Survival of Salmonella Enteritidis Phage Type 30 on Brazil nuts and pumpkin seeds stored at 8, 23, and 37°C.

2021 ◽  
Author(s):  
Bukola A Onarinde
Keyword(s):  
Water Activity ◽  
Salmonella Enteritidis ◽  
Phage Type ◽  
Storage Period ◽  
Decay Rates ◽  
Brazil Nuts ◽  
Significant Difference ◽  
Influence Of Temperature On ◽  
Pumpkin Seeds ◽  
Storage Temperatures

Experiments were performed to assess the survival of Salmonella on whole Brazil nuts and pumpkin seeds stored at 8ºC, 23ºC, and 37ºC. Brazil nut kernels and pumpkin seeds were inoculated with bacterial inoculum containing 10.4 Log 10 CFU/ml of Salmonella Enteritidis Phage Type 30 ( S E PT30) and then aseptically dried at room temperature for 24 hrs. After the drying step, levels of Salmonella recovered from Brazil nuts and pumpkin seeds were 8.67±0.01 and 9.27±0.03Log 10 CFU/g, respectively. The survival of Salmonella and change in water activity was assessed over a total of 413 days. Although Salmonella survived throughout the storage period, significant differences were recorded between the storage temperatures. Results showed that the survival of S E PT30 was more enhanced at 8ºC as compared to storage at 23ºC and 37ºC. Comparing the survival of Salmonella on the two products at different storage temperatures, there was no significant difference between the means of Salmonella counts for the two products. Although results show that Salmonella survived longer on pumpkin seeds stored at 8ºC (P=0.53, as compared to Brazil nuts) and  at 23 and 37ºC Salmonella survived longer on Brazil nuts (P=0.12, as compared to pumpkin seeds). The highest and lowest survival of Salmonella was observed on pumpkin seeds with decay rates of -0.003±0.001 and -0.015±0.001 Log10 cfu/g per day for pumpkin seeds stored at 8 and 37ºC, respectively.  The water activity values recorded at day 2 and day 413 for Brazil nuts stored at 8ºC, 23ºC, and 37ºC were 0.424 and 0.434, 0.383 and 0.385 and, 0.372 and 0.256, respectively. For pumpkin seeds stored at 8ºC, 23ºC, and 37ºC water activity values recorded at day 2 and day 413 were 0.754 and 0.412, 0.627 and 0.350 and, 0.787 and 0.205, respectively. The data obtained in this study provide useful insight on the influence of temperature on the survival of Salmonella on the surface of Brazil nuts and pumpkin seeds.

scholarly journals Survivability of Salmonella Pathogens and Physicochemical Characteristics of Powder Goat Milk Stored under Different Storage Treatment Regimens

Dairy ◽  
2020 ◽  
Vol 1 (3) ◽  
pp. 269-283
Author(s):  
Roshan Paswan ◽  
Abhinav Mishra ◽  
Young W. Park
Keyword(s):  
Water Activity ◽  
Salmonella Enteritidis ◽  
Storage Temperature ◽  
Goat Milk ◽  
Storage Period ◽  
Behenic Acid ◽  
Physicochemical Characteristics ◽  
Treatment Regimens ◽  
Two Temperatures ◽  
Salmonella Serotypes

