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1.
Infect Genet Evol ; 123: 105622, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38901622

RESUMEN

Men who have sex with men (MSM) are at high risk of acquiring hepatitis A virus (HAV) and in recent years several HAV outbreaks mostly affecting MSM have been described. These outbreaks were caused by subtype IA strains circulating in this high-risk population. After years of low incidence, an outbreak among MSM in Hungary caused a significant increase in reported HAV infections in 2022. Samples from 224 HAV IgM-positive patients diagnosed in 2022 were tested for HAV RNA and positive samples were genotyped by sequencing. In 171 patients a unique subtype IB virus was detected with 99.8-100% sequence identity in the VP1/P2A junction. It was distinct from previously published strains, but most closely related to an Egyptian isolate. Sequence analysis revealed one dominant and three minor variants based on VP1/P2A. Whole genome sequencing revealed limited variation among these variants, suggesting a recent common origin. Epidemiological data indicated that sexual transmission was driving the outbreak for most of the year, suggested by the high male to female ratio and the large number of coinfections with HIV and other sexually transmitted infections among the patients. The outbreak was also associated with a restaurant cluster, in which one of the variants was detected and frozen berries were implicated as the source of infections. The outbreak strain was also detected in other countries around Europe and remained frequently detectable in Hungary in 2023. This study provides insights into the molecular and epidemiological characteristics of the described HAV outbreak. The results show that sequencing is not only useful in connecting cases to an outbreak, but also helps to clarify the relatedness of detected variants. Prevention strategies focusing on vulnerable communities may reduce the burden of HAV infections in the future.


Asunto(s)
Brotes de Enfermedades , Virus de la Hepatitis A , Hepatitis A , Homosexualidad Masculina , Filogenia , Humanos , Hungría/epidemiología , Hepatitis A/epidemiología , Hepatitis A/virología , Masculino , Adulto , Virus de la Hepatitis A/genética , Virus de la Hepatitis A/clasificación , Persona de Mediana Edad , Genotipo , Frutas/virología , Alimentos Congelados/virología , Femenino , Adulto Joven , ARN Viral/genética
2.
J Food Prot ; 87(8): 100315, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38871223

RESUMEN

In recent years, there have been numerous recalls of frozen vegetable products due to Listeria monocytogenes contamination, which causes listeriosis. In pregnant women, listeriosis can cause miscarriage, stillbirth, and other serious complications. Manufacturing guidelines are created with the intention that frozen vegetables will be cooked prior to consumption. However, consumers may prepare and eat frozen vegetables without prior cooking. Therefore, it is necessary to assess behaviors that could be risky for L. monocytogenes exposure. A 10-question online survey was distributed to women between the ages of 18-54 to investigate frozen vegetable consumption behaviors. The prevalence of uncooked frozen vegetable consumption, reading preparation instructions, and listeriosis knowledge was assessed. Data were analyzed using logistic and ordered logit regression. Of 1,001 complete responses, 531 (53%) indicated that they consumed frozen vegetables in the past week, and of those 35.6% (n = 189) indicated that they consumed frozen vegetables without prior heating. Women who had not heard of listeriosis and had not read preparation instructions had significantly higher odds of uncooked frozen vegetable consumption (Odds Ratio (OR): 2.30, 95% Confidence Interval (CI): 1.48, 3.55; OR: 1.85, 95% CI: 1.13, 3.01, respectively). These results will guide future research on safe food handling practices for frozen vegetable products. The findings support the need for updating public health guidelines to include frozen vegetables as foods that are risky for listeriosis in pregnancy. Additionally, these findings have implications for future research to inform food policy governing labeling regulation on frozen vegetable products to reflect current consumer behavior.


