Umami ingredient from shiitake (Lentinula edodes) by-products as a flavor enhancer in low-salt beef burgers: Effects on physicochemical and technological properties

Abstract

The impact of salt reduction and addition of Umami Ingredient, obtained from shiitake stipes, on the physicochemical and technological properties of beef burgers was evaluated. Seven treatments were performed: one control (regular salt content) and six low-salt formulations with different levels of salt and Umami Ingredient. Cooked burgers with salt reduction and Umami Ingredient addition showed a slight increase in lightness and yellowness, but no effect was found for redness, pH, and water activity. There was no decrease in cooking loss and diameter reduction in any of the formulations and only samples with 70% salt reduction were significantly less hard and chewy in comparison to the control. An increase in the free amino acids proline and phenylalanine was observed in treatments with Umami Ingredient. In general, the treatments did not affect amino acid profiles compared to the control and the most abundant amino acids were those related to the umami taste (glutamic and aspartic acids). The volatile profile of beef burgers showed a slight increase in compounds also found in the Umami Ingredient, mainly 3-methylbutanal, (S)-(+)-1,2-Propanediol and dimethyl sulfide. Based on physicochemical and technological parameters, the Umami Ingredient can be considered a promising natural flavor enhancer for low-salt beef burgers.