Jm. Membre et M. Kubaczka, DEGRADATION OF PECTIC COMPOUNDS DURING PASTEURIZED VEGETABLE JUICE SPOILAGE BY CHRYSEOMONAS-LUTEOLA - A PREDICTIVE MICROBIOLOGY APPROACH, International journal of food microbiology, 42(3), 1998, pp. 159-166
Predictive modelling consists in describing effects of environmental f
actors on microbial growth parameters. With food spoilage bacteria, th
is approach must be extended to both growth and food damage characteri
sation. In order to study the incidence of storage temperature on vege
table damage, using predictive microbiology tools, kinetics of pectic
compound degradation were studied. Chryseomonas luteola has been chose
n because of its ability to grow on post-harvested vegetables. Experim
ents were performed at refrigerated temperatures (0-10 degrees C) with
low initial bacterial charges (10(1)-10(3.5) cfu/ml). Microbial speci
fic growth rate (mu), stability phase before pectic degradation (S-p)
and alteration percentage (A(p)) were chosen as reference parameters.
Then, sub-optimal temperature effects on these three parameters were e
stimated using modified Ratkowsky model. Results obtained in synthetic
medium were compared with data observed in endive juice to appreciate
the alteration of vegetable during post-harvest storage. (C) 1998 Els
evier Science B.V.