Soy Molasses: A Sustainable Resource for Industrial Biotechnology

Soy molasses, a byproduct of soy protein concentrate production, offers potential as a substrate for biotechnological applications due to its rich composition of carbohydrates, proteins, lipids, and bioactive compounds. Despite this, it remains underutilized, often relegated to low-value applications such as animal feed or waste, largely due to variability in its composition, the presence of microbial inhibitors, and limited industrial awareness of its potential. This review explores the biotechnological strategies for valorizing soy molasses, focusing on its chemical and physical properties, potential applications, and the challenges associated with its use. Its high carbohydrate content supports its utilization in producing biofuels, organic acids, and polyhydroxyalkanoates (PHA), addressing the global demand for sustainable energy and materials while costing approximately 20% of the value of conventional carbohydrate sources. Additionally, bioactive compounds have extended applications to nutraceuticals and cosmetics, while proteins and lipids enable enzyme and biosurfactant production. However, challenges such as variability in composition, the presence of inhibitory compounds, and scalability issues require innovative approaches, including pre-treatment methods and strain engineering. By integrating soy molasses into a circular bioeconomy framework, industries can reduce waste, lower their carbon footprint, valorize agro-industrial residues, and generate economic value. This review underscores the untapped potential of soy molasses as a versatile, sustainable resource, while highlighting the need for continued advancements to transform it into a key player in industrial biotechnology.