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1.
Int J Mol Sci ; 25(1)2023 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-38203712

RESUMEN

Gut microbiota plays a crucial role in inflammatory bowel diseases (IBD) and can potentially prevent IBD through microbial-derived metabolites, making it a promising therapeutic avenue. Recent evidence suggests that despite an unclear underlying mechanism, red cabbage juice (RCJ) alleviates Dextran Sodium Sulfate (DSS)-induced colitis in mice. Thus, the study aims to unravel the molecular mechanism by which RCJ modulates the gut microbiota to alleviate DSS-induced colitis in mice. Using C57BL/6J mice, we evaluated RCJ's protective role in DSS-induced colitis through two cycles of 3% DSS. Mice were daily gavaged with PBS or RCJ until the endpoint, and gut microbiota composition was analyzed via shotgun metagenomics. RCJ treatment significantly improved body weight (p ≤ 0.001), survival in mice (p < 0.001) and reduced disease activity index (DAI) scores. Further, RCJ improved colonic barrier integrity by enhancing the expression of protective colonic mucins (p < 0.001) and tight junction proteins (p ≤ 0.01) in RCJ + DSS-treated mice compared to the DSS group. Shotgun metagenomic analysis revealed an enrichment of short-chain fatty acids (SCFAs)-producing bacteria (p < 0.05), leading to increased Peroxisome Proliferator-Activated Receptor Gamma (PPAR-γ) activation (p ≤ 0.001). This, in turn, resulted in repression of the nuclear factor κB (NFκB) signaling pathway, causing decreased production of inflammatory cytokines and chemokines. Our study demonstrates colitis remission in a DSS-induced mouse model, showcasing RCJ as a potential modulator for gut microbiota and metabolites, with promising implications for IBD prevention and treatment.


Asunto(s)
Colitis , Microbioma Gastrointestinal , Enfermedades Inflamatorias del Intestino , Animales , Ratones , Ratones Endogámicos C57BL , Colitis/inducido químicamente , Homeostasis
2.
Food Microbiol ; 96: 103710, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33494891

RESUMEN

The enhanced heat resistance of Salmonella developed at low water activity makes it a serious challenge to eliminate them during thermal processing. The objectives of this research are to (i) investigate the effect of water activity on thermal inactivation of Salmonella cocktail (Agona, Tennessee, Mbandaka, Montevideo, and Reading) in dried basil leaves, and (ii) evaluate Enterococcus faecium NRRL B-2354 as an appropriate surrogate for Salmonella in dried basil leaves. Dried basil leaves, inoculated with a Salmonella cocktail and E. faecium separately, were equilibrated to different water activities (aw: 0.40, 0.55, and 0.70) in a humidity-controlled chamber. The basil samples were packed (1.6 ± 0.1 g) in aluminum pouches and thermally treated at 70, 75, and 80 °C using a dry heating method for 0-180 min to obtain the thermal death curve. The microbial survival data was fit using two primary models (Log-linear and Weibull model). Results from AICc showed that the log-linear model fits well for thermal inactivation of both microorganisms. As the aw decreases from 0.70 to 0.40 at 75 °C, the D-value increases from 3.30 to 9.14 min for Salmonella and 6.53 to 14.07 min for E. faecium. Based on the AICc values, the modified Bigelow model fits the D-values better than the response surface model for both the microorganisms. The kill ratio of surrogate to pathogen ranged from 1.4 to 2.8, indicating that it is a conservative surrogate for Salmonella for performing validation of the thermal pasteurization process. The identification of suitable surrogate and development of modified Bigelow model will help the spice industry in developing the thermal processes for improving the safety of basil leaves.


Asunto(s)
Enterococcus faecium/crecimiento & desarrollo , Conservación de Alimentos/métodos , Ocimum basilicum/microbiología , Salmonella/crecimiento & desarrollo , Recuento de Colonia Microbiana , Enterococcus faecium/química , Contaminación de Alimentos/análisis , Conservación de Alimentos/instrumentación , Calor , Cinética , Ocimum basilicum/química , Hojas de la Planta/química , Hojas de la Planta/microbiología , Salmonella/química
3.
Food Microbiol ; 94: 103656, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33279081

