“Recently, the consumption of beetroot juice, a food rich in nitrate and antioxidant, has gained attention in scientific literature because of the functional properties associated with this food,” wrote a team of researchers from the Federal University of Rio de Janeiro and the Fluminense Federal University.
In fact, it’s not just in scientific literature—beetroot juice has been gaining some attention commercially for its functional properties this last year in both packaged food and beverage. Researchers in Brazil argue that in gel form, a higher concentration of beetroot’s benefits can be consumed.
“Beet juice contains a high level of biologically accessible antioxidants as well as other nutrients such as sugars (mostly sucrose) and potassium,” they wrote in their study published in the International Journal of Food Sciences and Nutrition. “However, no data on nitrate bioaccessibility of beetroot-based nutritional gel has been published in the literature,” they added.
The researchers argued that foods in gel form tend to have higher concentrations of nutrients in a reduced volume. In the current study, they analysed in vitro bioaccessibility of beetroot’s nutrients delivered in gel form. Their findings suggest that it is “a new nutritional strategy to give high contents of bioaccessible nutrients that are potentially relevant to improve cardiovascular health and exercise performance.”
Sugar, potassium, nitrate, and antioxidants
For this study, the scientists used conventional beetroot from a market in Rio de Janeiro. They washed 2 kg of the roots in tap water, sanitized with a chlorine solution, and separated them in four different batches of 500 g each (three raw beetroots per batch).
Each batch was blended to create a juice, part of which was then filtered and passed into a spray-dryer to produce powder. Then, the juice and powder mixtures were mixed until gel consistency. The resulting gel batches were then assigned analyses: sugar, potassium, nitrate, and total antioxidant capacity and total phenolic content.
Analysis was done twice for each, with an in vitro digestion experiment conducted, as the researchers argued that it is “important to provide valuable information about the potential bioavailability of these nutrients for in vivo absorption.”
For the resulting product’s market appeal, the researchers conducted a sensory evaluation by recruiting 41 non-trained consumers (31 female, 10 male) ranging between 21 to 87 years old. They were tasked to evaluate the aroma, color, taste, and overall acceptability of each sample from a scale of 1 to 9. They were also asked to indicate their purchase intention.
Beetroot gel promising nutritional ingredient for functional food
The researchers found that the beetroot gel “may suggest a new nutritional strategy to increase dietary nitrate ingestion and the bioaccessibility of antioxidants and potassium.”
They found no significant losses in the nitrate content after the in vitro digestion, and that the gel offered a significant amount of nitrate (approximately 10mmol nitrate in a mass of 100g) compared to the commercial beetroot juice Beet It.
“Previous studies have demonstrated that dietary nitrate supplementation from vegetal sources have a beneficial effect on cardiovascular health and exercise performance,” the researchers wrote.
They also found that the total antioxidant capacity and total phenolics in beetroot gel were statistically higher than beetroot juice in non-digested form, and consistently remained more than juice in the gastric phase and duodenal phase. As for potassium, the researchers notice a significant decrease from the gastric phase to duodenal phase in both forms of beetroot.
The sensory survey results indicated that the product was palatable to consumers (it was flavored with artificial orang flavor), and that the sample of consumers think they would purchase it if it were on the market.
Dr. Anna Paola Pierucci, a professor at the Federal University of Rio de Janeiro’s Josue De Castro Nutrition Institute, told NutraIngredients-USA that there are plans to commercialize their findings as a functional food, though she could not disclose any more specifics.
She also said that further studies are being done on the beetroot gel product: “We have tested among athletes (manuscript under submission), and elderly people (titled: A single dose of a beetroot-based nutritional gel improves endothelial function in the elderly with cardiovascular risk factors. Journal of Functional Foods - accepted for publication).”
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Source: International Journal of Food Sciences and Nutrition
Published online: 17 Feb 2016
Authors: Marina Morgado, Gustavo Vieira de Oliveira, Julia Vasconcellos, Maria Lucia Monteiro, Carlos Conte-Junior, Anna Paola Trindade Rocha Pierucci, Thiago Silveira Alvares