The packaging of bakery products is closely interlinked with production, preservation, storage, transportation, and marketing. Packaging especially of the bakery products is science, art, and technology rolled in one. G.K. Goyal, Swati Shrivastava, and Tanweer Alam, explain how packaging protects products from the adverse effects of the environment.

Choice of the appropriate packaging material is governed by several factors such as (Goyal and Swati Shrivastava, 2006):

  • The specific sensitivities of the contents, e.g. moisture, oxygen, etc.
  • Weight and shape of the container.
  • Effect on filling and sealing speeds.
  • Contamination of food by constituents of the packaging material.
  • Storage conditions – How long the product needs to be protected?
  • Bio-degradability and recycling potential.
  • Many more peculiarities like product range, market, consumer needs and operating margins, which could be identified for determining the packaging of bakery products.

Bakery Industry in India

Bakery products are ready to eat, convenient to use, and possess satisfactory nutritional quality. India is the second-largest producer of biscuits. The two major bakery items, viz. bread and biscuit account for about 82% of the total bakery products. The annual production of bakery products, which includes bread, biscuits, pastries, cakes, buns, rusk etc., is estimated to be in excess of 3 million tonnes.

The production of bread and biscuits in the country, both in the organised and unorganised sectors, is estimated to be around 0.44 million tonnes and 11 million tones, respectively. The cake and pastry market estimated at 0.4 million tonnes, is the fast-growing market with volume growth of 16%. India’s bakery market at Rs. 49.5 billion makes it the third-largest market in Asia Pacific, only after Japan and Australia (Anon, 2006).

The bakery industry in India comprises of organised and unorganized sectors. The organised sector consists of large, medium and small-scale manufacturers who produce packaged biscuits and bread. The unorganized sector consists of small bakery units, cottage and household type, manufacturing their products without much packaging and selling them in the surrounding areas. The bread market is estimated to be growing at around 7% p.a. in volume terms, whereas the biscuit market has witnessed a higher growth at around 8-10%.

Within the biscuit category, cream and specialty biscuits are growing at a faster rate, i.e. 20% p.a. Though the bakery industry in India has been in existence since long, but the growth picked up only in the latter part of the 20th century. The contributing factors were urbanization, resulting in increased demand for ready-to-eat food at reasonable costs etc.

Packaging of Bakery Products

Most bakery products are marketed fresh and are stored at ambient temperature. However, other products, such as cream, fruit-filled pies, and cakes are stored under refrigerated or frozen storage conditions to achieve a longer shelf life. Bakery products, like most processed foods, are subject to physical, chemical, and microbiological spoilage.

Furthermore, the classification of products on the basis of their pH and aw is helpful in recognizing the spoilage and safety potential of bakery products. While physical and chemical spoilage problems limit the shelf life of low and intermediate moisture bakery products, microbiological spoilage is the main concern of intermediate and high moisture products (Smith et al., 2004). Though bakery products are cooked at high temperature, yet these are subject to spoilage. Thus proper packaging of bakery products, therefore, becomes essential.

Requirements for Packaging Materials for Bakery Products

Bread and Cakes: Bread and bun, generally loose moisture to the atmosphere as they have 85-90% equilibrium relative humidities. The slightly water-vapour proof packaging material for bread is needed in order to prevent the crust, from becoming soggy and mold sensitive on slices. The protection is mainly required against handling and dust. The use of a too water-vapour impermeable package would lead to inside condensation, fogging and consequently mould growth.

The recommended packaging materials are preferably heat-sealable waxed paper with high water-vapour permeability, semi moisture-proof cellophane or 15 gauge HDPE etc. Apart from waxed paper, plastic films used to pack them are LDPE and Polypropylene (PP). Cakes and other such items have requirements similar to those of bread and in addition, the package should be rigid enough to protect them against physical damage. Thermoformed containers of polystyrene (PS) and cellulose acetate are generally used (Kumar and Balasubrahmanyam, 1984).

Biscuits: Biscuits have low water activities 0.15 –0.2, and hence necessitate the use of highly water-vapour impermeable packages. The packaging material should also be fat-resistant, rigid, and O2 resistant. HDPE and PP pouches are suitable for short-term storage and perform well on machines. For longer storage life, the inclusion of PE or Biaxially oriented polypropylene (BOPP) liners in other packages are beneficial in reducing the water vapour ingress. BOPP films are widely used for the packaging of biscuits, which are very sensitive to humidity and oxygen. Laminates such as cellophane/PE, coated foils, and metallized polyester/PE are also used.