RESUMEN

The objectives of this study were to investigate the effects of processing parameters (relative humidity (RH), temperature, and exposure time) on the ethylene oxide (EtO) microbial inactivation of Salmonella spp. and to evaluate Enterococcus faecium NRRL B2354 as a suitable surrogate for Salmonella inactivation on cumin seeds. Five grams of cumin seeds inoculated with either Salmonella or E. faecium were treated with EtO at different temperatures (46, 53, and 60 °C) and RH (30, 40, and 50%) levels for different exposure time to investigate the effects of process parameters on the microbial inactivation. The Weibull model fit the survival data of both bacteria with a shape parameter p < 1, which showed a tailing effect with concave shape indicating that the sensitive cells were inactivated first, and the sturdy ones survived at low RH treatment conditions. In general, the log reductions of both bacteria on cumin seeds increased with the increasing RH and temperature for EtO treatment. RH is a critical factor for successful EtO inactivation treatment. RH must be higher than 40% to implement a successful and efficient EtO decontamination of cumin seeds. E. faecium consistently showed lower log reductions than those of Salmonella under all EtO treatment conditions investigated in this study, demonstrating that E. faecium is a suitable surrogate for Salmonella. Twenty minutes of EtO treatment at 50% RH achieved ~5 log reductions of both bacteria at all three temperatures. A response surface model was developed to predict the log reductions of both bacteria under different treatment conditions and the contour plots representing log reductions were created. Inactivation is positively correlated to temperature and RH. Therefore, a higher temperature is required to achieve the desired log reduction at lower RH and vice versa. The developed response surface model is a valuable tool for the spice industry in identifying the possible combinations of EtO process parameters (temperature, RH, and exposure time) required to achieve a desired microbial reduction of Salmonella for ensuring microbial food safety of spices.


Asunto(s)
Cuminum/microbiología , Enterococcus faecium/efectos de los fármacos , Óxido de Etileno/química , Óxido de Etileno/farmacología , Conservación de Alimentos/métodos , Salmonella enterica/efectos de los fármacos , Recuento de Colonia Microbiana , Enterococcus faecium/crecimiento & desarrollo , Conservación de Alimentos/instrumentación , Conservantes de Alimentos/química , Conservantes de Alimentos/farmacología , Inocuidad de los Alimentos , Gases/farmacología , Viabilidad Microbiana/efectos de los fármacos , Salmonella enterica/crecimiento & desarrollo , Semillas/microbiología , Especias/microbiología , Temperatura
4.
J Dairy Sci ; 104(1): 198-210, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33189289

RESUMEN

While the increase in thermal resistance of microorganisms at reduced water activity is demonstrated for low-moisture food products, the effect of storage time on the thermal resistance of microorganisms in low-moisture foods is not well established. As low-moisture foods are stored for long periods and are used as ingredients, cross-contamination can occur at any time period before the lethality step. Therefore, this study was designed to investigate the effect of storage time (30, 60, and 90 d) on the thermal resistance of Salmonella and Enterococcus faecium NRRL B-2354 in milk powders at a low water activity of 0.10 (conservative level). In this study, 2 milk powders, whole milk powder (WMP) and nonfat dry milk (NFDM), were inoculated with a 5-serotype Salmonella cocktail or E. faecium and equilibrated to a water activity of 0.10. The thermal resistance of Salmonella and E. faecium in WMP and NFDM were determined at different storage times (30, 60, and 90 d) at 85°C. The storage time had no effect on the thermal inactivation kinetics of Salmonella within 90 d of storage at 85°C. In the second part of this study, isothermal treatments were also conducted at higher temperatures (90 and 95°C) to evaluate the suitability of E. faecium as a surrogate for Salmonella in milk powders. The D-values of Salmonella in WMP with 30 d of storage at 85, 90, and 95°C were 7.98, 3.35, and 1.68 min. The corresponding values for E. faecium were 16.96, 7.90, and 4.16 min. Higher D-values of E. faecium indicates that it is a conservative surrogate. Similar results were found for NFDM. In general, D-values of both microorganisms are slightly higher in NFDM than WMP. Two primary models (log-linear and Weibull) were compared for their goodness-of-fit. The Weibull model was found to be more appropriate than the log-linear model. This study provides valuable information for establishing process validation for the pasteurization of milk powders.


