Thermal Treatment Greatly Improves Storage Stability and Monodispersity of Pea Seed Ferritin

Plant ferritin in holo form is considered as a novel, ideal iron supplement for human nutrition in the 21st century, but its self-degradation and self-association features limit its application on account of the presence of extension peptide (EP), a specific domain only found in plant ferritin. Although reported chemicals such as Phenylmethanesulfonyl fluoride (PMSF) can inhibit its self-degradation, they are not edible and toxic. In the present work, we found that thermal treatment of pea seed ferritin (PSF) in the range of 60 to 80 °C can prolong the storage time of PSF from 3 days to at least 10 days. In the meanwhile, the aggregated form can be inhibited upon such treatment, therefore promoting its monodispersity. More important, such treatment had little effect on the natural shell-like structure of holo PSF and its iron content. In contrast, thermal treatment at higher temperature (90 °C or above) resulted in a change in ferritin structure. These new findings pave the way to the application of plant ferritin as an iron supplement. PRACTICAL APPLICATION: Thermal treatment at 60 to 80 °C can prolong the storage stability of PSF from 3 days to at least 10 days and prevent it from self-aggregation without affecting the shell-like structure. It has been known that the stability of PSF is closely associated with the bioavailability of iron within PSF. From the standpoint of nutrition, the above-mentioned thermal treatment could be used as a cooking method in our daily life or in food industry to improve the bioavailability of ferritin iron, thereby being beneficial for exploration of plant ferritin as a novel, ideal iron supplement to fight against IDA.