Various bioactive compounds (BCs) often possess poor stability and bioavailability, which makes it difficult for them to exert their potential health benefits. These limitations can be countered by the use of nano-delivery systems (NDSs), such as nanoparticles and nanoemulsions. NDSs can protect BCs against harsh environments during food processing and digestion, and thereby, could enhance the bioavailability of BCs. Although various NDSs have been successfully produced with both synthetic and natural materials, it is necessary to fulfill safety criteria in the delivery materials for food applications. Food-grade materials for the production of NDSs, such as milk proteins and carbohydrates, have received much attention due to their low toxicity, biodegradability, and biocompatibility. Among these, whey proteins—from whey, a byproduct of cheese manufacturing—have been considered as excellent delivery material because of their high nutritional value and various functional properties, such as binding capability to various compounds, gelation, emulsifying properties, and barrier effects. Since the functional and physicochemical properties of whey protein-based NDSs, including size and surface charge, can be key factors affecting the applications of NDSs in food, the objectives of this review are to discuss how manufacturing variables can modulate the functional and physicochemical properties of NDSs and bioavailability of encapsulated BCs to produce efficient NDSs for various BCs.

It is necessary to understand the cellular uptake and cytotoxicity of food-grade delivery systems, such as β-lactoglobulin (β-lg) nanoparticles, for the application of bioactive compounds to functional foods. The objectives of this study were to investigate the relationships between the physicochemical properties of β-lg nanoparticles, such as particle size and zeta-potential value, and their cellular uptakes and cytotoxicity in Caco-2 cells. Physicochemical properties of β-lg nanoparticles were evaluated using particle size analyzer. Flow cytometry and confocal laser scanning microscopy were used to investigate cellular uptake and cytotoxicity of β-lg nanoparticles. The β-lg nanoparticles with various particle sizes (98 to 192 nm) and zeta-potential values (-14.8 to -17.6 mV) were successfully formed. A decrease in heating temperature from 70°C to 60°C resulted in a decrease in the particle size and an increase in the zeta-potential value of β-lg nanoparticles. Non-cytotoxicity was observed in Caco-2 cells treated with β-lg nanoparticles. There was an increase in cellular uptake of β-lg nanoparticles with a decrease in particle size and an increase in zeta-potential value. Cellular uptake β-lg nanoparticles was negatively correlated with particle size and positively correlated with zeta-potential value. Therefore, these results suggest that the particle size and zeta-potential value of β-lg nanoparticles play an important role in the cellular uptake. The β-lg nanoparticles can be used as a delivery system in foods due to its high cellular uptake and non-cytotoxicity.

Physicochemical Characterization and Potential Prebiotic Effect of Whey Protein Isolate/Inulin Nano Complex nano complex;whey protein isolate (WPI);inulin;prebiotic effect; The purposes of this study were to investigate the impacts of concentration levels of whey protein isolate (WPI) and inulin on the formation and physicochemical properties of WPI/inulin nano complexes and to evaluate their potential prebiotic effects. WPI/inulin nano complexes were produced using the internal gelation method. Transmission electron microscopy (TEM) and particle size analyzer were used to assess the morphological and physicochemical characterizations of nano complexes, respectively. The encapsulation efficiency of resveratrol in nano complexes was studied using HPLC while the potential prebiotic effects were investigated by measuring the viability of probiotics. In TEM micrographs, the globular forms of nano complexes in the range of 10 and 100 nm were successfully manufactured. An increase in WPI concentration level from 1 to 3% (w/v) resulted in a significant (p<0.05) decrease in the size of nano complexs while inulin concentration level did not affect the size of nano complexes. The polydispersity index of nano complexes was below 0.3 in all cases while the zeta-potential values in the range of -2 and -12 mV were observed. The encapsulation efficiency of resveratrol was significantly (p<0.05) increased as WPI and inulin concentration levels were increased from 1 to 3% (w/v). During incubation at 37℃ for 24 h, WPI/inulin nano complexes exhibited similar viability of probiotics with free inulin and had significantly (p<0.05) higher viability than negative control. In conclusions, WPI and inulin concentration levels were key factors affecting the physicochemical properties of WPI/inulin nano complexes and had potential prebiotic effect.

Food Science of Animal Resources (Food Sci. Anim. Resour.) is an international, peer-reviewed bimonthly journal publishing original research and reviews on basic and applied aspects of the use of animal resources including the meat, egg, and dairy product. Food Sci. Anim. Resour. is published and distributed by the Korean Society for Food Science of Animal Resources.