Asunto(s)
Listeria monocytogenes , Listeriosis , Verduras , Humanos , Femenino , Adulto , Persona de Mediana Edad , Adolescente , Adulto Joven , Conocimientos, Actitudes y Práctica en Salud , Contaminación de Alimentos , Encuestas y Cuestionarios , Embarazo , Microbiología de Alimentos , Manipulación de Alimentos , Alimentos Congelados/microbiología
3.
Foodborne Pathog Dis ; 21(8): 478-484, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38682437

RESUMEN

A microbiological study was conducted on 41 insect product samples (29 raw frozen [21 domestic and 8 imported], 10 powdered, and 2 processed), which were commercially available in Japan. The total aerobic count for raw frozen insects was 5.61 log cfu/g (range: 2.52-8.40), whereas the powdered insect count was 2.89 log cfu/g (range: 1.00-4.57). The bacterial count was significantly higher in raw frozen insects (p < 0.05). The coliform count for the raw frozen insects ranged from <1 to 6.90 log cfu/g, and that for the powdered insects ranged from <1 to 1.00 log cfu/g. The number of samples with values above the detection limit was significantly higher in raw frozen insects (p < 0.05). The detection frequencies of aerobic spores (<1-4.63 log cfu/g), anaerobic spores (<0-4.40 log cfu/g), and Bacillus cereus (<1.7-3.83 log cfu/g) showed no sample type-related significant difference. Listeria spp. was isolated from four samples of raw frozen insects, one of which was Listeria monocytogenes. We did not detect any of the following: Salmonella spp., Shiga toxin-producing E. coli (STEC), Campylobacter jejuni/coli, or pathogenic Yersinia. We isolated insect products retailed in Japan harboring food poisoning bacteria, including L. monocytogenes and B. cereus. In particular, raw frozen products displayed high levels of hygienic indicator bacteria.


Asunto(s)
Microbiología de Alimentos , Listeria monocytogenes , Japón , Animales , Listeria monocytogenes/aislamiento & purificación , Recuento de Colonia Microbiana , Bacillus cereus/aislamiento & purificación , Esporas Bacterianas/aislamiento & purificación , Contaminación de Alimentos/análisis , Insectos/microbiología , Alimentos Congelados/microbiología , Insectos Comestibles/microbiología , Escherichia coli Shiga-Toxigénica/aislamiento & purificación , Salmonella/aislamiento & purificación
4.
Food Environ Virol ; 16(2): 225-240, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38687458

RESUMEN

Accurate detection, identification, and subsequent confirmation of pathogens causing foodborne illness are essential for the prevention and investigation of foodborne outbreaks. This is particularly true when the causative agent is an enteric virus that has a very low infectious dose and is likely to be present at or near the limit of detection. In this study, whole-genome sequencing (WGS) was combined with either of two non-targeted pre-amplification methods (SPIA and SISPA) to investigate their utility as a confirmatory method for RT-qPCR positive results of foods contaminated with enteric viruses. Frozen berries (raspberries, strawberries, and blackberries) were chosen as the food matrix of interest due to their association with numerous outbreaks of foodborne illness. The hepatitis A virus (HAV) and human norovirus (HuNoV) were used as the contaminating agents. The non-targeted WGS strategy employed in this study could detect and confirm HuNoV and HAV at genomic copy numbers in the single digit range, and in a few cases, identified viruses present in samples that had been found negative by RT-qPCR analyses. However, some RT-qPCR-positive samples could not be confirmed using the WGS method, and in cases with very high Ct values, only a few viral reads and short sequences were recovered from the samples. WGS techniques show great potential for confirmation and identification of virally contaminated food items. The approaches described here should be further optimized for routine application to confirm the viral contamination in berries.