Survivability of Salmonella pathogens in commercial powdered goat milk (PGM) under different storage treatments was investigated using three batches of PGM products stored at two temperatures (4 °C and 25 °C) and ten storage periods (0, 3, 7, 14, 21, 30, 60, 90, 120 and 180 days). A cocktail of three Salmonella serotypes (Salmonella agona, Salmonella enteritidis and Salmonella tennessee) was inoculated to the PGM samples and then survival of Salmonella counts was enumerated in the inoculated and non-inoculated control groups. Results showed that the initial Salmonella counts were 7.103 Log CFU (colony forming unit)/g at both temperatures. At the first 3 days, the viable Salmonella counts were reduced about 0.94 and 1.40 Log CFU/g at 4 °C and 25 °C, respectively, where the same levels were sustained for 14 days. Further reductions continued and at the end of 180 days storage, Salmonella survivability was 1.15 Log CFU/g higher at 4 °C than at 25 °C under the same water activity condition. As the storage period advanced, viable pathogen counts were gradually decreased. The pH of samples stored at 4 °C for 0 and 4 month were higher than those stored at 25 °C except for 2 months, while no differences were found in water activity (aw) between treatments of the PGM products. With regard to physicochemical characteristics, the samples stored at 25 °C showed higher POV (peroxide value) values than those stored at 4 °C for 2 and 4 month periods, indicating that the rate of lipid oxidation in the PGM was elevated by a higher storage temperature and a longer storage period. The basic nutrient compositions of the experimental PGM were similar to those reported in recent studies. Oleic acid (C18:1) was the highest, caprylic acid (C8:0) was the second highest, and behenic acid (C22:0) was the lowest concentration among all fatty acids identified in the PGM samples. Most of the fatty acid concentrations tended to decrease with advanced storage periods. This research indicates that the survivability of Salmonella pathogens in the PGM products stored at 4 °C for 180 days was higher than those stored at 25 °C under the same aw condition.

scholarly journals Conservation of Alstroemeria cut flowers stored under refrigeration

2020 ◽  
Vol 43 ◽  
pp. e50016
Author(s):  
Vanessa Cury Galati ◽  
Ana Carolina Corrêa Muniz ◽  
João Emmauel Ribeiro Guimarães ◽  
Claudia Machado Fabrino Mattiuz ◽  
Ben Hur Mattiuz
Keyword(s):  
Storage Period ◽  
Postharvest Quality ◽  
Cut Flowers ◽  
Floral Longevity ◽  
Randomized Design ◽  
Significant Difference ◽  
Relative Water ◽  
Peroxidase Enzymes ◽  
Storage Temperatures

Alstroemeria flowers have shown great importance in the world trade of cut flowers due mainly to its beauty and wide variety of colors. However, the durability of its inflorescences is usually hampered by the rapid yellowing of the leaves, which impairs their decorative quality. Cut flowers require the use of technologies to improve postharvest quality and floral longevity. This research aimed to study the postharvest conservation of inflorescences of Alstroemeria cv. Ajax at different storage temperatures. Floral stems were placed in containers with distilled water and stored at four temperatures (4, 8, 12, and 22ºC) for 12 days. The following analyses were performed: fresh mass variation, respiratory activity, relative water content, soluble and reducing carbohydrate contents, polyphenol-oxidase and peroxidase enzymes, pigments (anthocyanin and carotenoids), and longevity. The experiment was conducted in a completely randomized design, the results were submitted to analysis of variance (ANOVA), and the effect of treatments submitted to F-test. Significant differences were compared using the least significant difference (LSD) at 95% confidence interval (p ≤ 0. 05). The temperatures of 8 and 12ºC were effective in maintaining the postharvest quality of inflorescences during storage period, as they remained turgid due to transpiration reduction caused by low temperatures, and longevity reaching 46 and 22 days, respectively.

Cryogenic Gas for Rapid Cooling of Commercially Processed Shell Eggs Before Packaging

1995 ◽  
Vol 58 (4) ◽  
pp. 389-394 ◽  
Author(s):  
PATRICIA A. CURTIS ◽  
KENNETH E. ANDERSON ◽  
FRANK T. JONES
Keyword(s):  
Salmonella Enteritidis ◽  
Egg Quality ◽  
Storage Period ◽  
Cryogenic Cooling ◽  
Commercial Application ◽  
Rapid Cooling ◽  
Shell Eggs ◽  
Significant Difference ◽  
Haugh Unit ◽  
Cryogenic Gases

