The search for safe and sustainable methods to preserve food is increasing in urgency and importance. Why? There is a strong desire to reduce our reliance on plastic especially as a wrapping and not only minimise pollution but also move slowly and inexorably away from the use of carbon-based fuels. We come then to edible films and coatings because of what they can offer the producer and the consumer.
Foods are covered with edible films and coatings: a great way to protect a food from water loss and unwanted gas transfer but still keeping the texture. An edible coating can also be used as an effective carrier of many functional ingredients, including antimicrobial agents, antioxidants, flavorings, and colorants (Chen, 1995). All edible coatings are transparent that are removed simply by washing them away. They are usually less than 0.3 mm in thickness (Ribeiro et al., 2021). In the last few years, a great deal of interest has been given over to applying edible coatings to highly perishable food products. Foods such as minimally processed products are especially apt for this work.
A large number of reviews covering edible coatings and films are available (Olivas and Barbosa-Canovas, 2005; Falguera et al., 2011; Rojas-Grau et al., 2009; 2012; Han, 2014; Kapetanakou et al., 2014; Trinetta, 2016).
Biopolymers according to Han (2014) have ‘multiple film-forming mechanisms, including intermolecular forces such as covalent bonds (e.g. disulfide bonds and crosslinking) and electrostatic, hydrophobic, or ionic interactions.’ The film-forming process needs to follow food manufacturing guidelines and principles. It is clear that control of production of films is also extremely important because changes in treatment conditions alter both kinetics and mechanisms of reaction (Guilbert et al., 1996; 1997).
The requirements for a good edible coating are the following:-
- biodegradable,
- biocompatible,
- nontoxic
- versatile chemical and physical properties.
Types of Edible Films And Coatings
The edible films and coating are classified into: (1) lipids (2) hydrocolloids and (3) mixtures and composites of these two components. The hydrocolloids can generally be further classified into either polysaccharides or proteins. The lipids are waxes, oils and resins. Composites will include both lipid and hydrocolloid components. The choice is dictated by the functional benefit and the type of food to be coated.
Coatings and films require different preparation and application procedures. Most polysaccharides and proteins in films require plasticizers. The lipids require some type of emulsifier.
Type of Coating
Edible films and coating are divided into specific compounds and polymers.
The polysaccharides most commonly used are starch, alginate, cellulose, pectin, chitosan and gums. The proteins most often used are whey, casein and soy.
The lipids are either waxes, fatty acids or resins. typical waxes include beeswax, paraffin and carnauba wax.
The composites are either polysaccharides with protein or with lipids, or with all three in some cases. Lipids and proteins are sometimes found together.
The Role Of Plasticizers And Emulsifiers
Plasticizers are low molecular weight agents which are incorporated into the polymer solution. These decrease the intermolecular forces between polymer chains to improve coating and film adhesion. Typical plasticizers include glycerol.
Emulsifiers act as surfactants and are often most useful in mixtures of hydrocolloids and lipids where they are added to promote the formation of an emulsion and improve interfacial stabilization. In such dispersions, the polysaccharides and proteins behave as stabilisers because they increase the viscosity of the continuous phase (polysaccharides) or form an adsorbed layer at the oil-water interface (protein) so promoting steric stabilization.
The stability of film-forming dispersions (FFDs) has an important part to play in the property of a lipid-hydrocolloid composite film for example. the lipid particle size greatly influences the development of the dispersion during the film drying process (Morillon et al., 2002).
Specific Types Of Edible Films
Some of the best food coatings for maintaining texture as well as providing a barrier to moisture are chitosan and alginates.
Alginates
Alginates are now being used on a regular basis. These are extracted from brown seaweeds of the Phaephyceae class. These polysaccharides are salts of alginic acid, a linear co-polymer of D-mannuronic and L-guluronic acid monomers (Sanderson 1981). They form an irreversible and instantaneous gel by binding with divalent or polyvalent metal ions (Ca2+, Mg2+, Mn2+). The polymers are water insoluble, impervious to fats and oils with a high water vapour permeability (Rhim, 2004).
