scholarly journals Coupling effects of structure, oxygen availability and temperature on microbial growth in a pastry filling

2021 ◽  
Vol 26 (2) ◽  
pp. 229-242
Author(s):  
Amanda Laca ◽  
Mario Diaz ◽  
Adriana Laca ◽  
Paula Mateos
Keyword(s):  
Microbial Growth ◽  
Food System ◽  
Incubation Temperature ◽  
Rheological Behaviour ◽  
Model Food ◽  
Key Factor ◽  
Different Temperatures ◽  
Frequency Sweeps ◽  
Specific Growth Rates ◽  
Aggregate Structures

The structure of real food is a key factor to be considered in order to control microbial growth. A pastry filling has been employed as model food to study the growth of Staphylococcus under different conditions. Additionally, the structure of the food system has been characterised by means of rheological measurements. Frequency sweeps showed that, in all cases, the elastic component determines the rheological behaviour of model pastry filling (G' > G''). Values obtained for the coordination number (z) and the proportional coefficient (A) indicated that the model food exhibits more aggregate structures and stronger links at lower temperatures. According to the maximum specific growth rates, the Staphylococcus growth in the model pastry filling was clearly conditioned by oxygen diffusion, which is limited by the food matrix, and also by the incubation temperature. In addition, the analysis of Staphylococcus growth at different temperatures suggested the influence of the pastry filling structure on microorganism behaviour.

scholarly journals Validation of Microbiological Testing of Tissue Preparations with Different Incubation Temperatures

2020 ◽  
Vol 48 (1) ◽  
pp. 23-31
Author(s):  
Frithjof Herrlinger ◽  
Tino Schulz ◽  
Axel Pruß ◽  
Eva Schulz
Keyword(s):  
Blood Culture ◽  
Microbial Growth ◽  
Incubation Temperature ◽  
Culture Media ◽  
Anaerobic Bacteria ◽  
Culture Bottle ◽  
Cutibacterium Acnes ◽  
Microbiological Testing ◽  
Different Temperatures ◽  
Bacteria And Fungi

<b><i>Introduction:</i></b> The European Pharmacopoeia (Ph. Eur.) provides principles for microbiological testing of tissue preparations. According to the Ph. Eur., tests should be performed at different temperatures for detection of aerobic bacteria and fungi (20–25°C) vs. anaerobic bacteria (30–35°C). Semiautomated systems using blood culture bottles are already widely used and they are adequate for growth detection. Resin-containing bottles and the addition of penicillinase permit testing of culture media containing antibiotics. <b><i>Materials and Methods:</i></b> At 3 temperatures (21, 30, and 35°C) cornea culture media with and without dextran (CM II and CM I) and thermal disinfected femoral head medium (FH) were spiked with the 6 reference strains recommended by the Ph. Eur. (additionally: <i>Enterococcus faecalis</i>, <i>Staphylococcus epidermidis,</i> and <i>Cutibacterium acnes</i>). Microbial growth was monitored with the BACTEC<sup>TM</sup> FX unit or visually at 21°C. <b><i>Results:</i></b> Growth for all strains was detected with each medium at all 3 temperatures, except for <i>C. acnes</i> at 21°C (all media) and 30°C with FH. <i>C. acnes</i> had the highest times to detection, requiring test durations of 14 days. Microbial growth was faster at 30 and 35°C compared to 21°C. <b><i>Conclusion:</i></b> The requirements according to the Ph. Eur. for a successful method suitability test could be fulfilled for the semiautomated blood culture bottle system with the BACTEC<sup>TM</sup> FX unit for the media and microorganisms used. In the presented validation study 35°C was shown to be the incubation temperature with the fastest growth, of the majority of the test strains used, and complete detection within 14 days.

Ability of Inactivated Yeast Powder To Adsorb Patulin from Apple Juice

2012 ◽  
Vol 75 (3) ◽  
pp. 585-590 ◽  
Author(s):  
CAIXIA GUO ◽  
TIANLI YUE ◽  
SHAIMAA HATAB ◽  
YAHONG YUAN
Keyword(s):  
Incubation Time ◽  
Apple Juice ◽  
Incubation Temperature ◽  
Absolute Ethyl Alcohol ◽  
Initial Concentration ◽  
Different Temperatures ◽  
Yeast Powder ◽  
Commercial Yeast ◽  
The Stability ◽  
Phosphate Buffered Saline

This study aimed to investigate the adsorption of patulin from apple juice, using two types of inactivated yeast powder: laboratory-prepared yeast powder (LYP) and commercial yeast powder (CYP). The effects of incubation time, pH, incubation temperature, adsorbent amount, and initial concentration of patulin and the stability of the yeast-mycotoxin complex were assessed. The results showed that the efficiencies of the two yeast types in adsorbing patulin were similar. The ability of the powders to remove patulin increased with longer incubation times, and patulin concentration was below detectable levels with LYP and CYP at approximately 36 and 30 h, respectively. The highest removal of patulin was achieved at pH 5.0 for both powder types, and there were no significant differences in patulin decrease at different temperatures (4, 29, and 37°C). Additionally, the adsorption percentage of patulin increased significantly with the increase of absorbent amount and decrease of initial concentration of patulin. Stability of the yeast-patulin complex was assessed, and patulin was more stable when washed in phosphate-buffered saline (pH 4.0) than in absolute ethyl alcohol. These results suggest that inactivated yeast powder has potential as a novel and promising adsorbent to bind patulin effectively.