Research was initiated to evaluate the effects on egg quality and microbial counts of rapidly cooling eggs by using cryogenic gases. Four trials were conducted utilizing a 2 × 2 factorial design with cryogenic cooling and Pseudomonas inoculation as the main variables. The 1440 eggs used in each trial were evaluated for cracked shells, Haugh units, and albumen pH. Cryogenically cooled treatment groups were successfully cooled from 37°C to 7°C in significantly less time than in a traditionally cooled pallet. The Haugh unit values obtained from traditionally cooled eggs were significantly (P > .001) lower than those from cryogenically cooled eggs. There was no significant difference in the albumen pH of the two groups. Internal and external bacterial counts revealed significantly fewer bacteria in the interior of cryogenically cooled eggs than in the interior of traditionally cooled eggs. However, after a 30-day storage period at 7°C, no difference was found in external and internal bacterial contamination rates. The results of this trial suggest that rapid cooling with cryogenic gases could be used in conjunction with current commercial egg processing to cool eggs prior to packaging. The successful commercial application of this procedure would reduce egg temperatures as well as the likelihood of Salmonella enteritidis growth in or on eggs. Thus, consumers would be provided with safer commercially processed shell eggs. In addition, the Haugh unit data indicate that rapid cooling with cryogenic gases enhances the quality of commercially processed shell eggs.

scholarly journals Kek ve Pilice İnoküle Edilen Salmonella Enteritidis’in Termal İnaktivasyonu

2018 ◽  
Vol 6 (4) ◽  
pp. 401
Author(s):  
Ceyda Dadalı ◽  
Duygu Kışla
Keyword(s):  
Heat Treatment ◽  
Thermal Treatment ◽  
Salmonella Enteritidis ◽  
Thermal Inactivation ◽  
Storage Period ◽  
Sensory Properties ◽  
Point Location ◽  
Heat Treated ◽  
Cold Point ◽  
Storage Temperatures

In this study, thermal inactivation of Salmonella Enteritidis inoculated to the cake dough and a whole raw chicken was investigated. The cake dough was inoculated with 6.15 log-cfu/g S. Enteritidis then, thermal treatment was applied at 160°C top-bottom fan cooking mode. The initial count of S. Enteritidis showed reductions 1.49 log-cfu/g, 2.06 log-cfu/g and 4.29 log-cfu/g in the samples from the cold point location from the geometric center of the cake at 5, 7 and 10 minutes of thermal treatment, respectively. Although S. Enteritidis is not detected at the end of 15 minutes of heat treatment, the center of the cake temperature has reached 85.69°C and the cake sample is uncooked and its sensory properties are not acceptable. The cake that is safe and favorable with the sensory properties to the consumers was obtained by heat treatment for 30 minutes. After the cold point of a whole raw chicken was inoculated with 7.29 log-cfu/g S. Enteritidis, thermal treatment was applied at 220°C top-bottom fan cooking mode. The temperature at the cold point of 35 and 45 minutes heat-treated chickens reached 59.33 and 74.08°C, respectively, and 1.93 log-cfu/g and 5.33 log-cfu /g S. Enteritidis reduction caused in the samples respectively. S. Enteritidis cells were not detected in the whole chicken heat treated at 220°C for 60 minutes. The cakes, heat treated at 160°C top-bottom fan cooking mode for 30 minutes, were stored at two different storage temperatures as 4°C and 25°C for 72 hours. The whole chicken, heat treated at 220°C top-bottom fan cooking mode for 60 minutes, was stored at 4°C for 72 hours. S. Enteritidis cells were not detected in the cake and the whole chicken samples after the storage period.

Thermal Resistance of Foodborne Pathogens and Enterococcus faecium NRRL B-2354 on Inoculated Pistachios

2020 ◽  
Vol 83 (7) ◽  
pp. 1125-1136
Author(s):  
MAHTA MOUSSAVI ◽  
JOHN C. FRELKA ◽  
IAN M. HILDEBRANDT ◽  
BRADLEY P. MARKS ◽  
LINDA J. HARRIS
Keyword(s):  
Foodborne Pathogens ◽  
Enterococcus Faecium ◽  
Thermal Tolerance ◽  
Salmonella Enteritidis ◽  
Phage Type ◽  
Weibull Model ◽  
Pilot Scale ◽  
Hot Water ◽  
Log Reduction ◽  
Significant Difference

