Methyl alcohol

β-carotene (purity > 97%) and poly (vinyl pyrrolidone) (PVP) K15, K30, and K90 were purchased from Tokyo Chemical Industries (Tokyo, Japan). PLGA (50:50, Mw 7000–17,000, Resomer^® RG 502H) was obtained from Evonik Industries AG (Essen, Germany). Poly (vinyl alcohol) (Mw 9000–10,000, 80% hydrolyzed) and sodium phosphate monobasic were obtained from Sigma-Aldrich Co. (St. Louis, MO, USA). Acetone was acquired from Echo Chemical Co. (Miaoli County, Taiwan). HPLC-grade acetonitrile was obtained from Fisher Scientific (Waltham, NJ, USA). Tetrahydrofuran (THF) and methyl alcohol were purchased from Duksan (Ansan, South Korea).

Chitosan from shrimp shells (75–85% degree of deacetylation and 1747.5 g/mol of molecular weight), 3-chloro-2-hydroxypropyl trimethylammonium chloride (CHPTAC) solution, and methylthiazolyldiphenyl-tetrazolium bromide (MTT) solution were obtained from Sigma-Aldrich (St. Louis, MO, USA). Acetic acid, sodium carbonate, methyl alcohol, sodium hydroxide, and iodine were purchased from Duksan Pure Chemicals Co., Ltd. (Ansan, Gyeonggi-do, Korea).
Tryptic soy broth (TSB), tryptic soy agar (TSA), yeast malt broth (YMB), and yeast malt agar (YMA) were purchased from KisanBio Co., Ltd. (Seoul, Korea). Potato dextrose broth (PDB), potato dextrose agar (PDA), and peptone water were gained from Difco (Becton Dickinson, Sparks, MD, USA). YM 3M Petri film was purchased from 3M Corporation (St. Paul, MN, USA). Test microbial strains, Staphylococcus aureus (ATCC 13565, enterotoxin A), Escherichia coli O157: H7 (ATCC 11234), Candida albicans (ATCC 18804), and Aspergillus flavus (ATCC 22546), were obtained from the Korean Culture Center of Microorganisms (KCCM, Seoul, Korea). Human keratinocyte HaCaT cells were provided by Dr S.J. Kim (CHA University, Seoul, Korea). Dulbecco’s modified Eagle’s medium (DMEM), fetal bovine serum (FBS), and 1% penicillin/streptomycin were purchased from Gibco (ThermoFisher Scientific, Waltham, MA, USA).

All chemicals used were of analytical grade. Potassium chromate, 0.1 N Sodium hydroxide, silver nitrate, methyl alcohol, ethyl alcohol, and sodium chloride were obtained from Duksan Pure Chemicals (Ansan, Gyeonggi-do, Korea). Sodium hydroxide, sodium hydrogen carbonate, and ammonium hydroxide were purchased from Junsei Chemicals (Tokyo, Japan). Formalin solution, standard methanol, ethanol, pentanol, propanol, and butanol were purchased from Sigma-Aldrich (St. Louis, MO, USA). Plate count agar, nutrient agar, potato dextrose agar (PDA), and potato dextrose broth were purchased from Difco (Becton, Dickinson and Company, Sparks, MD, USA). Mannitol egg yolk polymyxin agar (MYP), egg yolk emulsion, and polymyxin B supplement were purchased from Oxoid LTD (Basingstoke, Hampshire, UK). 3M Yeast and Mold Petrifilm was purchased from 3M Health Care (St. Paul, MN, USA). API 50CHB and API 20E were obtained from bioMerieux (Marcy I’Etoile, France).