Porous silicon and functional foods

Abstract

Functional foods are often described as those that can have a positive effect on health beyond basic nutrition. Examples include cholesterol-lowering oatmeal, bacteria-loaded yogurt for gut health, and iodine-fortified bread for prevention of thyroid disease. There is growing evidence that orthosilicic acid, the biodegradation product of porous silicon, can have a positive contribution to optimizing bone health. The relevant nutritional literature on silicic acid and trials related to osteoporosis are collated and discussed. Silica microparticles (and inadvertently nanoparticles) have been used for decades as an approved food additive. Preliminary studies have shown that porous silicon has high chemical stability in many stored foodstuffs and dissolves in intestinal fluid faster than in gastric fluid and that the taste and mouthfeel of oxidized porous silicon microparticles can be acceptable. The potential uses of mesoporous silicon or silica particles in both protecting and raising bioavailability of ingested high-value nutrients are analyzed. Despite its technical potential, inexpensive and very scalable fabrication routes are required if porous silicon is to have significant uptake by the food industry.