ABSTRACT Process control validations require knowledge of the resistance of the pathogen(s) of concern to the target treatment and, in some cases, the relative resistance of surrogate organisms. Selected strains of Escherichia coli O157:H7 (five strains), Listeria monocytogenes (five strains), and Salmonella enterica (five strains) as well as Salmonella Enteritidis phage type (PT) 30 and nonpathogenic Enterococcus faecium NRRL B-2354 were inoculated separately (as individual strains) onto inshell pistachios. The thermal tolerance of each strain was compared via treatment of inoculated pistachios to hot oil (121°C) or hot water (80°C) for 1 min. Survivor curves in hot oil or hot water (0.5 to 6 min, n = 6 to 15) were determined for one or two of the most resistant strains of each pathogen, as well as E. faecium NRRL B-2354 and Salmonella Enteritidis PT 30, and the Weibull model was fit to the data. A pilot-scale air-impingement oven was used to compare the thermal tolerance of E. faecium NRRL B-2354 and Salmonella Enteritidis PT 30 on pistachios with or without a brining pretreatment and at either dry (no steam) or 30% humidity (v/v) oven conditions. No significant difference in the time to a 4-log reduction in hot oil or hot water was predicted for any of the strains evaluated, on the basis of the 95% confidence interval. In the pilot-scale oven, E. faecium NRRL B-2354 was more thermally resistant than Salmonella in a broad set of differing treatments, treatment times, and temperatures. Salmonella is a suitable target pathogen of concern in pistachios for thermal processes because no other pathogen tested was more thermally resistant under the conditions evaluated. E. faecium NRRL B-2354 was at least as thermally resistant as Salmonella under all conditions evaluated, making it a good potential surrogate for Salmonella on pistachios. HIGHLIGHTS

Effect of Food Structure, Water Activity, and Long-Term Storage on X-Ray Irradiation for Inactivating Salmonella Enteritidis PT30 in Low-Moisture Foods

2019 ◽  
Vol 82 (8) ◽  
pp. 1405-1411
Author(s):  
PHILIP J. STEINBRUNNER ◽  
PICHAMON LIMCHAROENCHAT ◽  
QUINCY J. SUEHR ◽  
ELLIOT T. RYSER ◽  
BRADLEY P. MARKS ◽  
...  
Keyword(s):  
Water Activity ◽  
Salmonella Enteritidis ◽  
Raw Materials ◽  
Storage Period ◽  
Mitigation Strategies ◽  
Fruit Storage ◽  
X Ray ◽  
Log Reduction ◽  
Low Moisture Foods ◽  
And Storage

ABSTRACT Recent outbreaks and recalls of low-moisture foods contaminated with Salmonella have been recognized as a major public health risk that demands the development of new Salmonella mitigation strategies and technologies. This study aimed to assess the efficacy of X-ray irradiation for inactivating Salmonella on or in almonds (kernels, meal, butter), dates (whole fruit, paste), and wheat (kernels, flour) at various water activities (aw) and storage periods. The raw materials were inoculated with Salmonella Enteritidis PT30, conditioned to 0.25, 0.45, and 0.65 aw in a humidity-controlled chamber, processed to various fabricated products, and reconditioned to the desired aw before treatment. In a storage study, inoculated almond kernels were stored in sealed tin cans for 7, 15, 27, and 103 weeks, irradiated with X ray (0.5 to 11 kGy, targeting up to a ∼2.5-log reduction) at the end of each storage period, and plated for Salmonella survivors to determine the efficacy of irradiation in terms of D10-value (dose required to reduce 90% of the population). Salmonella was least resistant (D10-value = 0.378 kGy) on the surface of almond kernels at 0.25 aw and most resistant (D10-value = 2.34 kGy) on the surface of dates at 0.45 aw. The Salmonella D10-value was 61% lower in date paste than on whole date fruit. Storage of almonds generally had no effect on the irradiation resistance of Salmonella over 103 weeks. Overall, these results indicate that product structure (whole, meals, powder, or paste), water activity (0.25 to 0.65 aw), and storage period (0 to 103 weeks) should be considered when determining the efficacy of X-ray irradiation for inactivating Salmonella in various low-water-activity foods.

scholarly journals Physicochemical Properties of Flaxseed Fortified Extruded Bean Snack

