Effects of Duration of Storage and Storage Temperature on Cell Counts of Bovine Blood Samples as Determined by an Automated Haematology Analyser

2002 ◽  
Vol 11 (4) ◽  
pp. 211-216 ◽  
Author(s):  
U. BLEUL ◽  
U. BLEUL ◽  
A. SOBIRAJ ◽  
H. BOSTEDT
2021 ◽  
Vol 13 (4) ◽  
pp. 54-61
Author(s):  
Di Wang ◽  
Jianchao Deng ◽  
Xupeng Li ◽  
Xianqing Yang ◽  
Shengjun Chen ◽  
...  

Yellowfin tuna is one of the commercially important fish varieties, and inappropriate storing may deteriorate its safety and quality. This study aimed to investigate the microbial composition and quality characteristics of yellowfin tuna stored at different temperatures for varying amounts of time. With an increase in the storage temperature and storage time, the biogenic amines, the total volatile basic nitrogen TVB-N, and the total viable cell count steadily increased, which influenced the quality of tuna. The most significant histamine concerning food safety reached levels of 21.25, 235.05, 1166.18, and 3799.29 mg/kg, respectively. The values of total viable cell counts were increased to 7.04, 7.97, 8.24, and 8.91 log CFU/g after storage at 0, 4, 10, and 20 °C for 12 days, 7 days, 7 days, 3 days, respectively. Additionally, changes in microbial composition were evaluated by high-throughput sequencing, and the results showed that Pseudomonas was the dominant spoilage bacteria in yellowfin tuna. The bacterial dynamics and their correlation with biogenic amines and TVB-N in yellowfin tuna were analyzed. A positive correlation between Pseudomonas, Shewanella, Morganella, Acinetobacter, and biogenic amines was found. Pseudomonas showed significant correlation with histamine, cadaverine, and putrescine. This study provides insights into yellowfin tuna quality and microbial composition, which provide theoretical guidance for maintaining seafood safety and quality during distribution and storage.


Author(s):  
Edem Y. Agbozo ◽  
Edward Dumashie ◽  
Daniel A. Boakye ◽  
Dziedzom K. de Souza

Antigen-based rapid diagnostic tests for Lymphatic filariasis do not come with quality control (QC) materials, and research and disease control programmes rely on stored positive plasma samples. This study was undertaken to evaluate the use of freeze-dried Wuchereria bancrofti antigen positive plasma samples to serve as QC materials for LF RDTs. 10 well characterized W. bancrofti positive samples were lyophilized and stored at 4°C, 28°C and 40°C. The samples were evaluated using the Filaria Test Strips before lyophilization and after one and three (3) months of storage. The sensitivity and stability of the lyophilized samples were evaluated. The results revealed a loss of sensitivity and stability with increasing temperature and duration of storage. The results are further discussed in terms of the use of Dried Blood Spot (DBS) in diagnostics studies on LF requiring quantitative assessments, and the need for thoughtful DBS preparation and storage.


2005 ◽  
Vol 68 (8) ◽  
pp. 1628-1634 ◽  
Author(s):  
CHENG-AN HWANG

This study examined and modeled the behavior of Listeria monocytogenes in ham salad and potato salad as affected by the pH of mayonnaise and storage temperature. An eight-strain cocktail of L. monocytogenes was inoculated on the surface of diced cooked ham or potato. The inoculated ham or potato was then mixed with regular mayonnaise (pH 3.8) or mayonnaise that was adjusted with NaOH to pH 4.2 or 4.6. The cell counts of L. monocytogenes in the salads during storage at 4, 8, or 12°C were enumerated and used to model the behavior of L. monocytogenes in ham salad or potato salad. At each of the storage temperatures, L. monocytogenes was able to grow in ham salad, whereas L. monocytogenes was inactivated in potato salad. The growth rate (log CFU per hour) in ham salad or the inactivation rate (log CFU per hour) in potato salad increased as the storage temperature increased. The duration before growth in ham salad or inactivation in potato salad increased as storage temperature decreased. The mayonnaise pH showed no consistent effect on the growth rate or inactivation rate and duration before growth or inactivation occurred. Mathematical equations that described the growth rate or inactivation rate of L. monocytogenes in both salads as a function of mayonnaise pH and storage temperature were generated and shown to be satisfactory in describing the growth rate or inactivation rate of L. monocytogenes in the ham salad or potato salad.


