used a polyvinyl chloride (PVC) prototype, dimensioned 1.60 m in length, 0.30 m in diameter, and a static capacity of 60 kg of grains. AITC toxicity to insects was evaluated at the base, 0.5 m from the base, and top of the grain column (1.0 m). Different concentrations of AITC were tested for an exposure period of 48 h. RESULTS: In the system without AITC recirculation, insect mortality was verified only at the base of the grain column. However, insect mortality was considered uniform at the different positions of the column when the AITC recirculation system was adopted. In this system, there was also a marked reduction in the instantaneous population growth rate of S. zeamais, T. castaneum, and R. dominica, and a decrease in the dry matter loss of the grains, when the AITC concentrations were increased. CONCLUSION: AITC recirculation proved to be a viable strategy for protecting grains against the species S. zeamais, R. dominica, and T. castaneum. AITC fumigation ultimately did not cause changes in grain quality. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The present work aimed at the effectiveness of ozonated water in the control of Listeria monocytogenes, adopting different combinations of pH, contact time, and storage time under refrigeration. To obtain ozonated water, the dose applied was 21 mg L−1 min−1, for 15 min. Samples of 1.0 L of water were ozonated at the inlet ozone concentration of 21 mg L−1 and a flow rate of 1.0 L min−1. The initial concentrations of ozone dissolved in water were equal to 5.81 mg L−1 at pH 4.0, 5.20 mg L−1, at pH 7.0, and 7.20 mg L−1 at pH 8.2. Samples of ozonated water with different initial pHs were used and stored at 7℃ for up to 24 h. The storage times of the ozonated water under refrigeration were 0, 6, 12, 18, and 24 h. The contact times of L. monocytogenes with ozonated water were 3.0 and 6.0 min. Ozone decomposition kinetics was evaluated. Ozonated water stored at 7℃ proved effective in controlling L. monocytogenes, especially in water pH values of 7.0 and 8.2. The initial pH of the water affects the effectiveness of ozonated water regarding the control of L. monocytogenes. The sharp reduction in ozone concentration was observed in water with pH 4.0, with a half-life of 13 min. For pHs of 7.0 and 8.2, the half-lives were 65 and 45 min, respectively. It is viable to use ozonated water stored at 7℃, for up to 24 h, to inactivate L. monocytogenes, when adopting initial pHs of 7.0 and 8.2, adjusted with sodium bicarbonate. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effect of gaseous ozone on the physiological quality of corn seeds with different initial germination percentages. Seeds with initial germination percentages of 54.0% (low physiological quality) and 86.0% (high physiological quality) were used. Samples of 0.12 kg of seeds were exposed to different combinations of inlet ozone concentrations (10 and 30 mg L−1) and exposure times (0, 30, 60, 90, and 120 min). A flow rate of 1.0 L min−1 was used at a temperature of 25 °C. The percentage of germination, shoot, root, and seedling lengths, germination velocity index, and electrical conductivity were analyzed. Univariate and multivariate analysis were used for data analysis. Seeds with low initial germination percentage showed increase of 1.6 to 1.8 times in germination percentage and approximately 1.2 times in length of the seedlings when the inlet ozone concentration was 10 mg L−1 and the exposure times were 30 and 120 min. Regarding seeds of high physiological quality, there was an increase in the germination velocity index of 1.1 to 1.2 times in ozonated seeds at 10 mg L−1, compared to the non-ozonated seeds. According to the multivariate analysis, the inlet ozone concentration of 10 mg L−1 associated with exposure times of 30 and 120 min showed similar results for seeds with low initial germination percentage. Based on the obtained results, we concluded that regardless the initial corn seeds quality, the recommended treatment is made by the combination of inlet ozone concentration of 10 mg L−1 and exposure time of 30 min. Also, greater benefits are obtained from the application of ozone gas in corn seeds of low initial physiological quality. The ozonation proved to be a promising technique for seed treatment since it increased germination percentage and shoot and seedling lengths. [ABSTRACT FROM AUTHOR]

