Sweet Condensed Milk: Effect of Critical Storage Conditions on Metal Can Seams

Abstract

Sweet condensed milk is a popular canned milk product with a high nutritional value and a long shelf-life. It boasts high domestic demand because it is used in various sectors of the food industry. In addition, canned milk is part of state reserve and military supply. Due to its unique properties, it is indispensible in the Russian Arctic and is exported to countries with hot climate. However, extreme temperatures affect both the quality of the product and the safety of metal cans. This research featured the impact of extreme storage conditions on the integrity of seams. Seams were tested for overlaps and thickness after storage at single-stage and multi-stage temperature modes in the range of -50 ºC ↔ 50 ºC. The biggest gaps were found in the samples after a single-stage temperature route of 5 ºC → 50 ºC, 14 days → -50 ºC, 14 days → 5 ºC. The seam overlaps at the lids decreased by 1.45 % after 14 days of storage and by 1.67 % after 28 days; for the bottom seams, the measurements were 1.84 and 2.26 %, respectively. The single-stage freezing had a greater negative effect on the seam quality than the longer multi-stage freezing. However, the overlap values in all experimental samples corresponded to the standard and exceeded 57.76 % for lids and ≥ 59.75 % for bottoms. All mean thickness values of lids and bottoms maintained the standard 1.43 mm. The obtained seam geometry of metal cans with sweet condensed milk will make it possible to develop transportation and storage recommendations in countries with extreme climates.