Abstract
Objectives
Apple pomace (AP) is a byproduct of apple juice production and is a rich source of fiber. The goal of the present study was to determine the impact of adding AP to 100% apple juice (AJ) on the postprandial glycemic response compared to sugar matched AJ or whole apple fruit (WAF) in healthy human subjects.
Methods
Fifty-eight healthy subjects (aged 25 ± 3 years, BMI 22.9 ± 1.4 kg m−2, mean ± SD) participated in a randomized, 3-arm, cross-over clinical trial to test the glycemic response to AJ, 235 g, AJ with 5 g fiber from AP added (APF, 235 g total beverage weight) or whole Red Delicious apple with skin (WAF, 230 g edible portion with skin). Fiber content of APF was matched to WAF and all study products were matched for available carbohydrates (AJ/APF/WAF, 24 g). Blood samples were collected to measure glucose and insulin concentrations at fasting (0 min) and multiple time points over 2 h after consuming study product. The primary end point was the difference in maximal glucose concentrations (Cmax) among study products.
Results
Results indicated that Cmax values were not significantly different between 3 products (AJ −121.2 ± 1.8 mg/dL vs. APF- 120.8 ± 1.8 mg dL-1 vs. WAF 121.3 ± 1.8 mg dL-1, respectively, P > 0.05). Time to reach maximal glucose concentration (T max) was delayed in APF compared to AJ and WAF (33.2 ± 0.8 min vs. 29.9 ± 0.8 and 29.6 ± 0.8, respectively, P < 0.01), as was the insulin T max (APF 34.0 ± 0.9 min vs. 28.0 ± 0.9 and 28.7 ± 0.9, respectively, P < 0.001). Analysis of the 2 h glucose incremental area under the curve (iAUC0–2 h) was not significantly different among treatments, P > 0.05.
Conclusions
This study demonstrated that adding 5 g of fiber from AP into 235 g of AJ did not attenuate maximal postprandial glucose concentration. However, times to reach maximal glucose and insulin concentrations were significantly delayed in the group receiving pomace fiber added to apple juice compared to apple juice alone or whole apple fruit.
Funding Sources
Financial support for this study was provided by PepsiCo, Inc. The views expressed in this abstract are those of the authors and do not necessarily reflect the position or policy of PepsiCo, Inc.