Cultured meat, a sustainable alternative to conventionally produced meat, is gaining traction. While previous research has focused on developing scaffolds to replicate the texture and shape of meat, the crucial aspect of flavor has been largely neglected. Flavor in meat is primarily determined by the Maillard reaction, a chemical process involving the reaction of amino acids and sugars at high temperatures, producing volatile aromatic compounds. The amino acid profiles of in vitro cultured meat often differ significantly from those of traditionally raised meat, posing a challenge in replicating the characteristic Maillard flavors. This study aims to address this challenge by developing a functional scaffold that can mimic the Maillard reaction during cooking, thereby enhancing the flavor of cultured meat. The successful development of such a scaffold would represent a significant advancement in the field of cultured meat production, bridging the gap between the organoleptic properties of cultured and conventional meats and making cultured meat a more appealing and commercially viable product.

Existing research on cultured meat has primarily focused on mimicking the structural properties of meat using various scaffolding techniques. For example, 3D printing has been employed to create steak-like structures, and microtissue techniques have been used to produce meatball-like products. However, these studies largely overlook the crucial role of flavor. While some research has investigated the flavor profiles of cultured meat, it is generally acknowledged that the inherent differences in amino acid composition between cultured and traditional meat make it difficult to replicate the complex Maillard flavors. Studies have shown that cultured fat exhibits different flavor characteristics compared to traditional fat, and attempts to enhance flavor in cultured muscle tissue have shown limited success. Current methods to improve flavor involve enhancing cell proliferation and differentiation to increase the production of meat-like compounds, but these approaches do not fully address the Maillard reaction aspect of flavor development.

The researchers designed and synthesized a switchable flavor compound (SFC) capable of releasing Maillard reaction products upon heating. The SFC consists of a flavor group (furfuryl mercaptan, a compound known to contribute to the roasted meat flavor), and two binding groups that allow it to be covalently linked to a gelatin methacryloyl (GelMA) hydrogel. The disulfide bond in the SFC is designed to be temperature-responsive, remaining stable at cell culture temperatures (37 °C) but breaking down at cooking temperatures (150 °C), releasing the furfuryl mercaptan. The GelMA hydrogel, incorporating the SFC, was used as a scaffold for culturing bovine myoblasts. The stability of the SFC in the hydrogel under cell culture conditions was confirmed through weight measurements and 1H NMR analysis, showing that the SFC remained stable, preventing premature flavor loss. The temperature-responsive release of the flavor compounds was demonstrated through UV-Vis spectroscopy. Cultured meat was produced by culturing bovine myoblasts on the GelMA scaffolds, and the flavor profiles of the resulting cultured meat were analyzed using gas chromatography-mass spectrometry (GC-MS) and an electronic nose. To investigate the effect of diversifying flavor compounds, additional SFCs incorporating other Maillard reaction products were synthesized and tested. Cell viability and differentiation were assessed using CCK-8 assay and immunofluorescence staining for actin filaments and myosin heavy chain (MHC).

The SFC remained stable within the GelMA scaffold throughout the 15-day cell culture period, preventing premature release of flavor compounds. Upon heating to 150 °C, the SFC released the furfuryl mercaptan, leading to the generation of various meaty and savory flavor compounds. The cultured meat produced using the SFC-containing scaffold (CM+SFC) exhibited a significantly different flavor profile compared to the control group (CM-SFC), showing a marked increase in pleasant meaty, sulfurous, almond-like, floral, fatty, and fruity flavors and a decrease in off-flavors. When compared to traditional beef brisket, the CM+SFC showed a noticeable improvement in flavor similarity. Further experiments using SFCs containing a mixture of three different Maillard reaction products (CM+SFCV) resulted in an even closer resemblance to the flavor profile of traditional beef, with a higher ratio of meaty, floral, creamy, and fruity flavors. The electronic nose analysis and principal component analysis (PCA) showed clear separation between the CM-SFC, CM+SFC, and CM+SFCV groups, confirming the significant impact of the SFC system on flavor enhancement. The cell viability and differentiation assays showed that the introduction of the SFC into the scaffold did not significantly affect cell proliferation or myotube formation.

The study successfully demonstrated a novel strategy for enhancing the flavor of cultured meat by incorporating a temperature-responsive SFC into a biocompatible scaffold. The use of the disulfide bond as a temperature-responsive trigger allowed for stable entrapment of the flavor compounds during cell culture and controlled release during cooking. The findings address the critical challenge of replicating the complex flavor profiles of traditional meat in cultured meat products. The success of the SFC system in enhancing the sensory attributes of cultured meat brings it closer to commercial viability and consumer acceptance. The use of multiple flavor compounds in SFCV further improved the results, demonstrating that the approach is versatile and can be tailored to mimic the intricate flavor profiles of different types of meat.

This research successfully developed a flavor-switchable scaffold that significantly enhances the aromatic properties of cultured meat by mimicking the Maillard reaction. The temperature-responsive SFC system effectively releases desirable flavor compounds at cooking temperatures, resulting in a flavor profile similar to traditional beef. Further research could focus on expanding the range of SFCs to include a wider variety of flavor compounds to more accurately replicate the complexity of conventional meat flavors, potentially converging the SFC system with strategies to increase cell content for synergistic flavor enhancement. Exploring the use of plant-derived proteins instead of gelatin would make the system more sustainable.

The current study uses some non-food grade chemicals in the synthesis of SFC and GelMA. Further research should investigate the replacement of these chemicals with food-grade alternatives to improve the safety and commercial feasibility of the approach. While the study demonstrated enhanced flavor, the flavor profile of the cultured meat still differs from that of traditional meat, suggesting further optimization of the SFC composition is necessary. Future research should investigate the combined effects of the SFC system and cell-derived flavors in the improvement of cultured meat.