How can nutrients in spinach be optimally protected during preparation?
Can the positive effects of vegetables be improved when used in a smoothie? Swedish researchers have now discovered that spinach develops their nutrients even better when vegetables are turned into a smoothie.
Scientists at Linköping University have discovered in their current research that turning spinach into a smoothie allows the highest intake of nourishing lutein. The experts published the results of their study in the English-language journal "Food Chemistry".
What is lutein?
When the spinach is turned into a smoothie, the intake of nutrient lutein increases to the maximum. Lutein is a so-called antioxidant, which is associated with the reduction of inflammation, brain aging, improvement of intelligence and sight conservation. Lutein must be taken from food, particularly green leafy vegetables, but it is decomposed once heated. The team at Linköping University has therefore set itself the goal of determining the best method to preserve lutein. Experts have selected spinach for their experiments. Spinach contains a relatively high amount of lutein and are generally available everywhere.
Which preparation method is optimal for lutein?
The researchers bought spinach from a local supermarket and subjected the spinach to the usual cooking techniques: cooking, frying, steaming, microwave heating and cold preparation methods such as salads or smoothies. The unique feature of this study is that it uses cooking methods that are often used in preparing food at home. In addition, different temperatures and warm-up times were compared, says the author of Lena Jonasson of Linköping University.
Why does a smoothie maximize lutein intake?
As expected, the heat proved to be problematic for lutein. The more the spinach was cooked, the less nutrients remained. When the spinach was fried, this destroyed a large part of lutein in just two minutes. Spinach should not be warmed up properly, so most of lutein is conserved, the researchers report. This also explains why a smoothie is the best method of preparation. If spinach is cut into small pieces, even lutein in spinach will be better released. The fats added from milk or yogurt also add to the solubility of this lutein, the researchers add. (As)