Search Results (37)

Background: Long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD) is a rare autosomal recessive metabolic disorder affecting long-chain fatty acid β-oxidation. A hallmark feature of LCHADD is progressive chorioretinopathy, which may lead to severe visual complications, including macular neovascularization (MNV). The goal of the study was to analyze MNV in patients with genetically confirmed LCHADD. Methods: Data of 8 patients with LCHADD from the Kaszubia region in Poland followed in the clinic were retrospectively analyzed. The analyses included genetic confirmation, ophthalmologic examinations, spectral-domain optical coherence tomography (SD-OCT), and treatment responses. Results: Two patients with MNV in the course of LCHADD were identified. In Patient 1, a 9-year-old female, unilateral MNV at the fibrotic stage with a visual acuity of counting fingers was diagnosed in the right eye. No treatment was administered. The left eye remained stable, maintaining a best corrected visual acuity (BCVA) of 0.9 on the decimal Snellen chart. Patient 2, male, was followed from age 8 to 16 and during that time developed bilateral MNV. The right eye presented with inactive MNV at the age of 9, resulting in BCVA reduction to 0.3 without active fluid, and remained stable without intervention. The left eye developed active MNV at age 15 with subretinal fluid and retinal edema. Treatment with five intravitreal injections of ranibizumab led to complete resolution and recovery of BCVA to 1.0. Conclusions: MNV, although rare, can develop in pediatric LCHADD patients silently and bilaterally. Early detection through regular ophthalmologic screening is crucial, as timely anti-VEGF treatment can preserve or restore vision. Delayed diagnosis may result in irreversible damage and limited therapeutic benefit. Full article

High-pressure processing (HPP) is used as a non-thermal approach for controlling microbial viability. The purposes of this study were to (i) establish the decimal reduction times (D-values) for pathogenic bacteria during 350 MPa HPP treatment,; (ii) evaluate the impact of 350 MPa HPP on total plate count (TPC), yeasts and molds (YM), and lactic acid bacteria (LAB) in camel milk; (iii) investigate the behavior of several spoilage-causing bacteria during storage at 4 °C and 10 °C for up to 10 d post-HPP treatment; and (iv) assess the effect of HPP on the protein degradation of camel milk. The D-values for L. monocytogenes, E. coli O157:H7, and Salmonella spp. were 3.77 ± 0.36 min, 1.48 ± 0.08 min, and 2.10 ± 0.13 min, respectively. The HPP treatment decreased pathogenic microorganisms by up to 2 to 3 log cfu/mL (depending on treatment conditions). However, HPP reduced TPC, YM, and LAB by <1 log cfu/mL, regardless of the length of pressure exposure. HPP treatment, even at extended holding times, did not significantly alter either the proteolytic activity or casein micelle structure in camel milk. This study highlights HPP as a promising non-thermal technique for enhancing the microbiological safety of camel milk. Full article

This paper presents a programmable digital filtering unit dedicated to operating with signals from infrared (IR) detection modules. The designed device is quite useful for increasing the signal-to-noise ratio due to the reduction in noise and interference from detector–amplifier circuits or external radiation sources. Moreover, the developed device is flexible due to the possibility of programming the desired filter types and their responses. In the circuit, an advanced field-programmable gate array FPGA chip was used to ensure an adequate number of resources that are necessary to implement an effective filtration process. The proposed circuity was assisted by a 32-bit microcontroller to perform controlling functions and could operate at frequency sampling of up to 40 MSa/s with 16-bit resolution. In addition, in our application, the sampling frequency decimation enabled obtaining relatively narrow passband characteristics also in the low frequency range. The filtered signal was available in real time at the digital-to-analog converter output. In the paper, we showed results of simulations and real measurements of filters implementation in the FPGA device. Moreover, we also presented a practical application of the proposed circuit in cooperation with an InAsSb mid-IR detector module, where its self-noise was effectively reduced. The presented device can be regarded as an attractive alternative to the lock-in technique, artificial intelligence algorithms, or wavelet transform in applications where their use is impossible or problematic. Comparing the presented device with the previous proposal, a higher signal-to-noise ratio improvement and wider bandwidth of operation were obtained. Full article

