Research Advances in Preparation, Stability, Application, and Possible Risks of Nanoselenium: Focus on Food and Food-Related Fields.

Nanoselenium is a promising selenium supplement as a result of its low toxicity and high bioavailability. However, the understanding on the preparation, stability, bioavailability, possible risks, and related underlying mechanisms of nanoselenium is not in-depth. Thus, the above aspects were reviewed on the basis of the latest literature. The reducing capacity and stability of the reducing agent and binding force between nanoselenium and the template decide the nanoselenium stability. Although research on nanoselenium application in food, agriculture, livestock, and aquaculture has been widely carried out, it is not widely applied in the fields. Se-containing amino acids are synthesized using nanoselenium adsorbed by organisms, and they constitute Se-containing proteins with other amino acids, which improves the health of organisms via scavenging excessive radicals. Notably, excessive nanoselenium intake generates redundant Se-containing amino acids, leading to dysfunction of key proteins in organisms, and its toxic doses vary with organisms. Furthermore, some issues related to nanoselenium still need to be solved urgently.

Improvement of betalains stability extracted from red dragon fruit peel by ultrasound-assisted microencapsulation with maltodextrin.

Natural betalains can be potential food additives because of their antioxidant activities, but they have poor thermal stability. In this study, betalains were extracted from red dragon fruit peel, and then encapsulated with maltodextrin by ultrasound method to increase the physicochemical properties of betalains microcapsules. The encapsulation efficiency of the betalains was above 79%, and the particle size and Zeta potential values were 275.46 nm and -29.01 mV, respectively. Compared to the control sample, onset temperature and DPPH free radical scavenging of betalains microcapsules under the modest ultrasound treatment (200 W, 5 min) was increased by 1.6 °C and 12.24%, respectively. This increase could be due to the ability of ultrasonification to create interactions between maltodextrin and betalains (as evidenced by FT-IR). Therefore, modest ultrasound treatment can be used for microcapsulation to improve the stability of betalains, and then expand the application of betalains in heat processed food field.