Effect of Storage Temperature and Pyruvate on Kinetics of Anthocyanin Degradation, Vitisin A Derivative Formation, and Color Characteristics of Model Solutions

2000 ◽  
Vol 48 (6) ◽  
pp. 2135-2141 ◽  
Author(s):  
Concepcion Romero ◽  
Johanna Bakker
Keyword(s):  
Storage Temperature ◽  
Color Characteristics ◽  
Model Solutions ◽  
Kinetics Of ◽  
Anthocyanin Degradation

Oxidation Kinetics of Hazelnut Shelf-Life Prediction Model

2012 ◽  
Vol 200 ◽  
pp. 466-469
Author(s):  
Wen Li Dong ◽  
Xue Gong ◽  
Jing Dong ◽  
Ling Jin ◽  
Yu Xiang Wei
Keyword(s):  
Prediction Model ◽  
Shelf Life ◽  
Peroxide Value ◽  
Storage Temperature ◽  
Order Kinetic ◽  
Shelf Life Prediction ◽  
Changing Patterns ◽  
Kinetics Of ◽  
Life Prediction Model

The changing patterns of filbert peroxide value through the determination of different storage temperature conditions,research the dynamics characteristics of oxidative rancidity of filbert. By regression analysis base on the storage time and the logarithm of peroxide value,it concluded the grease oxidation reaction first-order kinetic equation of filbert.Using Arrhenius equation and Q10 model for 5 ~ 35 °C temperature within the shelf life of any temperature prediction model.

scholarly journals Effects of heat treatment and storage temperature on the use of açaí drink by nutraceutical and beverage industries

2012 ◽  
Vol 32 (1) ◽  
pp. 9-14 ◽  
Author(s):  
Tatiane Regina Albarici ◽  
José Dalton Cruz Pessoa
Keyword(s):  
Temperature Effect ◽  
Storage Temperature ◽  
Life Time ◽  
Reaction Rate Constant ◽  
Anthocyanin Content ◽  
Order Kinetic ◽  
First Order ◽  
The Stability ◽  
And Storage ◽  
Anthocyanin Degradation

This study assesses the storage temperature effect on the anthocyanins of pasteurized and unpasteurized açaí pulp. The data was obtained using a pasteurized and lyophilized pulp (PLP) to evaluate the temperature effect (0, 25, and 40 °C). Part of non-pasteurized frozen pulp (NPP) was pasteurized (NPP-P) at 90 °C for 30 seconds; both pulps were stored at 40 °C. The anthocyanin content reduction in the drink was evaluated from the half-life time (t1/2), activation energy (Ea), temperature quotient (Q10), and the reaction rate constant (k). The t1/2 of the PLP anthocyanins stored at 40 °C was 1.8 times less than that stored at 25 °C and 15 times less than that stored at 0 °C; therefore, the higher temperatures decreased the stability of anthocyanins. The pasteurization increased the t1/2 by 6.6 times (10.14 hours for NPP and 67.28 hours for NPP-P). The anthocyanin degradation on NPP-P followed a first order kinetic, while NPP followed a second order kinetic; thus it can be said that the pasteurization process can improve the preservation of anthocyanins in the pulp.

Growth Modeling of Listeria monocytogenes in Pasteurized Liquid Egg

2013 ◽  
Vol 76 (9) ◽  
pp. 1549-1556 ◽  
Author(s):  
MIHO OHKOCHI ◽  
SHIGENOBU KOSEKI ◽  
MASAAKI KUNOU ◽  
KATSUAKI SUGIURA ◽  
HIROKAZU TSUBONE
Keyword(s):  
Listeria Monocytogenes ◽  
Specific Growth ◽  
Storage Temperature ◽  
Growth Parameters ◽  
Root Model ◽  
Natural Flora ◽  
Mean Square Errors ◽  
Kinetics Of ◽  
Storage Temperatures ◽  
Maximum Population Density