Alginates lend themselves well to mixing with other materials suitable as biodegradeable packaging films. We have recently seen examples using pullulan or carboxymethyl chitosan that contained phages as part of a food safety study to combat Escherichia coli growth in foods (Shirani & Mustapha, 2024).
Producing Alginate Films
Different approaches and methods are available for obtaining casts of alginate types (coatings, films or beads). The initial step consists of the preparation of an alginate solution ranging from 0.5–3 per cent (w/v) concentration. The most commonly used plasticizer is glycerol (2–5 per cent w/v of alginate).
To cast an alginate coating, the food products are immersed into the alginate solution. Subsequent immersion or spraying by CaCl2 solution then occurs (Pranoto et al. 2005a). In contrast, films are produced by drying a thin layer of alginate solution for between 20 to 24 hours at 25–40°C and by adding calcium chloride (CaCl2) (2–20 per cent w/v) for 1–20 minutes (Pranoto et al. 2005a, Oussalah et al. 2006, 2007, Millette et al. 2007, Jiang et al. 2011a).
Cellulose And Its Derivatives
Cellulose is composed of linear chains of (1→4)-β-D-glucopyranosyl units and makes up the principal structural polysaccharide in plants (Whistler and Daniel 1985). Native cellulose is a crystalline, cold water-insoluble, and high molecular weight polymer. Chemical substitution of some hydroxyl groups at positions 2, 3, and 6 on the glucosyl-units of cellulose produces two types of derivatives: (1) ionic (carboxymethylcellulose), and (2) non-ionic cellulose ethers (methylcellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose).
Cellulose, especially methylcellulose is excellent for reducing lipid migration which ultimately ruins the mouthfeel of some foods such as grains and chocolate centers.
Producing Cellulose Films And Coatings
Cellulose and cellulose derivative solutions (1–6% w/v) are prepared by dissolution in distilled water with or without ethanol. The dispersion should take place under heating at temperatures close to 65–85°C for 10 min. to 2 hr. The casting of coatings may be carried out either by immersing the food in the biopolymer solution and drying under particular conditions (i.e. at 25°C for 2–3 hr).
The production of films takes place by drying a thin layer of solution at 20–35°C for 24–48 hours and applying it on the surface of food products (Imran et al. 2010, Sánchez -González et al. 2011, Sayanjali et al. 2011). A thickness of 0.5mm or less is desirable.
To increase bite, the plasticizer such as glycerol reduced 10 fold or not added at all.
Chitosan
Chitosan is also extremely versatile. This is a cationic linear polysaccharide made of D-glucosamine and to a smaller extent, N‐acetyl‐D‐glucosamine with a β‐1,4‐linkage (Rinaudo, 2006). Chitosan is derived mainly from shellfish exoskeletons which is chitin that is then deacetylated. A vegetarian form is obtained from various fungi and mushrooms. It is an effective antimicrobial and is now found in wound dressings as well as food applications where it works in combination with other antimicrobials.
Chitosan-Fatty Acid Mixtures
A very effective moisture barrier can be created from a chitosan-soap complex (Dastidar et al., 2014). In this case, a solution of chitosan is dissolved in water at 80 Cent. (20g/L chitosan, 20g/L citric acid). A solution of palm oil fatty acid (palmitate) is prepared by dissolving 40g of palmitate and 21g of sodium bicarbonate in a litre of water at 80 Cent. These two solutions are uniformly mixed using high-shear mixing. the suspension is sieved and washed repeatedly with hot water to remove particulates. The chitosan-soap complex can be dried at 50 C. in a hot air oven until the moisture content reaches 1-3%w/w.
To use the complex as a coating, the dried citisan-soap complex is mixed with a food oil in a 1:1 ratio for 8 hours to obtain a solution. The application level is 0.5g of the edible coating to between 10g and 50g of food material.