Asunto(s)
Enterococcus faecium/metabolismo , Microbiología de Alimentos , Leche/microbiología , Salmonella enterica/metabolismo , Animales , Cinética , Leche/química , Pasteurización , Polvos , Temperatura
5.
J Dairy Sci ; 104(9): 9607-9616, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34176627

RESUMEN

Salmonella persistence in milk powders has caused several multistate foodborne disease outbreaks. Therefore, ways to deliver effective thermal treatment need to be identified and validated to ensure the microbial safety of milk powders. In this study, a process of hot air-assisted radio frequency (HARF) followed by holding at high temperatures in a convective oven was developed for pasteurization of milk powders. Heating times were compared between HARF and a convection oven for heating milk powders to a pasteurization temperature, and HARF has been shown to considerably reduce the come-up time. Whole milk powder (WMP) and nonfat dry milk (NFDM) were inoculated with a 5-serotype Salmonella cocktail and equilibrated to a water activity of 0.10 to simulate the worst case for the microbial challenge study. After heating the sample to 95°C using HARF, followed by 10 and 15 min of holding in the oven, more than 5 log reduction of Salmonella was achieved in WMP and NFDM. This study validated a HARF-assisted thermal process for pasteurization of milk powder based on previously collected microbial inactivation kinetics data and provides valuable insights to process developers to ensure microbial safety of milk powder. This HARF process may be implemented in the dairy industry to enhance the microbial safety of milk powders.


Asunto(s)
Leche , Pasteurización , Animales , Recuento de Colonia Microbiana/veterinaria , Microbiología de Alimentos , Calefacción , Calor , Leche/química , Polvos , Agua/análisis
6.
J Environ Manage ; 285: 112152, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33609974

RESUMEN

Direct discharge of high concentration meat processing wastewater (MPW) into municipal sewage system will cause serious shock loading and reduce wastewater treatment efficiency, thus, efficient on-site pretreatment is usually required. Purpose of this study is to integrate ozone with microalgal biotreatment to achieve effective removal of both organic compounds and nutrients with one-step biodegradation and obtain high quality effluent dischargeable to municipal sewage system. Results showed that ozone pretreatment removed 35.0-90.2% color and inactivated 1.8-4.7 log CFU/mL bacteria in MPW. In post biotreatment using microalgae co-immobilized with activated sludge (ACS) bacteria, bacterial growth in ozone pretreated wastewater (7.1-8.1 log CFU/mL) were higher than non-pretreated control (6.0 log CFU/mL) due to enhanced biodegradability of wastewater pollutants. Algal biomass growth in wastewater pretreated with 0.5 (2489.3 mg/L) and 1 (2582.0 mg/L) minute's ozonation were improved and higher than control (2297.1 mg/L). Ozone pretreatment significantly improved nutrients removal. Following ozone pretreatment of 0.5 min, microalgal biotreatment removed 60.1% soluble chemical oxygen demand (sCOD), 79.5% total nitrogen (TN) and 91.9% total phosphate (PO43-) which were higher than control (34.4% sCOD, 63.4% TN, 77.6% total PO43-). Treated effluent contained 342.3 mg/L sCOD, 28.8 mg/L TN, 9.9 mg/L total PO43- and could be discharged into municipal sewage system. However, excessive ozone pretreatment displayed adverse impact on algal growth and sCOD removal. Therefore, integration of 0.5 min's ozone pretreatment with microalgae-based biotreatment is an efficient on-site treatment to simultaneously remove organic compounds and nutrients with one-step biodegradation.


Asunto(s)
Microalgas , Ozono , Bacterias , Carne , Aguas del Alcantarillado , Simbiosis , Aguas Residuales
7.
Compr Rev Food Sci Food Saf ; 20(5): 4950-4992, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34323364

