Listeria monocytogenes Inhibition by Whey Protein Films and Coatings Incorporating Lysozyme

2005 ◽  
Vol 68 (11) ◽  
pp. 2317-2325 ◽  
Author(s):  
SEACHEOL MIN ◽  
LINDA J. HARRIS ◽  
JUNG H. HAN ◽  
JOHN M. KROCHTA
Keyword(s):  
Elastic Modulus ◽  
Listeria Monocytogenes ◽  
Whey Protein ◽  
Oxygen Permeability ◽  
Protein Isolate ◽  
Lower Percentage ◽  
Growth Media ◽  
Antimicrobial Effects ◽  
Smoked Salmon ◽  
Yeasts And Molds

The effects of whey protein isolate (WPI) films and coatings incorporating lysozyme (LZ) on the inhibition of Listeria monocytogenes both in and on microbial media, as well as on cold-smoked salmon, were studied. The antimicrobial effects of LZ were examined using various growth media by turbidity and plate counting tests. Disc-covering and disc-surface–spreading tests were also used to evaluate the effects of WPI films incorporating LZ. Smoked salmon was used as a model food to test the antimicrobial effects of WPI coatings incorporating LZ, both initially and during storage at 4 and 10°C for 35 days. Tensile properties (elastic modulus, tensile strength, and percentage of elongation), oxygen permeability, and color (Hunter L, a, and b) of WPI films with and without LZ were also compared. LZ inhibited L. monocytogenes in broth and on agar media. The number of cells surviving after LZ treatments depended on the type of media. WPI films incorporating 204 mg of LZ per g of film (dry basis) inhibited the growth of a preparation of 4.4 log CFU/cm2 L. monocytogenes. WPI coatings prepared with 25 mg of LZ per g of coating solution initially inactivated more than 2.4, 4.5, and 3.0 log CFU/g of L. monocytogenes, total aerobes, and yeasts and molds in smoked salmon samples, respectively. The WPI coatings incorporating LZ efficiently retarded the growth of L. monocytogenes at both 4 and 10°C. The anti–L. monocytogenes effect of LZ-WPI coating was more noticeable when the coating was applied before inoculation than when the coating was applied after inoculation. Significantly higher elastic modulus values and lower percentage of elongation and oxygen permeability values were measured with the WPI films incorporating LZ than with the plain WPI films.

scholarly journals Dispersion and Performance of a Nanoclay/Whey Protein Isolate Coating upon its Upscaling as a Novel Ready-to-Use Formulation for Packaging Converters

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1410 ◽  
Author(s):  
Elodie Bugnicourt ◽  
Nicola Brzoska ◽  
Esra Kucukpinar ◽  
Severine Philippe ◽  
Enrico Forlin ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
Whey Protein ◽  
Oxygen Permeability ◽  
Whey Protein Isolate ◽  
Protein Isolate ◽  
Morphological Properties ◽  
Industrial Scale ◽  
Barrier Performance ◽  
Coating Formulations

Studies on composition optimisation showed that the mixing of nanoclays to whey protein-isolate (WPI)-based coating formulations offers an effective strategy to reduce the oxygen permeability of coated polymer films. The scaling up of the various processing stages of these formulations was undertaken to prove their industrial feasibility. The aim was to investigate the effect of various preparation methods at different production scales (pilot- and semi-industrial scale) on the barrier performance and morphological properties of the applied nanocomposites. A nano-enhanced composition was converted into a so-called “ready-to-use” formulation by means of a solid-state pre-dispersion process using ball-milling. The process yielded a nearly dust-free, free-flowing powder containing agglomerated particles, which can easily be mixed with water. The preparation of a coating formulation using the ready-to-use granules and its upscaling for roll-to-roll converting at pilot- and semi-industrial scale was also successfully implemented. The effects of both the production at various scales and ultrasound treatment on the morphology and barrier performance of the nanocomposites were characterized by transmission electron microscopy, scanning electron microscopy, as well as oxygen permeability measurements. Results have shown that the addition of nanoclays to WPI-based coating formulations ultimately led to significantly reduced oxygen permeabilities to 0.59 cm3, 100 µm·m−2·d−1·bar−1 (barrier improvement factor, BIF of 5.4) and 0.62 cm3, 100 µm·m−2·d−1·bar−1 (BIF of 5.1) in cases of pilot- and semi-industrial-processed coatings, respectively, compared to a reference without nanoclay. In both cases, a similar degree of nanoparticle orientation was achieved. It was concluded that the solid state pre-dispersion of the nanoplatelets during the production of the ready-to-use formulation is the predominant process determining the ultimate degree of nanoparticle orientation and dispersion state.

scholarly journals Properties of Whey Protein–Based Films Containing Organic Acids and Nisin To Control Listeria monocytogenes

2009 ◽  
Vol 72 (9) ◽  
pp. 1891-1896 ◽  
Author(s):  
CRISTINA M. B. S. PINTADO ◽  
MARIA A. S. S. FERREIRA ◽  
ISABEL SOUSA
Keyword(s):  
Listeria Monocytogenes ◽  
Organic Acids ◽  
Whey Protein ◽  
Malic Acid ◽  
Antimicrobial Agents ◽  
Loss Modulus ◽  
Inhibitory Effect ◽  
Edible Films ◽  
Protein Isolate ◽  
Weak Gel

