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International Journal of ChemTech Research CODEN (USA): IJCRGG, ISSN: 0974-4290, ISSN(Online):2455-9555 Vol.10 No.4, pp 233-244, 2017
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Antimicrobial Edible Film Based Whey Protein – A Review
Abdul Manab*
Animal Product Technology Department, Animal Husbandry Faculty, Brawijaya University, Jalanr Veteran Malang, East Java, Indonesia.
Abstract : Some perishable food need a edible packaging materials to protect it from deterioration, edible film whey protein containing antimicrobial compound is one of the most interest as packaging material. Whey protein edible film containing organic acid (propionic, benzoic, sorbic and lactic acid), enzyme (lysozyme) and liquid smoke showed an inhibition ability the growth some bacteria, yeast and mold in food which coated using whey protein edible film. Antimicrobial activity of whey protein edible film containing antimicrobial compound can prolong its inhibition activity if the antimicrobial compound attached in some substance such as beeswax, oleic acid and polyacrilic acid to controlling the release of antimicrobial compound from whey protein edible film.
Introduction
Foods are generally susceptible to microbiological, physical and chemical deterioration during storage and distribution, both as a function of food composition and the environmental conditions1. A selection of packaging materials can prevent food deterioration by providing barrier2, using the materials wich biodegradable, non-toxic and biocompatible3,4. Edible film based biodegradable substance showed antimicrobial activity5.
Food packaging is widely used for quality protection, to extending the shelf life of perishable food and ensuring food hygiene6. Edible films is an environmentally-friend and have ability to protect perishable food from deterioration by reducing microbial growth. Several research reported on the efficacy of films containing antimicrobials agent to control microbial growth on food, so edible films is considered as alternative method to extend the quality of food7,8,9,10.
Edible film provide additional protection against contamination of microorganism and modified atmosphere of food11. Food packaging become considerable attention attributed with natural polymers development as eco-friendly packaging materials. Such natural polymers may be lipid, polysaccharide or protein based could be used as edible films formula12.
Antimicrobial whey protein films.
Whey proteins are a renewable source and a by-product of cheesemaking industry13, it have been employed as biodegradable packaging material14 . Whey protein isolates (WPI) are the purer form of whey proteins15. WPI is isolated from a byproduct of cheese manufacturing, which makes bio-based packaging materials production (Ozer et al., 2016). WPI have excellent film forming14, produce transparent films and provide certain mechanical properties16,17, moderate moisture permeability18, and good gas barrier properties— comparable to high density polyethylene, low-density polyethylene (LDPE), vinyl alcohol, ethylene vinyl alcohol, polyvinylidene chloride (PVDC) and polyester19,20.
The ability of WPI edible films as barriers to solute and gas will enhance food shelf-life and quality21. However, these films have lower mechanical and higher water vapor permeability barrier because their hydrophilic properties21. The hydrophilic properties of WPI films causes active compound quickly release from the film when contact with water. The release of active compounds from WPI films mainly depends on hydrophilic properties of WPI and active compound22.
WPI films are good vehicles to incorporate antimicrobial compound, for example essential oils, bacteriocins such as nisin23 and natamycin 24 , plant extracts such as essential oils25 and viable cells of certain microorganisms. Nowadays, the development active package containing natural antimicrobials, increase consumer demand for natural food additives.
Edible films can serve as carriers for antimicrobial compound that can reduce pathogenic and food spoilage organisms growth on food surfaces. Some antimicrobial compound commonly used as preservatives26,27,28,29,30,31,32 are organic acids (e.g. acetic, citric, lactic and propionic acids), bacteriocins (e.g. nisin), enzymes (e.g. lysozyme), polysaccharides (e.g. chitosan), and several plant extracts33,34,35.
WPI films are excellent carriers of food additives as antimicrobials and spices to improve the functionality of the packaging based WPI36, 37.
The strategy for controlled release of antimicrobial compound from whey protein films.
The release of antimicrobial compound from hydrophilic edible film such as whey protein film while maintaining antimicrobial efficacy of the films over time is still a challenging issue. This is a large problem in the films made from hydrophilic polymers, because the swelling of polymer such as whey protein in the presence of water. The swelling of polymer increase free volume between polymer chains, in turn accelerating antimicrobial compound release. Considering some limitations of approaches, several strategy developed for sustained antimicrobial compound release from whey protein film14 as shown at Table 1..