RESUMEN

The outbreaks linked to foodborne illnesses in low-moisture foods are frequently reported due to the occurrence of pathogenic microorganisms such as Salmonella Spp. Bacillus cereus, Clostridium spp., Cronobacter sakazakii, Escherichia coli, and Staphylococcus aureus. The ability of the pathogens to withstand the dry conditions and to develop resistance to heat is regarded as the major concern for the food industry dealing with low-moisture foods. In this regard, the present review is aimed to discuss the importance and the use of novel thermal and nonthermal technologies such as radiofrequency, steam pasteurization, plasma, and gaseous technologies for decontamination of foodborne pathogens in low-moisture foods and their microbial inactivation mechanisms. The review also summarizes the various sources of contamination and the factors influencing the survival and thermal resistance of pathogenic microorganisms in low-moisture foods. The literature survey indicated that the nonthermal techniques such as CO2 , high-pressure processing, and so on, may not offer effective microbial inactivation in low-moisture foods due to their insufficient moisture content. On the other hand, gases can penetrate deep inside the commodities and pores due to their higher diffusion properties and are regarded to have an advantage over thermal and other nonthermal processes. Further research is required to evaluate newer intervention strategies and combination treatments to enhance the microbial inactivation in low-moisture foods without significantly altering their organoleptic and nutritional quality.


Asunto(s)
Microbiología de Alimentos , Salmonella , Calor , Pasteurización , Vapor
8.
Food Microbiol ; 85: 103306, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31500703

RESUMEN

Spray dried egg white powder (EWP) is traditionally processed by hot room treatment for a prolonged period of time (67 °C for 15 days) to enhance its functionality (foaming and gelling) and to improve microbial safety of EWP. Our prior research demonstrated that radio-frequency (RF) assisted thermal processing can considerably reduce the processing time, without compromising the functional properties of EWP. In this study, continuous RF processing was evaluated for pasteurization of EWP. EWP samples were inoculated with a 5-strain Salmonella cocktail or Enterococcus faecium NRRL B-2354 for the microbial challenge studies. To evaluate the inoculation method, stability and homogeneity tests were conducted for both Salmonella and E. faecium in EWP. Continuous RF heating of EWP was conducted in a 6-kW, 27.12 MHz pilot-scale parallel-plate RF heating system. RF-assisted thermal processing of EWP at 80 °C for 2 h provided >6.69 log reduction for Salmonella. E. faecium was found to be a suitable surrogate for Salmonella due to its higher resistance and similar inactivation kinetics during RF heating of EWP. The validated RF-assisted thermal process can be scaled up for use in the egg industry.


Asunto(s)
Clara de Huevo/microbiología , Microbiología de Alimentos/métodos , Análisis de Peligros y Puntos de Control Críticos/métodos , Calor , Pasteurización/métodos , Ondas de Radio , Recuento de Colonia Microbiana , Polvos/análisis , Salmonella
9.
J Dairy Sci ; 103(8): 6904-6917, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32475668

RESUMEN

Persistence of Salmonella in milk powders has caused several foodborne outbreaks. The determination of proper pasteurization processing conditions requires an understanding of the thermal inactivation kinetics of Salmonella in milk powders. However, there is a lack of knowledge related to the effects of water activity (aw) and fat content on Salmonella inactivation in milk powder during thermal processing. Two types of milk powders, nonfat dry milk and whole milk powder, with different fat contents (0.62 and 29.46% wt/wt, respectively) were inoculated with a 5-strain cocktail of Salmonella and equilibrated to 3 aw levels (0.10, 0.20, and 0.30) for isothermal treatments at 75, 80, and 85°C to obtain D-values (the time required to achieve a 10-fold reduction of the bacteria at the isothermal treatment temperature) and z-values (the increase in temperature required to achieve a 90% reduction of the decimal reduction time D). Stability tests showed that the inoculation method used in this study provided a high and stable population of Salmonella for thermal inactivation studies. A moisture sorption isotherm was measured to understand the relationship between aw and moisture content of milk powders. The thermal resistance of Salmonella was found to significantly increase as aw decreased, which suggested that a higher temperature or longer processing time would be required at low aw to achieve the desired inactivation of Salmonella. The microbial inactivation kinetics were not significantly different for the 2 milk powders; therefore, data were combined to develop a universal model. A response surface model was compared with a modified Bigelow model. The modified Bigelow model performed well to predict D-values [root mean square error (RMSE) = 1.47 min] and log reductions (RMSE = 0.48 log cfu/g). The modified Bigelow model developed here could be used to estimate D-value as a function of water activity and temperature to design a thermal pasteurization system for milk powders.


