Fruit and vegetables stored for a long time before being consumed suffer huge vitamin losses due to the slow progression of enzymatic decomposition. Vitamin C in this regard is particularly sensitive: in apples stored at home the content of vitamin C can be reduced by about one third of the initial value after only two or three months, while the vitamins of group B undergo very slight variations.
PACKAGING: riboflavin, cobalamia, folate, ascorbic acid, tocopherols and vitamin K are particularly sensitive to light .
FREEZING: Thiamine, riboflavin, nicotinic acid and pyridoxine are well preserved in frozen meat. In vegetables, ascorbic acid losses of up to 25% can occur.
WHITENING: treatment, to inactivate enzymes, to which plants are subjected before being canned or frozen. The reduction of the vitamin content varies according to the time and temperature at which the process takes place. It is believed that the losses vary between 13 and 60% for vitamin C, between 2 and 30% for thiamine and between 5 and 40% for riboflavin.
DEHYDRATION: The most significant losses are ascorbic acid (10 - 15%).
BOX STORAGE: Losses occur during the preparation phase (heating and sterilization). Losses are negligible during the storage period.
STERILIZATION: Concerns above all the tremulous vitamins. For example, sterilization at high temperatures and pasteurization of milk can lead to losses of vitamin C up to 20%, while there is no significant loss of vitamins A and D.
COOKING: During normal cooking operations of fresh vegetables in water, vitamin losses up to 60 - 70% can be avoided, in particular water-soluble vitamins such as B1, B2 and C.
REDUCTION OF LIPID CONTENT: involves a reduction in the content of liposoluble vitamins.
