Comparison of Sample Preparation Methods for Recovering Salmonella from Raw Fruits, Vegetables, and Herbs

2001 ◽  
Vol 64 (10) ◽  
pp. 1459-1465 ◽  
Author(s):  
ANDREA B. BURNETT ◽  
LARRY R. BEUCHAT
Keyword(s):  
Sample Preparation ◽  
Pathogenic Bacteria ◽  
Preparation Method ◽  
Morphological Characteristics ◽  
Processing Method ◽  
Sample Processing ◽  
Processing Methods ◽  
Preparation Methods ◽  
Wide Range ◽  
The Mean

Methods for preparing raw fruits, vegetables, and herbs for enrichment or direct plating to determine the presence and populations of pathogenic bacteria vary greatly. A study was done to compare three sample processing methods (washing in 0.1% peptone, stomaching, and homogenizing) for their influence on recovery of Salmonella inoculated onto 26 types of raw produce. The mean numbers of Salmonella recovered from 10 fruits, 11 vegetables, and 5 herbs using all three processing methods were 7.17, 7.40, and 7.27 log10 CFU/sample, respectively. Considering all 26 types of produce and all processing methods, the number of Salmonella recovered ranged from 7.24 to 7.29 log10 CFU/sample, with no significant differences attributable to a particular sample processing method. Mean percent recoveries of Salmonella from washed, stomached, and homogenized produce were 39.4, 44.7, and 42.4%, respectively. Mean percent recoveries from fruits, vegetables, and herbs, regardless of sample preparation method, were 41.7, 50.1, and 25.9%, respectively. The number of Salmonella recovered from stomached and homogenized produce, but not washed produce, with pH ≤ 4.53 was significantly less than the number recovered from produce with pH from 5.53 to 5.99, suggesting that the acidic environment in stomachates and homogenates was lethal to a portion of Salmonella. Reduced percent recoveries from herbs (pH 5.94 to 6.34) is attributed, in part, to antimicrobials released from plant cells during sample preparation. Overall, the type of processing method did not substantially affect the number of Salmonella recovered from the 26 types of raw produce representing a wide range of structural and morphological characteristics, composition, and pH. The influence of sample size, diluent composition, and processing time on efficiency of recovery of Salmonella and other pathogens needs to be evaluated before a method(s) for processing samples of raw produce can be recommended.

Older adults’ household cooking: card sort analyses

2016 ◽  
Vol 118 (2) ◽  
pp. 480-494 ◽  
Author(s):  
Stephanie M. Bostic ◽  
Carole A. Bisogni ◽  
Jeffery Sobal
Keyword(s):  
Older Adults ◽  
Preparation Method ◽  
Community Dwelling ◽  
Food Preparation ◽  
Preparation Methods ◽  
Content Type ◽  
Novel Approach ◽  
Wide Range ◽  
Cooking Equipment ◽  
The Mean

Purpose – The purpose of this paper is to examine food preparation practices of US older adults by assessing their conceptualization of food preparation methods and their routine use of food preparation methods and kitchen equipment. Design/methodology/approach – In total, 17 community-dwelling older adults used cards with names of food preparation methods and cooking equipment items to do one open sort and three closed sorts about: food preparation method classifications; food preparation method use frequency; kitchen equipment use frequency; and essential vs non-essential kitchen equipment. Descriptive statistics, cluster analysis, and qualitative thematic analysis were performed. Findings – Participants classified food preparation methods using multiple dimensions: ways to alter food, inputs, location, timing, and personal behavior. They used a wide range of food preparation methods and kitchen equipment items in routine cooking. The mean number of the 38 preparation methods sorted as used “often” was 16.5±5.0. In total, 15 of the 17 participants reported using more than 20 of the 40 equipment items “often.” The mean number of equipment items identified as “essential” was 21.5±9.3. Practical implications – Food professionals should consider access to equipment and food preparation skills and preferences when designing products and working with consumers. Addressing gaps in human and material capital may support adoption of food preparation practices. Originality/value – Food preparation method and equipment use frequency has rarely been examined from the household cook’s perspective. Using card sorts is a novel approach to examining consumer classification of an extensive list of preparation methods and kitchen equipment.

scholarly journals Application of the Dehydration Homogeneous Liquid–Liquid Extraction (DHLLE) Sample Preparation Method for Fingerprinting of Honey Volatiles