The objective of this work was to evaluate the effectiveness of ozone in the control of fungi and the degradation of fumonisins in maize and possible effects on the chemical composition of the product. Two cultivars of hybrid maize (30F53H and AS1581 PRO) were used. Initially, the saturation process of the porous medium with ozone was studied. The incidence of Fusarium verticillioides, Penicillium spp. and Aspergillus flavus; the suitability of ozone to detoxify grains contaminated by fumonisins and possible qualitative changes in the product were evaluated. Ozone was applied at an inlet ozone concentration of 13.5 mg L−1 and flow rate of 1.0 L min−1, in five exposure periods (0, 12, 24, 36, 48 and 60 h). The estimated daily intake of FB by horses from grains subjected to ozonation was obtained. For the hybrid AS1581PRO, the estimated saturation time and concentration were equivalent to 67.34 min and 5.91 mg L−1, respectively. With regard to the hybrid 30F53H, the saturation time and concentration were 41.74 min and 8.72 mg L−1, respectively. Ozone was an effective fungicidal agent. The use of a concentration of 13.5 mg L−1 over a 24 h-treatment led to a reduction of 81.2 and 86.2% in the concentrations of fumonisin B1 and fumonisin B2, respectively. The estimated daily intake of fumonisins was reduced to 17.21 µg kg−1BW per day, corresponding to half of the acceptable daily intake for equines. Ozone did not affect the chemical composition of the grain. Ozone is effective in controlling fungi and as a detoxifying agent in maize contaminated by fumonisins. [ABSTRACT FROM AUTHOR]

This study aimed to characterize ozone gas (O3) decomposition kinetics when injected at low pressure for controlling Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), and its effect on popcorn kernel quality. The ozonation of the kernels was conducted in a 70-L hypobaric chamber, using samples of 5.0 kg of grains packaged in woven polypropylene bags. Firstly, the internal pressure of the chamber was reduced to 250 hPa, and ozone was injected at concentrations of 5.0, 6.7, 8.5, and 13.0 mg L−1 until reaching a pressure of 940 hPa. The ozone concentration decay inside both the chamber and package was continuously monitored. The quality parameters assessed included the expansion volume, moisture content, electrical conductivity, and color of the popcorn kernels. The decomposition kinetics followed a first-order model in all concentrations studied. The values of decomposition rate constant (k) ranged from 0.030 to 0.014 min−1, inside the package, and from 0.030 to 0.015 min−1, inside the chamber. The ozone half-lives ranged from 22.7 and 49.8 min, inside the package, and from 20.6 and 46.5 min, inside the chamber. Ozone applied in a low-pressure system at 13.0 mg L−1 controlled 94.45% of the S. zeamais insects in the grain mass. The injection of ozone gas at low pressure did not change the expansion volume, moisture content, and electrical conductivity of the popcorn kernels. [ABSTRACT FROM AUTHOR]

The aim of this study was to isolate and characterize lactic acid bacteria (LAB) from spontaneous fermentation of jalapeno pepper. Three strains of LAB were isolated from the spontaneous fermentation of peppers: Lactobacillus brevis P.16564, Lactobacillus brevis P.36564, and Lactobacillus rossiae P.26562, which were identified by amplification of the 16S rRNA gene. All strains showed marked viability after exposure to simulated gastric and pancreatic juice. Strain P.36564 showed greater viability when exposed to sequential stress from gastric and pancreatic juice. All strains showed antimicrobial activity on Escherichia coli (ATCC 25922) and Salmonella sp. (ATCC 700623). As for safety aspects, all strains are considered safe for human consumption. All strains have a high percentage of hydrophobicity and autoaggregation. The percentage of coaggregation of LAB with E. coli was low. These results suggest that LAB isolated from pepper may have a probiotic potential. Practical applications: The spontaneous fermented pepper is an excellent source of lactic acid bacteria (LAB). In this study, it was possible to obtain strains of LAB with excellent probiotic potential and antimicrobial activity against Salmonella sp. (ATCC 700623) and E. coli (ATCC 25922). The isolated strains of peppers could be used in the preparation of different fermented foods. The results of this research demonstrate the potential of the strains for future use by the fermented food industry. [ABSTRACT FROM AUTHOR]