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Naveen Vadukapuram ◽  
Clifford Hall ◽  
Mehmet Tulbek ◽  
Mary Niehaus
Keyword(s):  
Bulk Density ◽  
Water Activity ◽  
Storage Period ◽  
Expansion Ratio ◽  
Scanning Electron Micrographs ◽  
Omega 3 ◽  
Peroxide Values ◽  
Significant Difference ◽  
Twin Screw ◽  
Milled Flaxseed

Milled flaxseed was incorporated (0–20%) into a combination of bean-corn flours and extruded in a twin screw extruder using corn curl method. Physicochemical parameters such as water activity, color, expansion ratio, bulk density, lipid content, and peroxide values of extruded snack were analyzed. Scanning electron micrographs were taken. Peroxide values and propanal contents were measured over four months of storage. Rancidity scores of extruded snack were measured using a trained panel. As expected, omega-3 fatty acids and bulk density increased with increasing flaxseed fortification levels. Extrudates with more flaxseed had decreased lightness values and expansion ratios. However, only the 15 and 20% flaxseed containing extrudates had expansion ratios that were significantly(P≤0.05)different from the control. In general, no significant difference(P>0.05)in water activity values was observed in the flaxseed fortified extrudates, except in the navy-corn based extrudates. Peroxide values increased with increased flaxseed levels and over a storage period. However, propanal values did not change significantly in the 5–10% flaxseed fortified extrudates but increased in extrudates with higher levels of flaxseed. Rancidity scores were correlated with peroxide values and did not increase significantly during storage under nitrogen flushed conditions.

scholarly journals The Effect of Post-Harvest Storage on the Physicochemical Properties and Phytochemical Content of Queen Garnet Plum

Proceedings ◽  
2020 ◽  
Vol 36 (1) ◽  
pp. 99
Author(s):  
Gethmini Kodagoda ◽  
Michael E. Netzel ◽  
Yasmina Sultanbawa ◽  
Tim O’Hare ◽  
Hung T. Hong
Keyword(s):  
Storage Temperature ◽  
Total Phenolics ◽  
Storage Period ◽  
Titratable Acidity ◽  
Soluble Solids ◽  
Physiochemical Properties ◽  
Phytochemical Content ◽  
Prunus Salicina ◽  
Significant Difference ◽  
Storage Temperatures

The Queen Garnet Plum (QGP), a cultivar of Japanese plum (Prunus salicina Lindl.), was developed as a high anthocyanin plum in a Queensland Government breeding programme. Anthocyanins have been associated with various health attributes, including diabetes control, cardiovascular disease prevention and anti-inflammatory activity. This study was aimed at identifying the changes in physiochemical properties and important phytochemicals of QGP when stored under two storage temperatures. QGP from two growers were stored at 4 and 23 oC for 0, 4, 7, 10 and 14 days. At the end of each storage period the peel, outer flesh (up to 7 mm from the peel) and inner flesh were separated and analysed for chroma, total soluble solids (TSS) and titratable acidity (TA). The grower source had a significant effect on the measured parameters when considered as a covariate. Chroma values of the peel, inner and outer flesh were significantly (P < 0.05) different at 4 and 23 oC, after 14 days. There was no significant difference in the inner flesh TSS (IF-TSS) and outer flesh TSS (OF-TSS) between the different storage temperatures, but compared to day 0, after 14 days IF-TSS and OF-TSS were significantly (P < 0.05) lower. TA of the inner and outer flesh were significantly (P < 0.05) different at the two storage temperatures, but only the inner flesh TA was significantly (P < 0.05) different after 14 days. Further analysis is in progress for anthocyanins, total phenolics, carotenoids, folates and vitamin C. The current study indicates that QGP is climacteric and grower source, storage temperature and time as well as tissue can significantly affect the studied physicochemical parameters.

scholarly journals Penurunan mutu dan pendugaan umur simpan sup krim instan labu kuning diperkaya tempe untuk lansia dengan metode accelerated shelf life testing (ASLT)