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2277
Author(s):  
Piotr M. Kuś ◽  
Igor Jerković
Keyword(s):  
Carboxylic Acid ◽  
Sample Preparation ◽  
Preparation Method ◽  
Liquid Extraction ◽  
Sample Preparation Method ◽  
Phenyllactic Acid ◽  
Homogeneous Liquid ◽  
Liquid Liquid Extraction ◽  
Wide Range ◽  
Chemical Groups

Recently, we proposed a new sample preparation method involving reduced solvent and sample usage, based on dehydration homogeneous liquid–liquid extraction (DHLLE) for the screening of volatiles and semi-volatiles from honey. In the present research, the method was applied to a wide range of honeys (21 different representative unifloral samples) to determine its suitability for detecting characteristic honey compounds from different chemical classes. GC-FID/MS disclosed 130 compounds from different structural and chemical groups. The DHLLE method allowed the extraction and identification of a wide range of previously reported specific and nonspecific marker compounds belonging to different chemical groups (including monoterpenes, norisoprenoids, benzene derivatives, or nitrogen compounds). For example, DHLLE allowed the detection of cornflower honey chemical markers: 3-oxo-retro-α-ionols, 3,4-dihydro-3-oxoedulan, phenyllactic acid; coffee honey markers: theobromine and caffeine; linden honey markers: 4-isopropenylcyclohexa-1,3-diene-1-carboxylic acid and 4-(2-hydroxy-2-propanyl)cyclohexa-1,3-diene-1-carboxylic acid, as well as furan derivatives from buckwheat honey. The obtained results were comparable with the previously reported data on markers of various honey varieties. Considering the application of much lower volumes of very common reagents, DHLLE may provide economical and ecological advantages as an alternative sample preparation method for routine purposes.

Development of a C12Im-Cl-assisted method for rapid sample preparation in proteomic application

2021 ◽  
Author(s):  
Chang Liu ◽  
Xiaoxia Si ◽  
Shumei Yan ◽  
Xinyuan Zhao ◽  
Xiaohong Qian ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Sample Preparation ◽  
Protein Extraction ◽  
Sample Processing ◽  
Processing Methods ◽  
Proteomic Analyses

Chromatography and mass spectrometry (MS) techniques have greatly improved the power of proteomic analyses. However, sample processing methods, including protein extraction and digestion, before MS remain as bottlenecks in the...

Effect of Preparation Method and Storage on Rifampin Concentration in Suspensions

1994 ◽  
Vol 28 (2) ◽  
pp. 182-185 ◽  
Author(s):  
Milap C. Nahata ◽  
Richard S. Morosco ◽  
Thomas F. Hipple
Keyword(s):  
Storage Time ◽  
Solution Method ◽  
Preparation Method ◽  
Hplc Method ◽  
Measured Concentration ◽  
Preparation Methods ◽  
Initial Concentration ◽  
Stability Indicating ◽  
The Mean ◽  
And Storage

OBJECTIVE: To determine the effect of four preparation methods and extended storage on rifampin concentration in extemporaneously prepared suspensions. DESIGN: Four preparation methods were used: mixing intravenous (iv) rifampin in syrup (A); manufacturer's recommended technique of mixing capsule (Rifadin) contents in syrup (B); triturating capsule contents in syrup into a paste and adding remaining syrup while mixing (C); and triturating capsule contents in syrup into a paste, adding syrup, retriturating the slurry, and adding remaining syrup while mixing (D). Samples were drawn from each of five bottles of each of the four preparations stored at 4 °C, immediately after mixing (day 0), and on days 7, 14, 28, 42, 56, 70, and 91 days during storage. Rifampin wes measured by a stability-indicating HPLC method. RESULTS: The measured mean concentrations of rifampin were nearly 100 percent of the initial concentration in the suspension prepared from iv rifampin solution (method A) during the first 56 days of storage. In contrast, the measured concentrations were substantially lower than expected in the suspensions prepared by methods B, C, and D. The mean rifampin concentrations in suspensions prepared by methods B, C, and D were only 14.5, 38.6, and 68 percent, respectively, of the initial concentration achieved by method A. The rifampin concentrations increased with storage time in suspensions prepared by methods B, C, and D. The mean rifampin concentration was lower than 90 percent during the first 14 days with methods B and C, and the first 7 days with method D. The highest mean concentrations were observed on day 42 with method B, and on day 28 with methods C and D. All methods yielded 90% of the labeled potency (10 mg/mL) on day 56. CONCLUSIONS: Our results showed that preparation method can influence the dispersion, and thus the measured concentration, of rifampin in aliquots of suspensions prepared from capsules and stored in plastic bottles. Suspensions prepared from capsules led to lower-than-expected rifampin concentrations; those prepared from iv rifampin did not. Rifampin was stable in each type of suspension for 56 days at 4 °C.

