scholarly journals Why Does Cronobacter sakazakii Survive for a Long Time in Dry Environments? Contribution of the Glass Transition of Dried Bacterial Cells

2021 ◽  
Author(s):  
Kyeongmin Lee ◽  
Kento Koyama ◽  
Kiyoshi Kawai ◽  
Shigenobu Koseki
Keyword(s):  
Glass Transition ◽  
Food Processing ◽  
Drying Methods ◽  
Bacterial Cells ◽  
Cronobacter Sakazakii ◽  
Drying Method ◽  
Content Type ◽  
Long Time ◽  
Operational Factor ◽  
Dry Food

The mechanical glass transition temperature ( T g ) of dried Cronobacter sakazakii cells varied depending on differences in drying methods and water activity (a w ) levels. Because the T g of the dried bacterial cells varied depending on the drying method and a w , the T g will play an important role as an operational factor in the optimization of dry food processing for controlling microbial contamination in the future.

COMPARISON OF METHODS DRYING AND VARIETY FISH OF TESTING APPEARANCE ON DRIEDFISH TYPICAL ACEH (KEUMAMAH)

2014 ◽  
Vol 4 (1) ◽  
pp. 40-47
Author(s):  
Ismail Sulaiman
Keyword(s):  
Food Processing ◽  
Traditional Food ◽  
Drying Method ◽  
Fish Processing ◽  
Fresh Fish ◽  
Long Time ◽  
Dried Fish ◽  
Processing Differences ◽  
Taste And Smell ◽  
Test Color

Fresh fish processing into a dried fish is a fish processing has been done a long time, the processing of fish based traditional food processing becomes important to preserve cultural heritage in fish processing. Differences drying method in the processing can affect the taste and texture of the fish produced timber. Types of tuna used significantly different to the color produced on the dried fish . The water content produced in this study is 15:57 (w/w %), ash content 1 , 58 ( % ), mean organoleptic test (color: 3.3, taste and smell 3:35, aroma : 3:34). Preferred types of fish are tuna and the most preferred method oven method.Keyword : 

scholarly journals Simultaneous Rapid Detection and Serotyping of Cronobacter sakazakii Serotypes O1, O2, and O3 by Using Specific Monoclonal Antibodies

2016 ◽  
Vol 82 (8) ◽  
pp. 2300-2311 ◽  
Author(s):  
Eva J. Scharinger ◽  
Richard Dietrich ◽  
Ina Kleinsteuber ◽  
Erwin Märtlbauer ◽  
Kristina Schauer
Keyword(s):  
Monoclonal Antibodies ◽  
Rapid Detection ◽  
Foodborne Pathogen ◽  
Cross Reactivity ◽  
Antigenic Determinants ◽  
Powdered Infant Formula ◽  
Bacterial Cells ◽  
Cronobacter Sakazakii ◽  
Content Type ◽  
Cell Counts

ABSTRACTCronobacter sakazakiiis a foodborne pathogen associated with rare but often lethal infections in neonates. Powdered infant formula (PIF) represents the most frequent source of infection. Out of the identified serotypes (O1 to O7), O1, O2, and O3 are often isolated from clinical and PIF samples. Serotype-specific monoclonal antibodies (MAbs) suitable for application in enzyme immunoassays (EIAs) for the rapid detection ofC. sakazakiihave not yet been developed. In this study, we created specific MAbs with the ability to bind toC. sakazakiiof serotypes O1, O2, and O3. Characterization by indirect EIAs, immunofluorescence, motility assays, and immunoblotting identified lipopolysaccharide (LPS) and exopolysaccharide (EPS) as the antigenic determinants of the MAbs. The established sandwich EIAs were highly sensitive and were able to detect between 2 × 103and 9 × 106CFU/ml. Inclusivity tests confirmed that 93% of serotype O1 strains, 100% of O2 strains, and 87% of O3 strains were detected at low cell counts. No cross-reactivity with >100 strains ofCronobacterspp. and otherEnterobacteriaceaewas observed, except for that withC. sakazakiiserotype O3 andCronobactermuytjensiiserotype O1. Moreover, the sandwich EIAs detectedC. sakazakiiin PIF samples artificially contaminated with 1 to 10 bacterial cells per 10 g of sample after 15 h of preenrichment. The use of these serotype-specific MAbs not only allows the reliable detection ofC. sakazakiistrains but also enables simultaneous serotyping in a simple sandwich EIA method.

scholarly journals The Influence of Different Drying Methods on Constituents and Antioxidant Activity of Saffron from China

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Yingpeng Tong ◽  
Xingyi Zhu ◽  
Yongqiu Yan ◽  
Ruoxi Liu ◽  
Feng Gong ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Microwave Drying ◽  
Drying Methods ◽  
Drying Method ◽  
Vacuum Oven ◽  
Oven Drying ◽  
Electric Oven ◽  
Long Time ◽  
Spectrum Effect

