Hen eggshells are a rich and natural source of calcium and can serve as a biofunctional food ingredient. Enriching the traditional Polish bread spread (sersmażony) with micronized eggshell is an attractive proposition for consumers who require easily available calcium. The present study aimed to evaluate the use of micronized eggshells as a source of bioavailable calcium in bread spread. The study evaluated the effect of selected biocomponents on calcium bioavailability by using an in vitro digestion model. The enrichment of bread spread with eggshell, lysine, vitamin D₃, and vitamin K enhanced all examined physicochemical variables except water activity. Enrichment with eggshells increased calcium levels >2.5-fold compared with the control sample. As an ingredient of bread spread, lysine is an important rheological factor. The bioavailability of calcium was higher in samples with lysine and vitamin K compared with samples that contained eggshell alone.

Nanoemulsion systems receive a significant amount of interest nowadays due to their promising potential in biomedicine and food technology. Using a two-step process, we produced a series of nanoemulsion systems with different concentrations of hemp seed oil (HSO) stabilized with Aesculus hippocastanum L. extract (AHE). Water and commercially-available low-concentrated hyaluronic acid (HA) were used as the liquid phase. Stability tests, including an emulsifying index (EI), and droplet size distribution tests performed by dynamic light scattering (DLS) proved the beneficial impact of AHE on the emulsion’s stability. After 7 days of storage, the EI for the water-based system was found to be around 100%, unlike the HA systems. The highest stability was achieved by an emulsion containing 5% HSO and 2 g/L AHE in water, as well as the HA solution. In order to obtain the detailed characteristics of the emulsions, UV-Vis and FTIR spectra were recorded, and the viscosity of the samples was determined. Finally, a visible microscopic analysis was used for the homogeneity evaluation of the samples, and was compared with the DLS results of the water system emulsion, which showed a desirable stability. The presented results demonstrate the possible use of oil emulsions based on a plant extract rich in saponins, such as AHE. Furthermore, it was found that the anti-inflammatory properties of AHE provide opportunities for the development of new emulsion formulations with health benefits.