Selection of Beef Quality Factors Represented by Time-Temperature Integrator (TTI)

Abstract

Beef qualities which can be properly predicted by time-temperature integrator (TTI), a chromatic indicator, were selected in terms of its similarity of temperature dependence between beef qualities and TTI, denoted by Arrhenius activation energy (E a ). The high similarity is required to afford accurate prediction. A devised enzymatic TTI based on laccase (an oxidase), which catalyses the oxidation on 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) producing color development, was applied. The factors of beef quality, such as volatile basic nitrogen (VBN), pH, color (CIE L*, a*), Warner-Bratzler shear force (WBSF), Pseudomonas spp. count, and lactic acid bacteria (LAB) count were considered for the selection. E a (55.48 kJ/mol) of the TTI was found to be similar to those of the beef qualities (all referred) in the order of LAB count (53.54 kJ/mol), CIE a* value (61.86 kJ/mol), pH (65.51 kJ/mol), Pseudomonas spp. Count (44.54 kJ/mol), VBN (67.98 kJ/ mol), WBSF (40.67 kJ/mol), and CIE L* value (33.72 kJ/mol). The beef qualities with more similar E a to that of the TTI showed less difference between real and TTI predicted levels. In conclusion, it was found out that when applying TTI to food packages, their E a similarity should be checked to assure accurate estimation of food quality levels from TTI response.