Whey Protein Films
The whey protein films are created by heat-catalyzed protein-protein interactions that involve a range of bonding systems. Hydrogen bonding, disulphide bridging and hydrophobic bonds are all employed. heating denatures the whey proteins an exposes internal SH and hydrophobic groups (Watanabe and Klostermeyer, 1976; Shimada and Cheftel, 1998). These bonds are promoted as the film is dried and moisture is removed. Improved films with moisture barrier properties are generated in alkaline solutions because the sulphydryl (-SH) groups are more reactive at pH values above 8. A low pH environment most likely prevents S-S bond formation in the protein matrix, thereby weakening the film structure.
These whey protein films can be modified by adding small amounts of nut oil between 0.5 and 1.0% using emulsification to incorporate the oil. These films are often opaque and are more hydrophobic when oil is employed (Galus & Kadzinska, 2016).
Whey protein isolate edible films have been constructed with essential oils for treatment of various products (Çakmak et al., 2020).
Caseinates
Caseinates have great potential in forming edible coatings because they have good nutritional value, suitable sensory properties and have been demonstrated to protect foods from moisture migration (Chen, 2002; Tomasula, 2009).
Zein
Zein is a natural storage protein extracted from corn kernels. Pure zein films are highly hydrophobic but are not used as coatings because they have a brittle nature unless a plasticizer such as an oil, oleic or palmitic acid for example is added. The level of plasticizer only needs to be 0.25% w/w to a zein solution in ethanol of 4% w/w (Scramin et al., 2011).
It is often used to coat nuts and confectionary to improve glossing, prevent oxidation and the formation of off-flavours and aromas. It has good barrier properties to lipid and oxygen migration. It is often applied as a coating for readily perishable fruit such as mango and apples (Baj et al., 2003). A zein-oleic acid (plasticizer) coating has been tested effectively on pears (Scramin et al., 2011).
Waxes
Carnauba wax is one of the hardest natural waxes because of its very high melting temperature, and extracted from the plant Copernica cerifens. The lipid helps to reduce oxidation when coated onto fatty foods because of its ability to reduce oxygen ingress.
One of the best additives to incorporate into other coatings are whey protein which not only reduces oxygen permeability but also raises mechanical stability and homogeneity because it contributes a high tensile strength and amphiphilic properties.
Starches
Starches lend themselves very well to edible films because it is a low-cost material, readily available from a variety of sources, offers various degrees of potential because of its range of componentry (amylose/amylopectin) and can be modified or mixed with other materials. Gums have often been tried which prevent loss of moisture. Likewise, maltodextrins produce changes to texture.
Starches are water-soluble polymers which may appear to be counter-intuitive solutions to impeding moisture migration from a food to one that needs to avoid moisture pick up. It does appear that starch-based coatings slow moisture migration (Hurtado et al., 2001; Chung & Lai, 2005). The decision to try a starch coating depends on whether shelf-life extension is needed and whether the coated material is meant to retain its texture. A starch film has moderately high tensile strength and becomes extremely brittle at low moisture contents (below 6%).
The addition of sodium caseinate to a starch-based film lowered the water vapour transmission rate relative to that of the pure starch film (Arvanitoyannis et al., 1997). The starches were obtained from either corn or wheat and plasticized with glycerol, sugars and water. Increasing the level of plasticizer such as water or the sugar/glycerol content reduced the brittleness and strength of the film.
Pea starch unlike other starches because of its higher amylose content (35% to 40%) compared with other starches serves as a binding agent between other components to provide additional stability and thickness.
The Incorporation of Fats and Oils
A number of applications have used lipids from fats and oils as additives into edible films to modify their barrier and antimicrobial properties .
Applications
Barrier Properties Of Edible Coatings
Edible coatings mainly serve as gas and water barriers. Reducing the deleterious effects of oxygen are paramount in preserving shelf-life. The factors which contribute to effectiveness of coatings are: coating integrity, their compositions, relative humidity and storage temperature. If coatings are made up of 2 to 3 components including the waxes then the cumulative advantages of both materials may be regarded.