More and more saffron has been cultivated in China because of the increasing saffron demand, but no paper has studied the influence of drying methods on the quality of Chinese saffron. In this paper, three different dehydration treatments applied in actual production were evaluated: dehydration with electric oven, vacuum oven, and microwave. We determined that the highest quality of saffron will be obtained when fresh saffron is treated at higher temperatures (no more than 70°C) for a long time by electric oven drying and vacuum oven drying. In microwave drying, treatments at lower microwave power and longer time benefit the quality of saffron. In addition, the influence of the drying method on antioxidants in saffron is discussed. The correlation between individual saffron profiles and the antioxidant value was estimated by spectrum-effect relationships analysis.

Effect of different drying methods on quality attributes of beetroot (Beta vulgaris) slices

2018 ◽  
Vol 15 (3) ◽  
pp. 287-298 ◽  
Author(s):  
Manhal Gobara Hamid ◽  
Abdel Azim Ahmed Mohamed Nour
Keyword(s):  
Chemical Composition ◽  
Beta Vulgaris ◽  
Quality Attributes ◽  
Rich Source ◽  
Total Phenolic ◽  
Drying Methods ◽  
Drying Method ◽  
Content Type ◽  
Oven Drying ◽  
Freeze Dried

PurposeThe purpose of this paper is to evaluate the effect of different drying methods on quality attributes of beetroot slices.Design/methodology/approachThree drying methods (sun, oven and freeze-drying) were applied to dry fresh slices of beetroot cultivar (Beta vulgaris). The chemical composition, minerals, nitrate, betalains, total phenolic, total flavonoid and color were measured for fresh and dried slices.FindingsThe chemical composition, minerals, nitrate, bioactive compounds and color were measured for fresh and dried slices. Regardless of the drying method, the results showed that the chemical composition, total energy, minerals and nitrate of the dried slices were significantly (p=0.05) increased compared to that of fresh slices. Sun and oven drying of the slices significantly (p=0.05) reduced total betalain and betacynin. However, betaxanthin was significantly (p=0.05) increased. Total phenolics content of fresh beetroot was significantly (p=0.05) increased after sun and oven drying but total flavonoids were decreased. The 2,2,-diphenyl-2-picryl-hydrazyl (DPPH) of fresh beetroot was increased significantly (p=0.05) after sun and oven drying. The measurement of the color of the powder showed that there is a decrease in lightness (L) depending on the drying method applied. A maximum reduction in lightness was observed in powder of sun-dried slices. The color of the powder obtained from freeze-dried slices was stable compared to other drying methods.Practical implicationsBeetroot is a rich source of nutrients but with short shelf life. Dried beetroot has more keeping quality than the fresh one.Originality/valueThe study uses beetroot as a rich source of nutrients as well as natural antioxidant source. Betalain compounds are preserved in beetroot and a high source of phenolics and flavonoids. Flavonoids are a group of phenolic products of plant metabolism with high antioxidant properties to protect against diseases without side effects.

scholarly journals Regulation of Cell Division in Bacteria by Monitoring Genome Integrity and DNA Replication Status

2019 ◽  
Vol 202 (2) ◽  
Author(s):  
Peter E. Burby ◽  
Lyle A. Simmons
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Division ◽  
Dna Replication ◽  
Cell Cycle Progression ◽  
Genome Instability ◽  
Sos Response ◽  
Bacterial Cells ◽  
Cycle Progression ◽  
Content Type

ABSTRACT All organisms regulate cell cycle progression by coordinating cell division with DNA replication status. In eukaryotes, DNA damage or problems with replication fork progression induce the DNA damage response (DDR), causing cyclin-dependent kinases to remain active, preventing further cell cycle progression until replication and repair are complete. In bacteria, cell division is coordinated with chromosome segregation, preventing cell division ring formation over the nucleoid in a process termed nucleoid occlusion. In addition to nucleoid occlusion, bacteria induce the SOS response after replication forks encounter DNA damage or impediments that slow or block their progression. During SOS induction, Escherichia coli expresses a cytoplasmic protein, SulA, that inhibits cell division by directly binding FtsZ. After the SOS response is turned off, SulA is degraded by Lon protease, allowing for cell division to resume. Recently, it has become clear that SulA is restricted to bacteria closely related to E. coli and that most bacteria enforce the DNA damage checkpoint by expressing a small integral membrane protein. Resumption of cell division is then mediated by membrane-bound proteases that cleave the cell division inhibitor. Further, many bacterial cells have mechanisms to inhibit cell division that are regulated independently from the canonical LexA-mediated SOS response. In this review, we discuss several pathways used by bacteria to prevent cell division from occurring when genome instability is detected or before the chromosome has been fully replicated and segregated.