scholarly journals Effect of Humidity-Controlled Dehydration on Microbial Growth and Quality Characteristics of Fresh Wet Noodles

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 844
Author(s):  
Jun-Jie Xing ◽  
Dong-Hui Jiang ◽  
Zhen Yang ◽  
Xiao-Na Guo ◽  
Ke-Xue Zhu
Keyword(s):  
Shelf Life ◽  
Microbial Growth ◽  
Treatment Time ◽  
Positive Influence ◽  
Quality Characteristics ◽  
Plate Count ◽  
Cooking Properties ◽  
Total Plate Count ◽  
Different Temperatures

Humidity-controlled dehydration (HCD) was innovatively applied in this paper to control the growth of microorganisms in fresh wet noodles (FWN). Effects of HCD treatment with different temperatures (40, 60 or 80 °C), relative humidity (RH, 50%, 70% or 90%) and treatment time (5–32 min) on the total plate count (TPC), the shelf-life, and qualities of FWN were investigated. The results showed that HCD reduced the initial microbial load on the fresh noodles and extended the shelf-life up to 14–15 days under refrigeration temperature (10 °C). A 1.39 log10 CFU/g reduction for the initial TPC was achieved after HCD treatment at the temperature of 60 °C and RH of 90%. HCD with higher RH had a more positive influence on quality improvement. The L* values, the apparent stickiness, and the cooking properties of the noodle body were improved by HCD while good sensory and texture quality of noodles were still maintained after the dehydration process.

Influence of baking time and matrix effects on the detection of milk allergens in cookie model food system by ELISA

2011 ◽  
Vol 127 (2) ◽  
pp. 669-675 ◽  
Author(s):  
Linda Monaci ◽  
Marcel Brohée ◽  
Virginie Tregoat ◽  
Arjon van Hengel
Keyword(s):  
Food System ◽  
Matrix Effects ◽  
Model Food

Analysis of the non-volatile Maillard reaction products formed in an extrusion-cooked model food system

1998 ◽  
Vol 61 (4) ◽  
pp. 521-524 ◽  
Author(s):  
Jennifer M Ames ◽  
Aklile B Defaye ◽  
Richard G Bailey ◽  
Lisa Bates
Keyword(s):  
Maillard Reaction ◽  
Food System ◽  
Maillard Reaction Products ◽  
Reaction Products ◽  
Model Food

Modelling microbial growth in modified-atmosphere-packed hake (Merluccius merluccius) fillets stored at different temperatures

2019 ◽  
Vol 122 ◽  
pp. 506-516 ◽  
Author(s):  
Adriana Antunes-Rohling ◽  
Ángela Artaiz ◽  
Silvia Calero ◽  
Nabil Halaihel ◽  
Silvia Guillén ◽  
...  
Keyword(s):  
Microbial Growth ◽  
Modified Atmosphere ◽  
Merluccius Merluccius ◽  
Different Temperatures

Thermal influence on the embryonic development and hatching rate of the flameback pygmy angelfish Centropyge aurantonotus eggs

Zygote ◽  
2019 ◽  
Vol 28 (1) ◽  
pp. 80-82
Author(s):  
Raoani Cruz Mendonça ◽  
Sarah Pittigliani Ikebata ◽  
Sérgio Leandro Araújo-Silva ◽  
João Vitor Azevedo Manhães ◽  
Mônica Yumi Tsuzuki
Keyword(s):  
Embryonic Development ◽  
Incubation Temperature ◽  
Abiotic Factors ◽  
Environmental Parameters ◽  
Hatching Rate ◽  
Influence Of Temperature ◽  
Different Temperatures ◽  
Influence Of Temperature On ◽  
Thermal Influence ◽  
Hatching Rates

SummaryThe flameback pygmy angelfish Centropyge aurantonotus, highly appreciated and valued by the aquarium market, is heavily harvested and traded. Temperature is one of the abiotic factors that has the most influence on fish development, especially in the early stages of life. For captive production, it is essential to know the appropriate environmental parameters for each species. In this sense, this study aimed to evaluate the influence of temperature on the embryonic development and hatching rates of C. aurantonotus incubated at six different temperatures (20, 22, 24, 26, 28, 30°C). Embryonic development events were very similar in terms of morphological and chronological characteristics compared with other species of the genus Centropyge. Incubation time was inversely proportional to temperature. The treatment at 22°C required twice the time of that required by 30°C treatment for hatching to occur. The best incubation temperature range was 24–28°C. Values below 22°C and at 30°C showed lower hatching rates compared with other treatments. Based on these results, the recommended temperature at which to incubate C. aurantonotus eggs is between 24–28°C.

Temperature–pH effect upon germination of bacterial spores

1976 ◽  
Vol 22 (2) ◽  
pp. 322-323 ◽  
Author(s):  
Yuzaburo Ishida ◽  
Takashi Ishido ◽  
Hajime Kadota
Keyword(s):  
Bacillus Subtilis ◽  
Spore Germination ◽  
Incubation Temperature ◽  
Ph Effect ◽  
Bacterial Spores ◽  
Optimum Ph ◽  
Different Temperatures

Using several kinds of criteria for the germination of bacterial spores, germination–pH curves were drawn for Bacillus subtilis spores observed at different temperatures. The experiments revealed that optimum pH for spore germination was markedly changed by changing the incubation temperature; the optimum pH for germination was 7.4 at 37 °C and 5.4 at 10 °C. A possible mechanism involved in this phenomenon is discussed.

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