Food safety knowledge, hygiene practices, and eating attitudes of academics and university students during the coronavirus (COVID-19) pandemic in Turkey

The purpose of this study is to assess the effect of the coronavirus (COVID-19) pandemic on food safety knowledge, hygiene practices, and eating attitudes of academics and university students in Turkey. A cross-sectional survey invitation was emailed to the participants from various academic ranks and departments at chosen universities from different region of country. Academics were requested to forward the invitation email to enrolled students to their classes. Responds were accepted in the period of 45 days in April and May 2020 during this pandemic. The relationships between socio-demographic factors (gender, marital status, parental status, faculty/student status, academic rank, and age) and food safety knowledge, hygiene practices, and eating attitudes of respondents were determined. Academics (n = 240) and university students (n = 479) responded to food safety knowledge statements with similar percentages during the coronavirus pandemic. Improved hygiene practices were observed for both groups to avoid disease during the coronavirus pandemic. Both groups had eating attitudes toward consumption at home due to the coronavirus pandemic. Gender was the most prominent factor associated with 9 out of 10 hygiene practices before and during the coronavirus pandemic (p < .05). No, single, and multiple socio-demographic factors were in association with food safety knowledge or eating attitudes of respondents. This study indicates that reactions of both academics and university students are similar during the coronavirus pandemic for food safety-associated knowledge, practices, and attitudes

Effect of Pulsed Ultraviolet Light on Natural Microbial Load and Antioxidant Properties of Fresh Blueberries

Blueberries have been drawn more attention in recent years for their antioxidant capacities and proposed health benefits. Pulsed ultraviolet (PUV) light is known for its disinfection effects on the surface of fresh fruits. This study’s aim was to examine the effects of PUV light on naturally present microbial load, antioxidant capacity, and antioxidant enzyme activity of fresh blueberries. Fresh blueberry samples were treated for 30, 60, 90, and 120 s. Samples were stabilized at 13 cm away from the PUV lamp before treatment. Total Aerobic Plate Count (TAPC) and yeast and mold count reduction were observed the highest in samples treated for 90 s, 1.97 and 1.27 log CFU/g, respectively. Antioxidant capacity levels were significantly different for treated samples for 60 and 90 s in FRAP analysis, whereas no differences were observed in results of DPPH analysis. Superoxide dismutase (SOD) activity as antioxidant enzyme had no difference, however, glutathione peroxidase (GPx) increased by 50% with PUV treatment for 120 s. PUV light treatment of fresh blueberries for 90 s was determined as ideal exposure time among tested time intervals of this study. PUV light illumination can generally enhance antioxidant capacity and antioxidant enzyme activity of fresh blueberries and decrease the population of natural microorganisms of fresh blueberries and similar small fruits

Comparing regression models with count data to artificial neural network and ensemble models for prediction of generic escherichia coli population in agricultural ponds based on weather station measurements Measurements

Abstract View references (58) Indicator microorganisms are monitored in agricultural waters to foster produce safety. Various prediction models are used to estimate the population of indicator microorganisms and pathogens when no observation is available. The purpose of this study was to compare the performance of regression models with count data (zero-inflated Poisson and hurdle negative binomial) to artificial neural network and ensemble models (random forest and AdaBoost) for the prediction of generic Escherichia coli population in agricultural surface waters in relation with weather station measurements. Two-part count data models were built on E. coli population count frequencies (0, [1,10), [10,100), [100,1000), [1000, 10000), (>=10000)) based on the data structure. The use of artificial neural network, AdaBoost, and random forest were determined based on the mean absolute error (MAE) value over pre-tested six models. The MAE was also used to compare the performance of two-part count data models with artificial neural network and ensemble models. Over-dispersed E. coli population count frequencies was calculated between 2.2 and 52.2% for all ponds. Observed and predicted zero E. coli population counts for all ponds were matched from 82 to 100% for zero-inflated Poisson and 100% for hurdle negative binomial regression models. Overdispersion reduced the performance of tested models. AdaBoost-Twelve Estimators had the best performance with the lowest MAE values for all ponds (from 0.87 to 46.60). The ensemble models used in this study provided more promising performance when compared to tested regression models with count data. © 202

Fate of Salmonella in Central Florida Surface Waters and Evaluation of EPA Worst Case Water as a Standard Medium

