# Microbial pigment review puts waste feedstocks through a commercial reality check > Food-processing residues could support colourant fermentation, but consistency, recovery and product-specific safety determine whether the route is practical. URL: https://foodradar.org/microbial-pigments-food-waste-feedstocks-scale-up Language: en Author: FoodRadar Editorial Published: 2026-10-07T11:40:11.584Z Updated: 2026-10-07T11:40:11.584Z Source publication date: 2026-07-09 Category: Sustainability Türkçe: https://foodradar.org/tr/microbial-pigments-food-waste-feedstocks-scale-up ## A waste stream can feed a process without solving it Fruit peels, whey, molasses and other residues are being explored as substrates for microbial pigment production. A July review examines how those streams could replace some refined fermentation inputs and fit within a circular production system. It also identifies the steps that can prevent a cheap raw material from becoming a competitive finished colourant. The paper covers pigments and applications across food, cosmetics, textiles and biomedical uses. Those uses are not interchangeable. A microorganism’s ability to produce an attractive pigment does not establish that the organism, pigment or extraction process is suitable or authorised for food. The review is a technology synthesis, not a new approval or a single industrial demonstration. ## Variable feedstocks need a controlled preparation route Residues differ in available sugars, nitrogen, water content and potentially inhibitory compounds. Their composition can also change with season and processing conditions. The authors therefore emphasise characterisation, pretreatment and nutrient balancing before fermentation, rather than assuming that any organic waste can be substituted directly into an existing recipe. Submerged and solid-state fermentation create different scale-up demands. Liquid systems still require adequate mixing, oxygen transfer and heat removal, while solid matrices add their own transfer constraints. Mixed cultures can broaden the process options but introduce another control problem: maintaining the intended microbial relationships. The cost of managing those variables belongs in the comparison with conventional substrates. ## Recovery can outweigh the raw-material saving Pigments differ in whether they remain inside cells, dissolve in water or associate with oil. Extraction and purification must match those properties. Cell disruption, solvents, separation and stabilisation can therefore become major energy and cost requirements after fermentation has produced the target material. For a food application, purity, residual substances, microbial contaminants and batch consistency require particular attention. Light, oxygen, temperature and pH can also change colour performance during processing and storage. A pigment that appears promising in a culture flask still needs to work in the intended food matrix through its actual manufacturing and shelf-life conditions. ## Environmental superiority has to be measured The review discusses techno-economic and lifecycle assessment as tools for comparing complete routes. Using a residue may reduce demand for refined inputs, yet specialised purification equipment, energy use and effluent treatment can offset part of that advantage. Environmental comparisons also depend on the electricity mix, system boundaries and assumptions about how the original waste would otherwise be managed. The authors note that established synthetic routes can perform better in some impact categories, so microbial or waste-derived origin is not a sufficient sustainability claim. For colourant developers, the practical agenda is to standardise the feedstock and assess fermentation, recovery, stability and intended-use requirements together. The review identifies a promising development space while keeping commercial and environmental performance as questions to demonstrate, rather than benefits guaranteed by the process description. ## Sources and rights - [Waste to wealth: circular approaches for microbial pigment production.](https://europepmc.org/articles/PMC13391545?utm_source=foodradar.org&utm_medium=referral&utm_campaign=editorial&utm_content=microbial-pigments-food-waste-feedstocks-scale-up-en). Frontiers Media SA. Devi M, Sarma AD, Deka S, Bhattacharyya R, Parasar DP. Waste to wealth: circular approaches for microbial pigment production. Frontiers in microbiology. 2026. DOI: 10.3389/fmicb.2026.1815563. Copyright © 2026 Devi, Sarma, Deka, Bhattacharyya and Parasar. [CC-BY-4.0](https://creativecommons.org/licenses/by/4.0/?utm_source=foodradar.org&utm_medium=referral&utm_campaign=editorial&utm_content=microbial-pigments-food-waste-feedstocks-scale-up-en-license). Adapted by FoodRadar. [Editorial standards](https://foodradar.org/editorial-policy)