2020 ◽  
Vol 8 (2) ◽  
pp. 134-142
Author(s):  
Salma Shafrina Aulia ◽  
Budi Setiawan ◽  
Tiurma Sinaga ◽  
Ahmad Sulaeman
Keyword(s):  
Lipid Oxidation ◽  
Shelf Life ◽  
Water Content ◽  
Water Activity ◽  
Critical Parameter ◽  
Storage Period ◽  
Life Testing ◽  
Quality Of Water ◽  
Long Time

Background: Instant pumpkin cream soup enriched with tempeh had fulfilled 10% Recommended Dietary Allowances (RDA) for elderly so that it can be used as an easy-to-serve snack, but decreasing quality of instant cream soup will be happened if the instant cream soup was stored for a long time. Objectives: This study aimed to analyze quality of water content, water activity and lipid oxidation in instant pumpkin cream soup during storage and estimated the shelf life of pumpkin cream soup enriched with tempeh.Method:  Quality storage was analyzed using of water content, water activity (aw) and lipid oxidation. Estimation of shelf life was analyzed using Arrhenius Accelerated Shelf Life Testing (ASLT) model.Results: The results showed that the water content, aw levels and lipid oxidation of instant pumpkin cream soup increased during the storage period. The critical parameter used in this study was lipid oxidation. Instant cream soup without the addition of tempeh can last 447 days  while the cream soup with the addition of tempeh has a shelf life of 433 days.Conclusion: Quality of instant pumpkin cream soup decreased during the storage period and it would be expired over a year.

scholarly journals Determinants of mRNA stability in Dictyostelium discoideum amoebae: differences in poly(A) tail length, ribosome loading, and mRNA size cannot account for the heterogeneity of mRNA decay rates.

1988 ◽  
Vol 8 (5) ◽  
pp. 1957-1969 ◽  
Author(s):  
R A Shapiro ◽  
D Herrick ◽  
R E Manrow ◽  
D Blinder ◽  
A Jacobson
Keyword(s):  
Steady State ◽  
Dictyostelium Discoideum ◽  
Mrna Decay ◽  
Decay Rates ◽  
Time Dependent ◽  
Translational Efficiency ◽  
Cdna Clones ◽  
Dependent Manner ◽  
Significant Difference ◽  
Kinetics Of

As an approach to understanding the structures and mechanisms which determine mRNA decay rates, we have cloned and begun to characterize cDNAs which encode mRNAs representative of the stability extremes in the poly(A)+ RNA population of Dictyostelium discoideum amoebae. The cDNA clones were identified in a screening procedure which was based on the occurrence of poly(A) shortening during mRNA aging. mRNA half-lives were determined by hybridization of poly(A)+ RNA, isolated from cells labeled in a 32PO4 pulse-chase, to dots of excess cloned DNA. Individual mRNAs decayed with unique first-order decay rates ranging from 0.9 to 9.6 h, indicating that the complex decay kinetics of total poly(A)+ RNA in D. discoideum amoebae reflect the sum of the decay rates of individual mRNAs. Using specific probes derived from these cDNA clones, we have compared the sizes, extents of ribosome loading, and poly(A) tail lengths of stable, moderately stable, and unstable mRNAs. We found (i) no correlation between mRNA size and decay rate; (ii) no significant difference in the number of ribosomes per unit length of stable versus unstable mRNAs, and (iii) a general inverse relationship between mRNA decay rates and poly(A) tail lengths. Collectively, these observations indicate that mRNA decay in D. discoideum amoebae cannot be explained in terms of random nucleolytic events. The possibility that specific 3'-structural determinants can confer mRNA instability is suggested by a comparison of the labeling and turnover kinetics of different actin mRNAs. A correlation was observed between the steady-state percentage of a given mRNA found in polysomes and its degree of instability; i.e., unstable mRNAs were more efficiently recruited into polysomes than stable mRNAs. Since stable mRNAs are, on average, "older" than unstable mRNAs, this correlation may reflect a translational role for mRNA modifications that change in a time-dependent manner. Our previous studies have demonstrated both a time-dependent shortening and a possible translational role for the 3' poly(A) tracts of mRNA. We suggest, therefore, that the observed differences in the translational efficiency of stable and unstable mRNAs may, in part, be attributable to differences in steady-state poly(A) tail lengths.

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