Cold plasma (CP) technology is a promising alternative to thermal treatments for the microbial decontamination of foods with low-water activity. The aim of this work is study the application of low-pressure CP (0.35 mbar) for the inactivation of Bacillus cereus in a soybean powder matrix using O₂ and synthetic air as ionizing gases. The parameters tested were an input power of 100, 200 and 300 W and an exposure time of 10 to 30 min. The excited reactive species formed were monitored by optical emission spectroscopy, and survival data were analyzed using the Weibull mathematical model. Treatments with both gases were effective in inactivating B. cereus. Air plasma resulted in a maximum 3.71-log reduction in bacterial counts at 300 W and 30 min, while O2 plasma showed the strongest inactivation ability, achieving levels higher than 5 log cycles at 300 W and > 25 min. This is likely due to the strong antimicrobial activity of oxygen-derived radicals together with carbon monoxide as an oxidation by-product. In addition, the Weibull distribution function accurately modeled the inactivation of B. cereus. Cold plasma technology is a promising approach for the decontamination of bacteria in low-water activity foods.
Berries contaminated with human norovirus (HuNoV) have been frequently identified as a cause of foodborne gastroenteritis. To prevent virus transmission while preserving sensory and quality parameters, non-thermal treatments, such as high-pressure processing (HPP), can be applied to the berries and products thereof. Here, strawberry purees contaminated with HuNoV genogroup I (GI.3[P13]) and II (GII.4 Sydney [P16]), along with murine norovirus (MNV) and Tulane virus (TV) serving as surrogates, were exposed to HPP at several pressuretime combinations. Virus inactivation was assessed by cell culture, including the novel human intestinal enteroids (HIE) model for HuNoVs. The infectivity results showed TV more resistant than MNV to HPP, as also confirmed by kinetic mathematical modelling. Results indicated that a holding pressure of 450 MPa and an exposure time of >= 5 min are reliable operational conditions for HPP process to successfully control viral contamination. In addition, the inactivation models deduced from MNV and TV viruses were challenged with experimental HuNoV GII.4 infectivity resulting in bias factors <1 for all treatment conditions. This finding validates the proposed models for the conservative estimation of HuNoV inactivation. Our work offers a blueprint for moving forward with inactivation studies using the HIE system, which provides useful practical information on optimum treatments for the best public health outcomes.
This study investigated the effects of low-pressure cold plasma on the inactivation of Bacillus cereus vegetative cells and spores in an inert matrix (borosilicate glass slide) and in rice grains, using oxygen as ionization gas. Greater reductions in B. cereus counts were observed in vegetative cells rather than spores. The experimental data obtained show that both the power of the plasma treatment and the matrix proved to be determining factors in the inactivation of both the spores and vegetative cells of B. cereus. To characterize the inactivation of B. cereus, experimental data were accurately fitted to the Weibull model. A significant decrease in parameter “a”, representing resistance to treatment, was confirmed with treatment intensification. Furthermore, significant differences in the “a” value were observed between spores in inert and food matrices, suggesting the additional protective role of the food matrix for B. cereus spores. These results demonstrate the importance of considering matrix effects in plasma treatment to ensure the effective inactivation of pathogenic microorganisms, particularly in foods with low water activity, such as rice. This approach contributes to mitigating the impact of foodborne illnesses caused by pathogenic microorganisms.
Primary Processed Foods are a class of food items that are ready for consumption after minimal processing in the supply chain. These products are ubiquitous in our daily diet, but so far a limited number of studies dealt with the optimization of quality control methods to check their content of contaminants. Among primary processed foods, bee pollen is a nutritionally acclaimed food supplement, whose contamination with pesticides and mycotoxins has been largely proven. For this reason, the present study aimed at optimizing for the first time a comprehensive LC-MS/MS method capable of analyzing 282 pesticides and 8 mycotoxins in bee pollen. To obtain a suitable method, two extraction procedures (QuEChERS and Accelerated Solvent Extraction), as well as different chromatographic gradients and columns, were tested. The optimized methodology, comprehending an extraction based on semi-automated QuEChERS, and an analytical method including inert LC column technology, was validated and applied to a sample set of 34 bee pollens. The analyzed samples collectively showed the presence of 41 pesticides and 1 mycotoxin.
