Factors that reduce the amount of thiamine available:
(1) prolonged heating
(2) delay in eating prepared food
(3) excessive washing
(4) presence of anti-thiamine factors
(5) chemical inactivation (high pH, etc; see above)
(6) discarding water used for cooking
Ways to minimize unnecessary loss of thiamine during food preparation:
(1) Use a minimum amount of water to cook foods.
(2) Use thiamine enriched foods if available.
(3) Cook the food for the minimum amount of time (cover the pot to hasten boiling, etc.).
(4) Do not discard any cooking water.
(5) Do not store cooked food.
(6) Wash vegetables before cutting them into pieces.
(7) If possible do not wash rice before cooking. If washing is necessary, wash once and use a minimum amount of water.
(8) Use parboiled rice (such as Uncle Ben's Converted Rice) if available.
(9) Cook rice with the minimum amount of water (usually 2 volumes water to 1 volume rice).
(10) Heat any food with thiaminase activity prior to eating.
Ways to maximize intake of thiamine while eating:
(1) Eat meals as soon as possible following preparation.
(2) Consume foods rich in vitamin C during the meal.
(3) Delay consumption of tea or coffee until after the meal.
