Terminal sterilization of food-grade coatings for cellular agriculture: robustness against water quality and regulatory feasibility.

High production costs remain a major obstacle to the commercialization of cell-based foods, primarily due to the reliance on costly pharmaceutical-grade reagents and infrastructure. This study introduces a practical solution using a dual technical/regulatory approach. We developed iCoater, a food-grade coating agent manufactured via terminal heat sterilization, a standard in food processing. This process results in no detectable bacterial growth and 12-month stability without filtration. In performance tests using primary duck liver-derived cells, iCoater showed efficacy in cell attachment and proliferation. Furthermore, we confirmed that this performance and low endotoxin levels were maintained when the tested water sources covered a wide hardness range from soft (< 1.0 mg/L) to hard (1468 mg/L) water. By aligning the food-grade manufacturing process, we proposed the regulatory pathway under Japanese legislation, identifying "gelatin-processed food" as a realistic and transparent labeling strategy. This integrated approach provides a practical reference for future developments in cellular agriculture.