PubMed ID: 31081689Salmonella persistence in sterile surface water, nonsterile surface water, or deionized water over 336 days was explored. The suitability of EPA (U.S. Environmental Protection Agency) Worst Case water as a standard medium was also evaluated. Salmonella was enumerated by spread plating or most probable number at set time points after inoculation into water (sterile and nonsterile surface, deionized, and EPAWorst Case waters) and held at 15, 21, or 288C. Total coliforms from nonsterile waters were enumerated by spread plating. Salmonella decreased most rapidly in nonsterile surface water. Addition of cycloheximide to nonsterile surface waters did not increase Salmonella survival compared with the same nonsterile surface water without cycloheximide except for the water held at 158C. Total coliform populations decreased to below the limit of detection at 112 days; Salmonella remained detectable throughout the entire 168-day experiment. Salmonella populations persist at least 336 days in all waters tested; coliforms remained detectable to 112 days. Rates of decline (time required for a 1-log reduction) in nonsterile waters were at least five times shorter than those of other water types. EPAWorst Case water is a suitable standard for surface water microcosms. This study adds to the limited knowledge regarding Salmonella survival in surface waters. It demonstrates the potential long-term survival of Salmonella in fresh water and the importance of biotic factors when designing microcosm-based experiments. © International Association for Food Protection. HIGHLIGHTS • Survival of Salmonella was studied in surface waters. • Salmonella stayed alive in nonsterile microcosms for 168 days. • Limited decline was seen in sterile surface, deionized, and EPA Worst Case water. • EPA Worst Case water offers potential as a standardized medium.Cooperative State Research, Education, and Extension Service: 2008-51180-04846We thank the U.S. Department of Agriculture Cooperative State Research, Education, and Extension Service (Specialty Crops Research Initiative 2008-51180-04846) and the University of Florida Alumni Fellowships Fund for financial support of this project. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the authors and do not necessarily reflect the view of the U.S. Department of Agriculture. We thank Gwen Lundy, Luis Martinez, and Brian Buzzie for technical assistance

Thermal Resistance of Acid Adapted and Non-Adapted Stationary Phase Escherichia coli O157:H7, Salmonella enterica Typhimurium and Listeria monocytogenes in Pomegranate Juice

Bu çalışmada, aside adapte olan ve adapte olmayan durağan faz Escherichia coli O157:H7, Salmonella enterica Typhimurium ve Listeria monocytogenes’in nar suyundaki termal dirençleri incelenmiştir. Ayrıca, jenerik E. coli’nin gösterge mikroorganizma olarak performansı değerlendirilmiştir. Aside adapte olmayan durağan faz hücreler şeker içermeyen tryptic soy broth’da (TSB-NG) 36±1°C’de 18±2 saat inkübe edilerek elde edilmiştir. Asit adaptasyonu için %1 glukoz içeren tryptic soy broth (10 g/l; TSBG) kullanılmıştır. L. monocytogenes için kullanılan besiyerleri %0,6 yeast ekstraktla desteklenlmiştir. Hücreler peptonlu su ile yıkandıktan sonra, 5 ml pastörize nar suyu pellet üzerine eklenerek 107 -109 log CFU/ml konsantrasyonunda inoküle nar suyu elde edilmiştir. İnoküle edilmiş nar suyu, mikrokapilar tüp içine mühürlenmiştir. Mikrotüpler 50, 52 ve 54±1°C’deki önceden belirlenmiş zaman aralıklarında su banyolarına batırılarak ısıl işlem uygulanmıştır. Canlı kalan bakteri popülasyonları tryptic soy agar (TSA) üzerinde sayılmıştır. S. Typhimurium nar suyunda en düşük termal direnci göstermiştir. Düşük sıcaklıklarda E. coli O157:H7 ısıl işleme karşı daha dirençliyken, yüksek sıcaklıklarda L. monocytogenes daha fazla termal tolerans göstermiştir. Asit adaptasyonu, E. coli O157:H7’nin direncini azaltırken, S. Typhimurium’un 50°C’de, L. monocytogenes’in ise bütün sıcaklıklarda termal inaktivasyon süresini artırmıştır. Aside adapte olmayan jenerik E. coli 50 ve 52°C’de, aside adapte L. monocytogenes 54°C’de uygulanan ısıl işleme en dayanıklı olan mikroorganizma olmuştur. Nar suyu için elde edilen termal inaktivasyon süreleri diğer meyve sularına göre daha düşük sıcaklıklarda test edilebilmiştir. Bunun sebebi olarak nar suyunun doğal antimikrobiyal etkisi ve diğer meyve sularına oranla daha asidik olmasından kaynaklandığı düşünülmektedir.The purpose of this study was to investigate the thermal resistance of acid adapted and non-adapted stationary phase Escherichia coli O157:H7, Salmonella enterica Typhimurium and Listeria monocytogenes in pomegranate juice. In addition, the performance of generic E. coli was evaluated as an indicator. Non-adapted stationary phase cells were grown by incubating inoculated tryptic soy broth without glucose (TSB-NG) at 36±1°C for 18±2 hours. Tryptic soy broth with 1% glucose (10 g/l; TSBG) was used for acid adaptation. All media used for L. monocytogenes was supplemented with 0.6% yeast extract. After washing the cells with peptone, 5 ml of pasteurized pomegranate juice was added onto the pellet to obtain inoculated juice with a initial concentration of 107 -1010 log CFU/ml. Inoculated pomegranate juice was sealed into the microcapillary tubes. Microtubes were heat treated in waterbaths at 50, 52 and 54±1°C by immersing at pre-determined time intervals. Survived populations were counted on tryptic soy agar (TSA). S. Typhimurium had the lowest thermal resistance in pomegranate juice. At 50°C, E. coli O157:H7 was the most resistant, whereas L. monocytogenes was more thermally tolerant at 52 and 54°C. Acid adaptation decreased the thermal resistance of E. coli O157:H7, but increased the heat resistance of L. monocytogenes at all tested temperatures significantly. Thermal tolerance of S. Typhimurium increased only at 50°C. The most resistant microorganism was non-adapted generic E. coli at 50 and 52°C; acid-adapted L. monocytogenes had the most thermal tolerance at 54°C. Thermal inactivation of microorganisms in pomegranate juice could be tested at lower temperatures compare to other fruit juices. This may be due to the natural antimicrobial effect and more acidic content of pomegranate juice