Analysis of the sample preparation methods based on piecewise variation coefficients of component mass fractions

2021 ◽  
pp. 15-19
Author(s):  
V. Z. Kozin ◽  
A. S. Komlev ◽  
E. V. Stupakova
Keyword(s):  
Sample Preparation ◽  
Relative Error ◽  
Preparation Method ◽  
Sampling Error ◽  
Theoretical Description ◽  
Random Errors ◽  
Copper Ore ◽  
Preparation Methods ◽  
Mass Fractions ◽  
Sample Preparation Methods

Sample preparation methods are usually developed following respective recommendations of the applicable sampling standards. Modern sampling theories allow designing and optimizing these methods. Random errors in sample preparation are calculated based on a theoretical description of the piecewise heterogeneity of the sample obtained using the formulas for the fundamental sampling error. The concept of a piecewise coefficient of variation is introduced and used to develop a formula for the relative error of the sample preparation method. Using a method compiled in accordance with GOST 14180-80 for copper ore as an example, the relative error is established for the preparation of an ore sample with the copper mass fraction of 1.3 %. It is shown that a change in the final preparation size from 0.1 to 0.08 mm affects the error only insignificantly, and sample size changes by stages allow designing a preparation method with the smallest error. It is advisable to analyze the method compiled and change its parameters on the basis of a structural assessment of the influence of individual preparation stages on the error. Sample preparation examples for copper and gold-bearing ore are used to demonstrate the analysis procedure and the parameter changes. Traditionally, the minimum sample masses are established for all stages based on the volumetric heterogeneity of the sample being tested and the size of the sample material. The minimum masses should be found depending on the grain size of the valuable mineral in the ore, the permissible relative error for the size reduction, and the material size for the sample reduced by a factor of 1.5 for nonferrous metal ores.

Study on Sample Preparation Method of DEM

2013 ◽  
Vol 671-674 ◽  
pp. 333-336
Author(s):  
Yang Liu ◽  
Xian De Zhu ◽  
Chen Ye Wan
Keyword(s):  
Sample Preparation ◽  
Discrete Element Method ◽  
Preparation Method ◽  
Descent Method ◽  
Mechanical Parameters ◽  
Sample Preparation Method ◽  
Preparation Methods ◽  
Dem Model ◽  
Compaction Method ◽  
Sample Preparation Methods

Three numerical sample preparation methods, namely, radius expand method, hierarchical compaction method and gravity descent method, were studied using discrete element method (DEM) to simulate the actual sample. The processes of these three methods were described in details and the differences of these three methods were discussed. The impacts of mechanical parameters in DEM model on the numerical results were analyzed.

scholarly journals Sample preparation method to improve the efficiency of high-throughput single-molecule force spectroscopy

2019 ◽  
Vol 5 (4) ◽  
pp. 176-183 ◽  
Author(s):  
Lei Jin ◽  
Li Kou ◽  
Yanan Zeng ◽  
Chunguang Hu ◽  
Xiaodong Hu
Keyword(s):  
Sample Preparation ◽  
High Throughput ◽  
Single Molecule ◽  
Preparation Method ◽  
Force Spectroscopy ◽  
Experimental Result ◽  
Sample Preparation Method ◽  
Dna Stretching ◽  
Single Molecule Force Spectroscopy ◽  
Preparation Methods

Abstract Inefficient sample preparation methods hinder the performance of high-throughput single-molecule force spectroscopy (H-SMFS) for viscous damping among reactants and unstable linkage. Here, we demonstrated a sample preparation method for H-SMFS systems to achieve a higher ratio of effective target molecules per sample cell by gas-phase silanization and reactant hydrophobization. Digital holographic centrifugal force microscopy (DH-CFM) was used to verify its performance. The experimental result indicated that the DNA stretching success ratio was improved from 0.89% to 13.5%. This enhanced efficiency preparation method has potential application for force-based DNA stretching experiments and other modifying procedures.

