In the world of functional foods and natural preservatives, a recent study has shed new light on the intricate balance between antibacterial and antioxidant properties in red mold rice (RMR), a fermented product with a rich history in Asian cuisine and traditional medicine. The research, led by Susana Ristiarini of Widya Mandala Surabaya Catholic University and published in *Advances in Food Science, Sustainable Agriculture, and Agroindustrial Engineering*, explores how different strains of *Monascus purpureus* and the addition of glycine to the fermentation media can influence the metabolic outputs of RMR, potentially opening new avenues for the agriculture and food industries.
Red mold rice, known as angkak in some regions, is traditionally used as a natural dye and flavor enhancer. It is produced through the fermentation of rice with *Monascus purpureus*, a fungus that generates a variety of secondary metabolites, including pigments with antioxidant properties and citrinin, a compound known for its antibacterial effects. However, citrinin is also associated with potential health risks, which has led researchers to seek ways to minimize its production while maintaining or even enhancing the beneficial properties of RMR.
The study focused on evaluating the antibacterial and antioxidant properties of RMR extracts from different *M. purpureus* strains with varying citrinin production levels, all grown in glycine-supplemented rice media. The researchers classified the strains into two groups: low citrinin producers (JK2 and JK9B) and high citrinin producers (JK9A). The results revealed distinct metabolic profiles among the strains, affecting the yield, pigment content, color value, and citrinin content of the RMR.
One of the most notable findings was that the JK2 strain, despite being a low citrinin producer, demonstrated superior antibacterial activity against *Staphylococcus aureus*, as indicated by a larger inhibition zone. This suggests that factors other than citrinin content may contribute to the antibacterial properties of RMR. On the other hand, the JK9B strain exhibited enhanced antioxidant properties, as evidenced by its superior performance in DPPH radical scavenging, FRAP, and TAC assays. This indicates that different strains may be optimized for specific functional properties, offering a tailored approach to producing RMR for various applications.
“Our findings highlight the complexity of the fermentation process and the potential to optimize the production of RMR for specific functional properties,” said Ristiarini. “By understanding the metabolic profiles of different strains, we can develop more targeted and efficient fermentation processes that minimize the production of unwanted compounds like citrinin while enhancing the beneficial properties of RMR.”
The implications of this research for the agriculture sector are significant. As the demand for natural and functional food ingredients continues to grow, the ability to produce RMR with enhanced antibacterial and antioxidant properties could open new markets and applications for this traditional fermented product. Moreover, the findings could inform the development of new fermentation strategies and strain selection criteria, ultimately leading to more sustainable and efficient production processes.
The study also underscores the importance of further research into the metabolic pathways and regulatory mechanisms underlying the production of secondary metabolites in *Monascus purpureus*. By unraveling these complex processes, researchers may be able to develop even more sophisticated strategies for optimizing the production of RMR and other fermented products with desirable functional properties.
As the global food industry continues to evolve, the insights gained from this research could play a crucial role in shaping the future of functional foods and natural preservatives. By harnessing the power of traditional fermentation processes and modern biotechnology, the agriculture sector can meet the growing demand for safe, sustainable, and functional food ingredients, ultimately contributing to a healthier and more resilient food system.