Aluminium Foil as Packaging Material for Bakery Products

Consumers appreciate the dependability and versatility of Al foil food containers. They combine all the features needed to deliver to the consumer fresh, wholesome and quickly accessible products to satisfy, quality and value demand. Bright and reflective, Al foil containers stay that way throughout processing and marketing. They can be embossed, colour lacquered or printed both inside and outside. Al foil containers withstand the extremes of all types of cooking and re-heating: grilling, fan and convection cooking, barbecue griddle, and microwave oven. They are easy to handle, to open, to use, and to dispose of. Adding versatility, a range of purpose-designed lidding materials including coated or laminated Al foil lids that can be sealed to the container rim, yet peel off easily when required are being used. The Al foil containers offer unique properties (Anon, 2004):

  • COMPATIBILITY: Even uncoated aluminium foil does not react with the vast majority of foods. A range of approved food-contact coatings add full protection against any possible reaction, which might be caused by unusually acid or alkaline ingredients.
  • HEAT CONDUCTIVITY AND RESISTANCE: Aluminium is very conductive to heat. This can help minimize processing, chilling and reheating times. It also evens-out the temperature gradient within its contents, helping product quality. Aluminium foil dishes can be used through a very wide temperature range from well below blast-freezing to the extremes of baking and grilling. There is no risk of cracking, melting, charring or burning.
  • HYGIENE: Aluminium is non-absorptive. It does not support or harbour bacterial growth, absorb moisture or grease.
  • DURABILITY AND STRENGTH: When stamped into a dish, Al foil becomes much stronger where it is shaped. Thickness, alloy, shape, and temper can be selected to create exactly the performance characteristics required.
  • MULTI-MODE HEATING OR COOKING: Food in Al foil dishes can be heated by convection, fan, or microwave oven.
  • DECORATIVE POTENTIAL: Al foil’s metallic finish plus compatibility with all printing methods provides designers with scope to create product and brand identity.
  • LIGHTNESS AND SPACE ECONOMY: Economies in both transport and storage result from lightness and nesting shapes.
  • STAINABILITY: Al foil packaging reduces spoilage of sensitive products due to its barrier properties, saves energy and material resources. Also, Al containers can be repeatedly recycled without loss of quality and at a fraction of their original energy cost. They are suitable for both separate and multi-material collection systems according to national and local conditions.

Available different shapes

Foil’s characteristics offer great scope for the packaging specifier seeking solutions that satisfy the many demands of chilled or frozen bakery products. It is due to the ready formability and robustness of Al foil, a large variety of standard shapes and sizes are available. For larger containers, extra strength can be designed into the walls. By incorporating corrugated sides, the rigidity of the container can be greatly enhanced. Also, there are folded containers especially for baked products, such as cakes, that need to present an extra-smooth surface when removed from the dish.

Lidding choices: A large range of lidding options go from the simple but effective fold-down rigid foil/board closure to snap-on covers in foil or plastic. Hermetic sealing with transparent films or heat resistant foil membranes is possible with smooth wall trays that have smooth horizontal rims.

Presentation trays: There are also sturdy Al foil serving trays that can be used as support for separate pastries, tarts, and are good looking, re-useable and offer convenience. Also, the possibilities of embossing and surface decoration are possible.

Compartmented trays: Originated for ‘ready meals’, the compartmented Al foil tray opened up ideas for other uses. For example a baked pastry or dessert using one compartment alongside a fruit sauce in the other section.

Smooth wall dishes: High-quality presentation can be greatly enhanced by specifying an elegant smooth-walled design. Equally suitable for baked products as the standard type of container, the smooth wall lends itself to the premium end of the market particularly if the outer surface is coloured or printed (Anon, 2004).

New Packaging Techniques for Bakery Products

Modified atmosphere packaging (MAP)

Bakery products are subject to chemical breakdown and mould growth. Fermentation may also cause problems in pastries or breads that have been packed. Mould spores present in the air mean that a product can be easily contaminated, as well as could be affected by equipment and through handling; one of the solutions to prevent mould growth is the use of preservatives or additives. Since mould is an aerobic microorganism, it can be effectively controlled by packaging the product in a modified atmosphere of carbon dioxide (CO2) and nitrogen (N2), thus minimizing the oxygen content. MAP extends the shelf life, preserves quality, and improves overall cost effectiveness (Tanweer Alam and Goyal, 2004).

Gases are also used for packaging. MAP, despite being costly to set up, is widely used to restrict spoilage of food products. CO2 and N2 are the most commonly used gases in gas packaging of bakery products. Carbon dioxide is soluble in water and fat, producing carbonic acid and lowering the pH of the product, resulting in changes in the flavour. Nitrogen is also very effective but only if the residual oxygen percentage is low. The antimicrobial effect may be lost if the headspace oxygen concentration increases by as little as 0.5-1 %. MAP is especially suited to breads, pastries, and pies (Anon, 2001).