Polyacrylic acid (PAA)
Encapsulated lysozyme incorporated into a food-grade polyelectrolyte, polyacrylic acid (PAA) a weak polyelectrolyte, to form lysozyme/PAA complexes. The complexes is mostly driven by oppositely charged groups in the protein and the polyelectrolyte via electrostatic interactions38,39,40,41. The complex is formed spontaneously under certain conditions by mixing proteins and polyelectrolytes, subsequently the complex incorporated to whey protein isolate films14. Lysozyme-polyacrylic acid complex can be used to achieve whey protein isolate film with long-lasting antimicrobial effect and whey protein isolate films prepared with lysozyme-polyacrylic acid complex suitable as food packaging materials14.
Lysozyme- polyacrylic acid complex incorporated into whey protein isolate films was effective to control the release rate of lysozyme from the film, allowing sustained lysozyme release for extended periods. The films prepared using Lysozyme- polyacrylic acid complex have a great potential for food shelf-life extension and food preservation14.
Beeswax
The whey protein films with beeswax have antimicrobial activity against Listeria innocua42. Whey protein film containing lysozyme using beeswax as hydrophobic compound of film increased the total of lysozyme released from whey protein film. Antimicrobial film based whey protein can improve food safety of food stored in the refrigerators42. . Beeswax in whey protein film containing organic acid decrease the release of organic acids from whey protein film and the film showed antimicrobial avtivity against Escherichia coli and Salmonella spp. 43.
Oleic acid
Whey protein-oleic acid film containing lysozyme showed inhibition of L. innocua, antimicrobial films of Whey protein-oleic acid could be activated to improve food safety42.
Antimicrobial activity of whey protein edible film containing antimicrobial compound
Edible film containing antimicrobial compoud has been approved have antimicrobial ability against several microorganism to extend the shelf life of food using several antimicrobial compound includes organic acids, enzyme, cell free supernatan and liquid smoke.
Lysozyme
Hen egg white lysozyme is the most potential candidates for antimicrobial compound incorporating into whey protein film, because its good stability and activity in edible films and food systems during storage in refrigerated temperatures44,45. Lysozyme is enzyme that found in hen, plants, mammals and bacteria, this enzyme is used as food preservative46. It have antimicrobial effect on Gram positive bacteria via peptidoglycan destroying especially to hydrolyze beta-glycosidic bonding between N-acetylmuramic and N-acetyl Glucosamine47, acetylglucosamine48,49, in the peptidoglycan of bacterial cell wall. It is frequently used in the antimicrobial edible film50.
The antimicrobial activity of lysozyme mainly on Gram-positive by destroying the peptidoglycan in cell walls bacteria especially by splitting the bonds between N-acetylmuramic acid and N-acetylglucosamine48,49. The application of lysozyme in film mainly the inhibition of Gram-positive. Listeria monocytogenes a Gram-positive pathogenic bacteria is inhibited by lysozyme to prevent bacterium infections51.
Cell-free supernatant of Lactobacillus sakei
Cell-free supernatants from probiotics bacteria contain some antimicrobial compound (such as bacteriocins, lactic acid and acetic acid) thus potential to incorporate into edible film52. Lactobacillus sakei is a lactic acid bacteria using as biopreservatives have been added to meat products, dur to their ability to inhibit E. coli O157:H753. WPI films incorporated with cell-free supernatant of Lb. sakei have ability to inhibit L. monocytogenes and E. coli growth during refrigerated storage54.
Potassium sorbate
Potassium sorbate can effectively restrain the activity of yeast, mould and aerophile bacteria. Potassium sorbate ionizes to form sorbic acid when dissolved in water. Potassium sorbate is a weak acid and increased the ability to penetrate into cytoplasmic membrane of bacteria especially in the undissociated form55.
The addition of potassium sorbate in whey protein concentrate films led to inhibit the growth of Shiga toxin-producing Escherichia coli (STEC) O15756. Potassium sorbate was incorporated into whey protein concentrate/glycerol edible films shows inhibition of the growth of Shiga toxin producing Escherichia coli (STEC). STEC growth inhibition was dependent on potassium sorbate content. The active packaging based on whey proteins and potassium sorbate to prevent STEC growth may be an effective and safe alternative to be used as active packaging in food industry57.