Preventing Moisture Migration
Moisture migration is an issue which has yet to be solved effectively but using edible films may well prove valuable. Moisture movement can occur in both directions.
For example, frozen ice-cream cones containing ice-cream will soften on thawing unless a barrier is added. Methods to overcome this include coating a food surface with glucomannan with a coagulating agent which produces acceptable barrier properties (S.C.C. patent, 2006).
Chitosan with a fatty acid complex has been tried with pharmaceutical applications to reduce lipid absorption (Furda, 1980). An application from Bevers et al., at Unilever showed a cross-linked polymer could be applied which contained lipid and bioplymer.
Improvements In Frying Batters
Albert & Mittal (2002) examined a variety of hydrocolloids in an application for reducing fat uptake of a deep-fried cereal pastry mix. They considered gelatine, gellan gum, κ-carrageenan-konjac-blend, locust bean gum, methyl cellulose (MC), microcrystalline cellulose, pectin (three types), sodium caseinate, soy protein isolate (SPI), vital wheat gluten and whey protein isolate (WPI). The single-coatings of SPI, WPI and MC were the most effective as were mixtures of SPI with MC or WPI which reduce both fat ingress and moisture loss.
Addition Of Antimicrobials
One of the most recent interesting applications is the inclusion of antimicrobials such as cinnamon bark oil and fennel oil into cassava starch coatings (2-3% w/v) which are active against Staphylococcus aureus and Salmonella choleraesuis (Oriani et al., 2014). These essential oils are natural ingredients and have GRAS (Generally Recognised as Safe) status. These essential oils also exploit their active properties by improving water vapour resistance (WVR) by raising the film’s hydrophobic fraction (Sanchez-Gonzalez et al., 2011)
One pesticide proving to be valuable for incorporation into a food type coating is cinnamon bark oil (CO) (Cinnamonium zeylanicum) which kills insects in stored products – the Indian Meal Moth being one of its most notorious victims. The major compounds in CO include trans-cinnamaldehyde (58.1%), benzaldehyde (12.2%) and eugenol (5.1%) (Yang et al. 2005).
Antioxidants
Antioxidants are used in the food industry to protect against degradation, rancidity and reduce enzymatic browning in fruits and vegetables. A variety of agents such as ascorbic acid, 4-hexylresorcinol, sulphur-containing amino acids (cysteine and glutathione) have all been added to coatings and films. They have been tried individually or as mixtures to give broader antioxidant protection.
Minimally processed fruits or those to be stored for longer at ambient have been treated. Alginate- and gellan-based coatings have been tested on freshly cut slices of apples and papaya using coatings carrying such antioxidants. the antibrowning agents are hydrophilic compounds and encourage or increase water transmission rates and also induce water loss when incorporated into films and coatings.
Coating And Films To Delay Fruit And Vegetable Ripening
The earliest work concerned coatings to delay the onset of ripening of fruits and vegetables. A variety of coatings films have been tried. The object is to reduce moisture loss from slowing down respiration and reducing the release of ethylene which stimulates ripening in other fruit for example.
Tomatoes for example benefit from coatings with alginates or zein because they delay such ripening processes by up to 6 days (Zapata et al., 2008). A level of between 5 and 10% w/w for both biopolymers is a suitable coating amount. Success has been achieved too with tomatoes using a 10%w/v gum arabic coating (Ali et al., 2010).
The amount of coating depends on the degree of preservation required. For example, only a 1% to 3% w/v alginate coating is required to extend the shelf-life of plums (Valero et al., 2013).
Coatings And Edible Films Carrying Nutrients
Films and coatings are good carriers of low levels of nutrients on fruits and vegetables so their nutritional value is increased.
