The kinetics of polyphenol degradation during the drying of Malaysian cocoa beans

The main objective of the study was to determine the kinetics of the polyphenol oxidation reaction in cocoa beans during air drying at various air temperatures and humidities. The temperatures used were between 40 and 60 °C and the relative humidities were between 50 and 80%. The higher the temperature and relative humidity of the drying air, the lower the amount of polyphenol residue in the cocoa beans, because of enzymatic oxidation of polyphenols. At higher drying temperatures, non-enzymatic oxidation of polyphenols could also occur. Computer simulation results gave rate constants for the polyphenol oxidation reaction (k 1 ) and the condensation reaction (k 2 ), at various air conditions, in the range of 0.055-0.200 and 0.136-0.155 h -1 respectively. The activation energies obtained for the polyphenol oxidation reaction were in the range of 27 800-30 312 J K -1 mol -1 . The reaction kinetics of the enzymatic browning reaction fitted a pseudo first-order reaction.

[1]  P. Goulding,et al.  Polyphenol Complexation: A Study in Molecular Recognition , 1992 .

[2]  A. J. Mcevily,et al.  Inhibition of Polyphenol Oxidase by Phenolic Compounds , 1992 .

[3]  J. E. Lozano,et al.  Nonenzymatic Browning in Apple Juice Concentrate during Storage , 1984 .

[4]  S. Jinap,et al.  Acidic Characteristics of Fermented and Dried Cocoa Beans from Different Countries of Origin , 1990 .

[5]  M. A. Jalal,et al.  Polyphenols of mature plant, seedling and tissue cultures of Theobroma cacao , 1977 .

[6]  T. Reynolds.  Chemistry of nonenzymic browning. II. , 1965, Advances in food research.

[7]  A. Spark.  Role of amino acids in non‐enzymic browning , 1969 .

[8]  P. A. Roelofsen.  Fermentation, Drying, and Storage of Cacao Beans , 1958 .

[9]  Tin Mar Kyi,et al.  Drying with Chemical Reaction in Cocoa Beans , 2007 .

[10]  T. Labuza,et al.  COMPUTER‐AIDED PREDICTIONS OF EXTENT OF BROWNING IN DEHYDRATED CABBAGE , 1970 .

[11]  E. Anklam,et al.  Polyphenols in chocolate: is there a contribution to human health? , 2000 .

[12]  J. Hodge.  Dehydrated Foods, Chemistry of Browning Reactions in Model Systems , 1953 .

[13]  Misnawi,et al.  Oxidation of polyphenols in unfermented and partly fermented cocoa beans by cocoa polyphenol oxidase and tyrosinase , 2002 .

[14]  T. Labuza,et al.  ACCELERATED SHELF‐LIFE TESTING OF AN INTERMEDIATE MOISTURE FOOD IN AIR AND IN AN OXYGEN‐FREE ATMOSPHERE , 1976 .

[15]  I. Ben-Gera,et al.  Storage Stability of Orange Juice Concentrate Packaged Aseptically , 1982 .

[16]  T. Labuza.  THE NONENZYMATIC BROWNING REACTION AS AFFECTED BY WATER IN FOODS , 1981 .

[17]  P. G. Keeney,et al.  Method of Analysis for (-)-Epicatechin in Cocoa Beans by High Performance Liquid Chromatography , 1983 .

[18]  R. Legault,et al.  Browning of dehydrated vegetables during storage. , 1947 .

[19]  W. Daud,et al.  Characteristic Drying Curves of Cocoa Beans , 1996 .

[20]  E. Anklam,et al.  Analysis of procyanidins in chocolate by reversed-phase high-performance liquid chromatography with electrospray ionisation mass spectrometric and tandem mass spectrometric detection. , 2001, Journal of chromatography. A.

[21]  J. Chirife,et al.  Effect of moisture content and temperature on some aspects of nonenzymatic browning in dehydrated apple , 1979 .

[22]  T. Labuza,et al.  Kinetics of Browning and Protein Quality Loss in Whey Powders During Steady State and Nonsteady State Storage Conditions , 1982 .

[23]  T. Labuza,et al.  FEASIBILITY OF ACCELERATED TESTS FOR BROWNING IN DEHYDRATED CABBAGE , 1970 .

[24]  Theodore P. Labuza,et al.  STABILITY OF INTERMEDIATE MOISTURE FOODS. 1. Lipid Oxidation , 1972 .

[25]  Theodore P. Labuza,et al.  Kinetics of lipid oxidation in foods , 1971 .

[26]  Rakesh K. Singh,et al.  Kinetics of nonenzymatic browning in dried skim milk , 1990 .

[27]  Elke Anklam,et al.  Review on polyphenols in Theobroma cacao: changes in composition during the manufacture of chocolate and methodology for identification and quantification , 2000 .

[28]  Chang Yong Lee.  Enzymatic Oxidation of Phenolic Compounds in Fruits , 1992 .

[29]  W. G. Forsyth,et al.  THE MECHANISM OF CACAO CURING. , 2006, Advances in enzymology and related subjects of biochemistry.

[30]  J. P. Danehy.  Maillard reactions: nonenzymatic browning in food systems with special reference to the development of flavor. , 1986, Advances in food research.