Discussion
When calculating the retention of nutrients during cooking, it
should be prioritized to use true retention factors, i.e. based on calculation
of weight and content of the nutrient in the raw and the
processed food, compared to apparent retention factors, i.e. content
of the nutrient calculated on dry weight, wherever possible
(Murphy et al., 1975). Furthermore, the tools used in the investigation
of retention of vitD during preparation of the different food
should be carefully evaluated in terms of the analytical methods
applied, and the information of the preparation conditions e.g.
temperature, time, sizes of pans and pots.