Organogel-Based Emulsion Systems, Micro-Structural Features and Impact on In Vitro Digestion

• Published in: Journal of the American Oil Chemists' Society 2009-08, Vol.86 (8), p.733-741
• Main Authors: Duffy, Nicola, Blonk, Han C. G, Beindorff, Christiaan M, Cazade, Magali, Bot, Arjen, Duchateau, Guus S. M. J. E
• Format: Article
• Language: English
• Subjects: Agriculture; Biological and medical sciences; Biomaterials; Biotechnology; Cell division; Chemistry; Chemistry and Materials Science; corn oil; Crystals; digestion; digestive enzymes; Edible oils; Emulsions; enzymatic hydrolysis; Fat industries; Fluorescence; Food industries; Food products; Food Science; Food structure; Fundamental and applied biological sciences. Psychology; gastrointestinal system; in vivo studies; Industrial Chemistry/Chemical Engineering; Linear crystals; Lipolysis; Micelles; Oils & fats; olive oil; Organogel; organogels; Original Paper; pancreatin; Phytosterols; SAFiN; saturated fatty acids; simulation models; sunflower oil; swine; Temperature; triacylglycerols; Tubes; Tubules; vegetable oil
• ISSN: 0003-021X; 1558-9331
• DOI: 10.1007/s11746-009-1405-4

Organogels based on edible oils and specific mixtures of phytosterols can serve as structured systems with a low saturated fat content. These low-SAFA organogels can be used also to create o/w emulsions. Little is known about the structures formed in these specific organogels and at the emulsion interface. We studied o/w organogels on different length scales to describe and understand their micro-structural features. Very basic processing conditions such as composition, temperature and storage time were taken into account. Two different types of structure were observed; at the smallest scale, long thin crystals are formed out of the oil phase into the continuous water phase. We propose that these are needle-like crystals. Next, tube-like structures are identified and can be visualized as tubular micelles. A model is proposed which fits the dimension (~7 nm) with the length scale of the molecular building blocks (TAGs and sterols). As edible fats from food products are enzymatically hydrolyzed in the gut prior to absorption, we also looked into the impact on the lipase reaction speed. Simple in vitro enzymatic hydrolysis experiments showed a slower enzymatic digestion. Organogel systems and emulsion made thereof have interesting food structuring properties with possible advantages in composition (low SAFA) and digestion speed.