Bearing in mind the sensitivity
of carotenoids, the impact of freezing/storage temperature
may be important, but no studies were found regarding to the effect
of freezing using the same food batch and the measurement
uncertainty to interpret the differences observed. Some researchers
choose to analyse products in the market, and acquired fresh,
frozen or canned fruits and vegetables as available to consumers.
In such cases, analysis of processing effects is difficult since raw
and processed foods cannot be obtained from the same batch,
and the mass fraction/profile of compounds may be different
depending on cultivar, harvest, ripeness, etc.