Sorbic acid
Incorporation for sorbic acid or or p-aminobenzoic acid into whey protein isolate films (pH 5.2) can inhibit Listeria monocytogenes, S. typhimurium and Escherichia coli O157:H7 growth58. Sorbic acid is used as preservative agents, due to its safety and low influence on organoleptic properties59. Sorbic acid is classified as GRAS additive and effective toward yeast and moulds but only partly retard bacterial growth 60,61. This antimicrobial compound has been used in antimicrobial films and effective in controlling the growth of microorganism62, such as Escherichia coli, Penicillium spp and Lactobacillus plantarum63.
Benzoic acid
Benzoic acid incorporated into whey protein film has been reported on the antimicrobial activity against Escherichia coli and Salmonella spp. 64.
Lactic acid
Whey protein film containing lactic acid has been reported on the antimicrobial activity against E. coli and Salmonella spp. 64. Edible film containing lactic acid and chitooligosaccharide showed the effect against Gram-negative bacteria (Escherichia coli, Pseudomonas fluorescens, Salmonella spp.) and Gram-positive bacteria (Listeria innocua, Staphylococcus aureus) and yeast (Yarrowi lipolytica) 13. Adding lactic acid to foods for preservation purposes, via elimination of spoilage and pathogenic bacteria growth65. However, lactic acid may not exhibit a significant antimicrobial activity toward yeasts and molds 66.
Propionic acid
Incorporating propionic acid in whey protein film showed antimicrobial activity against E. coli and Salmonella spp. 64. Propionic acid has antifungal performance and capable to inhibit the growth of Gram-negative and Gram-positive bacteria. Propionic acid is usually applied to inhibit mold growth on cheese and butter, as well as to hamper bacteria and yeasts growth in syrup67.
Liquid smoke
Liquid smoke is natural wood smoke flavors solution manufactured by condensing wood smoke68. Liquid smoke was offer many advantages than traditional smoking, namely speed of application, easy and product uniformity. Commercial liquid smoke products contain phenols, acetic acid and carbonyl compounds, which are shown bactericidal effect at relatively low content. Liquid smoke can inactivate food spoilage organisms and food-borne pathogens, including Salmonella sp., Staphylococcus aureus, Escherichia coli, and Listeria monocytogenes67,68,69,70,71,72,73,74. Based on these evidences, makes liquid smoke a potentially attractive as antimicrobial compound in antimicrobial edible films 75. The incorporation of commercial liquid smoke to whey protein concentrate-based edible films useful to prevent the growth of foodborne pathogen such as Listeria monocytogenes76.
Antimicrobial activity of whey protein edible film containing antimicrobial compound
Edible film containing antimicrobial compoud has been approved to extend the shelf life and food safety of food against against several microorganism includes bacteria, yeast and mold as shown at Table 1.
Table 1. Antimicrobial whey protein film
Treatment |
Antimicrobial agent |
Effect/result |
Microorganism |
Reference |
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Whey protein isolate (WPI) films supplemented with Lb. sakei cell-free supernatan performed on wrapped beef. |
Cell-free supernatant of Lactobacillus sakei NRRL B-1917 |
WPI films supplemented with Lb. sakei cell-free supernatant (containing a bacteriocin-like substance) exhibited antimicrobial activity against L. monocytogenes and E. coli, and maintained antimicrobial activity on beef inoculated with L. monocytogenes or E. coli.
