Production of short-chain fatty acids following in vitro fermentation of saccharides, saccharide esters, fructo-oligosaccharides, starches, modified starches and non-starch polysaccharides

A range of carbohydrates including modified starches and short-chain fatty acid esters of di-, tri-, tetra- and polysaccharides were subjected to an i n vitro fermentation using human-derived faecal bacteria. The production of the short-chain fatty acids (SCFAs) acetate, propionate and butyrate was m onitored at 6, 12, 24 and 36h for all substrates; however, it was found tha t the proportions of acids produced were reasonably constant after 6h. Betw een substrates there was variation in both the proportions and quantities o f acids produced. Relative substrate fermentability as measured by total ac id production at 24h was: sucrose octa-acetate > sucrose > stachyose > preg elatinised starch > Raftilose > verbascose > raffinose > starch acetate > b leached starch > phosphated distarch phosphate > locust bean gum > corn sta rch > oxidised starch = starch sodium octenyl succinate > di-starch phospha te > acetylated di-starch adipate = gum arabic > acid-treated starch > gum tragacanth > gum guar > acetylated di-starch phosphate = hydroxypropyl di-s tarch phosphate > hydroxypropyl starch > pectin > raffnose undeca-acetate > stachyose acetate > gum karaya = cellulose propionate > cellulose acetate > cellulose > cellulose butyrate > hydroxypropyl methyl cellulose, carragee nan > methyl cellulose. Chemically modified starches were similar to corn s tarch in the amounts of total SCFAs produced at 24h. Synthetic sugar esters could have potential application as vehicles to deliver supraphysiological amounts of SCFAs during in vivo studies of colonic fermentation. (C) 2000 Society of Chemical Industry.