The growth kinetics of Listeria monocytogenes and natural flora in commercially produced pasteurized liquid egg was examined at 4.1 to 19.4°C, and a growth simulation model that can estimate the range of the number of L. monocytogenes bacteria was developed. The experimental kinetic data were fitted to the Baranyi model, and growth parameters, such as maximum specific growth rate (μmax), maximum population density (Nmax), and lag time (λ), were estimated. As a result of estimating these parameters, we found that L. monocytogenes can grow without spoilage below 12.2°C, and we then focused on storage temperatures below 12.2°C in developing our secondary models. The temperature dependency of the μmax was described by Ratkowsky's square root model. The Nmax of L. monocytogenes was modeled as a function of temperature, because the Nmax of L. monocytogenes decreased as storage temperature increased. A tertiary model of L. monocytogenes was developed using the Baranyi model and μmax and Nmax secondary models. The ranges of the numbers of L. monocytogenes bacteria were simulated using Monte Carlo simulations with an assumption that these parameters have variations that follow a normal distribution. Predictive simulations under both constant and fluctuating temperature conditions demonstrated a high accuracy, represented by root mean square errors of 0.44 and 0.34, respectively. The predicted ranges also seemed to show a reasonably good estimation, with 55.8 and 51.5% of observed values falling into the prediction range of the 25th to 75th percentile, respectively. These results suggest that the model developed here can be used to estimate the kinetics and range of L. monocytogenes growth in pasteurized liquid egg under refrigerated temperature.

Mechanisms of anthocyanin degradation in grape must-like model solutions

1995 ◽  
Vol 69 (3) ◽  
pp. 385-391 ◽  
Author(s):  
Pascale Sarni ◽  
Hélène Fulcrand ◽  
Véronique Souillol ◽  
Jean-Marc Souquet ◽  
Véronique Cheynier
Keyword(s):  
Grape Must ◽  
Model Solutions ◽  
Anthocyanin Degradation

Viability of Salmonella, Escherichia coli O157:H7, and Listeria monocytogenes in Yellow Fat Spreads as Affected by Storage Temperature

2003 ◽  
Vol 66 (4) ◽  
pp. 549-558 ◽  
Author(s):  
SARAH L. HOLLIDAY ◽  
LARRY R. BEUCHAT
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Storage Temperature ◽  
Salt Content ◽  
Inactivation Kinetics ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Inhibition Of Growth ◽  
Time Required ◽  
Kinetics Of

A study was conducted to characterize the survival and inactivation kinetics of a five-serotype mixture of Salmonella (6.23 to 6.55 log10 CFU per 3.5-ml or 4-g sample), a five-strain mixture of Escherichia coli O157:H7 (5.36 to 6.14 log10 CFU per 3.5-ml or 4-g sample), and a six-strain mixture of Listeria monocytogenes (5.91 to 6.18 log10 CFU per 3.5-ml or 4-g sample) inoculated into seven yellow fat spreads (one margarine, one butter-margarine blend, and five dairy and nondairy spreads and toppings) after formulation and processing and stored at 4.4, 10, and 21°C for up to 94 days. Neither Salmonella nor E. coli O157:H7 grew in any of the test products. The time required for the elimination of each pathogen depended on the product and the storage temperature. Death was more rapid at 21°C than at 4.4 or 10°C. Depending on the product, the time required for the elimination of viable cells at 21°C ranged from 5 to 7 days to >94 days for Salmonella, from 3 to 5 days to 28 to 42 days for E. coli O157:H7, and from 10 to 14 days to >94 days for L. monocytogenes. Death was most rapid in a water-continuous spray product (pH 3.66, 4.12% salt) and least rapid in a butter-margarine blend (pH 6.66, 1.88% salt). E. coli O157:H7 died more rapidly than did Salmonella or L. monocytogenes regardless of storage temperature. Salmonella survived longer in high-fat (≥61%) products than in products with lower fat contents. The inhibition of growth is attributed to factors such as acidic pH, salt content, the presence of preservatives, emulsion characteristics, and nutrient deprivation. L. monocytogenes did not grow in six of the test products, but its population increased between 42 and 63 days in a butter-margarine blend stored at 10°C and between 3 and 7 days when the blend was stored at 21°C. On the basis of the experimental parameters examined in this study, traditional margarine and spreads not containing butter are not “potentially hazardous foods” in that they do not support the growth of Salmonella, E. coli O157:H7, or L. monocytogenes.