Consumers are driving food production toward the use of natural preservatives and minimal processing technologies. Green tea extract (GTE) at low concentration could be combined with high pressure processing (HPP) for reduced treatment times and quality impact on foods in a hurdle concept for synergistic effects on foodborne viral pathogens, specifically human norovirus and hepatitis A virus (HAV). Viral inactivation by HPP (at 300, 400, and 500 MPa for 5 min) combined with 3.3 mg/mL aged-GTE was initially evaluated in buffer (PBS) against murine norovirus (MNV), a culturable human norovirus surrogate, and HAV. Furthermore, human norovirus inactivation was evaluated by the novel human intestinal enteroid system (HIE) and a capsid integrity binding assay (ISC-RT-qPCR). HPP treatment completely inhibits human norovirus GII.4 infectivity when applied at 500 MPa alone and at 400 MPa combined with aged-GTE. Additional experiments investigated the reduction of MNV and HAV infectivity in apple and horchata juices exposed to combined aged-GTE and HPP treatments. Results demonstrated that the addition of aged-GTE to the juices exposed to HPP significantly inactivated MNV and HAV at reduced holding pressure time. This synergistic effect of aged-GTE combined with HPP treatments represents a hurdle technology that could be exploited as a control measure to improve the food safety of beverages.
The antimicrobial potential of grape extract was assessed in cooked rice against Bacillus cereus. Grape extract efficacy was tested at 1, 5 and 10 mL/L, at pH 4.5, 5.5 and 6.5; and at incubation temperatures simulating different storage scenarios, specifically temperature abuse (10 degrees C), cool chain break (20 degrees C) and optimal B. cereus growth temperature (30 degrees C). Survival curves for grape extract concentration versus time were obtained. The results indicate that antimicrobial activity of grape extract was dependent on temperature, pH and grape extract concentration. A bactericidal effect of the grape extract was shown at concentration levels >= 5 mL/L at all temperatures and pHs studied. Inactivation curves of B. cereus under grape extract exposure were fitted to a Weibull distribution function for 5-10 mL/L grape extract concentration. Observations showed that the higher the incubation temperature and grape extract concentration, the lower the kinetic rate value. In other words, lower resistance of the microorganism to environmental conditions. The maximum inactivation level was 6 log10 cycles after 24 h of exposure at 10 mL/L of grape extract concentration and pH 4.5. Results indicate that the grape extract could be a good additional control measure for preventing Bacillus cereus growth in cooked rice during storage.
The present study challenges the in vivo assessment of cold atmospheric pressure plasma (CAPP) technology on the bioactive activity (antioxidant/antiaging and antimicrobial potential) of Spirulina powder, using Caenorhabditis elegans as an animal model. Surface microdischarge cold atmospheric pressure plasma (SMD-CAPP) treatment was 3.3 W discharge power for 7 min. C. elegans lifespan and egg laying were used as indicators of antioxidant/antiaging potential of Spirulina (1 mg/mL), when grown with Spirulina CP-treated [E_SCP] and untreated [E_S], compared with a control [E_0] (non-supplemented with Spirulina). According to our results, under both Spirulina supplemented media [E_SCP and E_S] and for the first 17 days, nematodes experienced an increase in lifespan but without significant differences (p > 0.05) between control and Spirulina CP-treated. Regarding the in vivo assay of the antimicrobial potential of Spirulina against Salmonella enterica serovar Typhimurium (infected worms), no significant differences (p > 0.05) were found between the three exposure scenarios (control [S_0]; Spirulina supplemented media [S_S]; CP-treated Spirulina supplemented media [S_SCP]). According to present results, CAPP-treatment do not influence negatively the lifespan of C. elegans but a reduction in the Spirulina antiaging potential was found. No in vivo modifications in antimicrobial activity seem to be linked to CAPP-processed Spirulina.
In a clinical sample of 198 female patients with anorexia nervosa (N = 83) and bulimia nervosa (N = 115), 43% met criteria for major depression using the Structured Clinical Interview for DSMIII-R. This group had a mean score of 30.9 +/- 8.7 on the Beck Depression Inventory (BDI) which was significantly higher than the BDI mean score of 20.5 +/- 8.9 among the remainder of the sample (p < 0.0001). A score of 26 yielded the highest levels of sensitivity and specificity, while five items from the BDI (loss of satisfaction, discouragement, weight loss, suicidal ideation and decision-making) correctly classified approximately 80% of subjects into "depression-positive" or "depression-negative" categories. Detection of co-morbid depression in patients with eating disorders may have practical implications for treatment.
The heat resistance of Bacillus cereus spores inoculated in a rice substrate supplemented with insect chitosan as an alternative antimicrobial was studied. Two concentrations of insect chitosan were considered in order to assess the role of the insect chitosan concentration during the heat process. Results of the study indicated that the DT values were higher in the substrate without chitosan than in the substrate containing chitosan thus indicating a greater heat resistance to heat treatment of the microorganism inoculated in the substrate without chitosan. This behaviour was also evidenced in the survival curves. There were no great differences between either of the insect chitosan concentrations tested regarding the DT values. The z values were 9.8°C on rice substrate and8.9°C on rice substrate supplemented with insect chitosan at 150 μg/mL and 10.7°C on rice substrate supplemented with 250 μg/mL of insect chitosan. The chitosan concentration appears to affect the z value of the microorganism. Our results indicate that the combination of heat with insect chitosan as an antimicrobial on foodstuffs subjected to cooking is feasible and can improve the safety of rice derivatives.
