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Concentrated grape juice: Natural grape juice obtained from squeezing of Syrah or Shiraz, Cabernet Sauvignon and Malbec grapes was placed in the evaporation equipment, which is a flat, spiral, or tubular heat exchanger (concentrated grape juice is purchased from Shangri‐La Wine Co., Ltd.). The grape juice was heated in the evaporator and concentrated to 40 Brix. The concentrated grape juice was placed in containers and stored in a freezer at 15°C before use (Juchuang Environmental Protection Equipment Co., Ltd., Haier Group Co., Ltd.). After LC‐UV method and calibration of the standard curve were performed, the tartaric acid content in the concentrated grape juice was found to be 17.68%.
Reagents: NaOH, HCl, NaCl, KH₂PO₄, and acetonitrile were purchased from Xilong Chemical Co., Ltd. All of the chemicals used were of chromatographic reagent grade. Double‐distilled water was used throughout the study.
The following instruments were used: Waters 1525 Chromatograph and Waters 2489 UV‐detector (Waters Co., Ltd.), 335 anion‐exchange resins, D‐314 anion‐exchange resin, and D‐914 anion‐exchange resin with 150 mm × 4.6 mm and 5 µm particle size (Waters Atlantis T3).

Malathion was purchased from Texas Green Bar Fine Chemical Co. Ltd. Yeast extract, tryptone, and sodium lactate were purchased from Sangong Biological Engineering Co. Ltd. Magnesium sulfate (MgSO₄), potassium dihydrogen phosphate (KH₂PO₄), phosphate buffer solution (PBS), sodium chloride (NaCl), and other reagents were purchased from Xilong Science Co. ATPase, superoxide dismutase (SOD), catalase (CAT), total protein, and ROS assay kits were provided by the Nanjing Jiancheng Institute of Biological Engineering. All the chemicals were analytically pure.
Malathion masterbatch preparation: An appropriate amount of malathion emulsion (75%) was dissolved in methanol, and the concentration was adjusted to 2000 mg/L in a volumetric flask and stored in a refrigerator at 4 °C.

The simulated gastric fluid (SGF)-resistance of S. Typhimurium was determined by subjecting the bacteria to SGF (pH 2.0 or 3.0) [15 (link)]. SGF consisted of 8.3 g/L proteose peptone, 0.6 g/L KH₂PO₄ (Xilong Scientific Co., Ltd.), 2.05 g/L NaCl, 0.37 g/L KCl (Xilong Scientific Co., Ltd.), 0.11 g/L CaCl₂ (Xilong Scientific Co., Ltd.), 0.05 g/L oxgall (Sigma Aldrich, St. Louis, MO, USA), 1 g/L lysozyme (Solarbio, Beijing, China), and 13.3/L mg pepsin (1:3000; Solarbio, Beijing, China). Except for the oxgall, lysozyme and pepsin (sterilized by 0.25-μm filters), all the components were dissolved in deionized water and autoclaved. The solution was adjusted to pH 2 or 3, respectively, with 6.0 M HCl. Homogenized beef samples from the 405-nm LED illuminated and non-illuminated groups were transferred into SGF at a ratio of 1:9 (homogenized sample: SGF solution) and incubated with shaking (130 rpm) at 37 °C. At sampling times, each sample was serially diluted in PBS and plated on XLD-agar at 37 °C for 24 h for colony enumeration.