Orthophosphoric acid

A commercial yoghurt starter culture (YOFLEX^®—consisting of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus) and three probiotic strains (Lacticaseibacillus rhamnosus LGG, Lacticaseibacillus casei 431, Bifidobacterium animalis subsp. lactis BB-12) were kindly supplied by Chr. Hansen, Bayswater, VIC, Australia. Powdered skim milk (Australian instant skim milk powder, Coles) was obtained from a local supermarket in Melbourne, VIC, Australia. Pancreatin was purchased from Alfa Aesar (Ward Hill, MA, USA). Mangiferin, pyrogallol, gallic acid, caffeic acid, 3-hydroxy phenyl acetic acid, 3-(2-hydroxyphenyl) propionic acid, porcine pepsin, α-amylase from aspergillus oryzae, p-nitrophenyl-α-d-glucopyranoside, bile salts, LC-MS grade formic acid, acetic acid, 4-methyl valeric acid, guar, casein, tryptone, cysteine HCl, peptone, mucin, pectin, potato starch, yeast extract, and MRS agar were acquired from Sigma–Aldrich (Castle Hill, NSW, Australia). Sodium carbonate (anhydrous), HCl, NaHCO₃, NaOH, (NH₄)₂CO₃, KCl, NaCl, KH₂PO₄, MgCl₂(H₂O)₆, CaCl₂, K₂HPO₄, Na₃PO₄, MgSO₄.7H₂O Tween 80, orthophosphoric acid, acetonitrile, and methanol of HPLC grade were acquired from Chem-supply Pty Ltd. (Melbourne, VIC, Australia).

Graphite flakes, diethylene glycol (DEG), hydrogen peroxide
(H₂O₂), poly (vinyl alcohol) (PVA, Mw:
146000 ~ 186000) and hypophosphorous acid
(HPA) were purchased from Sigma-Aldrich. Concentrated sulphuric acid
(H₂SO₄, 98%), orthophosphoric acid
(H₃PO₄, 85%), and hydrochloric acid (HCl, 32%) were
obtained from Chem-Supply.
Poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS) pellets was
Orgacon™ DRY re-dispersible product from Agfa company.