Effect of ultrasound treatment on the properties of nano-emulsion films obtained from hazelnut meal protein and clove essential oil

Abstract

Hazelnut meal protein (4% (w/v)) and clove essential oil (CEO) (3% (v/v)) were homogenized with ultrasound (US) at different times (2, 4 and 6 min) and amplitudes (50, 75 and 100%) to obtain nano-emulsion films. Film forming nano-emulsions (FFNs) were analyzed for average particle size (D) and zeta potential, and edible film characterization were evaluated depending on US treatment, as well as antibacterial and antioxidant activities. D values and zeta potential of FFNs decreased with increasing acoustic energy delivered to nano-emulsion system. Thickness and water solubility of films significantly decreased with increasing US treatment. Films became more transparent depending on US treatment probably due to particle size reduction. Tensile strength (TS) of films significantly increased with US treatment, while elongation at break (EAB) slightly increased. Microstructure of films became more homogeneous after US treatment and caused to lower water vapor permeability. Enrichment with CEO has given the films antibacterial activity against L. monocytogenes, B. subtilis, S. aureus, P. aeruginosa and E. coli, and antioxidant activity, and US application has improved these activities. US technology can be used to improve mechanical, barrier and antimicrobial properties of hazelnut meal protein based edible films enriched with CEO.

Effect of Sonication on the Properties of Flaxseed Gum Films Incorporated with Carvacrol

“…The incorporation of carvacrol and sonication had significant effects on TS and EB (p < 0.05, Table 2). With the increasing content of carvacrol, the TS of FG-C film decreased gradually, but the EB slightly increased, which is in agreement with the findings of Klangmuang and Sothornvit [14] and Gul et al [15]. When the carvacrol content was the highest (2.0 mL/L), the TS was the lowest.…”

“…The opacity of film is vastly influenced by carvacrol addition and the internal structure of films (see Table 4). The internal structure of FG-C films is greatly influenced by the size of carvacrol droplets, the volume fraction of the dispersed carvacrol, coalescence, and emulsification during the drying process [15]. As listed in Table 2, the opacity of FG-0.5C, FG-1.0C, and FG-2.0C is 0.925, 0.866, and 0.821 mm −1 , respectively.…”

“…After the addition of carvacrol, anamorphous structure was formed in the crosssections of FG-C films with vacuoles and cavities distributed. The volatilization of carvacrol in the drying process will leave some holes, leading to the destruction of the homogeneity and compact structure of the film [15,47]. FG-C films with sonication improved the integration of carvacrol droplets into the FG matrix, resulting in a denser structure that provided good barrier properties to the film.…”

Thyme Antimicrobial Effect in Edible Films with High Pressure Thermally Treated Whey Protein Concentrate

“…Further the mix was homogenized by ultrasonication with equipment Sonoplus HD3100 Bandelin, Germany equipped with a sonication probe of 8 mm diameter, at 35% amplitudes, for 3 min. The sonication probe was immersed 1 cm below the liquid surface and the temperature of the film forming emulsion was kept at 23 ± 2 • C during sonication by placing the tube in an iced water bath [16].…”

“…In this study, combined high pressure at 600 MPa with thermal treatment (70 °C) was employed as original alternative to thermal treatment alone for whey protein aggregation, promoting intermolecular interactions between film forming substances, which are crucial for film forming step [ 15 ]. For obtaining a homogenous film forming emulsion, ultrasound treatment was used here [ 16 ].…”