Decolorization of β‐Carotene in Model Systems Simulating Dehydrated Foods. Mechanism and Kinetic Principles

Goldman, Mariana; Horev, Batia; Saguy, I. Sam

doi:10.1111/j.1365-2621.1983.tb14890.x

Cited by 97 publications

(71 citation statements)

References 13 publications

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“…2,3,5,6,27,45 An example of kinetic plots of degradation data for encapsulated beetroot pigment in the three wall materials stored at 50°C and a w = 0.64 is shown in Fig 5. The good ®ts of the ln A 537 nm vs time data imply that the beetroot pigment degradation follows ®rst-order reaction kinetics. Similar kinetic responses have also been reported for aqueous saffron extracts at a w = 0.11±0.75 and temperatures of 25±60°C, 46 for encapsulated saffron at a w = 0.43±0.75 and 35°C, 14 for the degradation of bixin (the major constituent of annatto), 47 for b-carotene 48 and for b-carotene oxidation in an oleoresin/cellulose model. 49 In all the samples examined, there was an obvious increase in the rate constant (k) and a corresponding decline in the half-life values (Table 3) for the reaction, particularly above the zone assigned to the intermediate-moisture regime.…”

Section: 45supporting

confidence: 78%

Degradation kinetics of beetroot pigment encapsulated in polymeric matrices

Serris

Βiliaderis

2001

J Sci Food Agric

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Kinetic studies on the degradation of water-soluble beetroot pigment, mainly consisting of the betalain betanin, encapsulated in three different matrices (pullulan and two maltodextrin samples differing in their molecular weight) were carried out under various water activity (a w = 0.23, 0.43, 0.64, 0.75 and 0.84) and temperature (30, 40 and 50°C) conditions. The water sorption behaviour of these materials was also examined. Degradation of the pigment was monitored by absorbance measurements at 537 nm (l max of betanin). The highest values of the rate constants for degradation were observed at an intermediate water activity level (a w = 0.64) for all matrices and all three storage temperatures examined. An attempt to relate the degradation kinetics to the molecular mobility of the wall material was not successful. Pigment losses were observed even at temperatures below the glass transition temperature (T g ) of the polymeric matrices, although degradation was largely slowed down in the glassy state. In the vicinity of the T g zone, where all polymers go through a glass → rubber transition, there was not a distinct change in the reaction rate, which could re¯ect the pronounced changes in molecular mobility of the wall material. In fact, some of the lower degradation rates were observed mostly under conditions where the matrices were fully plasticised (ie rubbery) and collapsed', implying that the degradation kinetics is not governed by factors related only to the physical state of the polymeric wall material.

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Section: 45supporting

confidence: 78%

Degradation kinetics of beetroot pigment encapsulated in polymeric matrices

Serris

Βiliaderis

2001

J Sci Food Agric

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“…Interestingly, a sigmoidal degradation course characterized by a linear period, a period of fast conversion and a final intercept of retardation has hitherto exclusively been reported for ascorbic acid degradation [28] and autocatalytic processes such as radical reactions during carotenoid decomposition [29]. Since the experiments of the present study were conducted on a similar molar basis, varying compound concentrations cannot be made responsible for the differing degradation patterns observed.…”

Section: Resultsmentioning

confidence: 54%

Thermal degradation kinetics of isoflavone aglycones from soy and red clover

Stintzing¹,

Hoffmann

Carle

2006

Molecular Nutrition Food Res

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Driven by their beneficial effects on human metabolism, isoflavonoids have gained considerable importance reflected by an increased number of isoflavone-rich foods, food supplements and pharmaceutical products on the market, mainly derived from soy and red clover. While it is well known that the genuine isoflavone pattern will be altered during processing, data on aglycone stability are rare. Therefore, a thorough study into the thermal sensitivities of biochanin A, daidzein, formononetin, flavone, genistein, glycitein and isoflavone was performed. Samples were heated at 150 degrees C over a period of 7 h at three different pH values, and degradation of the aglycones was monitored by HPLC-DAD analyses. Therefrom, structure-related stability characteristics could be established. While virtually no decay was observed at pH 7.0 and 5.6, degradation was most prominent at pH 3. 1. Individual aglycone retention was further dependent on heating time with daidzein being the most labile compound after any time interval. Curve fitting of the data revealed first-order degradation kinetics for flavone and glycitein, while the remaining aglycones exhibited a sigmoidal degradation pattern.

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“…The results show clearly that in anhydrous media decolouring of the carotenoids followed a zero-order kinetics, while in an aqueous medium the reaction was first order. These results show that the different and sometimes contradictory results reported in the literature (Goldman et al 1983) could be imputed to the reaction medium.…”

Section: Rate Of Decolouring Of Carotenoid Pigmentsmentioning

confidence: 52%

Kinetics of the decolouring of carotenoid pigments

Mínguez‐Mosquera

Jarén‐Galán

1995

J Sci Food Agric

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The decolouring reaction of carotenoids was studied using p-carotene, di-esterified capsanthin and capsanthin. The study was designed to determine what effects the increase in temperature, the nature of the reaction medium and the presence of light have on the kinetics of the reaction. The reactions that take place in an anhydrous medium follow a zero-order kinetics, while those that take place in an aqueous medium follow a first-order kinetics. Light and temperature accelerate the degradation reaction without changing the formal aspects of the reactions. The values for the thermodynamic parameters (activation energy and enthalpy of activation) of each reaction were different according to the conditions used, but this variation was due to a compensation effect. However, the existence of this effect confirms that the decolouring reaction is the first step of the carotenoid degradation, and this step is identical for all of the pigments irrespective of the reaction conditions, although the formal aspects and kinetics of this first step are strongly modulated by the nature of the pigment and the experimental conditions used.

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Decolorization of β‐Carotene in Model Systems Simulating Dehydrated Foods. Mechanism and Kinetic Principles

Cited by 97 publications

References 13 publications

Degradation kinetics of beetroot pigment encapsulated in polymeric matrices

Degradation kinetics of beetroot pigment encapsulated in polymeric matrices

Thermal degradation kinetics of isoflavone aglycones from soy and red clover

Kinetics of the decolouring of carotenoid pigments

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