Asunto(s)
Viabilidad Microbiana , Leche/microbiología , Pasteurización/métodos , Salmonella/fisiología , Agua , Animales , Recuento de Colonia Microbiana/veterinaria , Microbiología de Alimentos , Calor , Cinética , Polvos
10.
Food Microbiol ; 82: 388-397, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31027798

RESUMEN

Salmonella persistence in ground black pepper has caused several foodborne outbreaks and created public concern about the safety of low water activity (aw) foods. In this study, radiofrequency (RF) processing was evaluated for pasteurization of ground black pepper. Stability and homogeneity tests were done for both Salmonella spp. and E. faecium during moisture equilibration before RF heating to evaluate the inoculation method. Moisture content of samples were conditioned such that the final moisture content after RF heating reached the optimal storage moisture. RF heating was shown to provide more than 5.98 log CFU/g reduction for Salmonella spp. and the reduction of 3.89 log CFU/g for E. faecium with a 130 s of treatment time. The higher thermal resistance of E. faecium indicated its suitability as surrogate for Salmonella spp. during RF heating of ground black pepper. Piperine, total phenolics, volatile compounds, and antioxidant activity were assessed as quality parameters for ground black pepper. The results demonstrated that the RF processing provided effective inactivation of Salmonella spp. with insignificant (p > 0.05) quality deterioration.


Asunto(s)
Enterococcus faecium/crecimiento & desarrollo , Microbiología de Alimentos , Calefacción/métodos , Pasteurización/métodos , Piper nigrum/microbiología , Salmonella/crecimiento & desarrollo , Recuento de Colonia Microbiana , Enterococcus faecium/fisiología , Calidad de los Alimentos , Calor , Piper nigrum/química , Salmonella/fisiología , Especias/microbiología , Agua/análisis
11.
Crit Rev Food Sci Nutr ; 58(6): 1033-1057, 2018 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-27892683

RESUMEN

Radio frequency (RF) heating has great potential for achieving rapid and volumetric heating in foods, providing safe and high-quality food products due to deep penetration depth, moisture self-balance effects, and leaving no chemical residues. However, the nonuniform heating problem (usually resulting in hot and cold spots in the heated product) needs to be resolved. The inhomogeneous temperature distribution not only affects the quality of the food but also raises the issue of food safety when the microorganisms or insects may not be controlled in the cold spots. The mathematical modeling for RF heating processes has been extensively studied in a wide variety of agricultural products recently. This paper presents a comprehensive review of recent progresses in computer simulation for RF heating uniformity improvement and the offered solutions to reduce the heating nonuniformity. It provides a brief introduction on the basic principle of RF heating technology, analyzes the applications of numerical simulation, and discusses the factors influencing the RF heating uniformity and the possible methods to improve heating uniformity. Mathematical modeling improves the understanding of RF heating of food and is essential to optimize the RF treatment protocol for pasteurization and disinfestation applications. Recommendations for future research have been proposed to further improve the accuracy of numerical models, by covering both heat and mass transfers in the model, validating these models with sample movement and mixing, and identifying the important model parameters by sensitivity analysis.


Asunto(s)
Simulación por Computador , Manipulación de Alimentos , Calor , Ondas de Radio , Desecación , Desinfección , Fenómenos Electromagnéticos , Alimentos , Modelos Teóricos
12.
Water Environ Res ; 90(9): 851-863, 2018 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-30209000

RESUMEN

Recent changes related to antimicrobial intervention technologies and reduction in product loss have affected cattle slaughterhouse wastewater streams. In this study, wastewater samples were collected from two cattle slaughterhouses located in the Midwest of the United States, focusing on the overall wastewater, antimicrobial interventions, and viscera and offal processing. The wastewater concentrations were affected by the water use, dilution, processes, and wastewater pretreatment that occurs within the slaughterhouse. Even though there were differences in the wastewater concentrations, the overall wastewater loads for both slaughterhouses were similar. The overall mean total solids (TS), volatile solids (VS), 5-day biological chemical demand (BOD5), and chemical oxygen demand (COD) wastewater loads for the two slaughterhouses were 16.8, 10.0, 4.7, and 12.5 kg/1000 kg live weight killed, respectively. Wastewater streams from antimicrobial interventions have low pH and are potential sources of shock loadings. Wastewater from viscera and offal processing has high nutrient concentration; therefore, any improvement in this process could enhance the sustainability the industry.