Baby carrots are poor sources of calcium and vitamin E. Their nutritional properties were improved using the following coating method. Xanthan gum coatings containing high concentrations of calcium and vitamin E (5% Gluconal Cal and 0.2% alpha-tocopheryl acetate improved the nutritional and sensory quality of fresh baby carrots (Mei et al., 2002). The calcium and vitamin E content of the coated carrots increased from 2.6% to 6.6% and from 0 to 67% of the Dietary Reference Intake (DRI) values per portion size of 85g, respectively. There was no change in texture (crispness), flavour or sweetness or the beta-carotene levels in the carrot.
Soft fruits are not only prone to moisture loss and rapid decay but also lack some essential nutrients. One group added calcium and vitamin E to chitosan-based coatings which not only improved shelf-life of fruit like frozen strawberries and raspberries but also enhanced their nutritional properties (Han et al., 2004).
Edible Coatings For Dry Crackers And Baked Goods
Corn starch, methylcellulose (MC) and soybean oil as a plasticizer have been tested on dry crackers with improved shelf-life and greater resistance to water vapour transmission. This reduce their staling when sprayed as a coating (Bravin et al., 2006).
Application Of Edible Coatings: Monolayers To Layer-By-Layer Coatings
In the first instance, coatings have been applied to foods in single layers. Now however, bilayers and multilayers of different coating materials can be generated using layer-by-layer (LbL) assembly. This multi-layer approach means layers of different coating materials offer a more versatile level of control of coating properties and functionality.
The process of LbL involved alternate dipping of a substrate like a grain or particle into solutions containing oppositely charged polyelectrolytes. LbL assembly produces ultrathin polyelectrolyte multilayers on charged surfaces (Vargas et al., 2008).
Chitosan, poly‐L‐lysine, pectin, and alginate are the most commonly used biopolymers in LbL assembly (Bernabe et al., 2005; Marudova et al., 2005; Krzemiski et al., 2006).
References
, , & (2005). Swelling behaviour of chitosan/pectin polyelectrolyte complex membranes. Effect of thermal crosslinking. Polymer Bulletin, 55, pp. 367–375 (Article)
Bravin, B., Peressini, D., & Sensidoni, A. (2006). Development and application of polysaccharide–lipid edible coating to extend shelf-life of dry bakery products. Journal of Food Engineering, 76(3), pp. 280-290 (Article).
Çakmak, H., Özselek, Y., Turan, O. Y., Fıratlıgil, E., & Karbancioğlu-Güler, F. (2020). Whey protein isolate edible films incorporated with essential oils: antimicrobial activity and barrier properties. Polymer Degradation and Stability, 179, 109285 (Article).
Chen, H. (1995). Functional properties and applications of edible films made of milk proteins. J. Dairy Sci. 78 pp. 2563-2583.
Chen H. (2002). Formation and properties of casein films and coatings. In: Protein-based films and coatings. pp. 181-211
Dastidar, S. G., Panchanathan, A., Shankar, R., & Tonpe, G. T. (2014). U.S. Patent Application No. 14/363,024.
Falguera, V., Quintero, J.P., Jimenez, A., Munoz, J.A. , Ibarz, A.(2011) Edible films and coatings: structures, active functions and trends in their use. Trends Food Sci. Technol. 22(6) pp. 292–303 (Article)
Galus, S., Kadzinska, J. (2016) Whey protein edible films modified with almond and walnut oils. Food Hydrocolloids 52 pp. 78-86 (Article)
Han, J.H. (2014) Edible films and coatings: A Review. In: Innovations in Food Packaging (2nd edt.) Chapt. 9 pp. 213-255 Academic Press. (Article).
Han, C., Zhao, Y., Leonard, S. W., & Traber, M. G. (2004). Edible coatings to improve storability and enhance nutritional value of fresh and frozen strawberries (Fragaria× ananassa) and raspberries (Rubus ideaus). Postharvest Biology and Technology, 33(1), pp. 67-78 (Article).
Imran, M., S. El-Fahmy, A.-M. Revol-Junelles and S. Desobry. (2010) Cellulose derivative based active coatings: Effects of nisin and plasticizer on physico-chemical and antimicrobial properties of hydroxypropyl methylcellulose films. Carbohyd. Polym. 81(2): pp. 219–225.