Active packaging

Active packaging is the name given to a large group of packaging modifications that are meant to improve the shelf life of the foods. It improves the shelf life of foods by modifying the environment around the food so that growth of microorganisms is prevented or delayed. Examples of active packaging that relate to the bakery business are: oxygen-scavenging systems; moisture absorbers; antimicrobial incorporated directly into the packaging matrix; controlled release of antimicrobials or antioxidants; or the ability to absorb odours.

The mould-free shelf life of a product can be dramatically extended using oxygen absorbers, e.g. white bread can last for up to 45 days with this method. Other examples include an extension of 3 to 14 days for pizza crust; 1-year storage for gluten-free bread and a shelf life extension of three times on gas packaged crusty rolls. The sachets can also be used in conjunction with MAP to increase their efficiency, maintaining an oxygen-free environment during the whole shelf life of the product.

Sachet-type oxygen absorbers are available which are based on the latest biotechnology, consisting only of natural food-grade components. These absorber sachets generate carbon dioxide, replacing the removed oxygen; maintaining so maintaining package dimensions. Such absorbers allow natural and safe preservation of food’s original taste and freshness, resulting in extended shelf life without preservatives or additives (Anon, 2001).

Generally, active packaging involves incorporating agents into the package that can either interact directly with the spoilage organisms or interact with the environment inside the package. The modification of atmosphere in the package is usually used in combination with MAP. For example, the packaged product is gas flushed and sealed and also contains an oxygen-scavenging sachet that removes additional oxygen that moves in through the permeable packaging material. This is important because many spoilage microorganisms reproduce rapidly in the presence of oxygen (Sanderson, 2003).

Extension of shelf life of bakery products

There are two main concerns in the shelf life of bakery products; mould growth and staling. Mould growth is very common in the bakery business and in many cases mould growth determines the shelf life of bakery products. Unpreserved bread has a shelf life of 3-4 days, at which point visible mould becomes evident. In cakes, water activity and storage temperature are key factors that lead to mould growth and reduce shelf life of bakery products.

Bread staling is a process of chemical and physical changes including moisture redistribution, drying, starch retrogradation, increased firmness, as well as the loss of aroma and flavour. Bread moulding and staling result in the decrease of consumer acceptance for bakery products and also in great economic losses. Baking destroys most moulds but surface recontamination can occur during packaging.

The use of natural antimicrobials to extend the shelf life of bakery products is one example of active packaging. Many spices, herbs, and fruit contain volatile anti-microbial compounds. These compounds could be incorporated into the packaging material to reduce or delay the growth of microorganisms on bakery products. Mustard essential oil is one compound that is very effective at inhibiting microorganism growth.

The use of mustard at lower levels in combination with other shelf-life extending methods is recommended. Its use is however limited to stronger flavoured breads like rye and pumpernickel. Other inhibitory substances are incorporated into packaging materials. Enzymes like glucose oxidase, lysozyme, and muramidase have been reported to control microbial growth. Incorporation of food additives, such as propionic, benzoic, and sorbic acids into low-density polyethylene has also been used (Sanderson, 2003). Thus, active packaging combats microbial spoilage of bread and other bakery products.

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References

  1. Anon (2001) Oxygen absorbers in the packaging of bakery products, http://www.bioka.fi/products/applications.htm
  2. Anon (2004) Bakery Products. Alufoil, Part 3.1.7, Edition: Oct 2004.
  3. Anon (2005). Indian packaging sector, http//www. ciionline. org/news//htp
  4. Anon (2006) Packaging of bakery products, The Economic Times Polymers, April-May, 2006
  5. Goyal, G.K. and Swati Shrivastava (2006) Trends in packaging of traditional dairy products, in Compendium, 21st CAS Course on “Developments in traditional dairy products” , NDRI, Karnal, 10th Dec. to 30th Dec., 2006, pp 55-60.
  6. Kumar, K.R. and Balasubrahmanyam, N. (1984) Plastics in food packaging, In “Plastics in packaging” Indian Institute of Packaging, Mumbai-400 093, pp 319 –341.
  7. Sanderson,L. (2003) Active packaging, Bakers Journal, http://www.gftc.ca/index-e.cfm
  8. Smith, J., Daifas, D., El-Khoury, W., Koukoutsis, J., and El-Khoury, A. (2004)/ Shelf life and safety concerns of bakery products—A Review, Critical Reviews in Food. Sci. and Nutrition, 44(1), 19-25.
  9. Tanweer Alam and Goyal, G.K. (2004) MAP- a new frontier packaging in dairy and food industry, Indian Dairyman, 56 (8), 53-60.
  10. Unsweetened Bread: sliced, crusty, par-baked, ethnic; Rolls: soft, crusty; Crumpets; English muffins; Pizza base; Raw pastry Sweet Large cakes: plain, fruited; Pancakes; Doughnuts; Waffles; Cookies; Biscuits; American muffins; Buns; Wafers Filled Tarts: fruit, jam; Pies: meat, fruit; Pastries; Cakes: cream, custard; Pizza