Respiration Model for Fresh-cut Products as a Function of Degree of Cutting
K. Nakano and S. Maezawa
Book of Abstracts, Asia-Pacific Symposium on Assuring Quality and Safety of Agri-Foods, August 4-6, 2008, Radisson Hotel, Bangkok, Thailand.
2008
บทคัดย่อ
Respiration Model for Fresh-cut Products as a Function of Degree of Cutting
To extend Michaelis-Menten type respiration model for fresh-cut products so as to possible to describe the cutting effect, the respiration rates of four sizes of green pepper, eggplant and cucumber slices at different partial pressures of O2 were determined using a flow through system method at 20°C. Degree of cutting (D-value) was quantified by determining the surface area created through cutting per unit weight of the product. CO2 production of each product decreased in response to decreasing O2. In addition, increases in D-value resulted in increased respiration rates. Michaeli-Menten type equation was fitted to each data set of different cutting sizes by nonlinear least square method, and the parameters Km and Vmax were estimated, individually. With an increase in D-value, Km decreased and Vmax increased, but at higher rage of D-value, both parameters seemed to approach constant values. The dependences of both these parameters on D-value dould be expressed by exponential equations. The extended Micahelis-Menten type respiration madel including these equations coule provide a good prediction of respiration rate of fresh-cut products at any O2 partial pressures and degrees of cutting.