The effect of high hydrostatic pressure (HHP) combined with enzymatic methods or gelatin incorporation in the gelation process of protein isolated from Acheta domesticus was investigated. The results indicate that transglutaminase (TGasa) or glucose oxidase (GOx) enzymes can induce reversible aggregation in dispersions of insoluble protein fractions and increase viscosity in dispersions of soluble fractions, but does not induce gel formation even after HHP treatment; in consequence, enzymatic treatment on cricket protein can be used to increase viscosity but not to form gels. It is technically feasible to obtain gels by adding 2% porcine gelatin to dispersions of protein fractions and subjecting them to HHP. The firmness and syneresis variation values of those gels during storage depended on the protein extracted fraction (insoluble or soluble protein) and on the concentration of protein used. The highest hardness and lowest syneresis was found with the gels obtained from the insoluble fraction at 11 and 15% (w/w) protein concentration. Color difference (ΔE* > 3) appreciable to the naked eye was observed along the storage period and no noticeable pH variations were found after 28 days of storage. Results indicate that new raw materials of interest can be developed for the food industry based on cricket protein isolates, to make high-protein foods which could be applied in a wide variety of different food applications including 3D printing or fat substitution.
La poblacion mundial crece con la tendencia a concentrarse en las zonas urbanas. Disponer de alimentos para todos y de una correcta informacion sobre nutrientes y dieta, esta incluido en el alcance global de los Objetivos de Desarrollo Sostenible del milenio (ODS) de Naciones Unidas. El papel de la ciencia y la tecnologia son claves. Recientemente se ha puesto de moda en determinados circulos relacionados con la nutricion el termino “Ultra procesado” del ingles “Ultraprocessed”. Este termino esta generando mucha confusion en determinados grupos de consumidores y en el sector de produccion de alimentos, ya que su interpretacion genera controversia. El presente documento analiza el porque de esta confusion.
La poblacion mundial crece con la tendencia a concentrarse en las zonas urbanas. Disponer de alimentos para todos y de una correcta informacion sobre nutrientes y dieta, esta incluido en el alcance global de los Objetivos de Desarrollo Sostenible del milenio (ODS) de Naciones Unidas. El papel de la ciencia y la tecnologia son claves. Recientemente se ha puesto de moda en determinados circulos relacionados con la nutricion el termino “Ultra procesado” del ingles “Ultraprocessed”. Este termino esta generando mucha confusion en determinados grupos de consumidores y en el sector de produccion de alimentos, ya que su interpretacion genera controversia. El presente documento analiza el porque de esta confusion.
Rice is a very popular food throughout the world and the basis of the diet of the citizens of many countries. It is used as a raw material for the preparation of many complex dishes in which different ingredients are involved. Rice, as a consequence of their cultivation, harvesting, and handling, is often contaminated with spores of Bacillus cereus, a ubiquitous microorganism found mainly in the soil. B. cereus can multiply under temperature conditions as low as 4 °C in foods that contain rice and have been cooked or subjected to treatments that do not produce commercial sterility. B. cereus produces diarrhoeal or emetic foodborne toxin when the consumer eats food in which a sufficient number of cells have grown. These circumstances mean that every year many outbreaks of intoxication or intestinal problems related to this microorganism are reported. This work is a review from the perspective of risk assessment of the risk posed by B. cereus to the health of consumers and of some control measures that can be used to mitigate such a risk.
This work studies and models microbial inactivation by high hydrostatic pressure applied to insect protein (Acheta domesticus) enriched gels. The target microbial groups and pathogens studied were total aerobic mesophilic (TAM) bacteria, molds and yeasts (M&Y), Salmonella Typhimurium and Escherichia coli O157:H7. Results indicated that high hydrostatic pressure reduced the microbial load of both, the natural contaminating microorganisms (TAM and M&Y) and the intentionally inoculated pathogenic microorganisms. However, inactivation of the initial microbial load was lower than 5-log reductions. Kinetic inactivation parameters were deduced by using the Weibull distribution function which presented high goodness of fit. Kinetic parameters of the model showed that the most resistant microbial group was total aerobic mesophilic bacteria, followed by E. coli O157: H7, mold and yeast and Salmonella with kinetic parameters of 2.21, 1.58, 1.27, and 0.17 (min x mL/CFU) at 350 MPa, respectively. Regarding the pathogenic microorganisms inoculated in insect protein gels, E. coli O157:H7 may be a good candidate Gram negative target microorganism for high hydrostatic pressure process development, because it usually contaminates these products and was the one with the highest baro-resistance. These reasons support that high-pressure treatments for this type of food should be designed considering this microorganism as a target.
