Effect of anthocyanin-absorbed whey protein microgels on physicochemical and textural properties of reduced-fat Cheddar cheese.

Reduced-fat foods have become more popular due to their health benefits; however, reducing the fat content of food affects the sensory experience. Therefore, it is necessary to improve the sensory acceptance of reduced-fat foods to that of full-fat equivalents. The aim of this study was to evaluate the effect of adding whey protein microgels (WPM) with an average diameter of 4 µm, or WPM with adsorbed anthocyanins [WPM (Ant)] on the textural and sensory properties of reduced-fat Cheddar cheese (RFC). Reduced-fat Cheddar cheese was prepared in 2 ways: (1) by adding WPM, designated as RFC+M, or (2) by adding WPM (Ant), designated as RFC+M (Ant). For comparison, RFC without fat substitutes and full-fat Cheddar cheese were also prepared. We discovered that the addition of WPM and WPM (Ant) increased the moisture content, fluidity, and meltability of RFC, and reduced its hardness, springiness, and chewiness. The textural and sensory characteristics of RFC were markedly inferior to those of full-fat Cheddar cheese, whereas addition of WPM and WPM (Ant) significantly improved the sensory characteristics of RFC. The WPM and WPM (Ant) showed a high potential as fat substitutes and anthocyanin carriers to effectively improve the acceptance of reduced-fat foods.

Improved stability, epithelial permeability and cellular antioxidant activity of ß-carotene via encapsulation by self-assembled α-lactalbumin micelles.

The low aqueous solubility, stability and bioavailability of hydrophobic bioactive compounds, such as ß-carotene (ß-c), greatly hinder their application in foods. Nanocarriers could overcome this problem by facilitating the delivery of the functional ingredients. We prepared lactalbumin (α-lac) micelles by partial enzymatic hydrolysis in aqueous solution. ß-c can be incorporated into the cores of these micelles via hydrophobic interactions. The aqueous solubility and stability under 60 °C heating or UV light irradiation of encapsulated ß-c improved significantly compared with free ß-c. Moreover, it had an increased cellular uptake (3 times) and transmembrane permeability (13 times) in a Caco-2 cell monolayer model. It suggested that α-lac micelle-encapsulated ß-c had an enhanced cellular absorption and transport efficiency. Encapsulated ß-c also exhibited an enhanced cellular anti-oxidant activity (CAA) compared with free ß-c. This work demonstrates that α-lac micelles showed a great potential for delivery of hydrophobic bioactive compounds in foods.

The construction of enzymolyzed α-lactalbumin based micellar nanoassemblies for encapsulating various kinds of hydrophobic bioactive compounds.

Protein-based nanoassemblies can encapsulate hydrophobic compounds into their hydrophobic region and effectively improve their aqueous solubility and stability. However, hydrolyzed food protein based micellar nanoassemblies and their interaction with different hydrophobic compounds are less understood. Here, 20 nm α-lactalbumin (α-lac) micellar nanoassemblies were constructed via self-assembly of partially hydrolyzed α-lac peptides by Bacillus licheniformis proteinase. We identified three fractions of peptides which reorganized into this kind of nanomicelle after exposure of α-lac hydrophobic groups. Moreover, four hydrophobic compounds (curcumin, quercetin, astaxanthin, coenzyme Q10) were successfully loaded into nanomicelles mainly via hydrophobic interactions. Among these four compounds, curcumin was most encapsulated in micelles due to its smaller molecular weight, high hydrophobicity and less steric hindrance. The strongest interaction was also observed between curcumin and nanomicelles. Finally, their aqueous solubility and UV stability after micellar encapsulation were significantly improved. This demonstrated that α-lac micelles are promising delivery systems for hydrophobic compounds.

Enzymatically Partially Hydrolyzed α-Lactalbumin Peptides for Self-Assembled Micelle Formation and Their Application for Coencapsulation of Multiple Antioxidants.

The codelivery system for multiple antioxidants such as anthocyanins (Ant) and curcumin (Cur) of synergistic action may effectively enhance their stability and cellular absorption. We have reported that amphiphilic peptides obtained from enzymatic partial hydrolysis of α-lactalbumin (α-lac) can self-assemble into 20 nm monodispersed nanomicelles in aqueous solution. Cur and Ant could be coloaded into the micelles sequentially via hydrophobic and electrostatic interactions, which was proved by fluorescence quenching experiments for the Cur-micelle and Ant-micelle interactions. Circular dichroism spectra proved that the Cur and Ant binding did not affect their structure confirmation. Both Cur- and Ant-loaded micelles showed improved stability and also exhibited an intestinal pH responsive release property in simulated gastrointestinal fluid. In addition, the nanomicelles exhibited an advanced cellular uptake and transmembrane permeability based on Caco-2 cell monolayer models. Finally, the coloaded micelles possessed a synergistic efficiency such that cellular antioxidant activity (CAA) for Cur and Ant was markedly improved.