Correlation value determined to increase Salmonella prediction success of deep neural network for agricultural waters

The use of computer-based tools has been becoming popular in the field of produce safety. Various algorithms have been applied to predict the population and presence of indicator microorganisms and pathogens in agricultural water sources. The purpose of this study is to improve the Salmonella prediction success of deep feed-forward neural network (DFNN) in agricultural surface waters with a determined correlation value based on selected features. Datasets were collected from six agricultural ponds in Central Florida. The most successful physicochemical and environmental features were selected by the gain ratio for the prediction of generic Escherichia coli population with machine learning algorithms (decision tree, random forest, support vector machine). Salmonella prediction success of DFNN was evaluated with dataset including selected environmental and physicochemical features combined with predicted E. coli populations with and without correlation value. The performance of correlation value was evaluated with all possible mathematical dataset combinations (nCr) of six ponds. The higher accuracy performances (%) were achieved through DFNN analyses with correlation value between 88.89 and 98.41 compared to values with no correlation value from 83.68 to 96.99 for all dataset combinations. The findings emphasize the success of determined correlation value for the prediction of Salmonella presence in agricultural surface waters.Cankiri Karatekin UniversityThis study was supported by Cankiri Karatekin University

ASİDE ADAPTE VE ADAPTE OLMAYAN DURAĞAN FAZ ESCHERICHIA COLI O157:H7, SALMONELLA TYPHIMURIUM VE LISTERIA MONOCYTOGENES’İN NAR SUYUNDAKİ CANLI KALMA SÜRELERİNİN BELİRLENMESİ

The purpose of this study was to evaluate the survival of acid adapted and non-adapted stationary phase Escherichia coli O157:H7, Salmonella Typhimurium and Listeria monocytogenes in pomegranate juice at refrigeration and room temperatures. Inoculated juice samples were stored at 4 and 24 ± 2°C. Population of pathogens were enumerated for up to 28 days. Reduction rates, time required for one log reduction, of tested microorganisms were calculated. Enrichment was negative for E. coli O157:H7 after a week at all tested conditions. At refrigeration temperature, acid adapted S. Typhimurium and L. monocytogenes survived one week longer than non-adapted cells. At room temperature, S. Typhimurium population decreased up to 7 log CFU/ml in 28 days; L. monocytogenes survived less than 12 h. Rates of reduction (days) ranged between 0.06 and 4.29 for all tested pathogens (P<0.05). Tested pathogens can survive in contaminated pomegranate juice until consumption to cause foodborne illness.Bu çalışmanın amacı, aside adapte olan ve adapte olmayan durağan faz Escherichia coli O157:H7, Salmonella Typhimurium ve Listeria monocytogenes'in buzdolabı ve oda sıcaklıklarında canlı kalma sürelerini değerlendirmektir. İnoküle edilmiş meyve suyu örnekleri 4 ve 24 ± 2 ° C'de muhafaza edilmiştir. Patojenlerin popülasyonları 28'inci güne kadar sayılmıştır. Popülasyon indirgeme oranları, bir log indirgeme için gereken süre, test edilen mikroorganizmalar için hesaplanmıştır. Bir hafta sonunda E. coli O157:H7 için zenginleştirme bütün test edilen koşullarda negatif olarak belirlenmiştir. Buzdolabı sıcaklığında, asitle adapte S. Typhimurium ve L. monocytogenes, adapte olmayan hücrelere göre 1 hafta daha uzun süre hayatta kalmıştır. Oda sıcaklığında, S. Typhimurium popülasyonu 28 günde 7 log CFU/ml düşmüştür ama L. monocytogenes sadece 12 saat canlı kalabilmiştir. Popülasyon azalma oran aralıkları (gün) bütün test edilen patojenler için 0.06-4.29 aralığındadır (P<0.05). Test edilen patojenler kontamine olmuş nar suyunda gıda kaynaklı hastalığa neden olacak kadar uzun süre hayatta kalabilir