Effect of heating temperature on browning reaction in chicken extract = ผลของอุณหภูมิความร้อนที่มีต่อการเกิดสีน้ำตาลในสารสกัดจากเนื้อไก่


ปฏิมารัตน์ น้อยแรม


วิทยานิพนธ์. (2011) 69 หน้า



The kinetics of brown color formation and reactants (reducing sugar and free amino acids) consumption during non-enzymatic browning of chicken extract undergoing heating at different temperatures (100, 120, 140, 160 C) and times (0, 5, 10, 15, 20, 25, 30 min) were studied. The chicken extract was heated in a hermetically sealed stainless steel cup and held at constant temperatures. Reducing sugar and free amino acids concentrations were determined by high performance liquid chromatography (HPLC). The results indicated the presence of glucose as a reducing sugar and seventeen free amino acids in chicken extract. During heating browning pigments increased, while glucose concentration dramatically decreased when the temperature and time increased. The concentration of most amino acids in chicken extract were rather constant during heating; however, lysine concentration slightly decreased during heating. As total free amino acids concentration was rather constant throughout the study, it was assumed that free amino acids were presented in excess amount and glucose was a rate determining reactant for color formation via Maillard reaction. Multiresponse modelling technique was used to test the kinetic reaction. However, a simple kinetic reaction (either zero-, first-, second- or n-order) did not describe well both the glucose consumption and browning pigment formation in chicken extract system as indicated by low correlation coefficient (R2) As. the chemistry of Maillard reaction is very complex, many intemediates could be formed and/or degraded to form products through a series of reactions. Thus, the formation and degradation of intermediates was added to the reviscd model. A first-order reaction in series kinetics could describe brown pigment formation and glucose consumption. An increase in the heating temperature led to higher values of the rate constants of glucose loss (k = 1.56x10-2 - 8.8x10-2 min-1) and browning pigment fonnation (k = 3.55x10-3 3.5x10-2 min-1) The effect of heating temperature on these rate constants could be described by Arrhenius relationship with the estimated activation energy (E,) values of glucose consumption and browning pigmnent formation of 38.29 and 5 1.93 kJ/mol, respectively