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E. coli and L. monocytogenes
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75 |
Incorporating organic acids in whey protein film |
acetic, lactic, propionic and benzoic acids |
incorporating organic acids in whey protein film showed antimicrobial activity against Eschericia coli and Salmonella sp. |
Eschericia coli and Salmonella sp. |
62 |
The release of lysozyme from whey protein film containing |
Lysozyme |
Incorporating of beeswax decreasing the release of lysozyme from whey protein film, and stable antibacterial |
E. coli |
43 |
beeswax |
activity against E. coli
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Sodium cyanoborohydride addition on the release of lysozyme from whey protein film |
Lysozyme |
Increasing sodium cyanoborohydride content decreasing the release of lysozyme from whey protein film, and stable antibacterial activity against E. coli
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E. coli |
77 |
Whey protein film containing lysozyme as gouda cheese edible coating |
Lysozyme |
Antimicrobial composite edible film containing lysozyme effective to inhibit microorganism growth both at the surface and inside region of gouda cheese during ripening. |
Lactic acid bacteria, Enterococcus, Coliform, E. coli, Salmonella, S. aureus and yeast/mold). |
76 |
Controlling the release of lysozyme from WPI in smoked salmon |
Hen egg white Lysozyme |
Antimicrobial packaging using lysozyme, oleic acid and whey protein films showed inhibition of L. innocua growth on coated salmon slices stored at 4°C. |
L. innocua |
42 |
Incorporated polyacrylic acid lysozyme complexed on WPI film. |
Lysozyme |
Complexation of lysozyme-polyacrylic acid was an effective tool for controlling lysozyme release from WPI films. Complexation reduced the release rate of lysozyme from WPI films. |
Listeria innocula |
14 |
Incorporated pottasium sorbate into WPC films toretard non-O157 STEC |
Potassium sorbate |
The addition potassium sorbate in WPC films led to retard the growth of STEC pathogens, Antimicrobial edible films containing most organic acids frequently used as preservatives are more effective in an acidic environment. |
E. coli O157:H7 ATCC 43895, Eight non-O157 Shiga toxin-producing E. coli |
55 |
Potassium sorbate included into WPC films to retard Shiga toxin-producing E. coli |
Potassium sorbate |
WPC film containing potassium sorbate retarded the growth of Shiga toxin-producing E. coli may be an ecological, effective, safe and relatively cheap alternative to be food packaging industry. |
Shiga toxin-producing E. coli |
30 |
Inhibition of spoilage microflora in cheese using antimicrobial WPI film
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Chitooligosaccharide, lactic acid, sodium benzoate, ctric acid. nisin |
Lactic acid and chitooligosaccharide (COS) exhibited bacteriocidal effect on Gram-positive and Gram-negative bacteria, respectively, whereas sodium benzoate and COS exhibited the highest inhibitory effect against the yeast. Combinations of lactic acid |
Escherichia coli, Listeria innocua, Yarrowia lipolytica, Staphylococcus spp., Pseudomonas spp., Enterobacteriacea, yeasts and moulds |
80 |
and COS showed the highest effect to all microorganisms tested; The application on the cheese surface, they more active against bacteria, and less effective toward yeasts and moulds than their commercial coating counterparts. |
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Incorporation several organic acid on . from WPI film.
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lactic acid (LA) and propionic acid (PRO), chitooligosaccharides (COS) and natamycin (NA) |
WPI Films formulated with LA, PRO or COS showed antimicrobial activity toward all microorganisms tested. COS most active against Gram-negative bacteria, whereas LA was the most active toward Gram-positive ones. NA was not active toward bacteria, but showed strongest effect against yeasts. |
E. coli, S. aureus, Y. lipolytica |
13 |
WPC-based films incorporated with liquid smoke |
liquid smoke |
Incorporation liquid smoke into WPC films were effective to prevent L. monocytogenes growth, and it may be suitable for food surfaces protection and useful to inhibit L. monocytogenes. However, it was not effective to inhibit E. coli, S. aureus, and S. Typhimurium |
Escherichia coli, Staphylococcus aureus, Salmonella typhimurium, and Listeria monocytogenes |
74 |
WPI composite films incorporated with three different types of nano-clays
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three nano-clays, Cloisite Na+, Cloisite 20A, and Cloisite 30B. |
Incorporation of Cloisite 30B into WPI composite films exhibited higher bacteriostatic effect toward L. monocytogenes. The WPI/nano-clay composite films have a great potential for application in food packaging for extending the shelf life, improving quality, and enhancing safety of food packaged |
E. coli O157:H7 and L. monocytogenes |
78 |
WPI/Cloisite 30B organo-clay composite films to retard Listeria monocytogenes |
Cloisite 30B |
WPI/Cloisite 30B composite films showed a bacteriostatic effect against Listeria monocytogenes. |
L. monocytogenes and E. coli O157:H7. |
79 |
Incorporating oregano oil in WPI films to retard Pseudomonas; lactic acid bacteria |
oregano oil |
Incorporating oregano oil into sorbitol-plasticized WPI films inhibited pseudomonas growth, while lactic acid bacteria growth was completely inhibited. Whey protein films containing oregano oil increase fresh beef shelf life. |
Pseudomonas; lactic acid bacteria |
81 |
E. coli
WPI films supplemented with Lb. sakei cell-free supernatant (containing a bacteriocin-like substance) exhibited antimicrobial activity against E. coli, and maintained antimicrobial activity on beef inoculated with E. coli 77. Incorporating organic acids in whey protein film showed antimicrobial activity against E. coli 64. Incorporating of beeswax showed stable antibacterial activity against E. coli 43. Antimicrobial composite edible film containing lysozyme effective to inhibit E. coli growth both at the surface and inside region of gouda cheese during ripening78. Increasing sodium cyanoborohydride content showed stable antibacterial activity against E. coli 79.