scholarly journals Evaluation of Innovative Dried Purée from Jerusalem Artichoke—In Vitro Studies of Its Physicochemical and Health-Promoting Properties

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2644
Author(s):  
Jan Oszmiański ◽  
Sabina Lachowicz ◽  
Paulina Nowicka ◽  
Paweł Rubiński ◽  
Tomasz Cebulak
Keyword(s):  
Freeze Drying ◽  
Jerusalem Artichoke ◽  
Polyphenolic Compounds ◽  
Raw Material ◽  
Vacuum Drying ◽  
Drying Methods ◽  
Drying Method ◽  
Activity Inhibition ◽  
Health Promoting

The present study aimed to evaluate the effect of Jerusalem artichoke processing methods and drying methods (freeze drying, sublimation drying, vacuum drying) on the basic physicochemical parameters, profiles and contents of sugars and polyphenolic compounds, and health-promoting properties (antioxidant activity, inhibition of the activities of α-amylase, α-glucosidase, and pancreatic lipase) of the produced purée. A total of 25 polyphenolic compounds belonging to hydroxycinnamic phenolic acids (LC-PDA-MS-QTof) were detected in Jerusalem artichoke purée. Their average content in the raw material was at 820 mg/100 g dm (UPLC-PDA-FL) and was 2.7 times higher than in the cooked material. The chemical composition and the health-promoting value of the purées were affected by the drying method, with the most beneficial values of the evaluated parameters obtained upon freeze drying. Vacuum drying could offer an alternative to freeze drying, as both methods ensured relatively comparable values of the assessed parameters.

scholarly journals Spo0A Suppresses sin Locus Expression in Clostridioides difficile

mSphere ◽  
2020 ◽  
Vol 5 (6) ◽  
Author(s):  
Babita Adhikari Dhungel ◽  
Revathi Govind
Keyword(s):  
Diarrheal Disease ◽  
Toxin Production ◽  
The United States ◽  
Upstream Region ◽  
Pcr Analysis ◽  
Bacterial Cells ◽  
Master Regulator ◽  
Content Type ◽  
Clostridioides Difficile

ABSTRACT Clostridioides difficile is the leading cause of nosocomial infection and is the causative agent of antibiotic-associated diarrhea. The severity of the disease is directly associated with toxin production, and spores are responsible for the transmission and persistence of the organism. Previously, we characterized sin locus regulators SinR and SinR′ (we renamed it SinI), where SinR is the regulator of toxin production and sporulation. The SinI regulator acts as its antagonist. In Bacillus subtilis, Spo0A, the master regulator of sporulation, controls SinR by regulating the expression of its antagonist, sinI. However, the role of Spo0A in the expression of sinR and sinI in C. difficile had not yet been reported. In this study, we tested spo0A mutants in three different C. difficile strains, R20291, UK1, and JIR8094, to understand the role of Spo0A in sin locus expression. Western blot analysis revealed that spo0A mutants had increased SinR levels. Quantitative reverse transcription-PCR (qRT-PCR) analysis of its expression further supported these data. By carrying out genetic and biochemical assays, we show that Spo0A can bind to the upstream region of this locus to regulates its expression. This study provides vital information that Spo0A regulates the sin locus, which controls critical pathogenic traits such as sporulation, toxin production, and motility in C. difficile. IMPORTANCE Clostridioides difficile is the leading cause of antibiotic-associated diarrheal disease in the United States. During infection, C. difficile spores germinate, and the vegetative bacterial cells produce toxins that damage host tissue. In C. difficile, the sin locus is known to regulate both sporulation and toxin production. In this study, we show that Spo0A, the master regulator of sporulation, controls sin locus expression. Results from our study suggest that Spo0A directly regulates the expression of this locus by binding to its upstream DNA region. This observation adds new detail to the gene regulatory network that connects sporulation and toxin production in this pathogen.

scholarly journals Influence of Freezing and Different Drying Methods on Volatile Profiles of Strawberry and Analysis of Volatile Compounds of Strawberry Commercial Jams

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4153
Author(s):  
Doaa Abouelenein ◽  
Ahmed M. Mustafa ◽  
Simone Angeloni ◽  
Germana Borsetta ◽  
Sauro Vittori ◽  
...  
Keyword(s):  
Microwave Drying ◽  
Drying Methods ◽  
Volatile Profile ◽  
Drying Method ◽  
Drying Process ◽  
Total Volatile ◽  
Ethyl Hexanoate ◽  
Complete Destruction ◽  
Freeze Dried ◽  
Volatile Profiles

