Red torulene from yeast: Isolation, characterization, bioprocess development, and its underexplored pioneering application as a natural food colorant

Torulene, a red carotenoid produced by Rhodotorula species, has gained significant attention for its vibrant color and potential health benefits. However, while several reviews have explored its properties, there remains a lack of research on its practical applications across diverse industries. This study aims to fill this gap by isolating and characterizing a novel R. mucilaginosa strain (PUCV 645) from Chile, with a focus on evaluating the use of edible oils as extraction agents for the recovery of torulene-rich extracts (TRE). The COSMO-SAC predictive model was employed to explain the interactions involved in the green extraction process. Additionally, TRE has two innovative applications: its use as a natural food colorant in pasta and as a component in colored vegan mayonnaise, where it is combined with residual aquafaba as a potential egg replacer. Through molecular identification, phylogenetic analysis, and carotenoid characterization, this work provides the first comprehensive exploration of R. mucilaginosa PUCV 645's potential for food industrial applications. The findings highlight the promise of TRE as a sustainable, natural alternative in food manufacturing, paving the way for its integration into the food industry. This study also contributes to the understanding torulene's versatility and potential market applications.