Search

In this research, a novel kind of walnut (Juglans regia L.) peptides‐zinc (Zn‐WPs) chelate was obtained using the mass ratio of the walnut peptides (WPs) to ZnSO4.7H2O of 3.5:1 at pH 8.5 and 50°C for 84 min, with the chelation rate of 84.5%. In comparison to walnut peptides (WPs), the contents of aspartic acid and glutamic acid in Zn‐WPs chelate are approximately 27%, indicating that hydrophilic amino acids predominantly bind with walnut peptides. Following chelation with zinc ions, the ultraviolet‐visible (UV) characteristic absorption peak shifted from 213 nm to 210 nm, while the average particle size of the chelate increased to 8.0 ± 0.14 µm, presenting a loose spherical structure under scanning electron microscopy. These findings suggest the formation of new substances. Fourier‐transform infrared spectroscopy (FTIR) revealed carboxyl, amino, and peptide bonds as the chelation sites of WPs and zinc. The IC50 of walnut peptides‐zinc (Zn‐WPs) chelate is 2.91 mg/mL, indicative of a favorable DPPH radical scavenging rate. Furthermore, Zn‐WPs chelate microcapsules were produced via the spray drying method, achieving an encapsulation rate of 75.67 ± 0.83% under optimal conditions. These microcapsules demonstrate robust stability across diverse environmental conditions. This study underscores the potential of Zn‐WPs and its chelate microcapsules to enhance stability and bioactivity under varying circumstances. Practical Application: In this study, a new walnut peptide‐zinc (Zn‐WPs) chelate was prepared. The presence of zinc ions changes the structure and properties of walnut peptides and improves its stability. The production of Zn‐WPs chelate microcapsules enables Zn‐WPs to have strong in vitro stability under different pH and simulated gastrointestinal digestion conditions. These results provide novel insights for developing the walnut peptides as bioactive ingredients in functional foods. [ABSTRACT FROM AUTHOR]

Walnut oil is an edible oil with high nutritional value, and the roasting process influences its quality and flavor. This study aimed to investigate the effects of roasting on the fatty acid composition, bioactive compounds (tocopherols, polyphenols, and phytosterols), and antioxidant capacity of walnut oil. Additionally, the aroma compounds and sensory characteristics were evaluated to comprehensively assess the variations in walnut oil after roasting. Roasting resulted in no notable impact on the fatty acid composition of walnut oil but increased the content of tocopherols and polyphenols in walnut oil, increasing its antioxidant capacity. Heavy roasting (160°C/20 min) reduced the phytosterol content in walnut oil by 2.3%. In total, 146 volatile compounds were detected in both cold‐pressed and roasted walnut oil using headspace solid‐phase microextraction‐gas chromatography–mass spectrometry, and 32 key aroma compounds were identified. Aromatic aldehydes, aliphatic aldehydes, and heterocyclic compounds significantly contributed to fragrant walnut oil. Furthermore, the principal component analysis based on quality characteristics and sensory evaluation indicated that moderate roasting (130°C/20 min, 130°C/30 min, and 160°C/10 min) provided walnut oil with a sweet, nutty, and roasted aroma, as well as high levels of linoleic acid, phytosterols, and γ‐tocopherol. Although heavy roasting (160°C/15 min and 160°C/20 min) enhanced the antioxidant capacities of walnut oils due to high levels of polyphenols, the oils exhibited an unpleasant burnt aroma. This study showed that roasting promoted the quality and flavor of walnut oil, and moderate conditions endowed walnut oil with a characteristic‐rich flavor while maintaining excellent quality. [ABSTRACT FROM AUTHOR]

Superconformal field theory with $\mathcal{N}=2$ supersymmetry in four dimensional spacetime provides a prime playground to study strongly coupled phenomena in quantum field theory. Its rigid structure ensures valuable analytic control over non-perturbative effects, yet the theory is still flexible enough to incorporate a large landscape of quantum systems. Here we aim to offer a guidebook to fundamental features of the 4d $\mathcal{N}=2$ superconformal field theories and basic tools to construct them in string/M-/F-theory. The content is based on a series of lectures at the Quantum Field Theories and Geometry School (https://sites.google.com/view/qftandgeometrysummerschool/home) in July 2020.

The walnut oil oleogels prepared by beeswax and monoglyceride was used as the research object and the effects of ultrasound treatment before or after complex oleogelators melting on the structure and properties of the walnut oli oleogels were explored. The research results indicated that when the mass ratio of beeswax to monoglyceride was 3:7, the formed walnut oil oleogels had an oil bonding capacity (OBC) of over 95% and a smooth and stable surface morphology. All walnut oleogels showed solid-like elastic properties within a certain shear strain range, and the walnut oil oleogels prepared with 100 W-30 s parameters had the strongest mechanical properties. Ultrasound treatment could improve the crystal structure of walnut oil oleogels, produce more compact and fine crystal morphology, and effectively enhance OBC and thermal stability of walnut oil oleogels. The oleofoams obtained by whipping the oleogels exhibited excellent decorative performance, and ultrasound treatment could significantly increase the overrun of the walnut oil oleogels. In sum, ultrasound treatment could improve the structure and properties of walnut oil oleogel, and make it a good substitute for margarine. Key words:walnut oil oleogel;beeswax;monoacylglycerol;ultrasound treatment [ABSTRACT FROM AUTHOR]