Food waste (FW) presents a critical issue, representing an environmental liability and a largely untapped resource. Its heterogeneity and low valorization rate among main-stream alternative treatments challenge its integration into economically and environmentally sustainable bioprocesses. We explore biorefineries as a solution that can address the complexity of urban food waste through biological strategies capable of converting food waste into valuable products. Exploring the current landscape of FW biorefineries, this study focused on the interplay between feedstock heterogeneity, pretreatment strategies, microbial dynamics, and integration potential. We propose a framework distinguishing between robust fermentations that can use minimally treated FW and tailored fermentations, which require refined media pretreatment and/or supplementation to yield higher-value compounds. Drawing on recent techno-economic and life cycle assessments, this article evaluates process viability and environmental impacts across multiple scales, reinforcing the need for robust analysis to support decision-making. Real-world initiatives and policy frameworks are analyzed to contextualize technological advances within regulatory and infrastructural realities. By linking practical constraints to biochemical and operational strategies, this work outlines how food waste biorefineries can contribute meaningfully to circular economy goals. Instead of treating FW as an intractable problem, it is seen as a versatile feedstock that demands integration, investment, and adaptive process design.

This study aims to evaluate the use of sugarcane industry byproducts (bagasse and molasses), as well as glycerol from the liquor of the organosolv pretreatment of bagasse, to bioproduce 1,3-propanediol (1,3-PDO). For this purpose, Lentilactobacillus diolivorans was used, which can produce 1,3-PDO from a mixture of glycerol and sugars. First, experiments were conducted using the MRS medium to investigate the effect of various carbohydrate sources and their mixtures on the growth profile and 1,3-PDO production by L. diolivorans. Subsequently, the carbohydrates in the MRS medium were replaced with sugarcane byproducts. The results showed that the type of carbohydrate plays a crucial role in growth kinetics and 1,3-PDO production. Xylose and glucose showed the best results; however, sucrose was not enough to support biomass formation. The presence of xylose increased sucrose assimilation, resulting in a 4.5-fold increase in the concentration of 1,3-PDO from 1.3 to 6.18 g/L. An auspicious outcome was observed when the liquor of the acid pretreatment of sugarcane bagasse, molasses, and organosolv liquor were used as substrates, resulting in a production of 5.47 g/L 1,3-PDO with an efficiency of 82.77%. Therefore, producing a high-value chemical such as 1,3-PDO from the sugarcane byproducts seems to be a very promising strategy.