Development of packaging of meat product s Ágnes Kovács Hungarian Meat Research Institute

1. Development of packaging of meat products Ágnes Kovács Hungarian Meat Research Institute Leonardo da Vinci

2. Aim and history of packaging • Brief summary of packaging of different items • Fresh meat • Cooked sausages • Raw fermented products • Packaging of fermented sausages and salamis

3. Short history • Short history • How did packaging of meat and meat products start? • Butchers used earlier only paper over-wrapping either in the shop or in door-to-door delivery • Did it do? • Since at that time there was no efficient cooling, yes. (immediate consumption) • Radical changes due to spreading of efficient refrigerators and invention of plastic films • Continuous developing ever since

4. Aim of packaging • Protection • Marketing • Information

5. Protection • against moisture loss • against oxydation: color changes, rancidity • against oxygen loss: fresh meat in MAP • against CO2-loss (MAP) • against off odours further

6. Protection • against contamination of bacterial mould yeast viral physical chemical nature • against insects • against growth of microbes • against light (alu-laminates, printed films)

7. Consequences of this protective effect During this protection • Drying is avoided • Discoloration (greenish, brownish, greyish) is avoided • Rancidity is avoided • Contamination (physical, chemical, biological) is avoided • Shelf-life is extended • Color is improved (fresh meat in MAP) • Microbial growth of aerobic species is inhibited (not with fresh meat in MAP) • Food safety level is elevated

8. Marketing • Prepacked products make self-service possible • Attractive design enhances sale • Conscious consumers insist on renown logo (advantage to producer and retailer equally) • Health claims urge consumers to buying

9. Information • to wholesalers and retailers • to authorities • to consumers on identification of • farmer • slaughterhouse • packaging factory • date of slaughter and packaging etc. • best before date • storage temperature • weight • price (direct figure or barcode) • suggested preparation

10. What should not be expected from packaging? One has to be well aware of the fact that • Reduction of initial microbial load • Total inhibition of spoilage • Absolute food safety • Total protection against mechanical damage • Protection against temperature fluctuation and temperature abuse Must not be expected from packaging

11. As a consequence packaging can be considered as successful only if • Initial microbial load is low and • Storage temperature is low (critical mainly with fresh meat and cooled items) and • Packaging film and technology is optimal

12. Important features of packaging film and technology • Sufficient resistance to mechanical influences • No risk of delamination • Efficient seal • Proper gas barrier characteristics

13. Major types of packaging • Over-wrapping • Vacuum packaging • Modified atmosphere packaging (MAP) • Coatings (edible or inedible)

14. Over-wrapping • evidently no gas tight packaging, yet minimal moisture loss • sometimes for fresh meat to be frozen for export (PE) • in shops for freshly sliced („deli”) products • PE-laminated paper

15. Vacuum packaging For high level packaging like vacuum and MAP barrier films have been developed Gas permeability can be reduced by • laminating • coating • blending • co extrusion • metalizing (not transparent, not microwaveable in all mw ovens) when good gasbarrier films are combined with films of good sealability and moisture resistance.

16. Vacuum packaging Most common plastics: PE, PP, PA, EVOH, PVDC, EVA, PETP Permeability values: 1-20cm3/m2 /day/ atmosph. in general (The higher the permeability the lower the protection) Special gas barrier films have EVOH layer or are combined: SiOx coated PETP film or contain monomolecular layer of metal. Advantage of SiOx combined films: transparency, microwaveability and barrier effectiveness Disadvantage: lack of flexibility and crash resistance, high production cost For vacuum packaging pouches or vacuum thermoformed containers Rest oxygen concentration: below 1%

17. Advantages of vacuum packaging • with proper film and technology steady-state vacuum • low partial pressure of oxygen with microbial CO2-development exhibits inhibition of aerobic growth • good shelf life • easy handling (small, no voluminous package) • leakage is easily detectable, no unexpected safety risk

18. Modified Atmosphere Packaging (MAP) • With modified atmosphere packaging use of films with high barrier characteristics is equally important similarly as with vacuum packaging for preserving the initial ratio of gases in the mixture, CO2-barrier property of film plays also an important role. • Before sealing pouch or container, gas flush and fill with gas mixture. • Mixture differs depending on item (fresh meat with oxygen, cooked and fermented and products without oxygen gas)

19. Typical gas mixtures Aim of different gas mixtures • Basic difference in packaging of fresh meat and meat products: in case of fresh meat presence of relatively high oxygen concentration (60-80%) serves formation of bright red color carbon-dioxide is added (20-30% in package) to oxygen inhibiting to some extent growth of microbes, and also nitrogen is added (10-20% in package) in order to prevent collapse of package caused by absorption of CO2 by fresh meat

20. Typical gas mixtures Aim of different gas mixtures • In case of meat product, cooked and raw dried items, oxygen is exhausted from package as much as possible (rest oxygen concentration below 1%, with oxygen scavenger as low as 0,01%) and the package is filled with the mixture of carbon-dioxide and nitrogen in a ratio of approx. 30:70%.