Kinetic study of lipid oxidation in roasted coffee

1998 ◽  
Vol 4 (1) ◽  
pp. 67-73 ◽  
Author(s):  
M.D. Ortolá ◽  
C.L. Gutiérrez ◽  
A. Chiralt ◽  
P. Fito
Keyword(s):  
Moisture Content ◽  
Lipid Oxidation ◽  
Oxidation Process ◽  
Storage Temperature ◽  
Important Change ◽  
Second Step ◽  
Initiation Mechanism ◽  
Experimental Values ◽  
Second Period ◽  
Kinetics Of

The kinetics of lipid oxidation in ground roast Arabica coffee from Colombia stored under different conditions were studied. Rancidity was controlled by the analysis of the peroxide value at 30-day intervals. The influence of moisture content (26 and 43 g/kg), storage temperature (5, 25 and 35 °C) and packaging conditions (with non-sealed bags, under vacuum, 35 mbar, and packed under CO2 atmosphere) on the kinetics was determined. Experimental values were fitted with a kinetic model for the mechanism of lipid oxidation. Lipid oxidation is described by two steps, which implies a monomolecular and a bimolecular initiation mechanism for the first and second period respectively. The kinetic constants showed that the plastificant effect of water and CO2 lead to an important change in the reactants' mobility within the temperature range. However, the rise in moisture content seems to protect the product from formation of the peroxide. Furthermore, this effect is more important in the second step of the oxidation process.

scholarly journals Color Change of Birch Wood During Thermal Exposure

2017 ◽  
Vol 7 (3) ◽  
pp. 15-21 ◽  
Author(s):  
Михаил Ермоченков ◽  
Mihail Ermochenkov ◽  
Андрей Хроменко ◽  
Andrey Khromenko
Keyword(s):  
Heat Treatment ◽  
Thermal Decomposition ◽  
Thermal Degradation ◽  
Color Change ◽  
Thermal Exposure ◽  
Thermal Modification ◽  
Birch Wood ◽  
Color Characteristics ◽  
Physical And Chemical ◽  
Kinetics Of

Heat treatment is widely used to improve the properties of wood. Such processes include drying and thermal modification. Thermal modification is heating wood without oxygen, accompanied by heat destruction. Thermally modified wood can be used as structural and finishing materials. This puts the task of determining its thermal and physical, physical and chemical, biological, and ornamental properties and their change during heat treatment. The article presents the results of experimental and computational studies of color characteristics of the wood of birch, their change in the process of thermal modification. Thermal decomposition is a complicated multi-stage physical and chemical process. Thermal decomposition of material causes changes in its composition, structure, accompanied by alterations of its properties. Wood can be considered as a multicomponent composite material, consisting of hemicellulose, cellulose, lignin and other components. Each component decomposes in the temperature range that causes the multistage process of thermal degradation. The degree of thermal degradation of the material is determined by the kinetics of occurrence of each stage and the degree of its perfection. Thermal decomposition kinetics of wood can be determined by the results of thermal and gravimetric experiments. In the article the model of determining the color characteristics of wood as a function of the degree of completion of individual stages of thermal degradation is suggested. Model of decomposition of color for RGB components is used for identifying. Color identification of the samples of original birch wood in RGB coordinates was performed. The parameters of thermal effects, allowing to obtain wood with given degree of thermal decomposition are defined. Heat treatment of samples and identification of their color is made. The dependence of RGB parameters from time and intensity of heat treatment is studied. Empirical relations to determine the identifying characteristics of color, as a function of the degree of completion of stages of thermal destruction, in RGB and LAB systems are obtained in explicit form.

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