Asunto(s)
Contaminación de Alimentos , Enfermedades Transmitidas por los Alimentos , Fragaria , Frutas , Reacción en Cadena en Tiempo Real de la Polimerasa , Rubus , Secuenciación Completa del Genoma , Frutas/virología , Secuenciación Completa del Genoma/métodos , Contaminación de Alimentos/análisis , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Fragaria/virología , Humanos , Rubus/virología , Enfermedades Transmitidas por los Alimentos/virología , Genoma Viral/genética , Virus de la Hepatitis A/genética , Virus de la Hepatitis A/aislamiento & purificación , Virus de la Hepatitis A/clasificación , Alimentos Congelados/virología , Norovirus/genética , Norovirus/aislamiento & purificación , Norovirus/clasificación
5.
Food Environ Virol ; 16(2): 180-187, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38466479

RESUMEN

In March 2019, the Finnish Institute for Health and Welfare and Finnish Food Authority started an outbreak investigation after a notification of food business operators' recall of frozen bilberries due to a norovirus finding. A retrospective search was conducted in the food and waterborne outbreak notification system to identify the notifications linked to norovirus and consumption of bilberries in January-March 2019. Five outbreaks were found in which norovirus GII or GII.17 had been detected in patient samples. A pooled retrospective cohort study was performed for those four in which a questionnaire study had been done. A case was defined as a person with diarrhoea or vomiting within 2 days after consuming a meal studied at one of the outbreak locations. Of 79 participants, 45 (57%) cases were identified. Persons that had consumed foods containing unheated bilberries were three times more likely to get ill than those who had not consumed them (RR 3.1, CI 95% 1.2-8.1, p = 0.02). Norovirus GII.17 was found in 16/17 patient samples sent for further typing. Identical norovirus GII.17 was detected in frozen Finnish bilberries and patient samples. At the berry packaging premises, signs of norovirus GII contamination were found in packaging lines. A new procedure for extracting viral nucleic acid from food and environmental samples was used during the outbreak investigation. Consumption of industrially packed frozen berries as heated would be one of the means to prevent norovirus infections.


Asunto(s)
Infecciones por Caliciviridae , Brotes de Enfermedades , Contaminación de Alimentos , Gastroenteritis , Norovirus , Norovirus/genética , Norovirus/aislamiento & purificación , Norovirus/clasificación , Humanos , Finlandia/epidemiología , Infecciones por Caliciviridae/virología , Infecciones por Caliciviridae/epidemiología , Femenino , Adulto , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Contaminación de Alimentos/análisis , Gastroenteritis/virología , Gastroenteritis/epidemiología , Frutas/virología , Anciano , Adulto Joven , Alimentos Congelados/virología , Prunus armeniaca/virología , Enfermedades Transmitidas por los Alimentos/virología , Enfermedades Transmitidas por los Alimentos/epidemiología , Adolescente , Genotipo
6.
Chem Res Toxicol ; 36(6): 818-821, 2023 06 19.
Artículo en Inglés | MEDLINE | ID: mdl-37255213

RESUMEN

The French Lentil & Leek Crumbles frozen food product was recently recalled due to reports of gastrointestinal issues. So far, 393 adverse illness complaints and 133 hospitalizations have been reported from consumption of this food, and the tara (Tara spinosa) protein flour ingredient is hypothesized to be responsible. A multipronged approach resulted in identification of (S)-(-)-baikiain in tara as a compound of interest due to its abundance, possible metabolic fate, and close resemblance to irreversible inhibitors of L-pipecolate oxidase. Oral administration of baikiain in ND4 mice showed a statistically significant increase in blood ALT levels and a reduction in liver GSH.


Asunto(s)
Lens (Planta) , Animales , Ratones , Harina , Cebollas , Alimentos Congelados , Hígado
7.
Food Chem ; 417: 135850, 2023 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-36924716

RESUMEN

The effectiveness of static magnetic fields with different intensities (5, 10, 15 mT) combined with liquid carbon dioxide spray freezing (LCSF) technique in improving the quality of frozen honeydew melon was investigated. The results showed that LCSF with magnetic fields above 10 mT significantly improved ice nucleation and quality of frozen melons compared to conventional -20 °C freezing, -80 °C freezing and LCSF method without magnetic field assistance (P < 0.05). 15 mT strength static magnetic field assistance suggested the best results, with a 15.0% reduction in total freezing time, 17.7% increase in average freezing rate, 26.6% reduction in drip loss, and better maintenance of sample quality compared to LCSF. These findings demonstrate that LCSF with static magnetic field assistance is promising in improving the quality of frozen foods.


