Interaction of packaging materials and vegetable oils: oil stability
Introduction
Oils are an important part of the human diet. More than 90% of the world oil production from vegetable, animal and marine sources is used as food or as an ingredient in food products (Formo, Jungermann, Norris & Sonntag, 1979). Sunflower oil is used widely for deep frying. Palm oil is a major tropical product of great economic importance to a large number of developing countries and of considerable versatility within the edible oil industry (Clegg, 1973). It is used extensively in the manufacture of cooking fats, high quality confectionery fats and in filled milk type products. Olive oil, one of the world's most important and ancient oils, is the most widely used oil in the countries bordering on the Mediterranean Sea. It is used almost entirely for edible purposes as a cooking and salad oil (Formo et al., 1979). A large variety of packaged oils and fats is available in the retail trade. Glass, metals, and different kinds of plastic films are used for packaging of vegetable oils. Storage stability and shelf-life for fats and oils are now receiving attention among nutritionists, food processors, government regulators and consumers (Kaya, Tekin, Oner, 1993). The quality and shelf-life of the packaged food are mainly determined by the barrier properties of the package against moisture, oxygen and the interaction of food constituents with the packaging materials (Sharma, Madhura, Arya, 1990). Hence, the major function of packaging is to minimize reactions that affect the stability of the contained products (Karel & Heidelburgh, 1975, Gilbert & Mannheim, 1982). When certain reactions occur spontaneously without external agents, packaging does not affect stability. In most cases, however, the environmentally omnipresent gaseous reactants, water vapour and oxygen, can seriously restrict stability under normal food storage and distribution conditions (Gilbert, 1985).
One of the most important reactions leading to quality loss is rancidity of the food products. Rancidity is the development of an off-flavour by oxidation and hydrolysis which makes the food unacceptable (Labuza, 1971, Frankel, 1982Paquette, Kupranycz, van de Voort, 1985Robards, Kerr, Patsalides, 1988). Though most of the plastic films were found to be almost inert towards food constituents, a small amount of monomeric and oligomeric constituents or additives used in their manufacture, to provide stability, plasticity and other desirable functional characteristics, are known to migrate into foods. It was shown that migration can be particularly extensive through direct contact with fatty food surfaces and at high temperature (Crompton, 1979, Shepherd, 1982).
Additives, such as plasticizers, antioxidants, antistatic agents and lubricants, are compounded into the basic polymer before being molded into the respective plastic materials (Jayaraman & Vasundhara, 1976).
Maximum limits of leached-out substances of various plastic materials used for food packaging applications were agreed; their rates of migration influenced the quality and stability of foods. One of the additives, fat-soluble phenolic antioxidants present in the compounded polymer, will migrate at an appreciable rate into the stored fat. As representatives of these, butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) have been under study (Mahadeviah, 1975, Crosby, 1981). Many studies have followed the loss of the antioxidants from packaging materials to fat-releasing foodstuffs (Niebergall & Hartmann, 1983Freytag, Figge, Bieber, 1984Baner, Bieber, Figge, Franz, 1992). An extension of the shelf-life of the products was reported by Miltz, Hoojjat, Han, Giacin, Harte, & Gray, 1988.
Vitamin E is a fat-soluble vitamin; it is found at high concentrations in vegetable oils. Tocopherols, especially the α-isomer, have a great influence on shelf-life, preserving oils from rancidity by interrupting the chain reactions involved in the formation of hydroperoxides (Shahidi & Wanasundara, 1992).
