NO - Besoin d'assistance

Processing and Bioavailability (WG2) page 38
__________________________________________________________________________________________
14 Freezing O
Survey of references
Urbany and Horty (1989) evaluated colour and carotenoid changes during frozen storage of
quick-frozen tomato cubes. Total carotenoids (determined by solvent extraction, column
chromatography on magnesium oxide and spectrophotometric evaluation) decreased by
approximately 40% during 6 months' storage at -20°C. Lycopene degradation was almost
linear in time. Residual lycopene concentrations in 3 tomato varieties ranged from 75% to
12% after 1 year's storage. Colour intensity was linearly correlated to residual carotenoid
concentration in the products.
Labrador et al. (1998) studied the effect of processing technique on the colour and
lycopene content of tomato sauces for pizza during frozen storage. As stated above, sauces
prepared in an open stirred kettle (o.s.k.) (15 min at 95 °C, in the open air) had significantly
better colour attributes and lycopene content than those obtained in a tubular pasteuriser (105
°C for an unspecified time adequate to reach an Fo value ensuring product stability) but
showed a faster change in lycopene content during storage; this indicates lower stability (in
the product obtained in o.s.k., the lycopene content diminishes from 110 to 16 ppm in 6
months of storage at -10 °C, while for sauces obtained with the pasteuriser, the lycopene
reduction is from 95 to 30 mg/kg).
Comments and topics
The scant bibliography on the subject makes it impossible to make any affirmations or to
carry out an analysis of the hazards.
Is this step an RCPL ?
This aspect includes extremely varying aspects which cannot be grouped together, hence
a hazard analysis would not appear to be applicable.
.