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Abstract Liposomes have gained great interest in the food and pharmaceutical industry as colloidal carriers of bioactive compounds. In this work, liposomes of phosphatidylcholine (PC) and oleic acid (OA) encapsulating garlic extract (GE) were developed to determine its aptitude as antifungal agent in wheat bread. The influence of GE on the properties of liposomes were followed by determination of size, Zeta potential, Fourier transform infrared patterns (FTIR), morphology, differential scanning calorimetry (DSC) and thermogravimetric (TGA) techniques. The produced PC-OA-GE liposomes showed spherical morphology with narrow size distribution, entrapment efficiency of 79.7% and zeta potential of −27.9 mV. In vitro antifungal test showed noticeable inhibitory activities for free and encapsulated GE against selected fungal strains. TGA analysis revealed that the presence of OA and GE in the formulation retards the liposomal thermal decomposition, as compared with the pure PC liposomes and the DSC enthalpy and main transition temperature variation in PC-OA-GE liposomes suggested a strong heat-induced rigidifying effect that could be attributed to the presence of garlic polysaccharides in the liposome surface, observed by FTIR. In the in situ test, the bread formulations with free or liposome-encapsulated GE (0.65 mL/100 g of dough) were microbiologically more stable as compared with the controls, showing mold inhibition for five days. Therefore, liposomes formulated with OA and GE showed potential as natural antifungal agent in bakery products. Highlights • Garlic extract was encapsulated into phosphatidylcholine-oleic acid liposomes. • Nanometric liposomes of 113 nm were obtained and tested in wheat bread. • Nanoliposomes containing garlic extract inhibited fungal spoilage in wheat bread. • Liposomes formulated with oleic acid and garlic extract have antifungal impact on bakery products. [ABSTRACT FROM AUTHOR]

Aureocin A70 is the only four-component bacteriocin described to date. As it inhibits the growth of a wide range of Gram-positive bacteria, including Listeria monocytogenes strains isolated from food, its potential for improving food safety was investigated in this study. Aureocin A70 (10,240 AU/mL) proved to be bactericidal, but not extensively lytic, against listerial strains. The antibacterial activity of aureocin A70 (16 AU/mL) was then tested in UHT-treated skimmed milk inoculated with the food-associated L. monocytogenes L12 strain (4-log CFU/mL) during storage at 4 °C for one week. Aureocin A70 caused a time-dependent reduction in the listerial viable cell counts (5.51-log units) up to 7 days of incubation. Aureocin A70 was neither toxic to the Vero and the L-929 cell lines nor exhibited a hemolytic activity against sheep red blood cells. Aureocin A70 proved to be completely stable for one month at 25 °C, 16 weeks at 4 °C and 20 weeks at − 20 °C. Aureocin A70 exhibited a time-dependent susceptibility to simulated gastric juice and bile salts mimicking gastrointestinal conditions. The entrapment of aureocin A70 in an alginate/gelatin matrix revealed that this bacteriocin can be released from this matrix. Moreover, it remained adsorbed to and active on a low-density polyethylene plastic surface suggesting that aureocin A70 may be employed in bioactive packaging to control the growth of undesirable bacteria. Taken together these results suggest that aureocin A70 is a promising alternative to be used in food applications. [ABSTRACT FROM AUTHOR]

In this study, the sustained-release of clove essential oil (CEO) loaded into the structure of electrospun zein was used as a biopreservative to extend the shelf life of Iranian white cheese. CEO was loaded at levels of 5, 7.5, and 10% w/w in the structure of electrospun nanofibers. In this study, a concentration of 35% w/v zein was used to produce electrospun fibers, and in the field emission scanning electron microscope (FESEM) it was observed that by increasing the loading of CEO from 5 to 10% w/w in the fiber structure, their diameter decreased from 517.96 ± 41.57 nm to 457.88 ± 32.45 nm. Although increasing the level of CEO reduced the diameter of the electrospun nanofibers, Young's modulus, tensile strength, and a higher level of CEO increased elongation at break of the films. The results of mechanical properties showed that by increasing the amount of CEO application in the structure of electrospun zein nanofibers from 5 to 10% w/w tensile strength from 8.18 ± 0.62 to 4.43 ± 0.86 MPa, and Young's modulus from 38.25 ± 2.81 to 27.25 ± 3.48 MPa decreased. Successful encapsulation of CEO in designed structures and the absence of adverse bonds between the encapsulant material (zein) and the core (CEO) were confirmed by the Fourier-transform infrared spectroscopy (FTIR) test. The in vitro sustained-release of the CEO in 8% w/v brine during 45 days of storage at 4 °C was modeled. The Fickian diffusion was the dominant release mechanism of the CEO and the Peppas-Sahlin model was the best model describing the essential oil release behavior. The electrospun films containing CEO were well able to suppress the growth of Listeria monocytogenes and Escherichia coli O157: H7 in samples of Iranian white cheese kept in 8% brine for 45 days at 4 °C. The samples treated with the electrospun film containing 7.5% w/w of CEO had the highest acceptability among different treatments. [Display omitted] • Electrospun zein fibers loaded with clove essential oil (CEO) were produced. • Mechanical and morphological properties of the bioactive films were tested. • The Peppas-Sahlin model well described the sustained-release behavior of the CEO. • The bioactive electrospun films were applied to Iranian white cheese. • The growth of L. monocytogenes and E. coli O157: H7 was suppressed in the cheese. [ABSTRACT FROM AUTHOR]