Incubation of adipocytes with α-linolenic acid and non-protein-bound iron results in a higher accumulation of omega-3 fatty acids and iron and lower oxidized lipids compared to incubation with docosahexaenoic acid and protein-bound iron

Cultured meat may offer advantages over traditional meat production regarding, among other things, animal welfare and carbon footprint, while also providing an opportunity for targeted delivery of health-promoting compounds. This study investigates the targeted accumulation of iron and ω-3 fatty acids from different sources in 3T3-L1 adipocytes as a model for primary adipocytes used for cultured meat research. A higher iron accumulation in 3T3-L1 cells was observed for non-protein-bound iron (iron(II)sulfate heptahydrate (FeSO 4 ), 6.25 ± 2.40; ferrous bisglycinate (FeB) 5.59 ± 3.76 μg iron equivalents/mg protein) compared to protein-bound iron (holo-transferrin (holo-Tf), 1.06 ± 0.46; holo-lactoferrin (holo-LF), 1.55 ± 0.84 μg iron equivalents/mg protein, respectively). Incubation with α-linolenic acid (ALA) or docosahexaenoic acid (DHA) induced a 4-fold increase in PUFA content. However, the co-incubation of DHA with FeSO 4 or FeB reduced PUFA from 4 to 2 % and increased lipid peroxidation products (88.59 ± 16.13 and 118.16 ± 17.19 nmol TBARS/mg protein, respectively) compared to co-incubation with ALA. In conclusion, the combination of FeSO 4 and ALA is superior to combinations of DHA, FeB, holo-Tf and holo-Lf for the enrichment of iron and PUFA in cultured adipocytes and results in the highest concentrations of iron and increases in total ω-3 fatty acids and lower lipid peroxidation when co-incubated with iron compared to DHA. Furthermore, FeSO 4 seems to be most suitable to simultaneously enrich the iron content in cultured adipocytes and ultimately in cultured meat. • Non-protein-bound iron leads to higher iron accumulation in 3T3-L1 cells than protein-bound iron. • Incubation with ALA and DHA increases PUFA content in 3T3-L1 cells 3- to 4-fold. • Co-incubation of DHA with FeSO 4 and FeB significantly reduces DHA in 3T3-L1 cells. • The percentage of DHA but not of ALA is negatively correlated with the concentration of TBARS in 3T3-L1 cells.