Kiritsakis (1984)studied the oxidative stability of olive oil stored in glass and polyethylene (PE) plastic bottles. He concluded that glass bottles provide better protection from oxidation than polyethylene plastic bottles do. Sharma et al. (1990) studied the effect of plastic film contact, including PE, PP and BHA and BHT incorporated in polyethylene, on the storage stability of refined sunflower oil and groundnut oil at 37°C. These authors concluded that changes in peroxide value and thiobarabituric acid were significantly less in the presence of plastic films than in control samples. Both BHA and BHT were found to leach out from plastic films into vegetable oils during storage. Nkpa, Osanu, Arowolo, 1990, Nkpa, Arowolo, Osanu, 1992have shown that crude palm oil, packaged in clear plastic bottles, sealed polyethylene film and clear glass bottles, recorded higher total oxidation values than oils packed in either lacquered metal or amber and green glass bottles. Lacquered metal cans gave the greatest protection against oxidation. Kaya et al. (1993) studied the effect of permeability, and transparency of the packages (PET and glass bottles) on the shelf-life of sunflower and olive oils. The determinations were based on the oxidative stability of oils by measuring their peroxide values. The storage stability of oil increased in the following order with respect to packaging materials: PET<clear glass<coloured glass. Sirokhman (1983)controlled the oils quality by determination of peroxide, thiobarabituric acid values and acid number. Satue, Huang, Frankel, 1995reported that the extent of oxidation in oils was frequently evaluated by measuring peroxide value (PV). This index is related to the hydroperoxides, the primary oxidation products, which are unstable and readily decompose to form mainly mixtures of volatile aldehyde compounds. Because these compounds are directly responsible for rancid flavour (Frankel, 1982), they are considered important markers of oxidative rancidity.
The current study was undertaken to evaluate the effect of different factors including (1) type of packaging material (glass, polyethyleneterephthalate (PET), polyvinylchloride (PVC), polypropylene (PP), and polystyrene (PS)), (2) oxygen permeability, (3) storage time and temperature and (4) antioxidants, either in the oils (Vitamin E) or in the plastics (BHA and BHT), on the stability and quality of market vegetable oils (olive oil, sunflower oil, and palm oil).
Section snippets
Oils
Commercially refined sunflower, virgin olive and refined palm oils were obtained from a local company. Oils were free of synthetic antioxidants and preservatives.
Chemicals
Butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) were from Across Chemical N.V. (Belgium).
Vitamin E (α-tocopherol), butylalcohol and 2-thiobarbituric acid were from Sigma Co (St. Louis, MO).
All solvents were HPLC grade were obtained from Across Chemical.
Packs
Transparent glass bottles (1.5 l and 8 dm2) with screw cap were
Packaging materials and oil stability
Because edible oils are subject to oxidative rancidity, packaging in plastics poses some problems. Interaction between oxygen permeate and unsaturated fatty acid glycerides is the major cause of quality deterioration in vegetable oils during storage. Table 1 presents the thickness and the permeability to O2 of tested plastic types. At constant thickness of plastics it is noticed that the permeability is dependent on the plastic types. Oxygen is a major influence of food shelf-life, because it
Conclusions
It is concluded from the current study that the stability of vegetable oils is dependent on the following characteristics:
- •
The type of plastic film and its oxygen permeability (PS>PP>PET=PVC).
- •
The level of natural antioxidants in oils.
- •
The type of oil and its initial physical and chemical properties.
- •
The time and temperature of storage. It is found that there are significant differences in oil stability according to the storage time and temperature in all types of package materials.
It seems that
References (39)
Migration of additive from plastic film into edible oil and fat simulants
Food Cosmet. Toxicology
(1972)- et al.
Oxidative stability of sunflower and olive oils: comparison between a modified active oxygen. Method and long term storage
Lebensm. Wiss. Technol.
(1993) - et al.
The mechanisms of lipid autoxidation. 1 — Primary oxidation products
Canadian Institute of Food Science Technology Journal
(1985) - et al.
Migration of BHT and Irganox 1010 from low density polyethylene films to foods and food simulating liquids
Food Cosm. Toxicology
(1987) Trace contamination of foods by migration from plastics packaging — a review
Food Chemistry
(1982)- et al.
Alternative fatty food simulants for migration testing of polymeric food contact materials
Food additives and Contamination
(1992) Composition and related nutritional and organoleptic aspects of palm oil
Journal of Americal Oil Chemistry Society
(1973)- Crompton, T. R. (1979) Additive Migration from Plastic into Food. New York: Pergamon...
- Crosby, N. T. (1981) Food Packaging Material. Aspects of Analysis and Migration of Contaminates (pp. 89). London:...
- Formo, M. W., Jungermann, E., Norris, F. A., & Sonntag, N. O. V. (1979) Bailey's Industrial Oil and Fat Products, ed....