Strawberry is the most consumed berry fruit worldwide due to its unique aroma and flavor. Drying fruits to produce a powder represents one of the possible conservation methods to extend their shelf-life. The aim of the present study was to compare the influence of freezing and different drying methods on the volatile profile of strawberry using the HS-SPME/GC–MS method, in addition to analysis of strawberry jam volatiles. A total of 165 compounds were identified, accounting for 85.03–96.88% of the total volatile compositions. Results and PCA showed that freezing and each drying process affected the volatile profile in a different way, and the most remarkable representative differential volatiles were ethyl hexanoate, hexyl acetate, (E)-2-hexenyl acetate, mesifurane, (E)-nerolidol, γ-decalactone, 1-hexanol, and acetoin. Shade air-dried, frozen, freeze-dried, and oven-dried 45 °C samples retained more of the fruity and sweet aromas of strawberry, representing more than 68% of the total aroma intensity according to the literature. In contrast, the microwave-drying method showed drastic loss of fruity esters. Strawberry jams demonstrated complete destruction of esters and alcohols in most jams, while terpenes were significantly increased. These findings help better understand the aroma of strawberry and provide a guide for the effects of drying, freezing, and jam processing.

Integrated quality environmental management implementation in food processing SMEs

2019 ◽  
Vol 31 (5) ◽  
pp. 740-757 ◽  
Author(s):  
Syed Ali Raza Shah ◽  
Khairur Rijal Jamaludin ◽  
Hayati Habibah Abdul Talib ◽  
Sha’ri Mohd Yusof
Keyword(s):  
Environmental Management ◽  
Food Processing ◽  
Success Factors ◽  
Process Management ◽  
Empirical Studies ◽  
Sampling Technique ◽  
Developed Countries ◽  
Operational Performance ◽  
Snowball Sampling ◽  
Content Type

Purpose The purpose of this paper is to identify the critical success factors (CSFs) of integrated quality environmental management (IQEM) and analyze their impact on operational performance (OP) and environmental performance (EP) in food processing Small and medium-sized enterprises (SMEs) in Pakistan. Design/methodology/approach The study is based on collecting data using a survey questionnaire through snowball sampling technique. A total of 302 food processing SMEs operating in Punjab, Pakistan, responded to the survey. SPSS version-23 and SmartPLS-3 were used for data analysis. Findings The literature review identified leadership (LS), employee management (EM), strategic planning (SP), information management (IM), process management (PM), supplier management (SM) and customer focus (CF) as CSFs of IQEM. The results of this study found a significant relationship of all identified CSFs with operational performance in food processing SMEs whereas EM, IM, PM and SM were insignificant with the EP in the food processing SMEs. Research limitations/implications Although this study has collected data from one province, the Punjab province, it still relevant in identifying the CSFs for IQEM implementation within food processing SMEs to improve performance. Originality/value Despite the wide spread of integrated systems practices in the developed countries, little attention has been placed to implement and assess the IQEM initiatives by organizations in the developing countries. Thus, this study identified CSFs of IQEM based on empirical studies and analyzed their impact on OP and EP of food processing SMEs.

scholarly journals Influence of Pear Variety and Drying Methods on the Quality of Dried Fruit

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5146
Author(s):  
Agata Marzec ◽  
Hanna Kowalska ◽  
Jolanta Kowalska ◽  
Ewa Domian ◽  
Andrzej Lenart
Keyword(s):  
Principal Component ◽  
Acoustic Method ◽  
Drying Methods ◽  
Drying Method ◽  
Drying Time ◽  
Good Taste ◽  
Dried Fruit ◽  
Breaking Work ◽  
Alexander Lucas

In this study, the impacts of two different pear cultivars, “Conference” and “Alexander Lucas”, on the kinetics and the final quality of samples dried by convection (CD) and microwave-convection (MCD) methods, were investigated. The quality of dried material was evaluated by the analysis of water activity, porosity, color, acoustic emission (AE) and mechanical and sensory properties. The required drying time to obtain 0.2 kg H2O/kg dry solid (d.s.) was longer for “Conference” than “Alexander Lucas” and was 20 min by CD and 5 min by MCD. The pear cultivar, in conjunction with the drying method (CD or MCD), affected the number of AE events and the work of breaking. The CD pear of the “Conference” cultivar was characterized by higher force, higher breaking work and stronger AE relative to the CD pear of the “Alexander Lucas” cultivar. There were no differences in taste or overall quality, but the hardness was higher for the CD “Conference” pear. A principal component analysis showed that panelists preferred dried fruit with good taste and overall quality but lower hardness. A positive correlation was found between the number of acoustic events and sensory hardness; thus, an acoustic method can be useful for effectively evaluating the texture of dried pears. These results show that the dried pear slices that generated fewer AE events upon breaking were perceived as better by the panelists.

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