FOOD SECURI TY
As can be seen, a temperature elevation of two degrees centigrade, that is, storing the product at 6 °C rather than at 4 °C determines an approximate 25% reduction in the time necessary for the colony to become visible, falling from 1452 to 384 hours and causing an important reduction in the product’s survival time. In these conditions thus, variations that may appear minimal may have a noteworthy effect on the microorganism’s growth. Carrying out tests on shelf-life utilizing constant temperatures not consistent with the product’s real storage conditions along the distribution chain can lead to incorrect shelf-life values and alteration in the product before its best before date (t>teff ) or to times that are too short to ensure the product’s distribution or with respect to other products already on the market (t<teff ). To conclude, several studies and daily
experience confirm that the temperature of refrigerated products along a distribution chain is subject to relevant variations over time. In determining the shelf-life of a product, the producer must consider these variations and carry out isothermal tests at constant temperatures and scrutinize variations that can take place along the distribution chain. The effective temperature (Teff ) represents a useful instrument
that permits the producer to consider those fluctuations and their impact on the product’s stability and quality. Its calculation implies knowing the activation energy of a reaction which causes qualitative deterioration; that value can be inferred from experimental data by applying the Arrhenius equation or by consulting the appropriate literature. Stefano Zardetto
sources • Kennedy, J., Jackson, V., Blair, I., McDowell, I.S., Cowan, D.A., Bolton, D.J. (2005). Food safety knowledge of consumers and the microbiological and temperature status of their refrigerators. Journal of Food Protection, 68, 1421-1430. • James, S., Evans, J. (1992). Consumer handling of chilled foods: temperature performance. Rev. Int. Froid. 15, 299-306. • Jevsnik, M., Hlebec, V., Raspor, P. (2008). Consumers’ awareness of food safety from shopping to eating. Food Control, 19, 737-745. • Ovca, A., Jevšnik, J. (2009). Maintaining a cold chain from purchase to the home and at home: Consumer opinions. Food Control, 20, 167-172. • Rovere, P., Brutti, A., Franceschini, B., Trasatti, L., Pittia, P. (2009).
October/December 2017
Professional
Pasta
Applicazione del modello cinetico “Mean Kinetic Temperature” (MKT) alla valutazione della temperatura nella catena del freddo. Industria Conserve, 84, 153-165. • Steele, R. (2004). Understanding and measuring the shelf-life of food. CRC Press Cambrdge UK. • Zardetto, S. (2004). Effetto della temperatura e del confezionamento in atmosfera protettiva sullo sviluppo di penicillium aurantiogriseum isolato da pasta fresca farcita. Tecnica Molitoria, 55, 1, 1-9. • Zardetto, S.. (2005). Effect of modified atmosphere packaging at abuse temperature on the growth of Penicillium aurantiogriseum isolated from fresh filled pasta. Food Microbiology, 22, 367-371.
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