l-Theanine improves emulsification stability and antioxidant capacity of diacylglycerol by hydrophobic binding β-lactoglobulin as emulsion surface stabilizer

Diacylglycerol emulsion with different droplet size improves the gelation properties of Nemipterus virgatus myofibrillar protein

Effects of diacylglycerol (DAG) emulsions with different particle sizes on gel properties, microstructures and chemical forces of myofibrillar protein (MP) gels were investigated. DAG emulsions addition significantly improved the whiteness of MP gels. With the decrease of emulsion droplet size, G', G" and immovable water content of MP gels gradually increased, and cooking loss decreased, in which, emulsion prepared under 200 W reduced the cooking loss to the minimum value of 2.57 %. Furthermore, the gel strength and texture properties of MP gels were enhanced as the decreasing emulsion droplet size, and significant improvement (P < 0.05) appeared in gel strength and hardness when ultrasonic power reached 200 W, and then texture indexes tended to be stable as power continued to increase. Reducing the emulsion particle size facilitated the uniform distribution of DAG in the gel network and enhanced the chemical forces of composite gel, forming the more compact network structure.

L-Theanine Improves the Gelation of Ginkgo Seed Proteins at Different pH Levels

L-theanine (L-Th), a non-protein amino acid naturally found in teas and certain plant leaves, has garnered considerable attention due to its health benefits and potential to modify proteins such as ginkgo seed proteins, which have poor gelling properties, thereby expanding their applications in the food industry. The objective of this study was to investigate the impact of varying concentrations of L-Th (0.0%, 0.5%, 1.0%, and 2.0%) on the gelling properties of ginkgo seed protein isolate (GSPI) at various pH levels (5.0, 6.0, and 7.0). The GSPI gels exhibited the highest strength at a pH of 5.0 (132.1 ± 5.6 g), followed by a pH of 6.0 (95.9 ± 3.9 g), while a weak gel was formed at a pH of 7.0 (29.5 ± 0.2 g). The incorporation of L-Th increased the hardness (58.5-231.6%) and springiness (3.0-9.5%) of the GSPI gels at a pH of 7.0 in a concentration-dependent manner. However, L-Th did not enhance the gel strength or water holding capacity at a pH of 5.0. The rheological characteristics of the GSPI sols were found to be closely related to the textural properties of L-Th-incorporated gels. To understand the underlying mechanism of L-Th's effects, the physicochemical properties of the sols were analyzed. Specifically, L-Th promoted GSPI solubilization (up to 7.3%), reduced their hydrophobicity (up to 16.2%), reduced the particle size (up to 40.9%), and increased the ζ potential (up to 21%) of the sols. Overall, our findings suggest that L-Th holds promise as a functional ingredient for improving gel products.

Influence of 1,3-diacylglycerol on physicochemical and digestion properties of nanoemulsions and its enhancement of encapsulation and bioaccessibility of hydrophobic nobiletin

Lipid-based delivery systems are commonly used to encapsulate hydrophobic bioactive compounds for enhancing their bioaccessibility and bioavailability, especially for triacylglycerol (TAG) oil-based delivery systems. However, studies on the development of 1,3-diacylglycerol (DAG) oil-based delivery systems are rather limited. Herein, the influence of 1,3-DAG oil as a carrier oil on the properties of nanoemulsions and the bioaccessibility of encapsulated hydrophobic nobiletin (NOB) were investigated. High-purity 1,3-DAG (over 93% pure) was prepared by a combination of enzymatic esterification and ethanol crystallization. 1,3-DAG oil as a carrier oil could be used to formulate nanoemulsions with smaller droplet size, narrower size distribution and similar stability compared to TAG oil. Importantly, 1,3-DAG oil could efficiently encapsulate high-loading NOB (1.45 mg g-1) in nanoemulsions and significantly improve the bioaccessibility of NOB (above 80%), which is attributable to its massive lipolysis and higher encapsulation capacity than TAG oil. Moreover, the addition of the 1,3-DAG component in TAG oil significantly improved the properties of nanoemulsions and the loading and bioaccessibility of NOB, especially as the 1,3-DAG content was not less than 50%. The structure of lipids (DAG versus TAG) influenced the nanoemulsion properties and the bioaccessibility of encapsulated NOB. Based on the good properties of 1,3-DAG oil coupled with its health benefits, 1,3-DAG oil-based nanoemulsion delivery systems have great prospects for improving and extending emulsion properties and bioactivity as well as bioaccessibility enhancement.

