According to the study authors, this is the first study to “comprehensively characterize the physiological responses to slowly digestible starch…in in vitro and in vivo studies.”
Ingredion Inc. (Westchester, IL) announced the results of a new study1 indicating that its proprietary slowly digestible carbohydrate blend of tapioca flour and corn starch, Sustra 2434, may help balance energy and is highly digestible in vivo, yielding a lower glycemic index (GI) compared with a rapidly digestible control. According to the researchers, this is the first study to “comprehensively characterize the physiological responses to slowly digestible starch…in in vitro and in vivo studies.”
Vishnupriya Gourineni, global nutrition research and development scientist, Ingredion, said in a press release from the company that “Having a lower glycemic response to food is an indicator of prolonged digestion and absorption, which helps to yield more balanced energy throughout the day.” She continued: “Ingredion’s proprietary research has shown that consumers are interested in foods that deliver steady energy, particularly from early morning to mid-afternoon. At the same time, consumers are seeking low glycemic index foods to help manage blood sugar.”
The study, which was funded by Ingredion and published in the journal Nutrients, was conducted in three parts: 1) an in vitro study that sought to characterize the digestibility of Sustra 2434; 2) an in vivo rooster model study to confirm digestibility; and 3) a clinical study in a healthy population to assess Sustra 2434’s glycemic response.
In the in vitro study, researchers compared Sustra 2434 with a maltodextrin (Globe Pus 10 DE maltodextrin; Ingredion). Researchers measured the glucose release of both Sustra 2434 and the maltodextrin control to determine the digestibility profile of each using a modified Englyst assay. At the end of two hours digestion, the researchers wrote, slowly available glucose was higher for Sustra 2434 (79.4%) than for the control (9.3%).
In the in vivo rooster model, 10 roosters underwent 26 hours of feed withdrawal, after which they were tube-fed an average of 26.7 g of the test starches (five roosters were given Sustra 2434, and five were fed the control). The researchers then collected excreta for a period of 48 hours, which were then lyophilized, weighed, and ground prior to analysis. The true metabolizable energy for both carbohydrates was high, indicating their complete digestibility, but the energy value of Sustra 2434 was slightly lower than the maltodextrin in roosters, indicating that around 6% is non-digestible.
Finally, in the randomized, double-blind, placebo–controlled, crossover, clinical study, the study authors sought to examine the sustained energy effects of Sustra 2434 compared with a maltodextrin control in a cold–pressed bar and a pudding. Fourteen healthy male and female participants, aged 18–75 years, were evaluated on separate days over a period of two to six weeks. During that time, subjects completed six study visits during which they consumed one of the following: a bar featuring Sustra 2434 (24.9 g) and corn syrup (18.9 g); a bar featuring the maltodextrin control (22.1 g) and corn syrup (21.8 g); a pudding featuring Sustra 2434 (30.4 g) and dextrose (10.9); a pudding featuring the control (39.6 g dextrose); dextrose beverage 1 (50 g dextrose in 250 mL water); or dextrose beverage 2 (50 g dextrose in 250 mL water). The beverages were administered twice for glycemic index calculations.
At each test visit, researchers collected two fasting blood samples for glucose analysis five minutes apart. After the second blood sample was taken, participants were given one of the six test meals. At the first bite of each test meal, a timer was started, and additional blood samples for glucose analysis were taken at 15, 30, 45, 60, 90, 120, 150, 180, 210, and 240 minutes after subjects began eating. The subjects who consumed the pudding or bar with Sustra 2434 demonstrated a significantly lower glycemic index compared with the control groups. At individual time points, the researchers noted, the Sustra 2434 bar and pudding yielded blood glucose levels with significantly lower values at 30–60 min and significantly higher values at 120–240 min, indicating a more balanced energy release.
Of the study results, Gourineni said: “The balanced, more sustained energy that Sustra 2434 slowly digestible carbohydrate provides can help improve carbohydrate value in energy-focused nutritional foods, beverages and supplements.”