Jiang, Z., H. Neetoo and H. Chen. (2011a) Efficacy of freezing, frozen storage and edible antimicrobial coatings used in combination for control of Listeria monocytogenes on roasted turkey stored at chiller temperatures. Food Microbiol. 28: pp. 1394–1401.
Jiang, Z., H. Neetoo and H. Chen. (2011b) Control of Listeria monocytogenes on cold-smoked salmon using chitosan-based antimicrobial coatings and films. J. Food Sci. 76(1): M22–M26.
Kapetanakou, A. E., Manios, S. G., & Skandamis, P. N. (2014). Application of edible films and coatings on food. In: Novel Food Preservation and Microbial Assessment Techniques, (Edt. I.S. Boziaris Publ. Taylor & Francis) Chapt. 9 pp. 237-273. (Article)
, , , , , , & (2006). Deposition of Pectin/Poly‐L‐lysine multilayers with pectins of varying degrees of esterification. Biomacromolecules, 7, pp. 498–506 (Article).
, , , & (2005). Pectin‐chitosan multilayer formation. Carbohydrate Research, 340, pp. 2144–2149 (Article)
Mei, Y., Zhao, Y., Yang, J., & Furr, H. C. (2002). Using edible coating to enhance nutritional and sensory qualities of baby carrots. Journal of Food Science, 67(5), pp. 1964-1968 (Article).
Millette, M., Le Tien, C., Smoragiewicz. W., and Lacroix, M. (2007) Inhibition of Staphylococcus aureus on beef by nisin-containing modifi ed alginate films and beads. Food Control 18(7): pp. 878–884
Morillon, V., Debeaufort, F., Blond, G., Capelle, M., & Voilley, A. (2002). Factors affecting the moisture permeability of lipid-based edible films: A review. Critical Reviews in Food Science and Nutrition, 42(1), pp. 67–89.
Olivas, G.I., Barbosa-Canovas, G.V. (2005) Edible coatings for fresh-cut fruits. Crit Rev Food Sci 70.
Oriani, V.B., Molina, G., Chiumarelli, M., Pastore, G.M., Hubinger, M.D. (2014) Properties of Cassava Starch-Based Edible Coating Containing Essential Oils. J. Food. Sci., 79 (2) E189-E194
Oussalah, M., Caillet, S.,Salmieri, S., Saucier, L. and Lacroix, M. (2004) Antimicrobial and antioxidant effects of milk protein-based film containing essential oils for the preservation of whole beef muscle. J. Agr. Food Chem. 52: pp. 5598–5605.
______________________________________________________ (2006) Antimicrobial effects of alginate-based film containing essential oils for the preservation of whole beef muscle.
J. Food Protect. 69(10): pp. 2364–2369.
Oussalah, M., Caillet, S. Salmiéri, S. Saucier, L. and Lacroix. M. (2007) Antimicrobial effects of alginate-based films containing essential oils on Listeria monocytogenes and Salmonella Typhimurium present in bologna and ham. J. Food Protect. 70(4) pp. 901–908.
Pranoto, Y., Salokhe, V.M., Rakshit, S.K. (2005a). Physical and antibacterial properties of alginate-based edible fi lm incorporated with garlic oil. Food Res. Int. 38(3) pp. 267–272.
Pranoto, Y., S.K. Rakshit and V.M. Salokhe. (2005b). Enhancing antimicrobial activity of chitosan films by incorporating garlic oil, potassium sorbate, and nisin. Lebensm. Wiss. Technol. 8: pp. 859–65.
Rhim, J.W. (2004) Physical and mechanical properties of water resistant sodium alginate films. Lebensm. Wiss. Technol. 37 pp. 323–330.
