Smoothies are an attractive and convenient way to consume combinations of various fruits and vegetables and enjoy their potential health benefits. In fact, they provide the same health benefits as the raw ingredients when the beverage is consumed immediately after preparation, according to Dr Francisco Artés Hernández, head of the Post-Harvest and Refrigeration Group (GPR) of the Polytechnic University of Cartagena, which actively collaborates with with the non-profit association +Brócoli.
Most of the nutrients are preserved after turning the products into a shake, with the exception of some compounds that are highly degradable, such as vitamin C, whose levels begin to decrease in this process, since "we go from a stable compartmentalised cellular structure to a situation in which a quick decomposition of the more sensitive organic substances takes place," explains Artés Hernández.
In spite of this, as pointed out by the head of GPR, these reactions can be slowed down with the application of innovative processing treatments, which can extend the stability of these compounds by ten days and, therefore, improve their shelf life until consumption as part of the smoothie.
For example, red shakes get their colour from carotene, which is present in fruits such as tomatoes or watermelons. These produce lycopene levels that remain stable, without significant changes, for up to 28 days at 5ºC, but this can be increased up to 58 days through the use of alternative thermal treatments during processing, such as microwaves, for gentle pasteurization.
It is recommended for smoothies to be consumed first thing in the morning
Researchers and nutritionists say that the most appropriate time to consume a smoothie made from fruit and vegetables is first thing in the morning. When we still have an empty stomach, having done the whole process of digestion during the night, the absorption of nutrients is much more efficient. "On an empty stomach, these preparations offer us a much needed supply of vitamins, antioxidants, minerals, enzymes and natural fibre, which will help our body give a boost to the immune system and allow us to start the day full of energy," says Artés Hernández.
