[Study on vitamin B1, vitamin B2 retention factors in vegetables]

To study the influence factors of vitamin B1, vitamin B2 losses in vegetables during cooking.

12 types of fresh vegetables were selected and cooked by different cooking process, including roast, braise, fry, steam, scald and salt curing. vitamin B1 and vitaminB2 contents in raw and cooked samples were analysed respectively by GB/T 5009.84--2003 and GB/T 5009.85--2003 fluorometry. At the same time, weights of vegetables before and after cooking were recorded. Then CY and RF were calculated.

The results showed that the retention rate in leguminous vegetables was 66%-75% for vitamin B1 and 85%-190% for vitamin B. Scalding could cause bigger loss of vitamin B1 in leafy vegetables and root vegetables, RF was about 50. The values of vitamin B2 RF in leafy vegetables for roasting was bettering than for scalding. For vitamin B2, the retention rate in root and cucurbitaceous vegetables was about 77-79.

Vitamin B1 and vitamin B2 retention factors of roasting and steaming are more than that of frying and scalding. Temperature, time and variety of vegetable are the important influence factors of vitamin retention factors.