Author(s):  
Andrew S. Davison ◽  
Brian N. Green ◽  
Norman B. Roberts

Abstract: Electrospray ionization mass spectrometry (ESI-MS) can be used for the measurement of glycated adult hemoglobin. Here, we describe the evaluation of ESI-MS for measurement of glycated (GHbF) and acetylated (AcHbF) fetal hemoglobin and the identification by mass of different chains of fetal hemoglobin.: Blood samples were diluted in an acidic denaturing solvent, desalted with AG 50W-X8 resin and introduced directly into the mass spectrometer. Resulting mass spectra were processed to determine the percentage of GHbF and AcHbF and the γ-chain masses.: The procedure yielded reproducible quantitative assay of GHbF and AcHbF, with coefficients of variation <4.9%. Measurement of α-chain glycation was similarly reproducible and is suggested as an alternative marker of glycemic control. Marked increases in glycation occurred in dried spot blood samples, which were related to duration of storage, temperature and glucose concentration. Molecular masses of fetal hemoglobin chains were also determined and in 42 neonates studied, two types A and B were identified, two-thirds were type A with γ-chain masses corresponding to: ESI-MS can be used for the estimation of GHbF and AcHbF and the accurate measurement of fetal γ-chain masses. The use of whole blood is preferred for analysis.Clin Chem Lab Med 2008;46:1230–8.


Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2339
Author(s):  
So-Yul Yun ◽  
Jee-Young Imm

Age gelation is a major quality defect in ultra-high-temperature (UHT) pasteurized milk during extended storage. Changes in plasmin (PL)-induced sedimentation were investigated during storage (23 °C and 37 °C, four weeks) of UHT skim milk treated with PL (2.5, 10, and 15 U/L). The increase in particle size and broadening of the particle size distribution of samples during storage were dependent on the PL concentration, storage period, and storage temperature. Sediment analysis indicated that elevated storage temperature accelerated protein sedimentation. The initial PL concentration was positively correlated with the amount of protein sediment in samples stored at 23 °C for four weeks (r = 0.615; p < 0.01), whereas this correlation was negative in samples stored at 37 °C for the same time (r = −0.358; p < 0.01) due to extensive proteolysis. SDS-PAGE revealed that whey proteins remained soluble over storage at 23 °C for four weeks, but they mostly disappeared from the soluble phase of PL-added samples after two weeks’ storage at 37 °C. Transmission electron micrographs of PL-containing UHT skim milk during storage at different temperatures supported the trend of sediment analysis well. Based on the Fourier transform infrared spectra of UHT skim milk stored at 23 °C for three weeks, PL-induced particle size enlargement was due to protein aggregation and the formation of intermolecular β-sheet structures, which contributed to casein destabilization, leading to sediment formation.


Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 374
Author(s):  
Teresa Szczęsna ◽  
Ewa Waś ◽  
Piotr Semkiw ◽  
Piotr Skubida ◽  
Katarzyna Jaśkiewicz ◽  
...  

The aim of this study was to determine the influence of storage temperature and time on physicochemical parameters of starch syrups recommended for the winter feeding of bee colonies. The studies included commercially available three starch syrups and an inverted saccharose syrup that were stored at different temperatures: ca. 20 °C, 10–14 °C, and ca. 4 °C. Physicochemical parameters of fresh syrups (immediately after purchase) and syrups after 3, 6, 9, 12, 15, 18, 21, and 24 months of storage at the abovementioned temperatures were measured. It was observed that the rate of unfavorable changes in chemical composition of starch syrups and the inverted saccharose syrup, mainly the changes in the 5-hydroxymethylfurfural (HMF) content, depended on the type of a syrup and storage conditions (temperature, time). Properties of tested starch syrups intended for winter feeding of bees stored at ca. 20 °C maintained unchanged for up to 6 months, whereas the same syrups stored at lower temperatures (10–14 °C) maintained unchanged physicochemical parameters for about 12 months. In higher temperatures, the HMF content increased. To date, the influence of this compound on bees has not been thoroughly investigated.


Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 527
Author(s):  
Katarzyna Czyzewska ◽  
Anna Trusek

The current requirements of industrial biocatalysis are related to economically beneficial and environmentally friendly processes. Such a strategy engages low-temperature reactions. The presented approach is essential, especially in food processes, where temperature affects the quality and nutritional value foodstuffs. The subject of the study is the hydrolysis of lactose with the commercial lactase NOLA™ Fit 5500 (NOLA). The complete decomposition of lactose into two monosaccharides gives a sweeter product, recommended for lactose intolerant people and those controlling a product’s caloric content. The hydrolysis reaction was performed at 15 °C, which is related to milk transportation and storage temperature. The enzyme showed activity over the entire range of substrate concentrations (up to 55 g/L lactose). For reusability and easy isolation, the enzyme was encapsulated in a sodium alginate network. Its stability allows carrying out six cycles of the complete hydrolysis of lactose to monosaccharides, lasting from two to four hours. During the study, the kinetic description of native and encapsulated NOLA was conducted. As a result, the model of competitive galactose inhibition and glucose mixed influence (competitive inhibition and activation) was proposed. The capsule size does not influence the reaction rate; thus, the substrate diffusion into capsules can be omitted from the process description. The prepared 4 mm capsules are easy to separate between cycles, e.g., using sieves.


Sign in / Sign up

Export Citation Format

Share Document