L. monocytogenes
Incorporation liquid smoke into WPC films were effective to prevent L. monocytogenes growth76. Incorporation of Cloisite 30B into WPI composite films exhibited higher bacteriostatic effect toward L. monocytogenes80. WPI/Cloisite 30B composite films showed a bacteriostatic effect against Listeria monocytogenes81. WPI films supplemented with Lb. sakei cell-free supernatant (containing a bacteriocin-like substance) exhibited antimicrobial activity against L. monocytogenes and maintained antimicrobial activity on beef inoculated with L. monocytogenes77.
Listeria innocua
Lactic acid and chitooligosaccharide (COS) in WPI film exhibited bacteriocidal effect on Listeria innocula13. WPI-Beeswax, and WPI-Oleic acid film containing lysozyme showed antibacterial activity against Listeria innocula42. Complexation of lysozyme-polyacrylic acid was an effective tool for controlling Listeria innocula growth14.
Yarrowia lipolytica
Lactic acid and chitooligosaccharide (COS) in WPI film exhibited antimcrobial effect on Yarrowia lipolytica. The application on the cheese surface, they more active against bacteria, and less effective toward Yarrowia lipolytica and moulds than their commercial coating counterparts82. WPI Films formulated with NA was not active toward bacteria, but showed strongest effect against Yarrowia lipolytica 13.
Staphylococcus spp.
Antimicrobial whey protein edible film containing lysozyme effective to inhibit S. aureus growth both at the inside and surface region of gouda cheese during ripening78. WPI film containing lactic acid and chitooligosaccharide showed bacteriocidal effect on Staphylococcus spp. and the application on the cheese surface exhibited more active against bacteria but less effective toward yeasts and moulds82. WPI Films formulated with lactic acid (LA) and propionic acid (PRO), chitooligosaccharides (COS) and natamycin (NA) showed antimicrobial activity toward S. aureus 82. Incorporation liquid smoke into WPC films was not effective to inhibit S. aureus 76.
Pseudomonas spp.
Lactic acid and chitooligosaccharide (COS) in WPI film exhibited bacteriocidal effect on Pseudomonas spp. 82. Incorporating oregano oil into sorbitol-plasticized WPI films inhibited Pseudomonas growth 82.
Enterobacteriacea
Lactic acid and chitooligosaccharide (COS) in WPI film exhibited bacteriocidal effect on Enterobacteria 82.
Enterococcus
Antimicrobial composite edible film containing lysozyme effective to inhibit Enterococcus 78.
Salmonella Typhimurium
Incorporating organic acids in whey protein film showed antimicrobial activity against Salmonella sp. 64.
Yeasts and moulds
Combination sodium benzoate acid and chitooligosaccharide (COS) and combinations of lactic acid and in WPI film exhibited hight inhibitory effect against the yeast. The application on the cheese surface, they more active against bacteria, and less effective toward yeasts and moulds than their commercial coating counterparts 82. WPI Films formulated NA was not active toward bacteria, but showed strongest effect against yeasts82. Antimicrobial composite edible film containing lysozyme effective to inhibit microorganism growth both at the surface and inside region of gouda cheese during ripening 78.
Conclusion
Whey protein edible film containing antimicrobial compound is one of the most interest as biopackaging material due to its ability to retard the growth some bacteria, yeast and mold. Incorporated of antimicrobial compound which attached in some substance such as beeswax, oleic acid and polyacrilic acid can prolong its antimicrobial activity due to controlling the release of antimicrobial compound from whey protein edible film.
References
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