Asunto(s)
Mataderos , Bovinos , Eliminación de Residuos Líquidos , Aguas Residuales/química , Aguas Residuales/microbiología , Contaminantes Químicos del Agua , Animales , Factores de Tiempo , Estados Unidos , Microbiología del Agua , Purificación del Agua
13.
Food Microbiol ; 64: 39-46, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28213033

RESUMEN

Liquid egg products can be contaminated with Salmonella spp. during processing. A dynamic model for the growth of Salmonella spp. in scrambled egg mix - high solids (SEM) was developed and validated. SEM was prepared and inoculated with ca. 2 log CFU/mL of a five serovar Salmonella spp. cocktail. Salmonella spp. growth data at isothermal temperatures (10, 15, 20, 25, 30, 35, 37, 39, 41, 43, 45, and 47 °C) in SEM were collected. Baranyi model was used (primary model) to fit growth data and the maximum growth rate and lag phase duration for each temperature were determined. A secondary model was developed with maximum growth rate as a function of temperature. The model performance measures, root mean squared error (RMSE, 0.09) and pseudo-R2 (1.00) indicated good fit for both primary and secondary models. A dynamic model was developed by integrating the primary and secondary models and validated using two sinusoidal temperature profiles, 5-15 °C (low temperature) for 480 h and 10-40 °C (high temperature) for 48 h. The RMSE values for the sinusoidal low and high temperature profiles were 0.47 and 0.42 log CFU/mL, respectively. The model can be used to predict Salmonella spp. growth in case of temperature abuse during liquid egg processing.


Asunto(s)
Culinaria , Huevos/microbiología , Microbiología de Alimentos , Salmonella/crecimiento & desarrollo , Temperatura , Recuento de Colonia Microbiana , Yema de Huevo/microbiología , Humanos , Modelos Biológicos , Análisis de Regresión
14.
J Food Prot ; 87(2): 100209, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38142824

RESUMEN

Radiofrequency (RF) heating has been extensively studied for pasteurizing low-moisture foods. Currently, bulk foods are treated with radiofrequency; potential cross-contamination may occur during packaging of pasteurized products. As an alternative, in-package RF processing was evaluated for Salmonella inactivation on black peppercorns and dried basil leaves and prevention of cross-contamination during storage postprocessing. In-package steaming refers to the process in which the samples were heated in a steam vent package to generate and retain steam during the treatment. This treatment achieved good heating uniformity which could be because of the circulation of steam within the package. One-way steam vent allowed the release of excess steam once a threshold pressure was achieved and later returned to its original position to seal the package, when the RF energy was removed. In-package RF steaming of black peppercorns and dried basil leaves for 135 s and 40 s, respectively, resulted in more than 5 log reduction of Salmonella. The steam vent remained stable posttreatment and properly sealed the package to protect the product from any external contamination. These results indicate that the use of steam vent could effectively pasteurize black peppercorns and dried basil leaves could be beneficial in preventing the potential cross-contamination postprocessing.


Asunto(s)
Ocimum basilicum , Piper nigrum , Vapor , Recuento de Colonia Microbiana , Microbiología de Alimentos , Salmonella , Especias
15.
J Food Prot ; 87(5): 100264, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38493872

RESUMEN

A surrogate is commonly used for process validations. The industry often uses the target log cycle reduction for the test (LCRTest) microorganism (surrogate) to be equal to the desired log cycle reduction for the target (LCRTarget) microorganism (pathogen). When the surrogate is too conservative with far greater resistance than the pathogen, the food may be overprocessed with quality and cost consequences. In aseptic processing, the Institute for Thermal Processing Specialists recommends using relative resistance (DTarget)/(DTest) to calculate LCRTest (product of LCRTarget and relative resistance). This method uses the mean values of DTarget and DTest and does not consider the estimating variability. We defined kill ratio (KR) as the inverse of relative resistance.The industry uses an extremely conservative KR of 1 in the validation of food processes for low-moisture foods, which ensures an adequate reduction of LCRTest, but can result in quality degradation. This study suggests an approach based on bootstrap sampling to determine conservative KR, leading to practical recommendations considering experimental and biological variability in food matrices. Previously collected thermal inactivation kinetics data of Salmonella spp. (target organism) and Enterococcus faecium (test organism) in Non-Fat Dried Milk (NFDM) and Whole Milk Powder (WMP) at 85, 90, and 95°C were used to calculate the mean KR. Bootstrapping was performed on mean inactivation rates to get a distribution of 1000 bootstrap KR values for each of the treatments. Based on minimum temperatures used in the industrial process and acceptable level of risk (e.g., 1, 5, or 10% of samples that would not achieve LCRTest), a conservative KR value can be estimated. Consistently, KR increased with temperature and KR for WMP was higher than NFDM. Food industries may use this framework based on the minimum processing temperature and acceptable level of risk for process validations to minimize quality degradation.


