Incorporation Of Lactoferrin Research Articles

Effect of donkey milk lactoferrin and lysozyme on yoghurt properties

Food industry has mostly focused on natural preservatives due to the undesirable effects of chemical additives on the human health. Among milk proteins, lactoferrin and lysozyme are the best-known for their antimicrobial. In this study, lactoferrin and lysozyme were extracted from donkey milk and applied on the yoghurt surface by spraying. The obtained yoghurt samples enriched with antimicrobial proteins were compared with the control sample produced without the addition of any preservatives as well as the samples treated with natamycin, a commercial preservative used in dairy products. Thereby physicochemical, microbiological and textural properties of the samples were investigated during the 30 days of storage. Yoghurt samples treated with antimicrobial agents had lower microbial load than control samples, which indicated that the donkey milk lactoferrin and lysozyme inhibit microbial activity in yoghurts. However, the addition of the mentioned preservatives did not change the gross composition and the textural properties of the yoghurt samples. Most importantly, the incorporation of lactoferrin or lysozyme did not adversely affect the sensory properties of yoghurt samples, but achieved higher appreciation points than the control sample on the 30th day of storage. In brief, lactoferrin and lysozyme extracted from donkey milk could be used to control the undesirable microbial growth, hence extending the shelf life of yoghurt.

Formation and stability of single and bi-layer nanoemulsions using WPI and lactoferrin as interfacial coatings under different environmental conditions

Electrostatic deposition of lactoferrin (LF) on the stability of nanoemulsions stabilized by whey protein isolate (WPI) was investigated as a function of pH (2–10) and LF concentration (0.25–5% w/w). The WPI-stabilized nanoemulsions prepared by emulsification and solvent evaporation were diluted with LF solutions to form a series of bi-layer emulsions at different pH levels. At pH 2 and 4, the bi-layer nanoemulsions were stable regardless of LF concentrations but underwent droplet aggregation at pH 5 near to the pI of WPI. At pH 6, electrostatic interactions were favored for the deposition of LF onto the WPI-coated droplets. However, the emulsions were prone to droplet aggregation at low concentrations of LF (0.5–1% w/w), presumably due to bridging flocculation. Thus, a sufficiently high level of LF was necessary to stabilize the emulsions. At pH 7, 8, 9 and 10, there was sufficient electrostatic attraction between the protein molecules to form WPI-LF bi-layer at the droplet surface and the formed emulsions were stable. Based on the results, a stable bi-layer nanoemulsion can be formed using 3% (w/w) LF at ≥ pH 6. The incorporation of LF in bi-layer emulsions improved the stability of single layer WPI-stabilized emulsions at pH near the pI of WPI (pH 4–6) and salt addition (0–90 mM CaCl2) but the bi-layer emulsions were susceptible to droplet aggregation at temperatures above 60 °C. This study showed the overall potential benefits of having of a WPI-LF bi-layer to improve the stability of WPI-stabilized nanoemulsions.

Selenium-binding lactoferrin is taken into corneal epithelial cells by a receptor and prevents corneal damage in dry eye model animals.

The ocular surface is strongly affected by oxidative stress, which causes many ocular diseases including dry eye. Previously, we showed that selenium compounds, e.g., selenoprotein P and Se-lactoferrin, were candidates for treatment of dry eye. This paper shows the efficacy of Se-lactoferrin for the treatment of dry eye compared with Diquas as a control drug using two dry eye models and incorporation of lactoferrin into corneal epithelial cells via lactoferrin receptors. We show the efficacy of Se-lactoferrin eye drops in the tobacco smoke exposure rat dry eye model and short-term rabbit dry eye model, although Diquas eye drops were only effective in the short-term rabbit dry eye model. These results indicate that Se-lactoferrin was useful in the oxidative stress-causing dry eye model. Se-lactoferrin was taken into corneal epithelium cells via lactoferrin receptors. We identified LRP1 as the lactoferrin receptor in the corneal epithelium involved in lactoferrin uptake. Se-lactoferrin eye drops did not irritate the ocular surface of rabbits. Se-lactoferrin was an excellent candidate for treatment of dry eye, reducing oxidative stress by a novel mechanism.