Asunto(s)
Dióxido de Carbono , Cucurbitaceae , Congelación , Tiempo , Alimentos Congelados
8.
Se Pu ; 41(3): 233-240, 2023 Mar.
Artículo en Chino | MEDLINE | ID: mdl-36861206

RESUMEN

Quaternary ammonium compounds (QACs) are a class of cationic surfactants that can be used as the main active ingredient of disinfectants. The increased use of QACs is concerning as exposure from inhalation or ingestion to these compounds that has been associated with adverse effects on the reproductive and respiratory systems. Humans are exposed to QACs primarily by food consumption and inhalation of air. QAC residues pose significant threats to public health. Given the importance of assessing potential residue levels for QACs in food, therefore, a method was developed for the simultaneous detection of six common QACs and one emerging QAC (Ephemora) in frozen food by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) coupled with the modified QuEChERS method. The main factors governing the response, recovery, and sensitivity of the method, including extraction solvents, types and dosages of adsorbents, apparatus conditions, and mobile phases, were optimized in the course of sample pretreatment and instrument analysis. QAC residues in frozen food were extracted using 20 mL methanol-water (90∶10, containing 0.5% formic acid) for 20 min by the vortex shock method. The mixture was ultrasonicated for 10 min and centrifuged at 10000 r/min for 10 min. A 1-mL aliquot of the supernatant was transferred to a new tube and purified using 100 mg of PSA adsorbents. After mixing and centrifugation at 10000 r/min for 5 min, the purified solution was analyzed. Target analytes were separated on an ACQUITY UPLC BEH C8 chromatographic column (50 mm×2.1 mm, 1.7 µm) at a column temperature of 40 ℃ and a flow rate of 0.3 mL/min. The injection volume was 1 µL. Gradient elution was performed using methanol and 5 mmol/L ammonium acetate solution as the mobile phases. Multiple reaction monitoring (MRM) was conducted in the positive electrospray ionization (ESI+) mode. The matrix-matched external standard method was used to quantify seven QACs. The optimized chromatography-based method completely separated the seven analytes. Good linear relationships were obtained for the seven QACs in the range of 0.1-100.0 ng/mL. The correlation coefficient (r2) ranged from 0.9971 to 0.9983. The limits of detection and limits of quantification ranged from 0.5 to 1.0 µg/kg and 1.5 to 3.0 µg/kg, respectively. Accuracy and precision were determined by spiking salmon and chicken samples with 3.0, 10.0, and 100.0 µg/kg of analytes, in compliance with the current legislation, with six replicates per determination. The average recoveries of the seven QACs ranged from 65.4% to 101%. The relative standard deviations (RSDs) were between 0.64% and 16.8%. Matrix effects of the analytes were between -27.5% and 33.4% in salmon and chicken samples after purifying using PSA. The developed method was applied to the determination of seven QACs in rural samples. QACs were detected in only one sample; the level did not exceed European Food Safety Authority specified residue limit standards. The detection method has high sensitivity, good selectivity and stability, and the results are accurate and reliable. It is suitable for the simultaneous rapid determination of seven QAC residues in frozen food. The results provide valuable information for future risk assessment studies targeting this class of compounds.