Monascus ruber is an important fungus that causes spoilage in table olives, resulting in the darkening of the brine, the softening of the fruit, increased pH, and apparent mycelial growth. This study aimed to evaluate this resistance, providing a model to determine the optimal processing conditions for mitigating fungal contamination and prolonging shelf life without antifungal agents while optimizing pasteurization to reduce energy consumption. The resistance in brine (3.5% NaCl; pH 3.5) from Arauco cultivar green olives imported from Argentina was assessed. Four predictive models (log linear, log linear + shoulder, log linear + tail, log linear + shoulder + tail) estimated kinetic parameters for each survival curve. Log linear + shoulder + tail provided the best fit for 70 °C and 75 °C, with low RMSE (0.171 and 0.112) and high R² values (0.98 and 0.99), respectively, while the log linear model was used for 80 °C. Decimal reduction times at 70, 75, and 80 °C were 24.8, 5.4, and 1.6 min, respectively, with a z-value of 8.2 °C. The current regulatory processes are insufficient to eliminate M. ruber at requisite levels, considering reduced antifungal agents. Full article

The sterilization of liquid eggs plays a crucial role in the production of liquid egg products. Traditional pasteurization techniques can easily cause protein denaturation, while non-thermal sterilization techniques are often constrained by processing intensity and time. Improving the effectiveness of liquid egg sterilization while preserving the stability of its functional attributes poses a significant challenge. In response to this issue, a synergistic ultrasonic mild thermal sterilization system for liquid eggs is proposed, accompanied by the optimization of its process parameters. COMSOL is employed to simulate the acoustic field distribution of the ultrasonic–thermal system in the liquid egg medium. Verification is conducted through acoustic intensity measurements, and analysis is performed to obtain the optimal arrangement of ultrasonic transducers. Based on Modbus communication, an ultrasonic–thermal synergistic sterilization system is designed. Sterilization experiments are conducted with both 20 kHz + 28 kHz and 20 kHz + 40 kHz multifrequency ultrasound, compared with traditional 20 kHz single-frequency ultrasound. The results indicate that multifrequency ultrasound improves sterilization efficiency by approximately 15% compared to traditional single-source ultrasound. Utilizing multifrequency ultrasonic–thermal synergistic sterilization experiments, a three-factor, three-level response surface test is conducted with sterilization rate and foaming properties as evaluation criteria. The results indicate a strong correlation between ultrasonic frequency, processing time, heating temperature, and sterilization performance, with the impact magnitude being sterilization temperature > processing time > ultrasound frequency. Parameter optimization analysis is performed using a genetic algorithm, yielding sterilization conditions of 55 °C, 11 min and 30 s processing time, and 20 + 40 kHz ultrasonic frequency. The liquid egg sterilization rate is 99.32%, an average decimal reduction of 3.17 log values, and foaming properties are 42.79%.Through comparative analysis, it is determined that the sterilization rate of the ultrasonic–thermal synergistic sterilization system meets national standards, and functional properties such as foaming are superior to traditional pasteurization. This validates the proposed ultrasonic–thermal synergistic liquid egg sterilization control system as effective and feasible. Full article

There is currently increased interest in the use of alternatives to autoclaved culture media, in order to maintain the properties of the media, while saving energy and time. In this study, we assess a new system for culture media preparation, using a conventional microwave with a water bath and a glass bottle with a rubber cap that allows depressurization. Sterilization, using the proposed system (1000 W, 3 to 20 min), was compared with autoclaving for the preparation of tryptone soy agar (TSA), tryptone soy broth (TSB), Sabouraud 4% dextrose agar (SDA), and violet red bile glucose agar (VRBG). Microwave exposure for 7 min yielded sterile TSA plates. The productivity of both sterilization methods was assessed using the pour plate method, and significant increases in the growth of certain micro-organisms after using a microwave were observed for every culture medium, especially those that were sterilized by boiling (VRBG). The kinetics of microbial destruction showed that Escherichia coli and Bacillus subtilis spores were destroyed after 3 and 7 min in a microwave, respectively, while three decimal reductions were obtained for Geobacillus stearothermophilus spores after 15 min in an autoclave. This new sterilization method could be a feasible, rapid, and economical method to prepare microbiological media, with a quality similar to that obtained through autoclaving. Full article

