The dairy industry has long faced a fundamental challenge: how to produce the same proteins found in cow's milk without the cow. Plant-based milks made from soy, oats, or almonds imitate the texture and flavor of dairy, but they lack the precise protein composition — especially the caseins — that gives real milk its unique nutritional and functional properties. Molecular farming, the practice of engineering plants to produce animal proteins, has been proposed as a solution, but early attempts ran into a stubborn problem: the engineered proteins accumulated in cellular compartments where they were difficult to extract, or they triggered plant defense responses that suppressed yields.
The Hebrew University team, working with researchers from the New Zealand molecular farming company Miruku, took a different approach. They engineered Arabidopsis — a small flowering plant widely used as a model organism in plant biology — to produce bovine β-casein fused to a short segment of oleosin, a protein that naturally binds to the oil bodies inside plant seeds. The idea was to anchor the dairy protein to these lipid structures, where it might be easier to recover. What they found surprised them: instead of accumulating in the cellular vacuole, where similar recombinant proteins had previously been directed, the β-casein concentrated in entirely new, previously undescribed protein-rich structures closely associated with the seed's oil bodies.
This unexpected localization turned out to be advantageous. The plant-made β-casein reached a yield of 1.26 percent of the seed's total protein content — a competitive level for early-stage molecular farming research — and could be extracted using a much simpler process than earlier methods required. When tested, the protein demonstrated strong emulsification, stabilization, and cheese-melting properties comparable to native dairy β-casein, suggesting it could serve as a direct replacement in food manufacturing.
The implications extend beyond a single protein. If casein production can be scaled in commercial crops like safflower or soybean — Miruku's target species — it would decouple dairy protein supply from animal agriculture, reducing greenhouse gas emissions, land use, and water consumption associated with dairy farming. The global dairy industry produces roughly 900 million tons of CO₂-equivalent emissions annually, and dairy protein production via molecular farming could reduce that footprint by 80 to 90 percent on a per-protein basis.
Knowledge takeaway: Hebrew University researchers engineered plant seeds (Arabidopsis) to produce bovine β-casein fused with oleosin, targeting oil-body structures and achieving 1.26 percent protein yield; the plant-made casein showed cheese-melting and emulsification properties matching native dairy β-casein; the discovery opens a path to molecular farming of dairy proteins in commercial oilseed crops like safflower, with potential for an 80-90 percent reduction in greenhouse gas emissions versus conventional dairy.