Asunto(s)
Alimentos Congelados , Compuestos de Amonio Cuaternario , Humanos , Masculino , Cromatografía Liquida , Metanol , Antígeno Prostático Específico , Espectrometría de Masas en Tándem
9.
Food Chem ; 405(Pt A): 134780, 2023 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-36368096

RESUMEN

The effects of freeze-thaw (F-T) cycles on the shape retention of antifreeze peptides-based surimi ink (ASI) 3D structures were analyzed. The results showed that the ASI 3D structure has good shape retention ability, and the width, height, weight, and water holding capacity were 22.42 mm, 21.07 mm, 9.99 g, and 68.30 % even after F-T 4 times, respectively. The average area and equivalent diameter of ice crystals in ASI 3D structures only expand from 0.001 mm2 and 0.040 mm to 0.015 mm2 and 0.139 mm, respectively. The α-helix and ß-sheet of myofibrillar protein in ASI 3D structure were slightly decreased by 44.16 ± 0.98 % to 33.33 ± 0.92 % and increased by 18.28 ± 4.45 % to 24.43 ± 1.60 %, respectively. The chemical bond and protein interaction have changed to some extent. AFPs can prevent denaturation and juice loss of surimi 3D structures after F-T. The results provide theoretical guidance for maintaining the shape retention of frozen 3D food structures.


Asunto(s)
Proteínas Anticongelantes , Alimentos Congelados , Congelación , Proteínas Anticongelantes/química , Agua/química , Hielo
10.
Crit Rev Food Sci Nutr ; 63(22): 5874-5889, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-34996325

RESUMEN

Frozen storage is most widely adopted preservation method to maintain food freshness and nutritional attributes. However, at low temperature, food is prone to chemical changes such as protein denaturation and lipid oxidation. In this review, we discussed the reasons and influencing factors that cause protein denaturation during freezing, such as freezing rate, freezing temperature, freezing method, etc. From the previous literatures, it was found that frozen storage is commonly used to prevent freeze induced protein denaturation by adding cryoprotectants to food. Some widely used cryoprotectants (for example, sucrose and sorbitol) have been reported with higher sweetness and weaker cryoprotective abilities. Therefore, this article comprehensively discusses the new cryopreservation methods and providing comparative study to the conventional frozen storage. Meanwhile, this article sheds light on the freeze induced alterations, such as change in functional and gelling properties. In addition, this article could be helpful for the prolonged frozen storage of food with minimum quality related changes. Meanwhile, it could also improve the commercial values and consumer satisfaction of frozen food as well.


Asunto(s)
Crioprotectores , Alimentos Congelados , Congelación , Crioprotectores/química , Temperatura
11.
J Sci Food Agric ; 103(5): 2223-2238, 2023 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-36208477

RESUMEN

Freezing is an effective technique to prolong the storage life of food. However, the freeze-thaw process also brings challenges to the quality of food, such as mechanical damage and freeze cracks. Increasingly, physical fields have been preferred as a means of assisting the freezing and thawing (F/T) processes to improve the quality of frozen food because of their high efficiency and simplicity of application. This article systematically reviews the application of high-efficiency physical field techniques in the F/T of food. These include ultrasound, microwave, radio frequency, electric fields, magnetic fields, and high pressure. The mechanisms, application effects, advantages and disadvantages of these physical fields are discussed. To better understand the role of various physical fields, the damage to food caused by the F/T process and traditional freezing is discussed. The evidence shows that the physical fields of ultrasound, electric field and high pressure have positive effects on the F/T of food. Proper application can control the size and distribution of ice crystals effectively, shorten the freezing time, and maintain the quality of food. Microwave and radio frequency exhibit positive effects on the thawing of food. Dipole rotation and ion oscillation caused by electromagnetic waves can generate heat inside the product and accelerate thawing. The effects of magnetic field on F/T are controversial. Although some physical field techniques are effective in assisting F/T of food, negative phenomena such as uneven temperature distribution and local overheating often occur at the same time. The generation of hotspots during thawing can damage the product and limit application of these techniques in industry. © 2022 Society of Chemical Industry.


