Kinetics of colour changes during extrusion cooking of maize grits

1999 ◽  
Vol 39 (1) ◽  
pp. 73-80 ◽  
Author(s):  
S. Ilo ◽  
E. Berghofer
Keyword(s):  
Extrusion Cooking ◽  
Colour Changes ◽  
Kinetics Of

Impact of Storage and Packaging Material on the Nutritional, Product Properties and Microbial Count of Extruded Snacks

2020 ◽  
Vol 16 (4) ◽  
pp. 592-600
Author(s):  
Sajad A. Wani ◽  
Tariq A. Bhat ◽  
Nawaz A. Ganie ◽  
Pradyuman Kumar
Keyword(s):  
Bulk Density ◽  
Storage Period ◽  
Sensory Characteristics ◽  
Plate Count ◽  
Extrusion Cooking ◽  
Lateral Expansion ◽  
Total Plate Count ◽  
Sensory Score ◽  
Extruded Snacks ◽  
Kinetics Of

Background: The extrusion cooking is the most widely used process so the development and consumption of extruded snack products having health and nutritious benefits would help increase the health status of the population. Objective: The aim of this study was to investigate the effect of storage days on physical, microbial activity and sensory characteristics of extruded snacks and kinetics of extruded snacks. Methods: Extruded snacks were produced by extrusion cooking at optimized conditions of temperature, moisture and screw speed of 110°C, 12% (db) and 200 rpm. The products were packed in lowdensity polyethylene (LDPE) and laminated pouches (LP) and were stored at an accelerated temperature condition of 40 ± 2°C. The storage stability in terms of quality parameters such as moisture, hardness, bulk density, color, lateral expansion, sensory characteristics and total plate count was investigated. Results: An increase (p≤0.05) in the value of moisture, bulk density, a*, and total plate count was observed during the storage period, whereas hardness, L*, b*, ΔE and sensory characteristics showed significant (p≤0.05) decreased order with storage period. No significant effect on the lateral expansion of the extruded product was observed. A significant decrease in total carbohydrate, fat and protein content was found during the storage period. The average sensory score and microbial analysis suggested that extruded snacks packed in LDPE pouches can only be acceptable up to the 60th day and extruded snacks packed in LP can be acceptable to more than 90th day. The kinetics of color and hardness suggest first order kinetics. Conclusion: Overall investigation suggested that extruded snacks were more stable in the LP as compared to LDPE pouches.

Kinetics of colour changes in pasteurised strawberry juice during storage

2018 ◽  
Vol 216 ◽  
pp. 42-51 ◽  
Author(s):  
Carolien Buvé ◽  
Biniam T. Kebede ◽  
Cédric De Batselier ◽  
Celia Carrillo ◽  
Huong T.T. Pham ◽  
...  
Keyword(s):  
Colour Changes ◽  
Kinetics Of ◽  
Strawberry Juice

scholarly journals Effect of natural antioxidants on the colour and lipid stability of paprika salami

2013 ◽  
Vol 31 (No. 4) ◽  
pp. 307-312 ◽  
Author(s):  
B-A. Rohlík ◽  
P. Pipek ◽  
J. Pánek
Keyword(s):  
Natural Antioxidants ◽  
Rosemary Extract ◽  
Complicated Structure ◽  
Colour Measurements ◽  
Lipid Stability ◽  
Fermented Sausages ◽  
Dry Fermented Sausages ◽  
Colour Changes ◽  
Important Quality ◽  
Kinetics Of

The typical red colour of paprika salamis is a very important quality attribute but it is also very susceptible to oxidation. Rosemary extracts and lycopene appear to be efficient antioxidants for dry fermented sausages. The complicated structure of dried sausages with different kinetics of colour changes was evaluated using VIA software NIS-Elements 2.20 and lightness L*, redness a*, yellowness b*, mean red (R), mean green (G), and mean blue (B) were measured; the ratio of red r = R/(R + G + B) and hue h = arctg (a*/b*) were calculated. The addition of rosemary extract has positively affected the colour and suppressed lipid oxidation in both meat and lard particles in the paprika salami. Even more satisfactory results were obtained by adding both the rosemary extract and lycopene. Video image analysis enabled to perform colour measurements of meat and lard particles separately, which could not be done by any available method (reflective spectrophotometry).  

scholarly journals Thermal degradation kinetics of monomeric anthocyanins, colour changes and storage effect in elderberry juices

