Characterization of Structural Changes of Casein Micelles at Different PH Using Microscopy and Spectroscopy Techniques

Extracellular vesicles separated from goat milk by differential centrifugation coupled with sodium citrate pretreatments

Satisfactory separation of milk-derived extracellular vesicles (MEVs) is important for the downstream analysis of the functions and properties of MEVs. However, the presence of abundant proteins in milk hindered the separation of MEVs. In this study, three pretreatment methods, including sodium citrate (SC), acetic acid (AA), and high-speed centrifugation, were adopted to separate MEVs from goat milk while minimizing the impact of protein. The MEVs were then characterized by nanoparticle tracking, transmission electron microscopy and western blotting experiments. The results indicated that pretreatments with AA and SC greatly decreased the impact of casein, but AA pretreatment damaged the surface structure of MEVs. Additionally, the differential centrifugation process resulted in a slight loss of MEVs. Overall, MEVs with small size and high purity can be obtained under 125 k × g centrifugation combined with SC pretreatment, which suggests a promising method for separation of MEVs from goat milk.

Nanoformulations in Pharmaceutical and Biomedical Applications: Green Perspectives

This study provides a brief discussion of the major nanopharmaceuticals formulations as well as the impact of nanotechnology on the future of pharmaceuticals. Effective and eco-friendly strategies of biofabrication are also highlighted. Modern approaches to designing pharmaceutical nanoformulations (e.g., 3D printing, Phyto-Nanotechnology, Biomimetics/Bioinspiration, etc.) are outlined. This paper discusses the need to use natural resources for the "green" design of new nanoformulations with therapeutic efficiency. Nanopharmaceuticals research is still in its early stages, and the preparation of nanomaterials must be carefully considered. Therefore, safety and long-term effects of pharmaceutical nanoformulations must not be overlooked. The testing of nanopharmaceuticals represents an essential point in their further applications. Vegetal scaffolds obtained by decellularizing plant leaves represent a valuable, bioinspired model for nanopharmaceutical testing that avoids using animals. Nanoformulations are critical in various fields, especially in pharmacy, medicine, agriculture, and material science, due to their unique properties and advantages over conventional formulations that allows improved solubility, bioavailability, targeted drug delivery, controlled release, and reduced toxicity. Nanopharmaceuticals have transitioned from experimental stages to being a vital component of clinical practice, significantly improving outcomes in medical fields for cancer treatment, infectious diseases, neurological disorders, personalized medicine, and advanced diagnostics. Here are the key points highlighting their importance. The significant challenges, opportunities, and future directions are mentioned in the final section.

The Release Behavior of Anthraquinones Encapsulated into Casein Micelles during In Vitro Digestion

The degradation of anthraquinones extracted from aloe vera plants can be prevented by encapsulating them in casein micelles (CMs). The oral, gastric, and intestinal digestion behavior of spray-dried microcapsules of casein micelles loaded with aloe vera-extracted anthraquinone powder (CMAQP), freeze-dried powder (CMFDP), and whole-leaf aloe vera gel (CMWLAG) obtained through ultrasonication was investigated. The results found that CMAQP and CMFDP dissolved slowly and coagulated into large curds during gastric digestion, improving the retention of anthraquinones in the digestive tract. In contrast, CMWLAG structure was destroyed and increased amounts of anthraquinones were released during oral and gastric digestion phases, indicating increased amounts of surface anthraquinones instead of the encapsulation of anthraquinones in the interior of CMs. The strong hydrophobic interactions protected anthraquinones within the core of CM for CMAQP and delayed diffusion. However, during SIF digestion, both CMAQP and CMFDP released significant amounts of anthraquinones, although CMAQP showed a much more controlled release for both aloin and aloe-emodin over SIF digestion time. The release behavior of anthraquinones from CM microcapsules was a function of the type of anthraquinone that was used to encapsulate. The present study provides insight into the release behavior of loaded bioactive compounds using food-grade CMs as the wall material during in vitro digestion and highlights the importance of the type of bioactive component form that will be encapsulated.

Co-cultivation effects of Lactobacillus helveticus SNA12 and Kluveromyces marxiensis GY1 on the probiotic properties, flavor, and digestion in fermented milk

This study aimed to evaluate inoculating the lactic acid bacteria Lactobacillus helveticus SNA12 and the yeast Kluyveromyces marxiensis GY1 as starter cultures on milk fermentation. In this study, the probiotic properties of L. helveticus SNA12, K. marxiensis GY1 and co-culture of these two strains (L. helveticus SNA12-K. marxiensis GY1) were investigated, and the results showed that K. marxiensis GY1 had better gastrointestinal tolerance, aggregation, and cell adhesion properties than L. helveticus SNA12. After the co-cultivation of two strains, the presence of K. marxiensis GY1 significantly increased the gastrointestinal tolerance, aggregation, and adhesion characteristics of L. helveticus SNA12. In order to investigate the flavor changes, digestive characteristics, and antioxidant properties following co-cultivation fermentation, the optimal fermentation ratio of 8 %-2% (v/v) and fermentation temperature (37 °C) of L. helveticus SNA12-K. marxiensis GY1 were determined. The results of the electronic nose and electronic tongue showed that L. helveticus SNA12-K. marxiensis GY1 could increase the aroma components of fermented milk, such as terpenes and aromatic substances. Meanwhile, dynamic in vitro rat stomach-duodenum model was used to analyse the changes in the digestion of proteins and peptides (<10 kDa), and the results indicated that co-cultivation fermented milk could be digested faster compared to a single fermentation. Furthermore, the antioxidant capacity of co-cultivation fermented milk was higher than that of single fermentation.

Nanomechanical, Structural and Antioxidant Characterization of Nixtamalized Popcorn Pericarp

Expanded popcorn grain is widely consumed as a healthy snack all around the world; however, the study of the behavior of its components by processes such as nixtamalization is scarce. Therefore, the aim of this work was to characterize the nanomechanical, structural, and antioxidant properties of nixtamalized popcorn grain pericarp. FT-IR results showed that the secondary structure of proteins of the nixtamalized pericarp was α-helix with 42.10%, the turn was 21.5% and 36.33% β-sheet, and proteins of the pericarp did not present the random coil structure. Pericarp showed antioxidant activity, as their values were 550.1 ± 2.9 and 44.2 ± 1.6 (TE)/mL for ABTS and DPPH, respectively; total phenols content was 0.21 ± 0.008 (TE)/mL; reducing power values were around 29 to 31%; hydroxyl radical scavenging ranged from 36 to 55% and iron chelation around 115 to 140% compared to the standard acids. Thickness values of the nixtamalized pericarp by SEM image analysis were 0.15 ± 0.1 mm near the pedicel inferior tip, 0.07 ± 0.01 mm at middle, and 0.03 ± 0.02 mm at upper of the grain. Young’s modulus value was 261.72 ± 23.58 MPa with a Gaussian function fitting at the distribution of all values. This research provides novel and valuable information for understanding the nanomechanical and protein arrangement, as well as and the antioxidant activity of nixtamalized popcorn grain pericarp in order to promote other processes and uses for this kind of pericarp maize.