The U.S. Food and Drug Administration (FDA) together with the Department of Health and Human Services (HHS), recently announced plans to phase out several petroleum based synthetic food dyes from the U.S. food supply [1]. This shift is expected to accelerate investment in natural colorant development, creating new challenges for food and beverage manufacturers seeking to maintain color consistency, stability, and production efficiency.
As food and beverage manufacturers begin transitioning toward natural color alternatives, the challenge extends beyond simply replacing one ingredient with another. Companies must also develop reliable methods to extract, purify, and concentrate natural colorants while maintaining product quality and consistency.
Natural colorants such as butterfly pea flower extract, gardenia blue, algae-derived blue pigments, turmeric-derived curcuminoids, and anthocyanin-rich fruit extracts are sourced from complex biological matrices and often contain co-extracted solids, proteins, polysaccharides, sugars, and salts that can affect purification, stability, and product performance [2].
Compared to synthetic dyes, these colorants are more sensitive to temperature, pH, oxidation, and light, making color fading, hue shifts, and reduced shelf-life common challenges. As a result, manufacturers require concentration and purification processes that operate under mild conditions while maintaining tight control over product quality.
Why Membrane Filtration Matters
Membrane separation provides non-thermal clarification, fractionation, concentration, and desalting. Different membrane processes can address specific challenges throughout production:
- Microfiltration (MF) removes suspended solids, cell debris, and large particulates from crude botanical or fermentation-derived extracts.
- Ultrafiltration (UF) separates proteins, colloids, and higher-molecular-weight impurities from lower-molecular-weight pigment streams.
- Nanofiltration (NF) concentrates pigments while partially removing salts, sugars, or low-molecular-weight impurities depending on membrane selectivity.
- Reverse osmosis (RO) further concentrates purified streams by removing water at relatively mild temperatures compared with thermal evaporation.
Unlike evaporation-based concentration, membrane processes may better preserve pigment functionality and reduce thermal degradation risk for sensitive natural ingredients. This is important when manufacturers are trying to match color strength and shelf stability while transitioning from synthetic systems.
Supporting Natural Colorant Process Development
Selecting the right membrane and operating conditions is critical because every natural colorant presents a unique combination of pigments, impurities, and fouling characteristics. Before committing to commercial equipment, researchers often perform laboratory scale studies to identify the most effective membrane strategy.
As researchers and manufacturers move toward natural color systems, they need to evaluate rejection performance, flux, and fouling before scaling to a commercial process. Sterlitech’s membrane process development products and systems support feasibility studies by allowing researchers to evaluate membrane performance under controlled laboratory crossflow conditions.
1. Identify the Right Membrane for Natural Color Purification
With Sterlitech crossflow systems such as the HP4750, Cross Flow Cells, Benchtop Cross Flow Systems, or Skid Mounted Systems, users can test multiple membrane chemistries and MWCO ranges to determine which system enables the required balance of:
- dye rejection
- impurity passage
- permeate flux
- concentration factor
This is critical because natural color extracts can differ widely in molecular composition, and the success of the process depends on matching membrane selectivity to the target pigment and impurity profile. A membrane screen at lab scale reduces reformulation risk and provides data needed for downstream process design.
2. Understanding Fouling Before Scale Up
Natural color extracts frequently contain components that promote membrane fouling, including polysaccharides, proteins, fine particulates, and soluble organics. Sterlitech’s process development platforms allow users to measure flux decline, compare operating conditions, and assess the effectiveness of pretreatment and cleaning strategies before scale-up. Early fouling characterization is essential because natural ingredients tend to introduce greater variability than synthetic dyes, and that variability can directly affect membrane performance and operating cost.
3. Generating Scale Up Data for Commercial Process Design
The FDA’s timeline and the broader state-level momentum indicate that the transition to natural colorants is likely to accelerate across the food sector. Industry analysis also points to significant investment needs in quality systems, analytical testing, and manufacturing adaptation.