Asunto(s)
Conservación de Alimentos , Alimentos Congelados , Congelación , Conservación de Alimentos/métodos , Temperatura , Calor
12.
Virol Sin ; 37(6): 823-830, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36309306

RESUMEN

The spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from cold-chain foods to frontline workers poses a serious public health threat during the current global pandemic. There is an urgent need to design concise approaches for effective virus inactivation under different physicochemical conditions to reduce the risk of contagion through viral contaminated surfaces of cold-chain foods. By employing a time course of electron beam exposure to a high titer of SARS-CoV-2 at cold-chain temperatures, a radiation dose of 2 â€‹kGy was demonstrated to reduce the viral titer from 104.5 to 0 median tissue culture infectious dose (TCID50)/mL. Next, using human coronavirus OC43 (HCoV-OC43) as a suitable SARS-CoV-2 surrogate, 3 â€‹kGy of high-energy electron radiation was defined as the inactivation dose for a titer reduction of more than 4 log units on tested packaging materials. Furthermore, quantitative reverse transcription PCR (RT-qPCR) was used to test three viral genes, namely, E, N, and ORF1ab. There was a strong correlation between TCID50 and RT-qPCR for SARS-CoV-2 detection. However, RT-qPCR could not differentiate between the infectivity of the radiation-inactivated and nonirradiated control viruses. As the defined radiation dose for effective viral inactivation fell far below the upper safe dose limit for food processing, our results provide a basis for designing radiation-based approaches for the decontamination of SARS-CoV-2 in frozen food products. We further demonstrate that cell-based virus assays are essential to evaluate the SARS-CoV-2 inactivation efficiency for the decontaminating strategies.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , Embalaje de Alimentos , Alimentos Congelados , Electrones , Dosis de Radiación
13.
J Food Sci ; 87(9): 4082-4106, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-36049017

RESUMEN

A hybrid mixture theory (HMT)-based unsaturated transport (pores not saturated with liquid) model was applied to a food matrix subjected to freezing and freeze-thaw cycles. The model can explain the fluid, species, and heat transport, ice formation, thermomechanical changes, and the freezing point depression occurring inside food biopolymers during freezing. Volume changes during freezing were calculated using the stresses due to pore pressure and the phase-change based mechanical strain. The Eulerian-Lagrangian transformation was performed for solving the equations using a finite element mesh in Lagrangian coordinates. The predicted temperature profiles for constant and fluctuating freezing temperature conditions showed agreement with experimental data with reasonable accuracy (RMSE = 2.86°C and 2.23°C, respectively). The multiscale transport model coupled with a physical chemistry-based relation was able to predict solute concentration and the freezing point depression in potatoes with greater accuracy than an empirical equation published in the literature. Sudden temperature fluctuations representing the opening and closing of a freezer door were investigated using this solution scheme, and conditions causing less damage to the food were identified. PRACTICAL APPLICATION: Food materials are subjected to freeze-thaw cycles during storage, shipping, and distribution to the consumers. The study uses numerical modeling and experimental validation to elucidate the principles affecting ice formation, solute migration, and temperature changes. Outcomes will allow processors to improve the quality of frozen foods with improved design of freezing operation, and storage and distribution strategies.


Asunto(s)
Calor , Hielo , Biopolímeros , Congelación , Alimentos Congelados
14.
Anim Reprod Sci ; 242: 107001, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35660169

RESUMEN

The aim of this study was to determine the effect of completely or partially replacing fresh foods from the broodstock diet with an experimental diet. During a 40-day period, three dietary treatments were tested on Litopeaneus vannamei broodstock. As part of the first dietary treatment, denoted as "FF", broodstock shrimp were fed only fresh frozen food (squid, polychaete, mussel and Artemia biomass). The second treatment denoted as "ED" was 100% an artificial experimental diet. The third treatment, denoted as MD, comprised both the experimental diet and the fresh-frozen food (only squid and mussel were used). In terms of fertile spawns, females with ≥ 1 spawn, females with ≥ 2 spawn, and fecundity, the MD treatment did not differ significantly from the FF treatment. Fecundity was lowest among females receiving the ED treatment. MD treatment demonstrated equivalent fertility in females, and sperm rate in males to that of the FF treatment. The highest normal sperm rate was found in the ED and MD treatments. As a result, a combination of fresh food and the experimental diet resulted in a more balanced reproduction performance.


