1：Experimental Design and Method Selection:

A systematic survey was conducted to confirm the presence of CDs in various beer brands. Methods included extraction, purification, and characterization using techniques like TEM, XRD, FT-IR, UV-Vis, photoluminescence, XPS, and NMR. In vitro digestion, in vivo biodistribution in mice, acute toxicity evaluations, and cytotoxicity assessments using cell cultures were performed.

2：Sample Selection and Data Sources:

Five commercial beer brands (Snow, Harbin, Wernesgruner Dark, FAXE, Yanjing) were purchased from a local market in Dalian, China. Artificial digestive juices were obtained from Shanghai Yuanye Bio-Technology Co., Ltd. Male BALB/c mice and MC3T3-E1 cells were used for in vivo and in vitro studies.

3：List of Experimental Equipment and Materials:

Equipment included vacuum rotary evaporator, D101 macroporous adsorption resin column, JEM-2100 TEM, XRD spectrometer, FT-IR spectrometer, UV-Vis spectrophotometer, F-2700 spectrophotometer, XPS spectrometer, NMR spectrometer, in vivo imaging system, ADVIA 2400 Chemistry System, xCELLigence system, confocal laser fluorescence microscopy, FACSVerse flow cytometer. Materials included beers, artificial digestive juices, chemicals for synthesis and staining.

4：Experimental Procedures and Operational Workflow:

CDs were extracted from beer by concentration and purification. Characterization involved size, shape, optical properties, and structural analysis. In vitro digestion simulated mouth, stomach, and intestine conditions. In vivo studies involved oral administration to mice, organ imaging, and histological analysis. Cytotoxicity was assessed using real-time cell analysis, flow cytometry, and cell cycle analysis.

5：Data Analysis Methods:

Statistical analysis of particle sizes, fluorescence intensity measurements, biochemical parameter analysis using standard protocols, and flow cytometry data analysis were performed.