Postprandial Response of Fresh-squeezed and Processed Orange Juice on Appetite-related Biomarkers and Antioxidant-status in Lean and Obese Subjects

Non-randomized crossover clinical trial, in which eligible participants (n= 36) were allocated in accordance with their body mass index in two groups, lean (n = 18, 9 women/9 men) and obese (n = 18, 9 women/9 men). Subjects of both groups intake of one single dose (5 mL/kg body weight) of isoenergetic beverages in three different phases: (1) fresh-squeezed orange juice (FOJ), (2) commercial processed orange juice (POJ) and (3) an energy and sugars-matched orange-flavored drink (control), with a washout period of seven days among each beverage. Thirty minutes after the intake of each beverage, the participants had a flavonoid-free standard breakfast, which contained coffee (infusion), milk, sugar or sweetener, white bread sandwich with lean ham and light cream cheese, salted and sweet biscuits. Posteriorly, blood samples (10 mL) were collected at 30, 60, 120 and 300 min after each intervention with a catheter installed in a vein of the arm. After blood collection, the volunteers were instructed to record all meals throughout the day, noting the amount eaten of each food. The sample number took into account variations in blood serum glucose with a type I error α = 0.05 and a type II error β = 0.2 (80% power). Primary output were the modification on glucose or insulin concentration induced by different beverages in some point of the curves. The secondary output was the antioxidant activity induced by FOJ and/or POJ. Kolmogorov Smirnov and Levene test, respectively assessed normality and homogeneity of the data. Area under the curve (AUC0-300 min) was calculated by the clearance of the appetite related-biomarkers (glucose, insulin, leptin and adiponectin) during 300 min for each trial phase Other parameters, as maximum concentration (Cmax), and time to reach maximum blood concentration (Tmax) were also estimated. AUC was determined with the trapezoidal method by Microcal Software Inc., Origin® 6.0. One-way analysis of variance (ANOVA) followed by Sidak post hoc was applied to compared the effect of interventions on appetite related-biomarkers, anti-oxidant status and beverage composition. P significance was set up ≤ 0.05.