Bitterness-masking assessment of luteolin encapsulated in whey protein isolate-coated liposomes

Development and characterization of caffeine-loaded nanoliposomes decorated by cationic amylose and cationic amylose- menthol inclusion complex coatings; a novel oral co-delivery system

Nanoliposomes (NLPs) have evolved as compelling carriers for loading bioactive compounds. To improve the phospholipid bilayer membrane stability, caffeine-loaded NLPs were coated with cationic amylose (CA) and CA-menthol inclusion complexes (CAMICs). The zeta potential results indicated an electrostatic attraction between CA and the negatively charged NLPs. Observations from dynamic light scattering, atomic force microscopy, and Fourier transform infrared spectroscopy demonstrated the efficient deposition of both CA and CAMICs onto the surface of NLPs without altering their spherical shape. Raman spectra and X-ray diffraction patterns indicated that both CA and CAMICs can decrease membrane fluidity and enhance lipid packing laterally. Additional assessment through thermogravimetric analysis revealed that the coating of NLPs, particularly with CAMICs, protected caffeine against thermal degradation. These coated NLPs show promise for formulation advancement, facilitating the simultaneous delivery of functional compounds.

Gastrointestinal digestion behavior and bioavailability of greenly prepared highly loaded myofibrillar-luteolin vehicle

In this study, the highly loaded myofibrillar protein (MP)-luteolin (Lut) complexes were noncovalently constructed by using green high-pressure homogenization technology (HPH) and high-pressure micro-fluidization technology (HPM), aiming to optimize the encapsulation efficiency of flavonoids in the protein-based vehicle without relying on the organic solvent (i.e. DMSO, ethanol, etc.). The loading efficiency of Lut into MPs could reach 100 % with a concentration of 120 μmol/g protein by using HPH (103 MPa, 2 passes) without ethanol adoption. The in vitro gastrointestinal digestion behavior and antioxidant activity of the complexes were then compared with those of ethanol-assisted groups. During gastrointestinal digestion, the MP digestibility of complexes, reaching more than 70.56 % after thermal treatment, was higher than that of sole protein. The release profile of Lut encapsulated in ethanol-containing and ethanol-free samples both well fitted with the Hixson-Crowell release kinetic model (R2 = 0.92 and 0.94, respectively), and the total phenol content decreased by ≥ 40.02 % and ≥ 62.62 %, respectively. The in vitro antioxidant activity (DPPH, ABTS, and Fe2+) of the digestive products was significantly improved by 23.89 %, 159.69 %, 351.12 % (ethanol groups) and 13.43 %, 125.48 %, 213.95 % (non-ethanol groups). The 3 mg/mL freeze-dried digesta significantly alleviated lipid accumulation and oxidative stress in HepG2 cells. The triglycerides and malondialdehyde contents decreased by at least 57.62 % and 67.74 % after digesta treatment. This study provides an easily approached and environment-friendly strategy to construct a highly loaded protein-flavonoid conjugate, which showed great potential in the formulation of healthier meat products.

Bitter flavors and bitter compounds in foods: identification, perception, and reduction techniques

Bitterness is one of the five basic tastes generally considered undesirable. The widespread presence of bitter compounds can negatively affect the palatability of foods. The classification and sensory evaluation of bitter compounds have been the focus in recent research. However, the rigorous identification of bitter tastes and further studies to effectively mask or remove them have not been thoroughly evaluated. The present paper focuses on identification of bitter compounds in foods, structural-based activation of bitter receptors, and strategies to reduce bitter compounds in foods. It also discusses the roles of metabolomics and virtual screening analysis in bitter taste. The identification of bitter compounds has seen greater success through metabolomics with multivariate statistical analysis compared to conventional chromatography, HPLC, LC-MS, and NMR techniques. However, to avoid false positives, sensory recognition should be combined. Bitter perception involves the structural activation of bitter taste receptors (TAS2Rs). Only 25 human TAS2Rs have been identified as responsible for recognizing numerous bitter compounds, showcasing their high structural diversity to bitter agonists. Thus, reducing bitterness can be achieved through several methods. Traditionally, the removal or degradation of bitter substances has been used for debittering, while the masking of bitterness presents a new effective approach to improving food flavor. Future research in food bitterness should focus on identifying unknown bitter compounds in food, elucidating the mechanisms of activation of different receptors, and developing debittering techniques based on the entire food matrix.