Avocado seed by-product uses in emulsion-type ingredients with nutraceutical value: Stability, cytotoxicity, nutraceutical properties, and assessment of in vitro oral-gastric digestion

The avocado industry obtains 20-30% of the total by-products (peels and seeds). However, byproducts can be uses as sources of economic nutraceutical ingredients with functional potential. This work developed emulsion-type ingredients from avocado seed to evaluate its quality, stability, cytotoxicity, and nutraceutical properties before/after in vitro oral-gastric digestion. Ultrasound lipid extraction achieved an extraction yield of up to 95.75% compared with Soxhlet conventional extraction (p > 0.05). Six ingredients' formulations (E1-E6) were stable for up to day 20 during storage, preserving their antioxidant capacity and displaying low in vitro oxidation compared to control. None of the emulsion-type ingredients were considered cytotoxic according to the shrimp lethality assay (LC₅₀ > 1000 µg/mL). Ingredients E2, E3, and E4 generated low lipoperoxides' concentrations and high antioxidant capacity during the oral-gastric stage. The 25 min-gastric phase showed the highest antioxidant capacity and low lipoperoxidation. Results suggested avocado seed-derived could be used to develop functional ingredients with nutraceutical properties.

Physicochemical, antioxidant and sensory properties of Mango Sorbet containing L-theanine as a potential functional food product

The non-proteinous amino acid L-theanine (L-THE) is associated with a range of health benefits including improvements in immune function, cardiovascular outcomes and cognition. The aims of this study were to develop a food product (mango sorbet; ms-L-THE) containing physiologically relevant doses of L-THE (0.2/100 g w/w) and determine its antioxidant, physicochemical and sensory properties in comparison to a mango sorbet without L-THE (ms). Total phenolic and flavanol content, and antioxidant analysis (DPPH, FRAP and ABTS) were determined spectrophotometrically. Both products were also evaluated for acceptability and likeability in healthy participants using the 9-point hedonic scale. Any differences that could be caused by the addition of L-THE were examined using the triangle test. Results indicated no significant differences between ms-L-THE and ms in taste of the products (p > 0.05), and the ms-L-THE was well received and accepted as a potential commercial product. Findings of the DPPH assay indicated significant difference between the two products (p < 0.05). In conclusion, we have successfully created a mango sorbet that contains a potentially physiologically relevant concentration of L-THE with antioxidant properties that could be used as a novel method of L-THE delivery to clinical and healthy populations.

Diacylglycerol pre-emulsion prepared through ultrasound improves the gel properties of golden thread surimi

This study determined the influence of diacylglycerol (DAG) pre-emulsion on the gel properties and microstructure of golden thread surimi gels. DAG emulsion stabilized using sodium caseinate was pre-emulsified through ultrasound. The average particle size of DAG pre-emulsion decreased from 1324.15 nm to 41.19 nm, with notable improvements in apparent viscosity and storage stability. The surimi gels with different amounts (0%, 1%, 3%, 5%, and 7% w/w) of DAG pre-emulsion were prepared under heat induction. The whiteness of the composite gels markedly increased with the incorporation of DAG pre-emulsion. The peak T₂₂ value of immobilized water, the gel strength, and water-holding capacity increased gradually, but it slightly decreased with the addition of 7% pre-emulsion. The curve of G' and G″ kept climbing as the concentration of pre-emulsion, and the microstructure of the gel network tended to become denser and more orderly. Principal component analysis (PCA) of electronic nose results showed that the surimi gels containing pre-emulsion could be clearly distinguished from the control group. In conclusion, the addition of 5% DAG pre-emulsion to surimi not only improved gel properties to the highest extent but also be compensated for lipid loss during the rinsing of surimi.