Targeting foodborne pathogens via surface-functionalized nano-antimicrobials.

The incorporation of antibiotics and bioactive compounds into non-toxic nanoparticles has been popularly used to produce effective antimicrobial nanocarriers against foodborne pathogens. These systems can protect antimicrobials against harsh environments, control their release, and increase their antimicrobial activities; however, their functions can be decreased by some major barriers. Intracellular localization of bacteria protects them from the host immune system and antimicrobial agents. Also, bacteria can cause constant infection by nestling in professional phagocytic cells. In the last years, surface functionalization of nanocarriers by passive and active modification methods has been applied for their protection against clearance from the blood, increasing both circulation time and uptake by target cells. For achieving this objective, different functional agents such as specifically targeted peptides internalize ligands, saccharide ligands, or even therapeutic molecules (e.g., antibodies or enzymes) are used. In this review, techniques for functionalizing the surface of antimicrobial-loaded nanocarriers have been described. This article offers a comprehensive review of the potential of functional nanoparticles to increase the performance of antimicrobials against foodborne pathogens through targeting delivery.

The influence of thermal processing on emulsion properties of defatted hazelnut flour.

In this study, the influences of roasting and the amount of hazelnut flour on the formation and stabilization of emulsions containing different amounts of oil were investigated. After hazelnuts were roasted in an oven at 140°C for 40 min, the oil content was removed. The emulsions with defatted hazelnut flour containing corn oil at 3%, 10% and 50% were prepared. Roasting process significantly decreased the interfacial tension values of samples down to 1.9 mN/m due to protein denaturation. There was no significant difference between the particle sizes of oil droplets in emulsions with roasted and raw hazelnut flour at the same concentration. However, diffusion coefficients of oil droplets increased for emulsions containing roasted defatted flour samples. The zeta (ζ) potential values of all emulsions increased when roasted hazelnut flour was used, indicating the stabilization of suspensions and the solution resistance against aggregation. Storage modulus (G'), loss modulus (G″) and complex viscosity (η(∗)) of emulsions were measured. G' value was found to be greater than the G″ value, which fits into weak gel model. The roasting process resulted with lower transition temperatures but with increased transition enthalpies of the flour samples based on differential scanning (DSC) measurements. Lower transition temperatures may be attributed to the partial gelatinization of starch in the flour and partial denaturation of proteins. These results may help to tailor the properties of defatted hazelnut flour when it is used in food products containing emulsions such as sauces, dressings and creams for stabilizing purposes.