Asunto(s)
Recuento de Colonia Microbiana , Contaminación de Alimentos , Microbiología de Alimentos , Calor , Humanos , Contaminación de Alimentos/análisis , Manipulación de Alimentos/métodos , Seguridad de Productos para el Consumidor , Cinética
16.
Heliyon ; 10(10): e30921, 2024 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-38784533

RESUMEN

Millets are rich in nutritional and bioactive compounds, including polyphenols and flavonoids, and have the potential to combat malnutrition and various diseases. However, extracting these bioactive compounds can be challenging, as conventional methods are energy-intensive and can lead to thermal degradation. Green-assisted techniques have emerged as promising methods for sustainable and efficient extraction. This review explores recent trends in employing green-assisted techniques for extracting bioactive compounds from millets, and potential applications in the food and pharmaceutical industries. The objective is to evaluate and comprehend the parameters involved in different extraction methods, including energy efficiency, extraction yield, and the preservation of compound quality. The potential synergies achieved by integrating multiple extraction methods, and optimizing extraction efficiency for millet applications are also discussed. Among several, Ultrasound and Microwave-assisted extraction stand out for their rapidity, although there is a need for further research in the context of minor millets. Enzyme-assisted extraction, with its low energy input and ability to handle complex matrices, holds significant potential. Pulsed electric field-assisted extraction, despite being a non-thermal approach, requires further optimization for millet-specific applications, are few highlights. The review emphasizes the importance of considering specific compound characteristics, extraction efficiency, purity requirements, and operational costs when selecting an ideal technique. Ongoing research aims to optimize novel extraction processes for millets and their byproducts, offering promising applications in the development of millet-based nutraceutical food products. Therefore, the current study benefits researchers and industries to advance extraction research and develop efficient, sustainable, and scalable techniques to extract bioactive compounds from millets.

17.
Meat Sci ; 213: 109498, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38520828

RESUMEN

This study was conducted to evaluate the effects of relative humidity (RH) on moisture loss and flavor in dry-aged beef. Sixteen strip loins were assigned to one of the four aging treatments: vacuum (WET), dry-aging at 50% RH, dry-aging at 70% RH, or dry-aging at 85% RH and aged for 42 days at 2 °C. Loins were evaluated for evaporation loss, trim loss, tenderness, sensory, and microbiological characteristics. Results show that lower RH results in accelerated moisture loss during the first 3 days of the aging process without significantly affecting the total amount of moisture loss. Pseudomonadales dominated the aerobically dry-aged loins while Enterobacteriales was the most abundant in the wet-aged samples. Dry-aged samples had increased content of free amino acids in the cooked meat juice compared to the wet-aged counterpart. Dry aging at 50% RH tended to associate with more desirable flavor notes.


Asunto(s)
Manipulación de Alimentos , Humedad , Carne Roja , Gusto , Animales , Bovinos , Carne Roja/análisis , Carne Roja/microbiología , Manipulación de Alimentos/métodos , Humanos , Aminoácidos/análisis , Vacio , Agua/análisis , Microbiología de Alimentos
18.
J Food Prot ; : 100358, 2024 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-39245347

