Brazilian Journal of Food Technology
On-line version ISSN 1981-6723
DANTAS, Sílvia Tondella et al. Stability of canned peas in tinplate cans with reduced tin layer. Braz. J. Food Technol. [online]. 2011, vol.14, n.3, pp. 249-257. ISSN 1981-6723. http://dx.doi.org/10.4260/BJFT2011140300030.
Brazilian Federal Laws harmonized with MERCOSUL recommend that the tin layer of tinplate metallic packaging be technologically proven as adequate in the protection of the food against corrosion. The purpose of this study was to evaluate the stability of canned peas in welded three piece tinplate cans using a storage test, evaluating the performance relative to food/packaging interaction. The packaging was produced by tinplate using a 2.0 g Sn/m2 internal layer and organic coatings on the inner surface. The can was characterized according to the type of metallic material and an evaluation of the internal organic coatings. The storage test was carried out during a period of 540 days under a controlled temperature of 35 °C ± 2 °C, evaluating the internal visual appearance of the cans, metal dissolution (chromium, tin and iron) in the peas, and the vacuum level and composition of the gases oxygen, hydrogen, carbon dioxide and nitrogen present in the can headspace. The characterization of the cans showed that the metallic material layers (chromium and tin) were in agreement with the recommended standard and that the system of internal coating presented conditions suitable for all the parameters measured. The periodic evaluations of the product showed there were no significant changes in relation to metal dissolution in the product, which remained under acceptable conditions, as also the appearance of the inner surface of the packaging. During the storage period there was a reduction in internal vacuum and increase in the hydrogen concentration in the can headspace, indicating the development of internal can corrosion. The study concluded that a can produced with 2.0 g Sn/m2 tinplate with the internal coating used showed satisfactory performance for a storage period of 540 days at 35 °C. These results indicated the viability of using this packaging for canned peas.
Keywords : Stability; Can; Tinplate; Tin layer.