Asunto(s)
Penaeidae , Alimentación Animal/análisis , Animales , Dieta/veterinaria , Alimentos Congelados , Masculino
15.
Multimedia | Recursos Multimedia | ID: multimedia-9608

RESUMEN

Comida de Verdade - Aula 5: Como fazer comida de verdade só para mim? São muitos os obstáculos na cozinha individual. Mas nesta aula você aprende várias técnicas e descobre que o congelador é um grande aliado para contornar os desafios da cozinha para um. Vai aprender também a evitar o desperdício, variar o sabor e dimensionar a lista de compras


Asunto(s)
Alimentos Congelados , Persona Soltera , , Planificación de Menú
16.
Crit Rev Food Sci Nutr ; 62(3): 598-618, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-32960080

RESUMEN

During radio frequency (RF) thawing-tempering (defrosting) of frozen food products, some regions, mostly along the corners and edges, heat-thaw first due to the strong interaction of electric field and evolved heating leading to temperature increase. Resulting higher power absorption along these regions, compared to the rest of the volume, is the major cause of this problem. Besides, increase in temperature with phase change results in a significant increase of dielectric properties. This situation leads to runaway heating, which triggers the non-uniform temperature distribution in an accelerated manner. All these power absorption and temperature non-uniformity-based changes lead to significant quality changes, drip losses, and microbial growth. Based on this background, the objective of this review was to provide a comprehensive background regarding the most relevant and novel defrosting application studies using RF process, dielectric property data for frozen foods in the RF band, and novel mathematical modeling based computer simulation approaches to achieve a uniform process. Experimental and modeling studies were related with electrode position, sample geometry and size, electrode gap of the applied RF process, and the potential of charged electrode. Applying translational and rotational movement of the food product and the charged electrode vertical movement during the process to adjust the electric field and use of two-cavity systems and curved electrodes were also explained in detail. The data presented in this review is expected to give an insight information for further development of innovative RF thawing/tempering systems.


Asunto(s)
Alimentos Congelados , Ondas de Radio , Simulación por Computador , Manipulación de Alimentos , Congelación
17.
Food Sci Technol Int ; 28(8): 728-734, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34747238

RESUMEN

One of the key points in the frozen food processing is thawing with minimal damage to the quality. Since the commonly used methods for thawing of foods are slow and reduce the quality of the product, application of an efficient method seems necessary. In this research, thawing of tuna fish was performed by immersion ohmic method. Thawing rate roles a vital key in the quality and significantly increased by ohmic (0.2g/s, the mean of ohmic group) in comparison with conventional thawing (0.15g/s, the mean of conventional group) methods. Immersion ohmic thawing increased rate of thawing about 5 times. Parameters important in quality such as T-VBN, protein solubility, thawing evaporation loss, pH, thawing loss and press juice were measured. Group analyses showed significant difference between ohmic and conventional treatment in protein solubility, thawing evaporation and thawing loss (p < 0.05).


Asunto(s)
Inmersión , Atún , Animales , Congelación , Manipulación de Alimentos/métodos , Alimentos Congelados
18.
Multimedia | Recursos Multimedia | ID: multimedia-9345

RESUMEN

Organizar as compras ajuda a manter os alimentos em ótimo estado por mais tempo! Além de ter a cozinha com tudo no lugar, o que facilita o momento de cozinhar.


