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Pathogenic bacteria in food are a public health problem worldwide. Polyphenolic bioactive compounds with antimicrobial activity and antioxidant capacity represent a tangible alternative to overcome this problem. To preserve the biological functions of phenolic compounds such as tannic acid, which has been described to possess antioxidant and antimicrobial activity, this study describes the synthesis of a zinc nanohydroxide to stabilize its properties. Characterization by XRD, FT-IR, SEM, DLS, and UV-vis evidenced the presence of tannic acid in the nanohybrid TA-Zn-LHS which was further confirmed by DPPH, ABTS and FRAP antioxidant activity techniques. Bacterial growth inhibition of Escherichia coli ATCC 8739, Salmonella Enteritidis, and Staphylococcus aureus ATCC 25923 was over 80% at 50 mg/mL of the TA-Zn-LHS and over 90% with Zn-LHS. Antibiofilm evaluation of these same strains showed biofilm formation inhibition > 90% and > 80% for Zn-LHS and TA-Zn-LHS, respectively. The toxicity evaluation of the materials in Artemia salina showed a classification of the materials as non-toxic to slightly toxic in concentrations up to 1 mg/mL. These results allow us to introduce a new nanohybrid useful for food safety with safe biological functions., Competing Interests: Conflict of interestAll authors declare no conflict of interest., (© Association of Food Scientists & Technologists (India) 2023. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.)

Preterm infants are at high risk of infection due to opportunistic bacteria as Pseudomonas aeruginosa , causing infections among infants in neonatal intensive care units. Human lactoferrin (hLf) is a multifunctional protein and one of the most abundant in breast milk, and plays an important role in prevention of different infections in neonates. This work offers a strategy to obtain a lyophilisate of purified lactoferrin from breast milk. In addition, a reliable HPLC method for quantification of lactoferrin with a linear quantification range of 0.040-0.140 mg/mL with selectivity, accuracy and repeatability, is described. Lyophilized hLf was obtained by purification through a heparin affinity column followed by ultrafiltration with a 30 kDa membrane. The final solution was lyophilized and the product was analyzed using HPLC method, recovering about 70% of initial lactoferrin in the sample. This molecule was elucidated through FTIR spectroscopy and SDS-PAGE electrophoresis. In addition, the capacity against biofilm formation of P. aeruginosa was demonstrated with 75% of inhibition at 6 mg/mL. These results suggest that lyophilized hLf can be obtained by purification of breast milk and that it can provide antibiofilm activity against P. aeruginosa ., Competing Interests: Conflict of interestThe Author(s) declare(s) that they have no conflicts of interest to disclose., (© Association of Food Scientists & Technologists (India) 2022, Springer Nature or its licensor holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.)

The use of antimicrobial agents within a matrix, specifically layered compounds, is of growing interest for reducing contamination due to food borne pathogens and deteriorative microorganisms, one of the main health problems worldwide. In this study, zinc layered hydroxide nanoparticles were synthesized as a matrix for nisin immobilization. Layered materials were characterized by X-ray diffraction, Fourier-Transform Infrared and Ultra Violet-Visible spectra, Scanning Electron Microscopy, and by Thermogravimetric Analysis. Thermal, chemical, enzymatic, and biological stabilities were assessed against Lactobacillus brevis as control strain. Free and immobilized nisin in solution were previously subjected to 25 and 121 °C, pH (7, 9) and inactivation with protease before antimicrobial tests that lasted 21 days. Immobilized nisin was found to maintain the activity levels after the protease action while the pure nisin solution lost its activity gradually. Furthermore, immobilized nisin treated at 121 °C and pH 7 showed higher activity than pure nisin after 21 days. These results may support that immobilizing nisin in zinc layered hydroxide salts promoted extended nisin inhibitory activity in solution after thermal, chemical or enzymatic treatments. This research provides an alternative to nisin application that could be used in processes where such operating conditions take place, as in dairy products., Competing Interests: Conflict of interestAll authors declare that they have no conflicts of interest., (© Association of Food Scientists & Technologists (India) 2020.)