WPI-coated liposomes as a delivery vehicle for enhancing the thermal stability and antioxidant activity of luteolin

The practical application of luteolin in food systems faces challenges due to its inherent instability. This study aimed to develop luteolin-loaded liposomes coated with whey protein isolate (WPI) to enhance the thermal stability and antioxidant activity of luteolin. The physical characteristics of both luteolin-loaded liposomes (LUT-Lips) and WPI-coated luteolin-loaded liposomes (WPI-LUT-Lips) were assessed. At a 5% WPI concentration, WPI-LUT-Lips demonstrated excellent dispersibility and improved encapsulation efficiency. WPI interacted with the liposome membrane via hydrophobic forces, hydrogen bonding, and electrostatic contact force, resulting in an efficient coating. Differential scanning calorimetry confirmed that WPI-LUT-Lips exhibited greater thermal stability compared to LUT-Lips, attributed to the protective effect of the WPI. Furthermore, WPI-LUT-Lips displayed superior antioxidant activity, as evidenced by their DPPH scavenging activity (86.36 ± 1.95%), TBARS reduction (25.33 ± 1.90%), and reducing power (82.86 ± 1.42%). Therefore, WPI-coated luteolin-loaded liposomes offer a promising way to enhance luteolin's integration into food systems.

Encapsulation of (-)-epigallocatechin gallate (EGCG) within phospholipid-based nanovesicles using W/O emulsion-transfer methods: Masking bitterness and delaying release of EGCG

A novel phospholipid-based nanovesicle (PBN) was developed to encapsulate (-)-epigallocatechin gallate (EGCG), a major polyphenol in green tea, to mask its bitter taste and expand its application in food products. The PBN was formed using W/O emulsion-transfer methods and showed a multilayer membrane nanovesicle structure (around 200 nm) observed with TEM. The PBN possessed a high encapsulation efficiency (92.1%) for EGCG. The bitterness of EGCG was significantly reduced to 1/12 after encapsulation. Fourier transform infrared spectroscopy (FTIR) indicated the EGCG mainly interacted with the upper chain/glycerol/head group region of the lipid bilayerin PBN. Quartz crystal microbalance with dissipation (QCM-D) showed the addition of γ-cyclodextrin in PBN enhanced EGCG's adsorption with phospholipids and allowed for its good sustained release. Encapsulating EGCG in PBN inhibited its complexation with mucin, reducing bitterness and astringency. This provides a new method to improve EGCG's flavor, potentially expanding its application in the food industry.

Polysaccharide-coated quercetin-loaded nanoliposomes mitigate bitterness: A comparison of carrageenan, pectin, and trehalose

The intense bitterness of quercetin poses a challenge to its utilization in the food industry. To address this issue, three anionic polysaccharides (carrageenan, pectin, and trehalose) were individually incorporated to fabricate polysaccharide-coated liposome nanocarriers. Electronic tongue analysis revealed a significant decreasing bitterness value (10.34 ± 0.07 mV, sensory score 1.8 ± 0.2, taste weak bitter) in quercetin-loaded nanoliposomes, compared with the bitterness value of quercetin aqueous solution (14 ± 0.01 mV, sensory score 7.3 ± 0.3, taste strong bitter). Furthermore, the polysaccharide-coated nanoliposomes exhibited an even greater capacity to mask the bitterness of quercetin, with carrageenan coated nanoliposomes demonstrating the most pronounced effect. The superior bitter masking ability of carrageenan coated nanoliposomes can be attributed to its high charge and viscosity. In sensory evaluations, gummy incorporated with carrageenan-coated nanoliposomes received the highest ratings, exhibiting enhanced overall palatability and antioxidant activity. This study offers insights into expanding the use of bitter nutrients in food applications and paves the way for more appealing and healthful food products.