Enzymatic Browning of Fruits. III. Kinetics of the Reaction Inactivation of Polyphenoloxidase

1952 ◽  
Vol 74 (10) ◽  
pp. 2623-2626 ◽  
Author(s):  
Lloyd L. Ingraham ◽  
Joseph Corse ◽  
Benjamin Makower
Keyword(s):  
Enzymatic Browning ◽  
Kinetics Of

scholarly journals Non-enzymatic browning and flavour kinetics of vacuum dried onion slices

2015 ◽  
Vol 29 (1) ◽  
pp. 91-100 ◽  
Author(s):  
Jayeeta Mitra ◽  
Shanker L. Shrivastava ◽  
Pavuluri S. Rao
Keyword(s):  
Moisture Content ◽  
Colour Change ◽  
Enzymatic Browning ◽  
Vacuum Drying ◽  
Rehydration Ratio ◽  
High Quality ◽  
Optical Index ◽  
Hot Air ◽  
Colour Development ◽  
Kinetics Of

Abstract Onion slices were dehydrated under vacuum to produce good quality dried ready-to-use onion slices. Colour development due to non-enzymatic browning and flavour loss in terms of thiosulphinate concentration was determined, along with moisture content and rehydration ratio. Kinetics of non-enzymatic browning and thiosulphinate loss during drying was analysed. Colour change due to non-enzymatic browning was found to be much lower in the case of vacuum dried onion, and improved flavour retention was observed as compared to hot air dried onion slices. The optical index values for non-enzymatic browning varied from 18.41 to 38.68 for untreated onion slices and from 16.73 to 36.51 for treated slices, whereas thiosulphinate concentration in the case of untreated onion slices was within the range of 2.96-3.92 μmol g-1 for dried sample and 3.71-4.43 μmol g-1 for the treated onion slices. Rehydration ratio was also increased, which may be attributed to a better porous structure attained due to vacuum drying. The treatment applied was found very suitable in controlling non-enzymatic browning and flavour loss during drying, besides increasing rehydration ratio. Hence, high quality dried ready- to-use onion slices were prepared.

Note. Hydrolysis of Onion and Kinetics of Non-Enzymatic Browning of its Hydrolysate

2004 ◽  
Vol 10 (1) ◽  
pp. 41-44 ◽  
Author(s):  
J. M. Kim ◽  
K. S. Ra ◽  
H. J. Suh
Keyword(s):  
Zero Order ◽  
Total Sugar ◽  
Effect Of Temperature ◽  
Enzymatic Browning ◽  
Order Kinetic ◽  
Arrhenius Model ◽  
Browning Index ◽  
Order Kinetic Model ◽  
Kinetics Of ◽  
Hydrolysis Of

Enzymatic hydrolysis of onion was performed by three different commercial enzyme products (Econase, Rapidase and Viscozyme) for preparation of onion hydrolysates. The hydrolysis yield was determined through the analysis of reducing and total sugar contents in final hydrolysates. Total sugar contents after 2 h-hydrolysis with Econase, Rapidase and Viscozyme were 59.6, 64.1 and 62.2 mg/mL, respectively, and reducing sugar contents of 28.5, 42.7 and 35.9 mg/mL in the same order. According to these results Rapidase was more suitable for the hydrolysis of onion than the other enzymatic products. The effect of temperature on non-enzymatic browning reaction kinetics of the onion hydrolysate was determined. The browning index variation was adequately described by both the first- and the zero-order kinetic. However, the zero-order kinetic model was preferred because its fitting was higher. The values of kinetic constants were 0.081 (60 C), 0.185 (70 C), 0.270 (80 C) and 0.377 (90 C). According to the Arrhenius model, the activation energy for browning index in the range 60–90 C was 21.9 kJ/mol.

Nota. Cinética de pardeamiento no enzimático de zumo de pera concentrado Note./ Non-enzymatic browning kinetics of concentrated pear juice

1997 ◽  
Vol 3 (3) ◽  
pp. 213-218 ◽  
Author(s):  
A. Ibarz ◽  
O. Martín ◽  
G.V. Barbosa-Cánovas
Keyword(s):  
Zero Order ◽  
Enzymatic Browning ◽  
First Order ◽  
First Order Kinetics ◽  
Zero Order Kinetics ◽  
Soluble Solid ◽  
Pear Juice ◽  
Kinetics Of

Non-enzymatic browning kinetics of concentrated juice for three pear varieties (Alexandrine Douillard, Flor de Invierno and Blanquilla) was evaluated at three temperatures (90, 80 and 70 °C) and different soluble solid contents (52, 62 and 72 °Brix). The evolution of absorbance at 420 nm is described by zero order kinetics, but the formation of 5-hydroxymethyl-2 furfuraldehyde (HMF) and the reduction in formol index followed first order kinetics. The Alexandrine Douillard juices showed non-enzymatic browning which was less pronounced than in Flor de Invierno and Blanquilla juices.

scholarly journals Kinetics of non-enzymatic browning reaction from the l-ascorbic acid/l-cysteine model system

2016 ◽  
Vol 34 (No. 6) ◽  
pp. 503-510 ◽  
Author(s):  
A.-N. Yu ◽  
L.-P. Tang
Keyword(s):  
Ascorbic Acid ◽  
Order Reaction ◽  
Model Systems ◽  
Enzymatic Browning ◽  
Ascorbic Acid Concentration ◽  
First Order ◽  
Browning Reaction ◽  
Brown Colour ◽  
Colour Development ◽  
Kinetics Of

The kinetics of the non-enzymatic browning reaction from l-ascorbic acid/l-cysteine model systems was investigated at 125–155°C for 10–120 min by measuring the loss of reactants and monitoring the brown colour development. The result showed that the browning products were produced at the first order reaction kinetics requirement, with the E<sub>a</sub> being 114.33 kJ/mol. The mechanism for the browning development was proposed. The correlation coefficient between browning products and uncoloured intermediate products increased with the rising temperature. At temperatures below 110°C, the non-enzymatic browning reaction did not occur at all or the reaction was slow. Browning products could not be produced solely by self-degradation of l-cysteine. The amount of browning products negatively correlated with the l-ascorbic acid concentration.

Quantification of enzymatic browning kinetics of quince preserved by edible coating using the fractal texture Fourier image

2015 ◽  
Vol 9 (3) ◽  
pp. 375-381 ◽  
Author(s):  
Mohammad Noshad ◽  
Mohebbat Mohebbi ◽  
Elham Ansarifar ◽  
Behrooz Alizadeh behbahani
Keyword(s):  
Edible Coating ◽  
Enzymatic Browning ◽  
Fourier Image ◽  
Kinetics Of

Mechanism and kinetics of tyrosinase inhibition by glycolic acid: a study using conventional spectroscopy methods and hydrogen/deuterium exchange coupling with mass spectrometry

2017 ◽  
Vol 8 (1) ◽  
pp. 122-131 ◽  
Author(s):  
Da Ma ◽  
Zong-Cai Tu ◽  
Hui Wang ◽  
Lu Zhang ◽  
Na He ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Exchange Coupling ◽  
Glycolic Acid ◽  
Fruits And Vegetables ◽  
Enzymatic Browning ◽  
Hydrogen Deuterium Exchange ◽  
Tyrosinase Inhibition ◽  
Hydrogen Deuterium ◽  
Mechanism And Kinetics ◽  
Kinetics Of

Tyrosinase is an enzyme that promotes enzymatic browning of fruits and vegetables, thereby reducing product quality.

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