(2006). Chitin and chitosan: Properties and applications. Progress in Polymer Science, 31, pp. 603–632
, , & (2021). Preparation and incorporation of functional ingredients in edible films and coatings. Food and Bioprocess Technology, 14(2), pp. 209–231 (Article)
Rojas-Grau, M.A., Salvia-Trujillo, L., Soliva-Fortuny, R., Martın-Belloso, O. (2012) Edible films and coatings. In: Gomez-Lopez, V.M., editor. Decontamination of fresh and minimally processed produce. Ames, IA: Wiley-Blackwell. Pp. 247–67.
Rojas-Grau ,M.A., Soliva-Fortuny, R., Martın-Belloso, O.(2009) Edible coatings to incorporate active ingredients to fresh-cut fruits: a review. Trends Food Sci Technol 20(10) pp. 438–47.
Sanchez-Gonzalez, M.A., Vargas, M., Gonzalez-Martınez, C., Chiralt, A., Chafer, M. (2011) Use of essential oils in bioactive edible coatings. Food Eng Rev 3(1) pp. 1–16.
Sánchez-González, L., Pastor, C. Vargas, M. Chiralt, A. and González-Martínez, C. (2011) Effect of hydroxypropylmethylcellulose and chitosan coatings with and without bergamot essential oil on quality and safety of cold-stored grapes. Postharvest Biol. Technol. 60(1) pp. 57–63.
Sanderson, G.R. 1981. Polysaccharides in foods. Food Technol. 35(7): pp. 50–52, 54–57, 83.
Sayanjali, S.,Ghanbarzadeh, B. and Ghiassifar, S. (2011) Evaluation of antimicrobial and physical properties of edible film based on carboxymethyl cellulose containing potassium sorbate.
Scramin, J. A., de Britto, D., Forato, L. A., Bernardes‐Filho, R., Colnago, L. A., & Assis, O. B. (2011). Characterisation of zein–oleic acid films and applications in fruit coating. International Journal of Food Science & Technology, 46(10), pp. 2145-2152 (Article).
Shimada, K., Cheftel, J.C. (1998). Sulfhydryl group disulfide bond interchange during heat induced gelation of whey protein isolate. J. Agric. Food Chem. 37(1) pp. 161-168
Shirani, K., Mustapha, A. (2024) Antimicrobial Potential of novel CAM-21 Bacteriophase against Escherichia coli O157:H7 in biodegradeable films. IFT Poster 2024 Chicago USA.
Tomasula P.M. (2009). Using Dairy Ingredients to Produce Edible Films and Biodegradable Packaging Materials. In: Dairy-Derived Ingredients: Food and Nutraceutical Uses. M. Corredig: pp. 589-624
Trinetta, V. (2016) Edible Packaging. In: Reference Module in Food Science. Elsevier (Article)
Valero, D., Díaz-Mula, H. M., Zapata, P. J., Guillén, F., Martínez-Romero, D., Castillo, S., & Serrano, M. (2013). Effects of alginate edible coating on preserving fruit quality in four plum cultivars during postharvest storage. Postharvest Biology and Technology, 77, pp. 1-6 (Article).
, , , , & (2008). Recent advances in edible coatings for fresh and minimally processed fruits. Critical Reviews in Food Science and Nutrition, 48, pp. 496–511 (Article).
Watanabe, K., Klostermeyer, H. (1976). Heat induced changes in sulfhydryl and disulfide levels of -lactoglobulin A and formation of polymers. J. Dairy Res. 43(3) pp. 411-418 .
Whistler, R.L. and Daniel. J.R. 1985. Carbohydrates. In: O.R. Fennema (ed.). Food Chemistry. Marcel Dekker Inc., New York, pp. 69–137
Zapata, P. J., Guillén, F., Martínez‐Romero, D., Castillo, S., Valero, D., & Serrano, M. (2008). Use of alginate or zein as edible coatings to delay postharvest ripening process and to maintain tomato (Solanum lycopersicon Mill) quality. Journal of the Science of Food and Agriculture, 88(7), pp. 1287-1293.
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