Influence of process conditions on mechanical properties of osmotically dehydrated mango

The influence of osmotic treatments using 45° and 65° Brix sucrose containing calcium lactate at different levels (0%, 1% and 2%), applying or not a vacuum pulse at the beginning of the process, on the mechanical response of mango samples was studied. Mango samples were dehydrated till 30° Brix and were characterised as mechanical properties, sugar and calcium gain, water loss and changes in sample mass during treatments. Mechanical properties, measured through a compression test, were affected by treatment conditions. The influence of calcium on mechanical parameters was especially relevant at 2% in the osmotic solution, in treatments using 45° Brix sucrose and vacuum pulse, when calcium and solute gain were promoted. In this case, samples became notably stiffer, shorter and firmer. Calcium gain in the tissue partially explains the mechanical changes, but other factors such as concentration and structural profiles developed in the tissue also contribute to the mechanical pattern.