Effects of relative humidity on dry-aged beef quality.

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.

Interlaboratory Evaluation of Enterococcus faecium NRRL B-2354 as a Salmonella Surrogate for Validating Thermal Treatment of Multiple Low-Moisture Foods.

Abstract: This multi-institutional study assessed the efficacy of Enterococcus faecium NRRL B-2354 as a nonpathogenic Salmonella surrogate for thermal processing of nonfat dry milk powder, peanut butter, almond meal, wheat flour, ground black pepper, and date paste. Each product was analyzed by two laboratories (five independent laboratories total), with the lead laboratory inoculating (E. faecium or a five-strain Salmonella enterica serovar cocktail of Agona, Reading, Tennessee, Mbandaka, and Montevideo) and equilibrating the product to the target water activity before shipping.

Thermal Inactivation Kinetics of Salmonella and Enterococcus faecium NRRL-B2354 on Whole Chia Seeds (Salvia hispanica L.).

Abstract: Intervention technologies for inactivating Salmonella on whole chia seeds are currently limited. Determination of the thermal inactivation kinetics of Salmonella on chia seeds and selection of an appropriate nonpathogenic surrogate will provide a foundation for selecting and optimizing thermal pasteurization processes for chia seeds. In this study, chia seed samples from three separate production lots were inoculated with a five-strain Salmonella cocktail or Enterococcus faecium NRRL-B2354 and equilibrated to a water activity of 0.

Integration of ozone with co-immobilized microalgae-activated sludge bacterial symbiosis for efficient on-site treatment of meat processing wastewater.

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.

Ultimate pH effects on dry-aged beef quality.

This study aimed to evaluate pH effects on moisture loss and meat quality characteristics of dry-aged beef. Strip loins from six normal pH carcasses (pH = 5.47 ± 0.

A Comparison of Three Methods for Determining Thermal Inactivation Kinetics: A Case Study on Salmonella enterica in Whole Milk Powder.

Abstract: Different methods for determining the thermal inactivation kinetics of microorganisms can result in discrepancies in thermal resistance values. In this study, thermal resistance of Salmonella in whole milk powder was determined with three methods: thermal death time (TDT) disk in water bath, pouches in water bath, and the TDT Sandwich system. Samples from three production lots of whole milk powder were inoculated with a five-strain Salmonella cocktail and equilibrated to a water activity of 0.

HumidOSH: A self-contained environmental chamber with controls for relative humidity and fan speed.

Relative humidity can affect physical, biological, and chemical changes in biological samples through modification of water activity and is also known to be important in the fabrication of sensitive electronic devices. The HumidOSH is a free, open source, and self-contained system for creating a controlled relative humidity environment within the range of 3 to 97% with a 0.2% tolerance.

Color and lipid stability of dry aged beef during retail display.

The objective of this study was to determine color and lipid stability of steaks from dry-aged beef loins over 7 d of retail display (RD). Sixteen boneless strip loins were assigned to one of four treatments: wet-aging, dry aging at 50% relative humidity (RH), dry aging at 70% RH, or dry aging at 85% RH and aged for 42 days at 2 °C. Dry aging of beef resulted in decreased lightness (L*), redness (a*), and yellowness (b*) values and increased lipid oxidation compared to wet-aged counterparts (P < 0.

TDT Sandwich: An open source dry heat system for characterizing the thermal resistance of microorganisms.

The determination of the thermal death kinetics of microorganisms has traditionally been performed with liquid baths which have some disadvantages such as liquid spillage and liquid infiltration into samples. The TDT Sandwich was developed as a free, open source alternative that utilizes dry heat. The system is capable of heating samples up to 140 °C and maintaining it within 0.

Effect of water activity on the thermal inactivation kinetics of Salmonella in milk powders.

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 (a) and fat content on Salmonella inactivation in milk powder during thermal processing.

A microbial challenge study for validating continuous radio-frequency assisted thermal processing pasteurization of egg white powder.

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.

Radiofrequency pasteurization process for inactivation of Salmonella spp. and Enterococcus faecium NRRL B-2354 on ground black pepper.

Salmonella persistence in ground black pepper has caused several foodborne outbreaks and created public concern about the safety of low water activity (a) 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.

Radio-Frequency Processing for Inactivation of Salmonella enterica and Enterococcus faecium NRRL B-2354 in Black Peppercorn.

Several Salmonella outbreaks linked to black pepper call for effective inactivation processes, because current decontamination methods result in quality deterioration. Radio-frequency (RF) heating provides a rapid heating rate and volumetric heating, resulting in a shorter come-up time. This allows for choosing a high-temperature and short-time combination to achieve the desired inactivation with minimal quality deterioration.

Response Surface Methodology for Salmonella Inactivation during Extrusion Processing of Oat Flour.

An increase in the number of foodborne outbreaks and recalls due to Salmonella in low-moisture foods has resulted in the need for the development and validation of process controls to ensure their microbiological safety. Furthermore, the Food Safety Modernization Act Preventive Controls for Human Food final rule requires food processors to validate their process controls to ensure food safety. The objective of this study was to develop a response surface model to predict Salmonella inactivation in oat flour, as affected by moisture, fat content, screw speed, and temperature.

Evaluation of Enterococcus faecium NRRL B-2354 as a Surrogate for Salmonella During Extrusion of Low-Moisture Food.

Unlabelled: Salmonella in low-moisture foods is an emerging challenge due to numerous food product recalls and foodborne illness outbreaks. Identification of suitable surrogate is critical for process validation at industry level due to implementation of new Food Safety Modernization Act of 2011. The objective of this study was to evaluate Enterococcus faecium NRRL B-2354 as a surrogate for Salmonella during the extrusion of low-moisture food.

Radiofrequency Heating for Enhancing Microbial Safety of Shell Eggs Immersed in Deionized Water.

Unlabelled: Radiofrequency (RF) heating was simulated for improving the microbial safety of a shell egg immersed in deionized water using a finite element model. A regression equation that relates the top electrode voltage to the gap between the electrodes and vertical position of the egg was also developed. The root mean squared errors between the simulation and validation results ranged from 0.

Challenges in Radiofrequency Pasteurization of Shell Eggs: Coagulation Rings.

A total of 50 different configurations of simple radiofrequency (RF) heating at 27.12 MHz of a shell egg were simulated using a finite element model with the purpose of pasteurizing the egg. Temperature-dependent thermal and dielectric properties of the yolk, albumen, and shell were measured, fitted, and introduced into the model.