Volatile lipid oxidation products
Progress in lipid Research
Formation of headspace volatiles by thermal decomposition of oxidized fish oil vs oxidized vegetable oils
Journal of American Oil Chemistry Society
Migration of different plastics additives from various plastic into isooctane and into olive oil
Deutsche Lebensmittel-Rundschau
Study of the kinetics of changes in the quality indices of virgin olive oil during storage in commercial packages
Grasas-y-Aceites
Canning olive oil in commercial type containers. VI. Conservation in glass, tin, polyethylene and PVC containers. Results of organoleptic tests
Crasas-y-Aceites
Cited by (79)
Polylactic acid as a promising sustainable plastic packaging for edible oils
2023, Food Packaging and Shelf LifeUnpacking the complexity of the PET drink bottles value chain: A chemicals perspective
2022, Journal of Hazardous MaterialsCitation Excerpt :This highlights the need for these factors to be separately investigated for each FCC. To date, storage conditions have been investigated mainly for Sb, carbonyl compounds, phthalate esters and BPA, and to a lesser extent for other FCCs, such as metals (Reimann et al., 2012), colourants (O’Brien, 2010), antioxidants (Tawfik and Huyghebaert, 1999), monomers (Farhoodi et al., 2008b), volatile organic compounds (Pandey and Kim, 2011) and other additives (Franz et al., 2016; Begley et al., 1991; Wang et al., 2018). The reuse of PET drink bottles before their disposal is quite common particularly in developing countries, but the influence of reuse, and its frequency, on FCCs migration has not received much attention to date.
Brief characteristics of oxidative stability, fatty acids and metal content in selected berry seed extracts obtained by the SFE technique and used as potential source of nutrients
2022, Food ChemistryCitation Excerpt :The quality of oils is decreased by an oxidation as it leads to a loss of nutritional value but also generates unpleasant taste and smell of products. The extent of oxidation is dependent, among others on the composition of fatty acids (including unsaturated acids), the presence of oxidizing compounds (e.g. chlorophylls, metals) and natural antioxidants, such as carotenoids, tocopherols, sterols, phospholipids and phenolic compounds, as well as plant material storage conditions (e.g. temperature, exposure to light and oxygen) (Gogolewski et al., 1993; Kruszewski et al., 2013; Tańska and Rotkiewicz, 2003; Tawfik and Huyghebaert, 1999; Valasco and Dobarganes, 2002; Krygier et al., 2000). The aim of the present study was quality assessment of different seed extracts (especially from strawberry, blackcurrant, chokeberry, and raspberry seeds) obtained on a semi-industrial scale using carbon dioxide supercritical extraction technique under different conditions (temperature and pressure).
Investigation on food packaging polymers: Effects on vegetable oil oxidation
2020, Food ChemistryCitation Excerpt :Besides, the effects of those polymer on secondary oxidation of oil were different, indicating that the selection for the two oils require more careful consideration. Effect of food packaging polymers on oxidative stability of vegetable oils was studied (Kanavouras & Coutelieris, 2006; Kanavouras & Coutelieris, 2017; Narasimhan, Rajalakshmi, Chand, Mahadeviah, & Indiramma, 2001; Nkpa, Arowolo, & Osanu, 1992; Ramezani, 2004; Silvagni, Franco, Bagno, & Rastrelli, 2010; Tawfik & Huyghebaert, 1999). Many materials were believed to have great impacts on shelf-life of fats and oils (Coutelieris & Kanavouras, 2006; Warner & Mounts, 1984).
Rapeseed oil
2020, Green Sustainable Process for Chemical and Environmental Engineering and Science: Plant-Derived Green Solvents: Properties and ApplicationsPhysicochemical properties of cold pressed sunflower, peanut, rapeseed, mustard and olive oils grown in the Eastern Mediterranean region
2019, Saudi Journal of Biological SciencesCitation Excerpt :Since instable oils have undesirable taste and flavor, they may lose nutritional value and may produce toxic compounds. Antioxidants such as vitamin E (tocopherol) in oils promote the oxidative stability and prevent the oxidative degradability of oils (Tawfik and Huyghebaert, 1999; Cayuela and García, 2017). Crude oil quality is very important since it determines the upcoming processing and it is a good indicator of necessary treatments (Ceriani et al., 2008).