BACKGROUND: Lactoperoxidase is an enzyme of the oxidoreductase family. Lactoperoxidase is an important antimicrobial agent. Applications of lactoperoxidase are being found as a preservative in food and cosmetics. Immobilized LPO provides several significant benefits such as: easily separated from the reaction products, reducing production costs by efficient recycling and control of the process. Objectives: Purification and immobilization of lactoperoxidase extracted from camel milk using sodium alginate polymer. Methods: The lactoperoxidase was purified from camel milk by using sephadex G-100 gel filtration CM and sephadex C-50 ion-exchange chromatography. Encapsulation was carried out by using LPO, sodium alginate, glycerol and Tween 80. Afterward, the microcapsules were stablized by calcium ion (1%). Efficiency of encapsulation was calculated. The particle size and distribution were measured with particle size analyzer. Morphology and formation of the particles were studied  using Scanning Electron Microscope (SEM). Stability of encapsulated and uncapsulated  LPO was studied at 4 °C during 70 days. Results: After purification and purity measurement by SD-SPAGE, concentration of 0/28 micrograms per liter for each of the fractions was obtained. Microencapsulation efficiency was 84% and microcapsules  less than 200 nm were formed. Observation by SEM confirmed the formation of microparticles. Microcapsules have a relatively smooth surface, spherical with low tenacity as well. Stability of encapsulated enzyme at 70 days was obtained 81%. Conclusions: Immobilization of Lactoperoxidase extracted from camel milk  using sodium alginate is a good method to increase performance of the enzyme.

Objective: This study assessed the effect of cellulose sheets fortified with Natamycin-loaded algi¬nate nanoparticles on the growth of toxigenic Aspergillus flavus and aflatoxin production on the superficial layer of Egyptian Romy cheese after 12 weeks of maturation. Materials and Methods: Toxigenic A. flavus (GenBank accession No. MT645073) was inoculated into the outer surface of Egyptian Romy cheese (at 5 log CFU/gm) and wrapped with a cellulose sheet fortified with Natamycin-loaded alginate nanoparticles. Unwrapped control contaminated Romy wheels were made as well as non-contaminated wrapped cheese wheels for sensory eval¬uation. Romy cheese wheels were stored at a temperature similar to commercial methods for 12 weeks. Fungal counts were enumerated during this time, and enzyme-linked immune sorbent assay detected aflatoxin after the 4th week of maturation storage. Results: In cheese samples covered with cellulose sheets containing Natamycin-loaded alginate nanoparticles, the fungal count was reduced by 2 log approximately in contrast to control samples after the 2nd week of storage. However, within the 8th week of storage, the greatest significant reduction (p < 0.05) was seen where fungal growth was hindered entirely to the end of the rip¬ening period. The mean values for taste, color, flavor, and overall acceptability were 4, 4.7, 4.09, and 4.3, respectively. Furthermore, in the treated samples, the total aflatoxin concentration was decreased by 78.6% relative to the untreated control one. Conclusion: Using cellulose sheets fortified with Natamycin-loaded alginate nanoparticles in Egyptian Romy cheese wrapping could be an effective way of controlling A. flavus and subsequent aflatoxin production without influencing the typical taste, color, flavor, and overall appearance of traditional Romy cheese. [J Adv Vet Anim Res 2021; 8(1.000): 58-63]