Novel mango bars using gellan gum as gelling agent: Rheological and microstructural studies

This work aimed the development of mango bars, made with fresh mango puree and gellan gum. The influence of gellan concentration as well as the ratio of LA (low-acyl) and HA (high-acyl) gellan on the rheological and microstructural properties of the mango bars was studied. Rheological outcomes showed that both LA and HA, and in mixtures, were able to produce jellified products, within a rather low maturation time. Furthermore, a synergistic effect was observed at different ratios of LA/HA, enabling the production of mango bars with intermediate viscoelastic properties. Higher values of the dynamic moduli were perceived as the LA content increased. Confocal microscopy is in agreement with the rheological results, revealing a weakening of the gel structure with the increasing percentage of HA. Results suggest that 1 g of LA/HA 50/50 per 100 g of puree produces structures with suitable mechanical properties. However, the results need to be correlated to texture and sensory analysis, before proceeding to the next steps of product development.