This study explores the potential of thermosonication as an alternative to traditional heat treatments, such as pasteurization, in the processing of fruit juices. Conventional methods often lead to undesirable quality changes in fruit juices, whereas thermosonication offers promising results regarding microbial inactivation and quality preservation. This work focused on the inactivation kinetics of Listeria innocua 2030c, a surrogate for pathogenic L. monocytogenes, in kiwifruit juice using thermosonication at 45 °C, 50 °C, and 55 °C. These treatments were compared with equivalent heat treatments. Quality attributes of the juice were also evaluated to assess process efficiency. Survival data of L. innocua were fitted with the Weibull model, estimating first decimal reduction times (δ) and shape parameters (n). The results reveal temperature and process dependencies on δ, while n remains mostly temperature and treatment independent. Thermosonication outperforms heat treatment, achieving higher L. innocua reductions while retaining quality attributes like pH, soluble solid content, and total phenolics and chlorophylls. Thermosonication at 55 °C stands out, providing a 6.2-log-cycle reduction in just 3 min with superior quality retention. These findings highlight the synergistic effect of temperature and ultrasound, making mild heat processes feasible while enhancing product quality. Thermosonication, particularly at 55 °C, emerges as an effective alternative to traditional thermal treatments for fruit juices, offering improved microbial safety without compromising product quality. Full article

In this study, Salmonella Typhimurium, Escherichia coli, and Listeria monocytogenes were separately inoculated in sterilized carrot juice and subjected to various types of high-pressure processing (HPP) at 200–600 MPa for 0.1–15 min to observe the effects of HPP on the inactivation kinetics of foodborne pathogens in carrot juice. The first-order model fits the destruction kinetics of high pressure on foodborne pathogens during the pressure hold period. An increase in pressure from 200 to 600 MPa decreased the decimal reduction time (D values) of S. Typhimurium, E. coli, and L. monocytogenes. Under pressure ≥ 400 MPa, the D values of E. coli were significantly higher than those of S. Typhimurium and L. monocytogenes, indicating that E. coli had greater resistance to high pressures than the others. The Zp values (the pressure range that causes the D values to change by 90%) of E. coli, S. Typhimurium, and L. monocytogenes were 195, 175, and 170 MPa, respectively. These results indicated that L. monocytogenes and E. coli were the most and least sensitive, respectively, to pressure changes. Additionally, the three bacteria were separately inoculated into thermal-sterilized carrot juice and subjected to 200–600 MPa HPP for 3 min. The treated carrot juices were stored at 4 °C for 27 d. Following S. Typhimurium and E. coli inoculation, the bacterial counts of the control and 200 MPa treatments remained the same during the storage duration. However, they decreased for the 300 and 400 MPa treatment groups with increasing storage duration. During the storage period, no bacterial growth was observed in the 500 and 600 MPa treatments. However, the bacterial number for the control and pressure treatment groups increased with prolonged storage duration following inoculation with L. monocytogenes. Therefore, following HPP, residual L. monocytogenes continued growing stably at low temperatures. Overall, HPP could inhibit and delay the growth of S. Typhimurium and E. coli in carrot juice during cold storage, but it was ineffective at inhibiting the growth of L. monocytogenes. There was a risk of foodborne illness despite the low-temperature storage of juice. The innovation of this preliminary study is to find the impact of high pressure on the inactivate kinetics of three food pathogens in carrot juice and its practical application in simulated contaminated juice. Full article

The inactivation kinetics of an α-amylase enzymatic time-temperature integrator (TTI) from Bacillus subtilis (BAA) under continuous-flow microwave (MW) and conventional heating conditions were evaluated and compared in this study. The TTI dispersed in a buffer solution (pH 5.0 to 6.9) at 20 °C initially, and it was continuously circulated through two helical coils connected in a series for heating. The two coils were positioned in two domestic microwave ovens (2450 MHz and 1000 W nominal capacity each) and connected by a short tube. The sample flow rates were adjusted to result in a specific exit temperature in the range of 65 to 80 °C. A short fully insulated helical coil at the exit of the second oven was used as a holding tube. Test samples were drawn either at the exit of the second MW oven or immediately after the holding tube. The decimal reduction times obtained under conventional batch heating conditions decreased from 66 to 24 s as the temperature changed from 70 to 75 °C at pH 5.0 while they decreased from 8 to 5 s under MW in the same temperature range, but at pH 6.0, they increased both under conventional and microwave heating conditions (138 to 120 s and 89 to 61 s, respectively). The D-values under conventional thermal holding were four–eight times higher than under a continuous-flow MW heating condition. By varying the pH, the D-values could be modified to suit the validation of appropriate processing conditions. Full article

