Phosphate buffered saline (pbs)

The L. delbrueckii subsp. bulgaricus probiotic bacteria were used from the stock culture collections in the Food Microbiology Laboratory at the University of Melbourne. Fructooligosaccharides (FOS), Na-alginate, enzymes (salivary α-amylase, porcine pepsin, pancreatin), HCl, acetone, acetic acid, epicatechin, catechin, procyanidin B1, procyanidin B2, quercetin 3-O-galactoside, quercetin 3-O-glucoside were purchased from Sigma Aldrich (Castle Hill, NSW, Australia). A standard mixture of short chain fatty acids (SCFAs) was purchased from Cayman Chemical (Ann Arbor, MI, USA). The selective media DeMan, Rogosa and Sharpe (MRS), nutrient agar & broth, AnaeroGen sachets, yeast extract, beef extract, protease peptone, n-hexadecane, L-cysteine hydrochloride, bile salts, and trichloroacetic acid were purchased from Thermo Fisher Scientific Pty Ltd (Melbourne, VIC, Australia). NaOH, phosphate-buffered saline, CaCl₂, dextrose, K₂HPO₄, (NH₄)₂SO₄, MgSO₄·7H₂O, NaCl, KCl, NaHCO₃, MgCl₂(H₂O)₆, (NH₄)₂CO₃, potassium persulfate, potassium acetate, aluminum chloride were ordered from the Chem-Supply Pty Ltd. (Melbourne, VIC, Australia). Chocolates with 45% and 70% cocoa mass, cocoa powder (pure), cocoa liquor, cocoa butter, sugar, soy lecithin were purchased from local supermarket (VIC, Australia).