21. Non-edible coatings • Main aim of using non-edible coatings is to reduce evaporation of moisture from meat products, inhibiting weight loss during storage and to reduce the effect of oxygen in ambience thus inhibiting discoloration and rancidity. • A successful technology with liver sausages, less successful with fermented sausages in spite of several trials with different substances.

22. Active packaging • Packaging technologies discussed earlier (over-wrapping, vacuum packaging, non-edible coating) can be considered as passivepackaging, meaning that only passive characteristics, like gas and water-vapor-permeability are relied on influencing shelf-life of meat and meat products. • In so called active packaging biologically active substances are applied in addition to the use of films with good barrier characteristics, aiming at extending the shelf-life and quality improvement (Lee, 2010).

23. Possible solutions • Incorporation of active substance into the packaging film (direct release or reaction with product surface) • Incorporation of active substance into a sachet or tablet (O2-scavenger, CO2-generator, confinement odour scavenger,) • Edible films and coatings with bioactive substance

24. Possible antimicrobial agents • Bacteriocins (pediocin, sakacin) • Lactacin • EDTA • Organic acids • Tocopherol • Chitosan • Trichlosan • Horseradish extract • Grape fruit seed extract • Metals (silver, copper) • Fatty acids • Phenolics etc.

25. Promising: O2 scavenging and CO2-generating systems (O2-scavenging is accomplished by oxidative reaction of iron powder, ascorbic acid, photo-sensitive dye, catechol, enzymes etc.) Advantage: more efficient reduction of O2-concentration Disadvantage: more favourable environment for growth of anaerobic pathogens • Sealed Air Cryovac developed a system that helps eliminating off smells (Freshness Plus Odor Scavenging System).Additive mix in multilayer film scavenges sulphur and aldehyde volatiles to maintain freshness.

26. Antimicrobial systems Problems with their use • Legislative approval • Efficiency • Narrow spectrum • Technical solution

27. Edible coatings • In these coatings preservatives, antioxidants are used to improve quality and shelf-life. Application fields: fresh meat, cured meat, serving increase of barrier properties. • Practically no importance in case of fermented sausages. (Edible coatings are also used without additives, e.g. collagen films on cured meats yet these are not considered as active packaging.)

28. Packaging of fermented sausages and salamis Fermented sausages are offered in retail as • unpacked rods • rods in package • pieces in package • sliced in package • sliced and wrapped in deli shops

29. Packaging of fermented sausages and salamis • Products are either vacuum packed or packed in modified atmosphere • Although vacuum packaging offers more advantages (more extended shelf life, colour stability, easier detectability of leakage than MAP, this latter spread more. Advantage: slices can be separated easier) • Disadvantage: requires more space, leakage is detected only when product is discoloured, spoiled.

30. Shelf-life of fermented sausages • Products manufactured from ingredients of high hygiene with GMP and GHP in accordance with HACCP while applying correct packaging technology (proper film, exhaustion, gas mixture, good seal) can be stored for several months also at ambient (room) temperature without change of sensory characteristics. • Further criteria for extended shelf-life - sufficiently low aw-value (traditional products) - combination of sufficiently low aw- and pH-value

31. Packaging of salamis with mould cover Contrary to fermented sausages and salamis without mould, where air/gas tight and moisture proof packaging can be and are used, this method cannot be applied when mould layer is on the product.

32. Packaging of salamis with mould cover Reason why other type of packaging is needed Mould layer stays intact on surface only if moisture migrating from the core outwards can evaporate. In films of modern packaging moisture cannot evaporate. Possibilities for offering in retail: • Rods unpacked • Rods in cellophane • Rods in perforated PP • Smaller pieces, peeled, in vacuum or in MAP • Slices peeled, in vacuum or in MAP

33. A longer shelf-life only from the last two methods can be expected, that also guarantee that no weight loss occurs. • Unpacked rods preserve the intact mould layer but weight loss is remarkable. • As a compromise cellophane wrap or perforated PP sealed reduce weight loss and mould layer integrity remains. None of the abovementioned forms ensures an extended shelf-life with good product quality.

34. Failures of prepackaged products and their possible reasons Reasons • Not properly selected or faulty film • Faulty or not properly programmed packaging machine (insufficient vacuum, improper gas mixture) • Inefficient seal (contamination or wrinkles at seal) • Handling of packaging not carefully

35. Possible consequences • Sensory defect (discoloration, rancidity) • Growth of spoilage microbes • Growth of pathogens (safety risk) • Reduction of shelf-life as a result of oxigen infiltration carbon-dioxide leakage secondary contamination with microbes

36. Special type of failure Swelling of packaged fermented sausages Reason: • No total carbohydrate break-down during technological process, carbohydrate rest is broken down to CO2 during storage • Occurs both with vacuum and MA packaging • Prevention: reduction of carbohydrate and final aw-value