The aim of this study is to compare the efficacy of selected food disinfectants on planktonic populations of Staphylococcus aureus and Escherichia coli and on the same microorganisms (MOs) incorporated in a biofilm. Two disinfectants were used for treatment: peracetic acid-based disinfectant (P) and benzalkonium chloride-based disinfectant (D). Testing of their efficacy on the selected MO populations was performed using a quantitative suspension test. The standard colony counting procedure was used to determine their efficacy on bacterial suspensions in tryptone soy agar (TSA). The germicidal effect (GE) of the disinfectants was determined based on the decimal reduction ratio. For both MOs, 100% GE was achieved at the lowest concentration (0.1%) and after the shortest exposure time (5 min). Biofilm production was confirmed with a crystal violet test on microtitre plates. Both E. coli and S. aureus showed strong biofilm production at 25 °C with E. coli showing significantly higher adherence capacity. Both disinfectants show a significantly weaker GE on 48 h biofilms compared to the GE observed after application of the same concentrations on planktonic cells of the same MOs. Complete destruction of the viable cells of the biofilms was observed after 5 min of exposure to the highest concentration tested (2%) for both disinfectants and MOs tested. The anti-quorum sensing activity (anti-QS) of disinfectants P and D was determined via a qualitative disc diffusion method applied to the biosensor bacterial strain Chromobacterium violaceum CV026. The results obtained indicate that the disinfectants studied have no anti-QS effect. The inhibition zones around the disc therefore only represent their antimicrobial effect. Full article

We assessed the disinfection efficacy of an ozone generator prototype in ambulances used to transport patients with coronavirus disease (COVID-19). This research consisted of three stages: in vitro tests using microbial indicators, such as Candida albicans, Escherichia coli, Staphylococcus aureus and Salmonella phage, which were experimentally inoculated onto polystyrene crystal surfaces within a 23 m³ enclosure. They were then exposed to ozone at a 25 ppm concentration using the ozone generator (Tecnofood SAC) portable prototype, and the decimal reduction time (D) was estimated for each indicator. The second stage involved the experimental inoculation of the same microbial indicators on a variety of surfaces inside conventional ambulances. The third stage consisted of exploratory field testing in ambulances used to transport patients with suspected COVID-19. During the second and third stages, samples were collected by swabbing different surfaces before and after 25 ppm ozonisation for 30 min. Results suggested that ozone was most effective on Candida albicans (D = 2.65 min), followed by Escherichia coli (D = 3.14 min), Salmonella phage (D = 5.01 min) and Staphylococcus aureus (D = 5.40 min). Up to 5% of the microbes survived following ozonisation of conventional ambulances. Of the 126 surface samples collected from ambulances transporting patients with COVID-19, 7 were positive (5.6%) for SARS-related coronavirus as determined on reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR). Ozone exposure from the ozone generator prototype inside ambulances at a concentration of 25 ppm for 30 min can eliminate gram positive and negative bacteria, yeasts, and viruses. Full article

This study aimed to purify and partially characterize a keratinolytic protease produced by Bacillus sp. P45 through bioconversion of feather meal. Crude protease extract was purified using a sequence of an aqueous two-phase system (ATPS) in large volume systems (10, 50, and 500 g) to increase obtaining purified enzyme, followed by a diafiltration (DF) step. Purified protease was characterized in terms of protein profile analysis by SDS-PAGE, optimum temperature and pH, thermal deactivation kinetics at different temperatures and pH, and performance in the presence of several salts (NaCl, CaCl₂, MnCl₂, CaO, C₈H₅KO₄, MgSO₄, CuSO₄, ZnSO₄, and FeCl₃) and organic solvents (acetone, ethanol, methanol, acetic acid, diethyl ether, and formaldehyde). ATPS with high capacities resulted in purer protease extract without compromising purity and yields, reaching a purification factor up to 2.6-fold and 6.7-fold in first and second ATPS, respectively, and 4.0-fold in the DF process. Recoveries were up to 79% in both ATPS and reached 84.3% after the DF step. The electrophoretic analysis demonstrated a 25–28 kDa band related to keratinolytic protease. The purified protease’s optimum temperature and pH were 55 °C and 7.5, respectively. The deactivation energy (E_d) value was 118.0 kJ/mol, while D (decimal reduction time) and z (temperature interval required to reduce the D value in one log cycle) values ranged from 6.7 to 237.3 min and from 13.6 to 18.8 °C, respectively. Salts such as CaCl₂, CaO, C₈H₅KO₄, and MgSO₄ increased the protease activity, while all organic solvents caused its decrease. The results are useful for future studies about ATPS scale-up for enzyme purification and protease application in different industrial processes. Full article

