Behaviour of umami compounds that are associated with non-volatile compounds on slow cooking regimes remains less explored. This study aims to assess the ability of the electronic tongue system on the umami taste from sous-vide beef semitendinosus. The identification was based on the taste-enhancing synergism between umami compounds 5'-nucleotides (IMP, GMP, AMP, inosine, and hypoxanthine) and free amino acids (glutamic and aspartic acid) using the estimation of equivalent umami concentration (EUC) and electronic tongue system. Sous-vide cooked at 60 and 70 °C for 6 and 12 h and cooked using the conventional method at 70 °C for 30 min (as control) were compared. The temperature had a significant effect on 5'-nucleotides, but aspartic and glutamic acid were not influenced by any treatments applied. Sous-vide cooked at 60 °C tended to have higher inosine and hypoxanthine. Meanwhile, desirable 5'-nucleotides IMP, AMP, and GMP were more intensified at the temperature of 70 °C. The principal component analysis predicted a good correlation between EUC and the electronic tongue, with sous-vide at 70 °C for 12 h presenting the most umami. Therefore, the electronic tongue system is a useful tool in food processing, particularly in determining complex sensory properties such as umami, which cannot be evaluated objectively.

The main objective of this study was to incorporate soy-based textured vegetable protein (TVP) into beef patties in different quantities (10-40%) and compare various characteristics of these innovative formulations with a regular beef patty as a control. Incorporation of 10-40% TVP resulted in significantly lower (p < 0.05) moisture and fat contents, while higher crude fiber contents were detected compared to beef as the control. In addition, cooked patties showed higher pH levels (p < 0.05), with color coordinates expressing lighter, yellowish, and slightly redder indices than raw patties. Similarly, a plant protein that includes TVP minimizes (p < 0.05) WHC (water holding capacity), both RW% (release water) and CL% (cooking loss). Furthermore, hardness, cohesiveness, and thickness were reduced significantly (p < 0.05), while gumminess and chewiness increased (p < 0.05) considerably with the substitution of TVP (10-40%) compared to the control. Patties made without TVP received higher scores for sourness, bitterness, umami, and richness than the rest of the formulations. However, a higher tendency was detected for sourness, astringency, umami, and saltiness values with increasing additions of TVP. Nevertheless, hierarchical clustering revealed that the largest group of fatty acid profiles, including palmitoleic acid (C16:1), stearic acid (C18:0), and palmitic acid (C16:0), was slightly reduced with the addition of TVP, while arachidic acid (C20:0), lauric acid (C12:0), and oleic acid (C18:1) increased moderately with increasing levels of TVP. Meanwhile, the second-largest cluster that included linoleic acid (C18:2), arachidonic acid (C20:4), and linolenic acid (C18:3) increased enormously with higher levels of TVP incorporation. Taken together, it is suggested that incorporation of TVP up to 10-40% in beef patties shows promising results.