The shift away from petroleum-based synthetic dyes is reshaping food formulation and ingredient processing. The technical challenge is not only finding a natural replacement colorant, but also developing a robust method to extract, purify, and concentrate at scale. From membrane screening and fouling evaluation to pilot-scale process development, Sterlitech supports researchers and manufacturers throughout the filtration development process. Ask an Expert to learn how our membrane filtration solutions can help optimize your natural colorant application.
References
[1] Office of the Commissioner, “HHS, FDA to phase out Petroleum-Based synthetic dyes in nation’s food supply,” U.S. Food And Drug Administration, Apr. 22, 2025. https://www.fda.gov/news-events/press-announcements/hhs-fda-phase-out-petroleum-based-synthetic-dyes-nations-food-supply
[2] W. M. Neal, A. G. Osman, I. A. Khan, and A. G. Chittiboyina, “Natural product-based colorants as substitutes for petroleum-based synthetic food dyes: sources, chemistry, and characteristics,” Food Chemistry, vol. 501, p. 147561, Dec. 2025, doi: 10.1016/j.foodchem.2025.147561.
Legionnaires’ Disease is a type of pneumonia that is caused by Legionella bacteria, which commonly grows in warm, stagnant water. Infection is acquired by inhalation of contaminated water from man-made water sources [1]. Due to the public health risks associated with Legionella, routine monitoring of water systems is an important component of water quality management programs. ISO 11731: 2017 provides standardized methods in the isolation and enumeration of Legionella in water [2].
Overview of ISO 11731:2017
Clause 8 of ISO 11731:2017 describes the analytical workflow used for Legionella testing, including:
- Sample preparation (8.1)
- Concentration of microorganisms from water samples (8.2)
- Sample pretreatment (8.3)
- Culture methods (8.4)
- Confirmation of Legionella colonies (8.5)
Among these sections, Clause 8.2 is particularly important because it outlines the membrane filtration techniques commonly used to concentrate microorganisms prior to culturing.
Membrane Filtration Approaches
Membrane filtration procedures for the isolation and enumeration of Legionella utilize equipment commonly found in microbiology laboratories. Laboratories processing smaller sample volumes often use a single filtration assembly such as Rocker Scientific VF3 Glass Filtration Set or a Rocker Scientific VF6 Glass Filtration Set.
For higher throughput workflows, glass microanalysis filters paired with stainless steel vacuum manifolds are often preferred. Multi-place, autoclavable manifolds allow laboratories to process multiple water samples simultaneously, improving efficiency while maintaining consistent filtration conditions. Depending on the model, manifolds can concentrate up to 12 samples in a single filtration cycle.
Direct Filtration Method (8.2.2)
The direct filtration method described in section 8.2.2 utilizes Mixed Cellulose Ester (MCE) membranes to capture microorganisms from water samples. Following filtration, the membrane filter is carefully transferred to a Petri Dish containing the growth media. Common membrane specifications used for Legionella testing include MCE or cellulose nitrate membranes with pore sizes of 0.2 µm or 0.45 µm and a diameter of 47 mm. Examples include:
- SKU A020G047A Advantec MCE Membrane Filter w/o Pad & Grid, 0.22µm, 47mm
- SKU A020H047K Advantec MCE Membrane Filter w/o Pad, Gridded, 0.2µm, 47mm
- SKU A020H047A Advantec MCE Membrane Filter w/o Pad, Gridded, 0.22µm, 47mm
- SKU A020G047J 0.2µm MCE Membrane Filter w/o Pad, 47mm, Plain w/ Edge
Concentration and Recovery Method (8.2.3)
The concentration and recovery method described in section 8.2.3 incorporates an additional recovery step prior to culturing. Water samples are filtered through a Polyethersulfone Membrane or a Hydrophilic Polycarbonate Membrane Filter this concentrates the cells on the membrane to avoid loss of residual cells and maximum cell collection. After filtration, the membrane is removed from the filter holder and placed in a sterile container with a screw cap, with optional sterile glass beads. 5 to 10 ml of sterile diluent is then added, and the sample is shaken vigorously. An ultrasonic water bath or a vortex mixer may also be used to improve recovery efficiency. Following recovery, the suspension may be plated directly or subjected to membrane filtration before transfer to culture media using the direct filtration workflow described in section 8.2.2.
