An evaluation of the acidogenic potential of maltodextrins in vivo

Abstract

Maltodextrins are a group of oligosaccharides, which are being increasingly used as a source of carbohydrate in many commercially available foods and drinks. This study investigated the effect of three different maltodextrins on the pH of dental plaque, in vivo, in 10 adult volunteers using the plaque harvesting method. The three maltodextrins tested in this study were DE=5.5, 14.0 and 18.5 (DE=dextrose equivalents), made up as 10% solutions. Also, three commercially available maltodextrin containing children's drinks were evaluated for their acidogenicity. 10% sucrose and 10% sorbitol solutions were used as positive and negative controls, respectively. The minimum pH achieved for DE=5.5, 14.0 and 18.5 was 5.83±0.30, 5.67±0.24 and 5.71±0.29, respectively, and were significantly higher as compared with that for 10% sucrose (5.33±0.17). The area under the curve was the least for DE=5.5 (12.03±4.64), followed by DE=18.5 (13.13±8.87) and DE=14.0 (17.35±6.43), but were all significantly smaller as compared with 10% sucrose (24.50±8.64). The minimum pH achieved for the infant drinks was 6.01±0.24, 5.99±0.28 and 5.8±0.19 for the Lemon Barley and Camomile Herbal baby drink, Mixed Citrus and Hibiscus baby drink, and Infant Milk, respectively. It was concluded that though maltodextrins appeared to be significantly less acidogenic than 10% sucrose, they can lead to a substantial drop in plaque pH and may, therefore, have a potential to cause demineralisation of enamel.

Introduction

In nature, starch exists as long chain polymers of anhydroglucose units. These polymers can be hydrolysed into products with chain lengths varying from the monomer d-glucose to products with many linked glucose units (such as maltose, maltotriose and higher saccharides). Maltodextrins are carbohydrates derived from maize starch and are a group of oligosaccharides (long chain polysaccharides) composed of glucose, three units and above in length. They are obtained by acidic and/or enzymatic hydrolysis of corn starch, with subsequent drying to make free flowing powders [1]. They usually contain glucose, maltose, maltotriose and higher polymers of glucose, depending on the degree and method of hydrolysis. Therefore, maltodextrins are also called glucose polymers. Glucose polymers are virtually tasteless and odourless and their exact composition determines their sweetening power, as the sweetness increases with an increased concentration of low molecular weight saccharides [1]. Maltodextrins are increasingly being used in the food industry especially in baby drinks and baby dried food as an alternative carbohydrate. However, there are few data in the dental literature on the effect of these carbohydrates on pH of dental plaque in vivo. A study carried out by Moynihan et al. [2] investigated the acidogenicity of glucose polymers as 10% solutions in water, in cow's milk, or in a solution of milk substitute (calogen). They reported that glucose polymers caused a decrease in plaque pH but to a significantly lesser extent than 10% sucrose, and also the glucose polymers were equally acidogenic when given in water, milk or calogen. Another study [3] studied the effects on plaque pH in vivo of sucralose (alone or bulked with maltodextrin or with maltodextrin/dextrose) in iced tea. They found that tea with sucralose/maltodextrin and tea with sucralose/maltodextrin/dextrose did not differ from each other and both produced smaller pH drops compared with tea, which contained sucrose. In these studies, maltodextrins were not tested separately, therefore, direct comparisons between maltodextrin and other solutions were not available.

As far as the authors are aware there are no studies that have specifically investigated the acidogenicity of different types of maltodextrins, which are most commonly used in commercial products. It is essential to have information on their acidogenic potential so that advice can be given to health professionals, parents and patients on their safety and the safest mode of their use. The aims of this study were to investigate the ability of three different maltodextrin solutions to depress plaque pH in vivo, and to assess the acidogenic potential of three commercially available drink formulations for children containing maltodextrins using the plaque harvesting technique.