Evaluation of <i>Enterococcus faecium</i> NRRL B‐2354 as a Surrogate for <i>Salmonella</i> During Extrusion of Low‐Moisture Food

Verma, Tushar; Wei, Xinyao; Lau, Soon Kiat; Bianchini, Andréia; Eskridge, Kent M.; Subbiah, Jeyamkondan

doi:10.1111/1750-3841.14110

Cited by 40 publications

(12 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The fat content did not have a significant effect on the D-values of the RSM and therefore was not included in the final model. Although the protective effect of fat on Salmonella inactivation has been observed in many high-moisture foods (Ahmed et al, 1995;Verma et al, 2018), a similar protective effect was not found in milk powders. A protective effect of fat was not observed in milk powder during this short storage time (5 d).…”

Section: Thermal Resistance Of Salmonella In Wmp and Nfdmmentioning

confidence: 76%

“…Hildebrandt et al (2016) suggested that a lawn-based pelletized inoculum, which was used in this study, could provide a stable Salmonella population before isothermal treatment and yield consistent D-values. Several studies have shown that this lawn-based inoculation method provides consistent and stable Salmonella inoculated samples of different low-a w foods, such as spices (Chen et al, 2019;, oat and wheat flour (Liu et al, 2018;Verma et al, 2018), and egg white powder (Wei et al, 2020). Also, this wet inoculation method could simulate a common contamination scenario of milk powders, in which Salmonella-contaminated liquid drips from the roof of a processing plant into the powders being processed.…”

Section: Stability Tests Of Powder Inoculationmentioning

confidence: 99%

“…Additionally, the different fat and carbohydrate contents of different types of milk powders could contribute to the variation in bacterial inactivation in milk powders. Relatively high fat content has been shown to have a protective effect on Salmonella during thermal processing (Ahmed et al, 1995;Verma et al, 2018). Thus, it is also important to evaluate the effect of fat content on the microbial inactivation kinetics of Salmonella in milk powders.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

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

Wei

Lau

Chaves

et al. 2020

Journal of Dairy Science

Self Cite

View full text Add to dashboard Cite

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 w ) 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 a w 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 a w and moisture content of milk powders. The thermal resistance of Salmonella was found to significantly increase as a w decreased, which suggested that a higher temperature or longer processing time would be required at low a w 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.

show abstract

Section: Thermal Resistance Of Salmonella In Wmp and Nfdmmentioning

confidence: 76%

Section: Stability Tests Of Powder Inoculationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

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

Wei

Lau

Chaves

et al. 2020

Journal of Dairy Science

Self Cite

View full text Add to dashboard Cite

show abstract

“…The results showed that all the parameters except temperature had a significant effect on the mean residence time during the single‐screw extrusion of oat flour. Additionally, Verma and Subbiah (2020) reported that replacing the screw speed with mean residence time did not significantly improve their previously developed inactivation models for Salmonella and E. faecium (Verma et al., 2018a, 2018b). Therefore, it was suggested to use screw speed instead of mean residence time for conducting the extrusion validation studies as it is easier and convenient for the food processors to control.…”

Section: Process Technologies For Microbial Inactivation In Low‐moist...mentioning

confidence: 99%

Validation of process technologies for enhancing the safety of low‐moisture foods: A review

Wason

Verma

Subbiah

2021

Comp Rev Food Sci Food Safe

Self Cite

View full text Add to dashboard Cite

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 CO 2 , highpressure 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.

show abstract

“…Also, due to the difficulty of directly introducing the target pathogen into the processing plant, the use of a surrogate to replace the pathogen is recommended by FDA (2013) to conduct the validation study in the industrial processing plant. Several studies (Bianchini et al, 2014;Liu et al, 2018;Verma et al, 2018;Wei et al, 2018) have previously demonstrated that Enterococcus faecium NRRL B-2354 is a suitable surrogate for Salmonella during thermal processing of low water activity foods.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Enterococcus faecium NRRL B-2354 as a surrogate for Salmonella enterica in milk powders at different storage times and temperatures

Wei

Agarwal²,

Subbiah

2021

Journal of Dairy Science

Self Cite

View full text Add to dashboard Cite

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 lowmoisture 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, Dvalues 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.

show abstract

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

Cited by 40 publications

References 23 publications

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

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

Validation of process technologies for enhancing the safety of low‐moisture foods: A review

Evaluation of Enterococcus faecium NRRL B-2354 as a surrogate for Salmonella enterica in milk powders at different storage times and temperatures

Contact Info

Product

Resources

About