Optimization of enzymatic treatment to produce yacon juice clarified by microfiltration with high levels of chlorogenic acid and fructooligosaccharides

Effect of the consumption of yacon flour and energy-restricted diet on glycation markers, and association between these markers and factors linked to obesity in adults with excess body weight: A randomized, double-blind, placebo-controlled clinical trial

OBJECTIVES

Regardless of the positive effect of yacon on metabolic markers, this food contains fructose molecules, which can originate advanced glycation end products (AGEs). High AGEs serum concentrations can contribute to excess body weight. We evaluated the effect of consuming an energy-restricted diet and yacon flour on glycation markers concentrations, and the associations between these markers and factors linked to obesity in adults with excess body weight.

METHODS

Twenty-six adults with excess body weight were included in this randomized, parallel, double-blind, placebo-controlled, 6-week clinical trial. Subjects were randomly allocated to the control group (n = 13) or the yacon-flour group (n = 13), and daily consumed a breakfast drink either not containing or containing 25 g of yacon flour (8.7 g of fructooligosaccharides). Energy-restricted diets were prescribed for both groups. Biochemical markers, anthropometric variables, and body composition were evaluated at baseline and the end of the study.

RESULTS

AGEs and early glycation products did not increase in the yacon flour group. Soluble receptor for AGEs (sRAGE) decreased regardless of group. Besides, changes in AGEs were positively associated with changes in body fat (β = 0.04, P = 0.038) and in sRAGE, with insulin (β = 0.02, P = 0.035) and homeostasis model assessment index of insulin resistance (β = 0.01, P = 0.049).

CONCLUSIONS

The consumption of 25 g of yacon flour associated with an energy-restricted diet did not increase concentrations of glycation markers. Changes in glycation markers were positively associated with changes in consolidated anthropometric and biochemical markers related to being overweight. Assessing glycation markers may be a useful strategy for monitoring responses to dietary interventions in subjects with excess body weight.

Acute postprandial effect of yacon syrup ingestion on appetite: A double blind randomized crossover clinical trial

Yacon syrup is a rich source of fructooligosaccharides (FOS); however, its diet supplementation effect on subjective sensation and appetite biomarkers in human is still unknown. This study aimed to evaluate the acute postprandial effect of yacon syrup ingestion on appetite. The double-blind crossover clinical trial was carried out with 40 adult women: 20 eutrophic and 20 obese grade I. On each day, the first blood collection was performed after a 12-h fast. Then, the volunteers ingested either intervention A (breakfast + 40 g of placebo) or intervention B (breakfast + 40 g of yacon syrup, containing 14 g of FOS). New aliquots of blood were collected at 45, 60, 90, 120, and 180 min. Appetite was assessed by estimating ghrelin and glucagon-like peptide-1 (GLP-1) levels and by assessing subjective appetite sensation. Analysis was performed using two-way ANOVA, followed by Bonferroni's multiple comparison test. No effect of yacon syrup was observed on postprandial ghrelin and GLP-1 levels at all times evaluated. Similar observations were made after stratifying the analysis by BMI (body mass index) (eutrophic and obese). The effect of yacon syrup on postprandial subjective sensations of hunger, satiety, fullness, and desire to eat was not evident in the total group of women evaluated and even after BMI stratification. We concluded that yacon syrup had no effect on postprandial ghrelin and GLP-1 levels and on the subjective appetite sensation in young adult women.

Yacon syrup reduces postprandial glycemic response to breakfast: A randomized, crossover, double-blind clinical trial

Yacon is a root rich in fructooligosaccharides (FOS), which act as prebiotics. Numerous studies have shown promising results in the technological aspects of producing yacon syrup. However, uncertainties exist concerning whether yacon syrup can modulate postprandial glucose and lipid profiles. In order to assess the effect of yacon syrup on postprandial glucose, insulin and triglyceride (TG) responses, a randomized, crossover, double-blind clinical intervention with 40 women (20 normal weight and 20 grade I obese) was performed. Participants underwent two-arms of intervention with at least a one-week wash-out period between visits. On each intervention day, after 12 h of fasting, an aliquot of blood was collected. For intervention A, volunteers consumed breakfast +40 g of placebo, whereas for intervention B, participants consumed breakfast +40 g of yacon syrup (14 g of FOS). Blood samples were drawn at 15, 30, 45, 60, 90, and 120 min. Glucose and insulin concentrations were lowered after yacon syrup intake as compared to placebo at following times: 30 min for glucose and 15, 30 and 45 min for insulin. In conclusion, yacon syrup has a postprandial decreasing effect glucose and insulin concentrations in adult women. This effect was not evident for triglyceride concentration. Clinical trial registry: RBR-33wf46. Available in: http://www.ensaiosclinicos.gov.br/rg/RBR-33wf46/.