Allium/chemistry; Antioxidants/analysis; Flavonoids/analysis; Food Preservation; Plant Leaves/chemistry; Plant Stems/chemistry; Allium/microbiology; Antioxidants/metabolism; Belgium; Coumaric Acids/analysis; Coumaric Acids/metabolism; Cysteine/analogs & derivatives; Cysteine/analysis; Cysteine/metabolism; Fermentation; Flavanones/analysis; Flavanones/metabolism; Flavonoids/metabolism; Food, Organic/analysis; Food, Organic/economics; Food-Processing Industry/economics; Gram-Negative Bacteria/metabolism; Gram-Positive Bacteria/metabolism; Industrial Waste/analysis; Industrial Waste/economics; Kaempferols/analysis; Kaempferols/metabolism; Luteolin/analysis; Luteolin/metabolism; Plant Leaves/microbiology; Plant Stems/microbiology; Salts/chemistry