RESUMEN

Historically, low-moisture foods were considered to have minimal microbial risks. However, they have been linked to many high-profile multistate outbreaks and recalls in recent years, drawing research and extension attention to low-moisture food safety. Limited studies have assessed the food safety research and extension needs for the low-moisture food industry. The objectives of this needs assessment were to explore the food safety culture and education needs, identify the food safety challenges and data gaps, and understand the barriers to adopting food-safety-enhancing technologies in the U.S. low-moisture food industry. This needs assessment was composed of two studies. In Study 1, food safety experts from the low-moisture food industry upper management participated in online interviews and a debriefing discussion session. In Study 2, an online anonymous survey was disseminated to a different group of experts with experience in the low-moisture food industry. The qualitative data were analyzed using deductive and inductive coding approaches, while the quantitative data were analyzed via descriptive analysis. Twenty-five experts participated in the studies (Study 1: n=12; Study 2: n=13). Common commodities that participants had worked with included nuts and seeds, spices, flour, and dried fruits and vegetables. A food safety culture conceptual framework was adapted, which included three main components: infrastructure conditions (foundation), individual's food safety knowledge, attitudes, and risk perceptions; and organizational conditions (supporting pillars). Major barriers to establishing a positive food safety culture were identified to be limited resources, difficulties in risk communication, and difficulties in behavioral change. For continual improvement in food safety performance, two major themes of food safety challenges and data gaps were identified: cleaning, sanitation, and hygienic design; and pathogen reduction. Participants perceived the main barriers discouraging the low-moisture food industry from adopting food-safety-enhancing technologies were: (1) budgetary priorities, (2) operation constraints, (3) technology validation, (4) consumer acceptance, and (5) maintaining desired product characteristics such as quality and sensory functionality. The findings of this needs assessment provide guidance for the food industry, academia, and government agencies about the direction of future research and the development of targeted extension programs that might help improve food safety in the low-moisture food industry.

19.
Am J Physiol Regul Integr Comp Physiol ; 305(3): R291-9, 2013 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-23720135

RESUMEN

Peripheral arterial disease (PAD), which affects ~10 million Americans, is characterized by atherosclerosis of the noncoronary arteries. PAD produces a progressive accumulation of ischemic injury to the legs, manifested as a gradual degradation of gastrocnemius histology. In this study, we evaluated the hypothesis that quantitative morphological parameters of gastrocnemius myofibers change in a consistent manner during the progression of PAD, provide an objective grading of muscle degeneration in the ischemic limb, and correlate to a clinical stage of PAD. Biopsies were collected with a Bergström needle from PAD patients with claudication (n = 18) and critical limb ischemia (CLI; n = 19) and control patients (n = 19). Myofiber sarcolemmas and myosin heavy chains were labeled for fluorescence detection and quantitative analysis of morphometric variables, including area, roundness, perimeter, equivalent diameter, major and minor axes, solidity, and fiber density. The muscle specimens were separated into training and validation data sets for development of a discriminant model for categorizing muscle samples on the basis of disease severity. The parameters for this model included standard deviation of roundness, standard deviation of solidity of myofibers, and fiber density. For the validation data set, the discriminant model accurately identified control (80.0% accuracy), claudicating (77.7% accuracy), and CLI (88.8% accuracy) patients, with an overall classification accuracy of 82.1%. Myofiber morphometry provided a discriminant model that establishes a correlation between PAD progression and advancing muscle degeneration. This model effectively separated PAD and control patients and provided a grading of muscle degeneration within clinical stages of PAD.


Asunto(s)
Músculo Esquelético/patología , Enfermedad Arterial Periférica/patología , Anciano , Algoritmos , Biopsia , Análisis Discriminante , Progresión de la Enfermedad , Femenino , Colorantes Fluorescentes , Humanos , Procesamiento de Imagen Asistido por Computador , Modelos Lineales , Masculino , Microscopía Fluorescente , Persona de Mediana Edad , Modelos Biológicos , Fibras Musculares Esqueléticas/patología , Miosinas/metabolismo , Sarcolema/patología
20.
Food Chem ; 404(Pt A): 134533, 2023 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-36444011

RESUMEN

Radiofrequency (RF) assisted thermal processing can significantly enhance the gel firmness of egg white powder compared to the traditional hot room (HR) processing. Thus, the present study aims to delineate the impact of RF processing on the proteins' structure and bio-functional properties of egg white protein gels. The secondary protein conformations of egg white proteins exhibited no significant alteration upon RF-assisted thermal processing over traditional HR processing. In-vitro gastrointestinal (GI) digestion of egg white gels demonstrated that the RF processing did not compromise the accessibility of digestive proteases despite a more robust gel network. Peptides from the GI digest of egg white gel showed that Ovalbumin and Ovotransferrin were the parent proteins of most of the unique peptides generated, and minor structural differences accounted for these peptides. The bioavailability of the egg protein-derived peptides remains unaffected after RF processing without compromising the viability and integrity of the GI epithelial cells.


Asunto(s)
Conalbúmina , Proteínas del Huevo , Ondas de Radio , Ovalbúmina , Huevos
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