Submitted to: Nutrients
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/3/2017
Publication Date: 2/13/2017
Citation: Chen, C., Rasmussen, H., Kamil, A., Du, P., Blumberg, J.B. 2017. Orange pomace improves postprandial glycemic responses: an acute, randomized, placebo-controlled, double-blind, crossover trial in overweight men. Nutrients. 9:130. doi: 10.3390/nu9020130. Interpretive Summary: Diets rich in plant-based foods are associated with reduced risk of a number of chronic diseases, e.g. cardiovascular disease and type 2 diabetes mellitus. These beneficial correlations can be partly attributed to the nutrients in plant-based foods, including vitamins, minerals, phytochemicals, and fiber. During orange juice production, orange pomace is produced. It is a fiber-rich waste byproduct, which also contains an edible portion of the fruit that includes segments, broken pulp sacs, and a center core. Orange pomace is not fully utilized as an ingredient providing added value to the processed foods. Besides fiber, orange phytochemicals entrapped in the fiber are also lost during juice production and may help regulate the postprandial glucose response and prevent and protect against metabolic syndrome and type 2 diabetes. In this human study, we examined the effect of a beverage containing orange pomace on blood glucose and insulin responses to a standard high fat and high carbohydrate breakfast in overweight men. We found that the acute consumption of an orange pomace-containing beverage containing 5.48 g fiber benefits postprandial glycemic excursion and insulinemic responses. Furthermore, these benefits appear to continue to the second meal. Thus, our study suggests that the inclusion of high fiber foods, such as drinks made with orange pomace, in breakfast may be beneficial to controlling postprandial glucose spikes.
Technical Abstract: Orange pomace (OP), a fiber-rich byproduct of juice production, has the potential for being formulated into a variety of food products. We hypothesized that OP would diminish postprandial glycemic responses to a high carbohydrate/fat breakfast and lunch. We conducted an acute, randomized, placebo-controlled, double blind, crossover trial with 34 overweight men who consumed either 255 g placebo (PLA), a low (35% OP (LOP)) or a high (77% (HOP)) dose OP beverage with breakfast. Blood was collected at 0, 10, 20, 30, and 45 min and 1, 1.5, 2, 3, 4, 5, 5.5, 6, 6.5, 7, and 8 h. Lunch was consumed after the 5.5-h blood draw. OP delayed the time (Tmax1) to the maximum concentration (Cmax1) of serum glucose during the 2-h period post breakfast by >36% from 33 (PLA) to 45 (HOP) and 47 (LOP) min (p = 0.055 and 0.013, respectively). OP decreased post-breakfast insulin Cmax1 by >10% and LOP delayed the Tmax1 by 14 min, compared to PLA at 46 min (p < 0.05). HOP reduced the first 2-h insulin AUC by 23% compared to PLA. Thus, OP diminishes postprandial glycemic responses to a high carbohydrate/fat breakfast and the second meal in overweight men.