Detecting leaks in modified atmosphere packaging 283 to find all defective packages. New reliable and cost-effective systems are needed. One candidate for this could be the use of hydrogen as a tracer gas Another possibility could be oxygen indicator labels or dyes printed onto packaging material and read automatically at a distance lay, application of intelligent package leak-indicating systems in Europe has been limited to some time-temperature indicators. However, some food saucers are increasingly seeking extra merchandising and safety features Intelligent leak indicators marketed, e.g., as 'premium quality labels' can be seen to give added value to the product/brand image. The visible indicators are ideal in many cases, however, in the future it can be expected that an intelligent package can contain more complex invisible messages that can be read at a distance. A label could be introduced as a chip but advances in ink technology might enable the use of printed circuits as well. The security tags and radio frequency identity/tracebility tags are the first examples of electronic label Another approach for the future is the development of different optically read Development of these ' next generation' intelligent labels/printing systems is very challenging, e.g., in terms of cost demands, effectiveness and logistics Standardisation will undoubtedly be one of the key issues when new systems are pushed onto the market. The basic requirement for success in making intelligent systems work in real life is collaboration between research institutes, authorities, and companies from product manufacturers and raw material supplier to retailer 13.6 References 1. CHEN, C, HARTE, B, LAL, C, PETSKA, J. and HENYON, D. Assessment of package integrity using a spray cabinet technique. J. Food Prot. 1991, 54 643-7 2. KELLER, S W, MARCY, J.E., BLACKISTONE, B.A., LACY, G.H., HACKNEY, C.R. and CARTER, W.H. Bioaerosol exposure method for package integrity testing.J. Food Prot. 1996, 59: 768-71 3. AHVENAINEN, R, MATTILA-SANDHOLM, T, AXELSON, L and WIRTANEN, G The effect of microhole size and foodstuff on the microbial integrity of aseptic plastic cups. Pack. Techn. Sci. 1992, 5: 101-7 4. BLACKISTONE, B.A., KELLER, S.W., MARCY, J.E., LACY, G.H., HACKNEY, C.R. and CARTER, W.H. Contamination of flexible pouches challenged by immersion biotesting J. Food Prot. 1996. 59: 764-7 5. HURME. E. WIRTANEN. G. AXELSON-LARSSON. L. PAChERO. A. and AHVENAINEN, R. Penetration of bacteria through microholes in semirigid aseptic and retort packages. J. Food Prot. 1997, 60: 520-5 6. EILAMO, M, AHVENAINEN, R, HURME, E, HEINIO, R.L. and MATTILA- SANDHOLM, T. The effect of package leakage on the shelf-life of modified atmosphere packed minced meat steaks and its detection Lebensm.-liss Techi.1995.28:62-71to find all defective packages. New reliable and cost-effective systems are needed. One candidate for this could be the use of hydrogen as a tracer gas. Another possibility could be oxygen indicator labels or dyes printed onto packaging material and read automatically at a distance. Today, application of intelligent package leak-indicating systems in Europe has been limited to some time-temperature indicators. However, some food producers are increasingly seeking extra merchandising and safety features. Intelligent leak indicators marketed, e.g., as ‘premium quality labels’ can be seen to give added value to the product/brand image. The visible indicators are ideal in many cases, however, in the future it can be expected that an intelligent package can contain more complex invisible messages that can be read at a distance. A label could be introduced as a chip but advances in ink technology might enable the use of printed circuits as well. The security tags and radio frequency identity/tracebility tags are the first examples of electronic labelling. Another approach for the future is the development of different optically read systems. Development of these ‘next generation’ intelligent labels/printing systems is very challenging, e.g., in terms of cost demands, effectiveness and logistics. Standardisation will undoubtedly be one of the key issues when new systems are pushed onto the market. The basic requirement for success in making intelligent systems work in real life is collaboration between research institutes, authorities, and companies from product manufacturers and raw material supplier to retailer. 13.6 References 1. CHEN, C., HARTE, B., LAI, C., PETSKA, J. and HENYON, D. Assessment of package integrity using a spray cabinet technique. J. Food Prot. 1991, 54: 643–7. 2. KELLER, S.W., MARCY, J.E., BLACKISTONE, B.A., LACY, G.H., HACKNEY, C.R. and CARTER, W.H. Bioaerosol exposure method for package integrity testing. J. Food Prot. 1996, 59: 768–71. 3. AHVENAINEN, R., MATTILA-SANDHOLM, T., AXELSON, L. and WIRTANEN, G. The effect of microhole size and foodstuff on the microbial integrity of aseptic plastic cups. Pack. Techn. Sci. 1992, 5: 101–7. 4. BLACKISTONE, B.A., KELLER, S.W., MARCY, J.E., LACY, G.H., HACKNEY, C.R. and CARTER., W.H. Contamination of flexible pouches challenged by immersion biotesting. J. Food Prot. 1996, 59: 764–7. 5. HURME, E., WIRTANEN, G., AXELSON-LARSSON, L., PACHERO, A. and AHVENAINEN, R.. Penetration of bacteria through microholes in semirigid aseptic and retort packages. J. Food Prot. 1997, 60: 520–5. 6. EILAMO, M., AHVENAINEN, R., HURME, E., HEINIO¨ , R-L. and MATTILA￾SANDHOLM, T. The effect of package leakage on the shelf-life of modified atmosphere packed minced meat steaks and its detection. Lebensm.-Wiss. - Techn. 1995, 28: 62–71. Detecting leaks in modified atmosphere packaging 283