JCPDS — International Centre for Diffraction Data Sample Preparation Methods in X-Ray Powder Diffraction

1986 ◽  
Vol 1 (2) ◽  
pp. 51-63 ◽  
Author(s):  
R. Jenkins ◽  
T. G. Fawcett ◽  
D. K. Smith ◽  
J. W. Visser ◽  
M. C. Morris ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Preparation Method ◽  
Correct Choice ◽  
Stress And Strain ◽  
Diffraction Experiment ◽  
Preparation Methods ◽  
X Ray ◽  
Accuracy And Precision ◽  
Diffraction Angle ◽  
The Ideal

The aim of any diffraction experiment is to obtain reproducible data of high accuracy and precision so that the data can be correctly interpreted and analyzed. Various methods of sample preparation have been devised so that reproducibility, precision and accuracy can be obtained. The success of a diffraction experiment will often depend on the correct choice of preparation method for the sample being analyzed and for the instrument being used in the analysis.A diffraction pattern contains three types of useful information: the positions of the diffraction maxima, the peak intensities, and the intensity distribution as a function of diffraction angle. This information can be used to identify and quantify the contents of the sample, as well as to calculate the material's crystallite size and distribution, crystallinity, and stress and strain. The ideal preparation for a given experiment depends largely on information desired.

scholarly journals Sample Preparation Methods for Lipidomics Approaches Used in Studies of Obesity

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5307
Author(s):  
Ivan Liakh ◽  
Tomasz Sledzinski ◽  
Lukasz Kaska ◽  
Paulina Mozolewska ◽  
Adriana Mika
Keyword(s):  
Sample Preparation ◽  
Metabolic Pathways ◽  
Chemical Structure ◽  
Analytical Procedure ◽  
Preparation Methods ◽  
Wide Range ◽  
Obese Subjects ◽  
Composition Properties ◽  
Important Branch ◽  
Sample Preparation Methods

Obesity is associated with alterations in the composition and amounts of lipids. Lipids have over 1.7 million representatives. Most lipid groups differ in composition, properties and chemical structure. These small molecules control various metabolic pathways, determine the metabolism of other compounds and are substrates for the syntheses of different derivatives. Recently, lipidomics has become an important branch of medical/clinical sciences similar to proteomics and genomics. Due to the much higher lipid accumulation in obese patients and many alterations in the compositions of various groups of lipids, the methods used for sample preparations for lipidomic studies of samples from obese subjects sometimes have to be modified. Appropriate sample preparation methods allow for the identification of a wide range of analytes by advanced analytical methods, including mass spectrometry. This is especially the case in studies with obese subjects, as the amounts of some lipids are much higher, others are present in trace amounts, and obese subjects have some specific alterations of the lipid profile. As a result, it is best to use a method previously tested on samples from obese subjects. However, most of these methods can be also used in healthy, nonobese subjects or patients with other dyslipidemias. This review is an overview of sample preparation methods for analysis as one of the major critical steps in the overall analytical procedure.

Detection and Analysis of Subsurface Cracks of Single Crystal SiC Wafers Based on Cross-Sectional Microscopy Method

2014 ◽  
Vol 1027 ◽  
pp. 240-245
Author(s):  
Qiu Sheng Yan ◽  
Sen Kai Chen ◽  
Ji Sheng Pan
Keyword(s):  
Sample Preparation ◽  
Single Crystal ◽  
Crack Detection ◽  
Preparation Method ◽  
Subsurface Crack ◽  
Cross Sectional ◽  
Preparation Methods ◽  
Subsurface Cracks ◽  
Single Crystal Sic ◽  
Sic Wafer

For subsurface crack detection of single crystal SiC wafer, this paper proposed a cross-sectional cleavage detection method and compared with traditional cross-sectional sample preparation method. The characteristics and detection results of two cross-sectional sample preparation methods were compared and the subsurface crack characteristics in SiC wafer grinding were researched. The results show that the configurations and depth of subsurface cracks measured by two cross-sectional sample preparation methods were similar. The cross-sectional cleavage sample preparation method is simpler and more rapid in subsurface crack detection. The subsurface crack system of single crystal SiC wafer grinding mainly includes lateral crack and median crack.

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