Asunto(s)
Conservación de Alimentos , Alimentos Congelados , Alimentos Integrales
19.
Compr Rev Food Sci Food Saf ; 20(6): 5548-5569, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34564951

RESUMEN

Over the recent decades,protein oxidation in muscle foods has gained increasing research interests as it is known that protein oxidation can affect eating quality and nutritional value of meat and aquatic products. Protein oxidation occurs during freezing/thawing and frozen storage of muscle foods, leading to irreversible physicochemical changes and impaired quality traits. Controlling oxidative damage to muscle foods during such technological processes requires a deeper understanding of the mechanisms of freezing-induced protein oxidation. This review focus on key physicochemical factors in freezing/thawing and frozen storage of muscle foods, such as formation of ice crystals, freeze concentrating and macromolecular crowding effect, instability of proteins at the ice-water interface, freezer burn, lipid oxidation, and so on. Possible relationships between these physicochemical factors and protein oxidation are thoroughly discussed. In addition, the occurrence of protein oxidation, the impact on eating quality and nutrition, and controlling methods are also briefly reviewed. This review will shed light on the complicated mechanism of protein oxidation in frozen muscle foods.


Asunto(s)
Alimentos Congelados , Carne , Congelación , Carne/análisis , Músculos , Oxidación-Reducción
20.
PLoS Med ; 18(9): e1003729, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34491999

RESUMEN

BACKGROUND: Previous product placement trials in supermarkets are limited in scope and outcome data collected. This study assessed the effects on store-level sales, household-level purchasing, and dietary behaviours of a healthier supermarket layout. METHODS AND FINDINGS: This is a prospective matched controlled cluster trial with 2 intervention components: (i) new fresh fruit and vegetable sections near store entrances (replacing smaller displays at the back) and frozen vegetables repositioned to the entrance aisle, plus (ii) the removal of confectionery from checkouts and aisle ends opposite. In this pilot study, the intervention was implemented for 6 months in 3 discount supermarkets in England. Three control stores were matched on store sales and customer profiles and neighbourhood deprivation. Women customers aged 18 to 45 years, with loyalty cards, were assigned to the intervention (n = 62) or control group (n = 88) of their primary store. The trial registration number is NCT03518151. Interrupted time series analysis showed that increases in store-level sales of fruits and vegetables were greater in intervention stores than predicted at 3 (1.71 standard deviations (SDs) (95% CI 0.45, 2.96), P = 0.01) and 6 months follow-up (2.42 SDs (0.22, 4.62), P = 0.03), equivalent to approximately 6,170 and approximately 9,820 extra portions per store, per week, respectively. The proportion of purchasing fruits and vegetables per week rose among intervention participants at 3 and 6 months compared to control participants (0.2% versus -3.0%, P = 0.22; 1.7% versus -3.5%, P = 0.05, respectively). Store sales of confectionery were lower in intervention stores than predicted at 3 (-1.05 SDs (-1.98, -0.12), P = 0.03) and 6 months (-1.37 SDs (-2.95, 0.22), P = 0.09), equivalent to approximately 1,359 and approximately 1,575 fewer portions per store, per week, respectively; no differences were observed for confectionery purchasing. Changes in dietary variables were predominantly in the expected direction for health benefit. Intervention implementation was not within control of the research team, and stores could not be randomised. It is a pilot study, and, therefore, not powered to detect an effect. CONCLUSIONS: Healthier supermarket layouts can improve the nutrition profile of store sales and likely improve household purchasing and dietary quality. Placing fruits and vegetables near store entrances should be considered alongside policies to limit prominent placement of unhealthy foods. TRIAL REGISTRATION: ClinicalTrials.gov NCT03518151 (pre-results).


Asunto(s)
Comercio , Comportamiento del Consumidor , Dieta Saludable , Alimentos , Valor Nutritivo , Supermercados , Adolescente , Adulto , Dulces , Conducta de Elección , Comercio/economía , Comportamiento del Consumidor/economía , Dieta Saludable/economía , Inglaterra , Femenino , Alimentos/efectos adversos , Alimentos/economía , Preferencias Alimentarias , Alimentos Congelados , Frutas , Humanos , Análisis de Series de Tiempo Interrumpido , Persona de Mediana Edad , Proyectos Piloto , Estudios Prospectivos , Factores de Tiempo , Verduras , Adulto Joven
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