Glycaemic index, glycaemic load and dietary fibre characteristics of two commercially available fruit smoothies

Abstract

In light of the updated Eatwell Guide and the corresponding change in the consumption of fruit smoothies, the aim of this study was to measure the glycaemic index and load of two commercial fruit smoothies and to investigate the retention of dietary fibre following production. In vitro analysis was performed to identify fibre material (cellulose and pectins) using calcofluor staining and immunocytochemical labelling. A repeated measures cross-over study was conducted (n 10) to determine the glycaemic index (GI) and glycaemic load (GL) of the smoothies. Results showed that dietary fibre was still present in the smoothies after processing (16.9–17.5% cellular material by dry weight). The GI was low for both smoothies (39 and 36), whereas the GL was medium and borderline-low, respectively (11.4 and 9.7). The retention of fibre in these smoothies may have a potential positive effect on glycaemic response and may contribute to daily fibre requirements.

Keywords:

• Glycaemic index
• glycaemic load
• mango and passion fruit smoothie
• strawberry and banana smoothie
• cellulose
• pectin

Acknowledgements

G.S., P.K.S. were, at the time this study was conducted, employees of the Oxford Brookes Centre for Nutrition and Health and H.S. was a research student at the Department of Biological & Medical Sciences. Innocent Ltd has had no involvement in the analysis of the results.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The study was funded by Innocent Ltd, London, UK.