Vitamin losses: Retention during heat treatment and continual changes expressed by mathematical models

Processing and cooking conditions cause variable losses of vitamins. Losses vary widely according to cooking method and type of food. Degradation of vitamins depends on specific conditions during the culinary process, e.g., temperature, presence of oxygen, light, moisture, pH, and, of course, duration of heat treatment. The most labile vitamins during culinary processes are retinol (vegetable boiling, 33% retention), vitamin C (the most damaging factors are cooking and oxidation), folate (leaching into the cooking water, 40% retention), and thiamin (cooking, retention 20–80%). Niacin, biotin, and pantothenic acid are quite stable, but information on some vitamins, especially vitamins D and K, is incomplete. The percentage losses of some nutrients in foods after cooking treatment were frequently reported: not continual changes during heat treatment, only modifications at the beginning and after heat treatment. Changes of nutrients in food during the culinary process have not yet been sufficiently investigated. A few authors have attempted to summarize the kinetic data which can be used to describe the time–temperature effect on nutrients.