Human norovirus (HNoV) GII.4 and Vibrio parahaemolyticus may be found in sea squirts. Antimicrobial effects of floating electrode-dielectric barrier discharge (FE-DBD) plasma (5–75 min, N₂ 1.5 m/s, 1.1 kV, 43 kHz) treatment were examined. HNoV GII.4 decreased by 0.11–1.29 log copy/μL with increasing duration of treatment time, and further by 0.34 log copy/μL when propidium monoazide (PMA) treatment was added to distinguish infectious viruses. The decimal reduction time (D₁) of non-PMA and PMA-treated HNoV GII.4 by first-order kinetics were 61.7 (R² = 0.97) and 58.8 (R² = 0.92) min, respectively. V. parahaemolyticus decreased by 0.16–1.5 log CFU/g as treatment duration increased. The D₁ for V. parahaemolyticus by first-order kinetics was 65.36 (R² = 0.90) min. Volatile basic nitrogen showed no significant difference from the control until 15 min of FE-DBD plasma treatment, increasing after 30 min. The pH did not differ significantly from the control by 45–60 min, and Hunter color in “L” (lightness), “a” (redness), and “b” (yellowness) values reduced significantly as treatment duration increased. Textures appeared to be individual differences but were not changed by treatment. Therefore, this study suggests that FE-DBD plasma has the potential to serve as a new antimicrobial to foster safer consumption of raw sea squirts. Full article

The peels of many fruits are rich sources of nutrients, although they are not commonly consumed. If they are properly decontaminated, they can be used as healthy food ingredients reducing food waste. The objective was to apply thermosonication processes to kiwi peel and evaluate the impact on Listeria innocua survival (a non-pathogenic surrogate of L. monocytogenes) and key nutrients and quality indicators: proteins, fibers, minerals (Ca, K, Mg, Na, and P), chlorophylls, and phenolic contents. Kiwi peels were artificially inoculated with L. innocua and thermal and thermosonication treatments were performed at 55 °C and 60 °C for 30 and 15 min maximum, respectively. Bacteria were enumerated through treatment time, and quality indicators were assessed before and at the end of treatments. A Weibull model with a decimal reduction time (D-value) was successfully used in L. innocua survival data fits. Results showed that coupling temperature to ultrasound had a synergistic effect on bacteria inactivation with significant decreases in D-values. Thermosonication at 60 °C was the most effective in terms of protein, fiber, chlorophylls, and phenolics retention. Minerals were not significantly affected by all treatments. Applying thermosonication to kiwi peel was more effective for decontamination than thermal treatments at the same temperature while allowing the retention of healthy compounds. Full article

(1) Background: Influenza is a viral infection that has claimed many millions of lives over the past 100 years, and there is always a risk that a new influenza virus will emerge and cause another pandemic. One way to reduce such a potential new influenza virus will be heat inactivation. The question in this study is how much the heat sensitivities of previous influenza viruses differ. If they are very similar, it is expected that a new influenza virus can be inactivated with the same heat parameters as previous influenza viruses. (2) Methods: Through a literature search, published heat inactivation results are compiled and analyzed using Arrhenius models and regression equations for decimal reduction times for different temperatures and media determined. (3) Results: There are about 50 studies on heat inactivation of human and avian influenza viruses so far, showing large differences in heat sensitivity of influenza viruses in different media. However, within a single medium the differences between viruses are rather small. (4) Conclusions: At a temperature of 60 °C, previous influenza viruses can be reduced by 4 or more orders of magnitude within approximately 30 min in almost all media, and this is likely to be true for a potential new influenza virus. Further studies, especially on human influenza viruses, would be desirable. Full article