High hydrostatic pressure is a non-thermal treatment of great interest because of its importance for producing food with additional or enhanced benefits above their nutritional value. In the present study, the effect of high hydrostatic pressure processing parameters (200–500 MPa; 1–10 min) is investigated through response surface methodology (RSM) to optimize the treatment conditions, maximizing the phenol content and antioxidant capacity while minimizing microbiological survival, in milkshakes prepared with chokeberry pomace (2.5–10%). The measurement of fluorescence intensity of the samples was used as an indicator of total phenolic content and antioxidant capacity. The results showed that the intensity of the treatments had different effects on the milkshakes. The RSM described that the greatest retention of phenolic compounds and antioxidant capacity with minimum microbiological survival were found at 500 MPa for 10 min and 10% (w/v) chokeberry pomace. Therefore, this study offers the opportunity to develop microbiologically safe novel dairy products of high nutritional quality.
The main objective of this work was to study the antimicrobial effect of a cauliflower by-product infusion into an affordable in vivo model (Caenorhabditis elegans). The infusion demonstrated some protective effect on non-infected and infected worms with Salmonella Typhimurium as indicated by higher survival percentile values (75, 50, 25, and 5% percentiles) as compared with those from worms unexposed to the infusion. The antimicrobial effect of the infusion was evaluated on Salmonella intestinal colonization of infected worms (24, 48, and 96 h post-infection). At 96 h post-infection, the concentration of Salmonella was reduced around 2 log cycles in infected cauliflower treated group (p < 0.05) as compared with infected non-cauliflower group. Here we show that cauliflower by-products extend survival and have an antimicrobial effect in an in vivo nematode model, C. elegans, as a previous validation step to longer and costlier farm animal studies.
El presente trabajo revisa el reconocimiento del derecho humano al agua y al saneamiento en América Latina, tanto en su regulación internacional como local. Para esto, se analiza el desarrollo de los contenidos que se han reconocido en el sistema universal de derechos humanos y que han hecho posible su comprensión como un derecho autónomo, lo que revela la importancia de la protección ambiental. En un segundo acápite, se analiza el desarrollo que ha tenido este reconocimiento en la jurisprudencia de la Corte Interamericana de Derechos Humanos, se revisa su construcción y se da cuenta de la evolución que ha dado la Corte en sus últimas sentencias al reconocer el derecho humano al agua y al saneamiento como un derecho autónomo. Por último, se analiza la consagración de este derecho fundamental en las constituciones del nuevo constitucionalismo latinoamericano, para reflexionar sobre la manera en que estos contenidos han ido asentándose en las normas de derecho interno.
Fruits are valuable vegetable products rich in bioactive compounds (vitamins, proteins, carbohydrates, fiber, antioxidants) with a described positive impact in human health. Due to environmental exposure and fruits soil contact, microbial contamination could be high and difficult to be removed from the fresh raw material. Nowadays, the offer of fruits and derivative products arriving at the market is really versatile and extended (fresh fruits, juices, smoothies, jellies, canned fruits). However, one of the main concerning points regarding the commercialization of these fresh matrices is the retention of nutritional factors intact after the required treatments to ensure microbial load reduction. Novel nonthermal technologies are presented as promising preservation processes to be respectful with food quality, being at the same time effective in the guarantee of food safety. The present chapter overviews the effect of some nonthermal treatments and technologies applied in the decontamination of fruits, being currently research about these processes covering different stages of development and industrial implementation. Future trends are discussed regarding the comparative effectiveness of conventional and novel decontamination processes and the medium-short term applicability of novel technologies at the agri-food industry.
The antimicrobial capability of chitosan from Tenebrio molitor as compared with chitosan from crustacean (Penaeus monodon) on different pathogenic microorganisms of concern in food safety was studied. The antimicrobial effect was tested at pH 5 and pH 6.2 and at two different initial concentrations (103 or 106 CFU/mL). Results indicated that chitosan from both sources have antimicrobial activity, although the effect depended on the microorganism considered (Salmonella Typhimurium, Listeria monocytogenes and Escherichia coli O157:H7). Our results indicated that Salmonella was the most resistant bacteria, and that chitosan from insect was less active than chitosan from crustacean, especially against Salmonella. Another important factor on antimicrobial activity was the pH of the sample. When chitosan was added to a solution with a pH of 6.2 it was more active against Listeria and Escherichia coli, than at pH 5.00. Besides, the effect of chitosan appears to decrease with the incubation time, since some increases in counts were observed on E. coli and Salmonella after the 24 and 49 hours of incubation.