2015 ◽  
Vol 5 (1) ◽  
pp. 29-39 ◽  
Author(s):  
Carolina Busso Casati ◽  
Rosa Baeza ◽  
Virginia Sanchez ◽  
Alejandra Catalano ◽  
Paula López ◽  
...  
Keyword(s):  
Thermal Degradation ◽  
Degradation Kinetics ◽  
Thermal Degradation Kinetics ◽  
Storage Effect ◽  
Colour Changes ◽  
And Storage ◽  
Kinetics Of ◽  
Monomeric Anthocyanins

scholarly journals Kinetics of Starch Degradation during Extrusion Cooking of Steady State Flow Konjac (Amorphophallus oncophyllus) Tuber Flour in a Single Screw Extruder

2020 ◽  
Vol 15 (2) ◽  
pp. 591-602
Author(s):  
Andri Cahyo Kumoro ◽  
Diah Susetyo Retnowati ◽  
Ratnawati Ratnawati
Keyword(s):  
Reaction Rate Constant ◽  
Starch Degradation ◽  
Extrusion Cooking ◽  
Screw Extruder ◽  
High Quality ◽  
Exponential Factor ◽  
Single Screw ◽  
Single Screw Extruder ◽  
Refining Method ◽  
Kinetics Of

The presence of glucomannan in Konjac (Amorphophallus oncophyllus) tuber flour has promoted its various applications, especially in the food, drink, drug delivery and cosmetics. Starch is the main impurity of Konjac tuber flour. Although the common wet refining method may result in a high purity Konjac tuber flour, it is very tedious, time consuming and costly. This research aimed to study the kinetics of starch degradation in the extrusion cooking process of dry refining method to produce high quality Konjac tuber flour. In this research, Konjac tuber flour with 20% (w/w) moisture was extruded in a single screw extruder by varying screw speeds (50, 75, 100, 125, 150 and 175 rpm) and barrel temperatures (353, 373, 393, 413 and 433 K). The results showed that the starch extrusion cooking obeys the first reaction order. The reaction rate constant could be satisfactorily fitted by Arrhenius correlation with total activation energy of 6191 J.mol−1 and pre-exponential factor of 2.8728×10−1 s−1. Accordingly, thermal degradation was found to be the primary cause of starch degradation, which shared more than 99% of the energy used for starch degradation. Based on mass Biot number and Thiele modulus evaluations, chemical reaction was the controlling mechanism of the process. The results of this research offer potential application in Konjac tuber flour refining process to obtain high quality flour product. Copyright © 2020 BCREC Group. All rights reserved 

Phagocytosis studied by acridine orange-crystal violet fluorescent staining

1984 ◽  
Vol 42 ◽  
pp. 696-697
Author(s):  
C.E. Musclow ◽  
H. Farkas-Himsley ◽  
A. Kormendy ◽  
M. Goldner
Keyword(s):  
Acridine Orange ◽  
Crystal Violet ◽  
Fluorescent Microscopy ◽  
Base Line ◽  
Polymorphonuclear Cells ◽  
Fluorescent Staining ◽  
Test Conditions ◽  
Normal Individuals ◽  
Colour Changes ◽  
Kinetics Of

Bacteria can be examined by fluorescent microscopy, using the flurochrome dye acridine orange (AO) which distinguishes between viable (green) and nonviable (red-orange) organisms. (Fig. 1) The colour changes when increased amounts of AO intercalate with the phosphate sugar backbone of DNA, as it becomes denatured. This metachromatic shift can be used in phagocytosis studies to record viability and monitor killing of ingested bacteria. To avoid counting extracellular bacteria, crystal violet (CV) is used subsequently to quench the fluorescence in the external environment. At supravital concentration (0.05%) CV enters the prokaryotic cells, but will not penetrate the eukaryotic phagocytes. This study establishes the reliability of counting viable and nonviable cells by AO fluorescence in comparison to conventional methods; studies the kinetics of phagocytosis by polymorphonuclear cells (PMN) and monocytes; optimizes the test conditions; evaluates a phagocytic base line in normal individuals and determines if deliberate interference of some phagocytic parameter, such as inhibition of killing, can be recognized by AO-CV assay.

Reaction kinetics of heat-induced colour changes in soymilk

1999 ◽  
Vol 40 (1-2) ◽  
pp. 15-20 ◽  
Author(s):  
K.C. Kwok ◽  
D.B. MacDougall ◽  
K. Niranjan
Keyword(s):  
Reaction Kinetics ◽  
Colour Changes ◽  
Kinetics Of
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