Selection of filtration equipment should be based on laboratory throughput requirements and sample volume. The choice between direct filtration and concentration/recovery methods depends largely on the water source and expected microbial load. Clean water, like those present in municipal water systems distributed into the household is expected to have fewer cells so a concentration step ( 8.2.3) is preferred. In contrast, environmental samples from stagnant water systems, cooling towers, ponds, or rainwater collection systems may contain higher microbial loads, making direct filtration an effective and efficient approach.
Whether utilizing a single filtration assembly or a high-throughput vacuum manifold, proper membrane selection and sample handling are critical for achieving accurate and reproducible Legionella testing results in accordance with ISO 11731:2017.
References:
([1] About Legionnaires' Disease | Legionella | CDC
[2] ISO 11731:2017 - Water quality — Enumeration of Legionella
The future of biomedical research is evolving rapidly. In 2026, the National Institutes of Health (NIH) announced a $150 million investment to advance human based research technologies and reduce reliance on animal models [1].
This initiative reflects a growing focus on research methods that better replicate human biology while improving reproducibility and reducing ethical concerns. According to the NIH, animal models can have limitations in predicting human responses due to differences in physiology and disease progression [1].
As a result, researchers are increasingly turning to new approach methodologies, including organoids, tissue chips, and advanced cell culture systems.
The Growing Role of Cell Culture in Human Relevant Research
Human cell culture systems offer several advantages over traditional animal models:
- Improved relevance to human physiology
- Better reproducibility between experiments
- Reduced ethical concerns
- Faster experimental timelines
- Lower overall research costs
- Greater compatibility with high throughput screening and precision medicine applications
As research institutions continue investing in human-based methodologies, laboratories require reliable, scalable cell culture tools that support consistent experimental performance.
How Sterlitech Supports Human Based Research with cellQART®
Sterlitech supports the advancement of human based research with the cellQART product line, including cellQART Cell Culture Inserts and Well Plates designed to support modern in vitro workflows while aligning with 3Rs principle of reducing, refining, and replacing animal testing.
With cellQART Cell Culture Inserts, researchers can access high quality cell culture products that support human relevant research applications without the excessive costs often associated with traditional branded products.
As the NIH expands investment into new approach methodologies (NAMs) and human focused technologies, high quality cell culture systems will continue to play an increasingly important role in research involving:
- Drug discovery and development
- Toxicology studies
- Disease modeling
- Personalized medicine
- Regenerative medicine
- Organoid development
- issue engineering
Supporting the Future of Ethical and Predictive Research
NIH’s recent investment highlights a broader industry transformation toward research methods that better represent human biology while reducing animal use [1].
For researchers already adopting advanced cell culture methods, this shift validates years of innovation focused on improving scientific relevance and experimental efficiency. For others, it signals an opportunity to modernize laboratory workflows and explore technologies that align with the future of biomedical science.
Sterlitech remains committed to supporting this evolving research landscape by providing dependable cell culture and filtration solutions through the cellQART product line.
As human based research technologies continue to advance, laboratories equipped with scalable, high quality cell culture tools will be better positioned to drive innovation, accelerate discovery, and contribute to more predictive and ethical scientific outcomes.
Ask An Expert
As researchers continue adopting human relevant research methods, selecting the right cell culture tools is critical for achieving reliable and reproducible results.
Connect with Lexi Simpkins, Sterlitech's dedicated Bioprocessing and Cell Culture Specialist, to discuss your application and discover the cellQART® cell culture inserts and well plates best suited for your research needs.
Whether you're developing organoids, advancing drug discovery programs, conducting toxicology studies, or building more predictive in vitro models, Lexi can help identify cost effective cell culture solutions that support your workflow and research goals.
References
[1] National Institutes of Health (NIH). “NIH Invests $150 Million in Human Based Research to Reduce Use of Animal Models.” NIH Common Fund. https://commonfund.nih.gov/complementarie/news/nih-invests-150-million-human-based-research-reduce-use-animal-models
