蔬菜中钙、磷、钾、钠烹调保留因子的研究

STUDY ON RETENTION FACTORS OF CALCIUM PHOSPHORUS POTASSIUM AND SODIUM IN COOKING VEGETABLES

目的:研究蔬菜在不同烹调方法下钙、磷、钾、钠的保留因子,为进行膳食营养评价提供参考。方法:选择常用的11种蔬菜,以炒、炖、焯等方法进行烹调,记录烹调前后的重量,用国标方法测定烹调前后蔬菜中钙、磷、钾、钠的含量,计算相应的保留因子。结果:根菜类、鲜豆类、薯类、茄果类蔬菜炒后钙保留因子多在80%以上,叶菜炒后在60%～80%之间;焯后略低于其它烹调方法。鲜豆烹调后磷的保留因子依次为焯>炖>炒,其他蔬菜为炖>炒>焯。茄果类蔬菜钾的保留因子大于90%,经焯后叶菜、根菜类低于60%,其它蔬菜在60%～90%之间。钠的保留因子依次为炖>炒>焯,炖后在80%以上,焯后接近70%。结论:不同烹调方法处理后蔬菜中矿物质元素的损失程度差异很大,宜建立不同蔬菜的烹调后营养素保留因子库。进行膳食营养评价和选择烹调方法时,应考虑不同方法的烹调损失。

Objectives： To study the mineral retention factors （RF） of vegetables after cooking for evaluating the nutritional value of diets. Method： Eleven types of fresh vegetables were studied, including legumes, root vegetables, leafy vegetables, tubers, or cucurbitaceous vegetables. Each vegetable was cooked by different methods, such as frying, braising, boiling, according to custom. The weights of vegetables before and after cooking were recorded. Mineral contents were analyzed with the national standard methods. Results： Calcium RF in root vegetables and legumes were mostly more than 80% for frying, 60%-80% in leafy vegetables, and less for boiling than other cooking methods. Phosphorus RF in legumes for different cooking methods were boiling 〉 braising 〉 frying and in other vegetable were braising 〉 frying 〉 boiling. Potassium RF in cucurbitaceous vegetables were more than 90%; less than 60% in root and leafy vegetables for boiling ; and 60%-90% for other cooked vegetables. Sodium RF for different cooking methods were braising 〉 frying 〉 boiling, more than 80% for braising, but near 70% for boiling. Conclusion： Cooking may cause loss of minerals, and the mineral retention factors are different in different vegetables for the same cooking method.