Study on Use of Lactoferrin for the Biopreservation of <i>Paneer</i>

Paneer is an Indian traditional milk product which occupies an important place as a base product for the production of various culinary preparations. The shelflife of paneer is a major constraint in its utilization. Lactoferrin, a member of transferrin family of proteins, is one of the most important milk proteins naturally found in the milk of mammals and is an iron-binding glycoprotein which has antimicrobial properties. Studies were conducted on incorporation of lactoferrin at different levels (10, 15 &amp; 20 ppm) in paneer. It was observed that, as the level of lactoferrin in the product increased, there was a significant decrease in the bacterial growth when compared to the control; thereby increasing the shelflife of paneer. Lactoferrin-treated paneer, up to 20 ppm showed an increase in shelf life up to 7 days at room temperature (30°C) and 15 days at refrigerated temperature (4°C) compared with the control with a shelf life of 2 days at 30°C and 7 days at 4°C, respectively. Similarly, as the level of lactoferrin increases, paneer had significantly higher hardness, cohesiveness, springiness and chewiness. The sensory evaluation of the paneer samples treated with 20 ppm lactoferrin was acceptable up to 7 days at ambient temperature and up to 15 days at refrigerated temperature. <em>Tropical Agricultural Research Vol. 23 (1): 70-76 (2011)</em> DOI: <a href="http://dx.doi.org/10.4038/tar.v23i1.4633">http://dx.doi.org/10.4038/tar.v23i1.4633</a>

Physico-chemical characterization of chitosan-based edible films incorporating bioactive compounds of different molecular weight

Chitosan packaging films containing different bioactive compounds (a peptide fraction from whey protein concentrate (WPC) hydrolysate, glycomacropeptide (GMP) and lactoferrin) were produced and their mechanical and barrier properties were evaluated. The molecular weight of protein-based compounds was determined using SDS–PAGE. The addition of GMP and lactoferrin to chitosan film caused a significant reduction of tensile strength and the elongation-at-break significantly increased with the incorporation of lactoferrin. The addition of protein-based compounds also affected gas permeability: a significant decrease in water vapor permeability was observed with the incorporation of lactoferrin; oxygen permeability significantly decreased with the addition of GMP and lactoferrin and carbon dioxide permeability significantly decreased with the incorporation of all of the protein-based compounds. Such results were related with film’s hydrophilicity and crystallinity. This manuscript contributes to the establishment of an approach to optimize edible films performance based on physico-chemical properties, aiming at a higher benefit for the consumer.

Antimicrobial Activity of Lactoferrin against Foodborne Pathogenic Bacteria Incorporated into Edible Chitosan Film

The objectives of this research were to develop and characterize edible chitosan film containing lactoferrin as a natural antimicrobial agent, and to investigate the combination effects of lactoferrin with lysozyme in chitosan film against the growth of Escherichia coli O157:H7 and Listeria monocytogenes. Chitosan films containing lactoferrin, lysozyme, or nisin were fabricated, and the antimicrobial concentrations were 0.5, 1, or 2 mg in a circular disc of chitosan film. Three concentrations of lactoferrin or EDTA (0.28, 0.56, or 1.12 mg per disc) were also incorporated into the chitosan film containing lysozyme to investigate the combination effects of lactoferrin. The water barrier properties of the chitosan films containing lactoferrin were characterized. The antimicrobial activities against E. coli O157:H7 and L. monocytogenes were determined using the agar diffusion assay and cell count assay. The chitosan films containing lactoferrin less than 1 mg per disc did not alter the water vapor permeability of the chitosan film. Although the film containing lysozyme exhibited significant antimicrobial activity, the incorporation of lactoferrin alone into chitosan film did not exhibit significant antimicrobial activity against both E. coli O157:H7 and L. monocytogenes. However, the combination of lactoferrin with lysozyme-containing chitosan film significantly decreased the growth of E. coli O157:H7, exhibiting a comparable effect to that of the combination of EDTA with lysozyme (P < 0.05). Furthermore, the combination of lactoferrin with lysozyme in chitosan film exhibited greater reduction in the growth of L. monocytogenes than did the combination EDTA with lysozyme, resulting in an approximate 3-log reduction.

Interaction of Human Lactoferrin with Cell Adhesion Molecules through RGD Motif Elucidated by Lactoferrin-binding Epitopes

Lactoferrin (LF) is an iron-binding secretory protein, which is distributed in the secondary granules of polynuclear lymphocytes as well as in the milk produced by female mammals. Although it has multiple functions, for example antimicrobial, immunomodulatory, antiviral, and anti-tumor metastasis activities, the receptors responsible for these activities are not fully understood. In this study, the binding epitopes for human LF were first isolated from a hexameric random peptide library displayed on T7 phage. Interestingly, two of the four isolated peptides had a representative cell adhesion motif, Arg-Gly-Asp (RGD), implying that human LF interacts with proteins with the RGD motif. We found that human LF bound to the RGD-containing human extracellular matrix proteins, fibronectin and vitronectin. Furthermore, human LF inhibited cell adhesion to these matrix proteins in a concentration-dependent manner but not to the RGD-independent cell adhesion molecule like laminin or collagen. These results indicate that a function of human LF is to block the various interactions between the cell surface and adhesion molecules. This may explain the multifunctionality of LF.