Corn is a cereal of great economic and social importance worldwide. The objective of the present work was to evaluate the effects on the physiological quality and the performance in the field of corn seeds with different quality standards before and after hydropriming with ozone. To evaluate the effects on the physiological quality, two batches (one with high physiological quality and the other with low physiological quality) of corn seeds were used. Seeds from both batches were immersed in distilled water and bubbled with atmospheric air (control - 0 mg L-1) or ozone. Three inlet concentrations of ozone (0, 10, and 20 mg L−1) and five periods of preconditioning (0, 30, 60, 90, and 120 min) were used. To evaluate the physiological quality of the seeds, different tests were carried out both in the laboratory and in the field. The use of the corn seed hydropriming with atmospheric air or ozone favored the physiological quality of the corn seeds when considering laboratory and field variables. There was an increase of emergence in the field of seeds not submitted to aging (high physiological quality) only due to the preconditioning period. The use of ozone was positive in lowering the loss of cellular solutes in seeds submitted to aging. Ozonation also caused significant increases in the plant heights and in the first ear insertion height. The binomial 20 mg L−1/60 min is the most suitable for preconditioning corn seeds in ozonated water. [ABSTRACT FROM AUTHOR]

The present work aimed to evaluate the decomposition kinetics of ozone in aqueous media with Brazil nuts. It also intended to investigate the potential of ozonation for inactivating Aspergillus flavus, and to determine changes in nut color and crude oil lipid profile. To do so, an inlet ozone concentration of 13.0 mg L−1, at a flow rate of 1 L min−1 and 25°C, was adopted. For the ozonation process, distilled sterilized water at the pH levels of 8.1, 7.1, and 3.0 was used. The second-order kinetic model was fit to the residual ozone concentration data. To evaluate the effect of ozonation on A. flavus, the treatment was performed for 120 min at the different water pH levels aforementioned. The quality of Brazil nuts was appraised by analyzing their moisture content, as well as their color and the lipid profile of the crude oil. The sharpest decrease in the ozone concentration was noticed at pH 3.0, at which the ozone within the medium with Brazil nuts displayed a half-life of 16.14 min. At the pH levels 7.1 and 8.1, the half-life values were equal to 37.42 and 188.54 min, respectively. The A. flavus count reduced by 1.25 and 1.28 log cycles, when the water was ozonated at the pH levels of 7.1 and 3.0, respectively. Despite promoting some color alteration in the nuts, the ozonation did not change the fatty acid profile of the crude oil. In conclusion, the second-order kinetic model satisfactorily represented the ozone decomposition in aqueous media containing Brazil nuts. Moreover, as the pH reduces, there is an increase of the initial concentration of ozone dissolved in aqueous media in the presence of Brazil nuts and, consequently, a trend of reduction of the ozone half-life. The ozonation proved to be more efficient at controlling A. flavus in Brazil nuts when performed in an aqueous medium with an acid pH. [ABSTRACT FROM AUTHOR]

Post-harvest fungal diseases, such as anthracnose, are common causes of spoilage in papaya fruits, accounting for considerable economic losses. The use of ozone gas is an alternative to tackle this problem, as it is a strong oxidizing and antimicrobial agent. Thus, the objective of the present work was to evaluate the efficiency of ozonized water for controlling anthracnose in papayas. It also aimed at assessing the influence of this treatment in CO2 production, weight loss, and fruit coloration. Papayas inoculated with Colletotrichum gloeosporioides and C. magna were exposed to ozone dissolved in water at the concentration of 0.8 mg L−1 for 40, 80, 120, and 160 min. At the temperature of 11 °C, the longest exposure times implied in a decline of CO2 production and a reduction of fruit firmness. The storage at 25 °C resulted in a lower percentage of injured areas, less CO2 production, and less effect on firmness, in comparison with the untreated fruits. The application of ozone dissolved in water at 0.8 mg L−1 for up to 160 min is a feasible alternative for controlling the severity of anthracnose in post-harvested papaya of the variety Golden, without negatively affecting the quality of the fruits. [ABSTRACT FROM AUTHOR]