Whey protein isolate and glycerol were mixed to form a matrix to incorporate antimicrobial agents and produce edible films with antimicrobial activity against Listeria monocytogenes strains isolated from cheeses. Various organic acids were used to decrease pH down to approximately 3. In a preliminary assay without nisin, the effect of each organic acid was evaluated with respect to the rheological properties of the film solutions and the inhibitory and mechanical properties of the films. Lactic, malic, and citric acids (3%, wt/vol), which were used in a subsequent study of their combined inhibitory effect with nisin (50 IU/ml), had significantly higher antilisterial activity (P < 0.05) compared with the control (2 N HCl, 3% [wt/vol], with nisin). The largest mean zone of inhibition was 4.00 ± 0.92 mm for malic acid with nisin. Under small-amplitude oscillatory stress, the protein-glycerol-acid film solutions exhibited a predominantly viscous behavior or a weak gel behavior, with the storage modulus (G′) slightly higher than the loss modulus (G″). The malic acid–based solution was the only one whose viscosity was not influenced by the addition of nisin. The addition of nisin resulted in a nonsignificant (P > 0.05) increase in the percentage of elongation at break. Results from tensile and puncture stress were variable, but in general no significant differences were found after the incorporation of nisin. The overall results support the use of malic acid with nisin to produce effective antimicrobial films to control L. monocytogenes growth.

scholarly journals Preparation and Compatibilization of PBS/Whey Protein Isolate Based Blends

Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3313 ◽  
Author(s):  
Maria-Beatrice Coltelli ◽  
Laura Aliotta ◽  
Vito Gigante ◽  
Maria Bellusci ◽  
Patrizia Cinelli ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Protein Content ◽  
Whey Protein ◽  
Protein Isolate ◽  
Glycerol Monostearate ◽  
Soy Lecithin ◽  
Butylene Succinate ◽  
Elongation At Break

In this paper the production of biopolymeric blends of poly(butylene succinate) PBS and plasticized whey protein (PWP), obtained from a natural by-product from cheese manufacturing, has been investigated for the production of films and/or sheets. In order to add the highest possible whey protein content, different formulations (from 30 to 50 wt.%) were studied. It was found that by increasing the amount of PWP added to PBS, the mechanical properties were worsened accordingly. This trend was attributed to the low compatibility between PWP and PBS. Consequently, the effect of the addition of soy lecithin and glycerol monostearate (GMS) as compatibilizers was investigated and compared to the use of whey protein modified with oleate and laurate groups obtained by Schotten-Baumann reaction. Soy lecithin and the Schotten-Baumann modified whey were effective in compatibilizing the PWP/PBS blend. In fact, a significant increase in elastic modulus, tensile strength and elongation at break with respect to the not compatibilized blend was observed and the length of aliphatic chains as well as the degree of modification of the Schotten–Baumann proteins affected the results. Moreover, thanks to DSC investigations, these compatibilizers were also found effective in increasing the PBS crystallinity.

scholarly journals Advances in Fabricating the Electrospun Biopolymer-Based Biomaterials

2021 ◽  
Vol 12 (2) ◽  
pp. 26
Author(s):  
Sebastian Wilk ◽  
Aleksandra Benko
Keyword(s):  
Mechanical Properties ◽  
Whey Protein ◽  
Antimicrobial Properties ◽  
Protein Isolate ◽  
Review Article ◽  
Animal Tissues ◽  
Green Material ◽  
Good Potential ◽  
Fibrous Morphology ◽  
Selection Of

Biopolymers formed into a fibrous morphology through electrospinning are of increasing interest in the field of biomedicine due to their intrinsic biocompatibility and biodegradability and their ability to be biomimetic to various fibrous structures present in animal tissues. However, their mechanical properties are often unsatisfactory and their processing may be troublesome. Thus, extensive research interest is focused on improving these qualities. This review article presents the selection of the recent advances in techniques aimed to improve the electrospinnability of various biopolymers (polysaccharides, polynucleotides, peptides, and phospholipids). The electrospinning of single materials, and the variety of co-polymers, with and without additives, is covered. Additionally, various crosslinking strategies are presented. Examples of cytocompatibility, biocompatibility, and antimicrobial properties are analyzed. Special attention is given to whey protein isolate as an example of a novel, promising, green material with good potential in the field of biomedicine. This review ends with a brief summary and outlook for the biomedical applicability of electrospinnable biopolymers.

scholarly journals Physicochemical and Microstructural Characterization of Whey Protein Films Formed with Oxidized Ferulic/Tannic Acids

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1599
Author(s):  
Yaosong Wang ◽  
Youling L. Xiong
Keyword(s):  
Whey Protein ◽  
Microstructural Characterization ◽  
Protein Isolate ◽  
Light Transmittance ◽  
In Vitro Digestibility ◽  
Protein Films ◽  
Film Forming ◽  
Protein Sulfhydryl ◽  
Reduced Light

Protein-based biodegradable packaging films are of environmental significance. The effect of oxidized ferulic acid (OFA)/tannic acid (OTA) on the crosslinking and film-forming properties of whey protein isolate (WPI) was investigated. Both of the oxidized acids induced protein oxidation and promoted WPI crosslinking through the actions of quinone carbonyl and protein sulfhydryl, and amino groups. OTA enhanced the tensile strength (from 4.5 MPa to max 6.7 MPa) and stiffness (from 215 MPa to max 376 MPa) of the WPI film, whereas OFA significantly increased the elongation at break. The water absorption capability and heat resistance of the films were greatly improved by the addition of OTA. Due to the original color of OTA, the incorporation of OTA significantly reduced light transmittance of the WPI film (λ 200–600 nm) as well as the transparency, whereas no significant changes were induced by the OFA treatment. Higher concentrations of OTA reduced the in vitro digestibility of the WPI film, while the addition of OFA had no significant effect. Overall, these two oxidized polyphenols promoted the crosslinking of WPI and modified the film properties, with OTA showing an overall stronger efficacy than OFA due to more functional groups available.

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