Structural changes of filling creams after in vitro digestion. Application of hydrocolloid based emulsions as fat source

Abstract

The objective of this study was to evaluate the application of hydrocolloid-based o/w emulsions as fat source in filling creams. Emulsions containing sunflower oil stabilized by different hydrocolloids (hydroxypropyl methylcellulose (HHPMC), methylcellulose (MC) and xanthan gum (XG)), were employed. The changes in the structure of the systems before and after in vitro digestion were studied by textural analysis and confocal and light microscopy, and they were related to lipid digestibility after intestinal digestion. The presence of XG led to a significant increase in consistency in the stomach digestion phase compared to stomach water dilution incubation (6.32 N s and 4.72 N s respectively). After the intestinal phase, an increase in globule size was observed in all creams (MC: from 8.4 (fresh cream) to 15.4 μm (after intestinal step); HHPMC: from 12.8 to 17.6 μm; XG: from 27.5 to 32.0 μm), as well as the appearance of coalescence phenomena due to changes in fat stability, although fat globules are still visualized. Filling creams formulated with hydrocolloid-based o/w emulsion were more resistant to in vitro digestion than the control cream, exhibiting a significant decrease in fat digestibility (MC 240 g/Kg, HHPMC 230 g/Kg and XG 490 g/Kg reduction of fatty acids released).