Homemade juices are a popular way for health-conscious people to consume their vegetables. But the method of juicing makes a difference, a recent study suggests.
The researchers found that three different techniques – using a low-speed or high-speed blender or juicer – produced beverages with different levels of antioxidants and various plant compounds.
The way you make your juice determines the nutrients it contains. Photo: Pixabay
But anyone hoping for a simple verdict on the best buy is out of luck.
The nutrient findings were mixed, with no device « winning », according to senior researcher Bhimanagouda Patil.
« We are not making any recommendations on which method is best, » said Patil, director of the Center for Vegetable and Fruit Improvement at Texas A&M University.
Overall, the study found, both extractors outperformed the blender on the activity of antioxidants and phenolics, a broad group of plant compounds. Low-speed extractors, in particular, often produced the highest concentrations.
But this also depended on the vegetable in question: for example, with kale, low speed extraction clearly removed the most phenolics. But this did not happen with beets or carrots.
On the other hand, blenders were not always last. They performed well with compounds called alpha-amylase inhibitors, which help control blood sugar levels after a meal.
« It’s complicated, » said Patil.
Additionally, the study evaluated only a limited number of plant and plant compounds, what Patil called « the tip of the iceberg. »
The findings, published in a recent issue of the journal ACS Food Science & Technology, are based on analyzes of 19 vegetables, which included various types of beets, carrots, cauliflower, kale and turnip.
Each was juiced using all three methods, which differ in the way they transform solid vegetables and the amount of heat they produce, for example.
Patil explained that blenders squash vegetables and create a thicker juice that retains more fiber. The researchers said that is the likely reason for the high levels of alpha-amylase inhibitors.
On the other hand, high speed centrifugal extractors pulverize vegetables and separate the juice from the pulp and fiber. Low-speed extractors also remove pulp and fiber, but create less heat than the other two methods, particularly blenders, which could explain the higher levels of plant compounds.
« The bottom line is that each method had a benefit over the others, » said Sonya Angelone, a registered dietitian and spokesperson for the Academy of Nutrition and Dietetics. Angelone was not involved in the study.
When it comes to eating vegetables in general, he said, whole foods are a better option than juices because they contain more intact fiber.
« Fiber is important, because it feeds the good gut bacteria that keep you healthy, » Angelone emphasized. « And most people don’t eat enough fiber to optimize health. »
With that said, she noted that juices made in a blender retain more fiber. And he said juices can be a way to get some servings of vegetables, or to help « fill in nutritional gaps. »
But Angelone added that people should limit fruit juices. « Juice is mostly sugar, which is high in calories without the benefit of vitamins, minerals, fiber, and other healthy compounds from plants. »
Patil said that he too is a « staunch advocate » of eating whole vegetables and fruits. But he added that if people dislike the taste or texture of certain vegetables, consuming them in juice form might be more palatable for them.
And, based on these findings, any of the three home methods produces vegetable juices with « a variety of health-promoting compounds, » Patil noted.
This is definitely better than buying sugar-sweetened drinks, added Patil.
The study was funded by the US Department of Agriculture.