In the contemporary environmental milieu, the issue of marine fish oil contamination has become an escalating concern of paramount importance. The world’s oceans are increasingly besieged by a spectrum of noxious pollutants, encompassing heavy metals, pesticides, plasticizers, benzopyrene, and dioxins. Exacerbating this predicament is the ecological hierarchy in which marine fish, positioned as apex predators, predominantly subsist on seaweeds and plankton. Regrettably, these organisms have an inherent propensity to amass these deleterious substances.

The discernible presence of these undesirable constituents within crude fish oil serves as a pivotal barometer of raw material quality and safety. It provides an indirect yet salient revelation of the pollution levels endemic to the fish oil production regions. Consequently, it becomes incumbent upon us to delineate a process that can efficaciously and methodically eliminate plasticizers from fish oils. This process should ideally embody qualities of simplicity, cost-effectiveness, and scalability for large-scale industrial implementation.

Therefore, the overarching purpose of this blog post is to furnish our readers with an exhaustive compendium of meticulously crafted solutions and state-of-the-art technologies specifically tailored for the eradication of plasticizers from fish oil. In a world where purity and safety standards are non-negotiable, this discourse is intended to serve as a beacon, illuminating the path toward the preservation of the integrity of this indispensable product.

Definition of Plasticizers and Their Role in Food Products.

Plasticizers, alternatively known as microplastic or nanoplastic particles, depending on their respective diameters, exceeding 0.5-1 micrometers or falling within the range of 0.001-0.1 μm (according to size), represent prevalent environmental hormone compounds extensively utilized within the plastics industry. Their primary function lies in enhancing the flexibility, ductility, and processability of plastic materials. Diverse substances, including but not limited to phthalates, fatty acid esters, polyesters, and epoxy esters, can serve as plasticizers.

It is crucial to emphasize that plasticizers do not qualify as approved food additives in China, nor are they classified as food ingredients. Consequently, they are strictly prohibited from direct incorporation into food products. However, plasticizers that have undergone comprehensive safety assessments may be employed as additives in food contact materials and products. Such usage is subject to strict adherence to China’s national food safety standard, GB 9685-2016, titled “Standard for the Use of Additives in Food-Contact Materials and Products,” as well as relevant supplementary notifications.

Recognizing the potential health risks, several prominent regions, including China, the United States, Japan, and the European Union, have designated plasticizers for inclusion on their “Priority Controlled Contaminants List.” These regions have established specific limits governing the permissible quantities of plasticizers that can be incorporated into food contact materials, thereby reinforcing the imperative of stringent regulation and oversight in this critical domain.

The Impact of Plasticizer Contamination on Product Quality and Safety

The introduction of “plasticizers” into the realm of food is a multifaceted issue, characterized by the remarkable ease of mobility exhibited by these substances. Their origins can be traced to two primary sources:

1. Contact Materials: Plastic containers, pipes, packaging materials, and sealing materials, which come into direct contact with food material, have the capacity to migrate plasticizers into the consumables.
2. Environmental Impact: The influence of plasticizers within the environment, notably in soil and water system, can result in their infiltration into the food chain, thereby impacting food products.

In recent years, the progressive deterioration of marine pollution, coupled with the cumulative effects within the marine organism food chain, has led to the inevitable presence of diverse environmental pollutants within crude fish oil. These pollutants encompass pesticide residues, heavy metals, dioxins, benzo(a)pyrene, and plasticizers, etc. Their constant intrusion into the marine ecosystem has precipitated the degradation of this ecosystem.

The perpetual existence of these substances within fish oils has given rise to serious toxicity concerns among the global community of fats and oils producers, as well as nutritional additive manufacturers. The repercussions of this contamination extend to human health, fostering significant apprehension and prompting a collective call for heightened vigilance and remedial actions within this sector.

Common Types of Plasticizers Found in Fish Oil

A diverse array of plasticizers exists, numbering in the hundreds, with notable categories encompassing aliphatic dibasic acid esters, phenylpolyacids, polyol esters, epoxides, polyesters, benzene dicarboxylic esters, benzoates, citrates, among others. Presently, the predominant choice among these options is phthalate compounds, which command approximately 80% of the plasticizer market.

Phthalates manifest as colorless and transparent oily liquids at standard room temperature, displaying insolubility in water while being soluble in methanol, ethanol, ether, and various organic solvents. Additionally, they exhibit fat-soluble properties. Phthalates typically exhibit stability when exposed to heat and chemical reagents, with most existing in the form of high boiling point liquids or low volatility solids.

Benzene dicarboxylate plasticisers are a class of chemicals that provide a softening effect and are the main representatives of plasticizers. According to the use, phthalate esters can be divided into two categories: short carbon chain category (alkyl carbon number l to 6) and long carbon chain category (alkyl carbon number 7 to 13). The short carbon chain class has a small relative molecular mass, mainly including dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), diisobutyl phthalate (DIBP), and butylbenzyl phthalate (BBP), etc. Its typical use is as a solvent for cosmetics and personal care products. The long carbon chain class has a large relative molecular mass, mainly including di-n-octyl phthalate (DNOP or DOP), di(2-ethylhexyl) phthalate (DEHP), diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), etc., which are mainly used in the plastics industry as plastisolators/flexibilizers.

Functioning as ester compounds, phthalates share excellent compatibility with the plastic products they permeate, with the two entities remaining integrated post-mixing, negating phase separation. However, it’s important to underscore that phthalates lack a strong chemical bond, such as covalent bonding, with the plastic matrix molecules. Instead, their association relies upon hydrogen bonding, van der Waals forces, and similar interactions, which maintain their independent chemical structure.

Over time and through use, phthalates within plastic products have the propensity to continuously leach into the environment, including the atmosphere, soil, and water, thereby inducing environmental contamination and potentially impacting human health. For instance, when plastic products interface with food items, phthalates within these products can gradually dissolve into the food, ultimately being ingested by consumers. In response to this concern, China has established maximum allowable levels for DEHP, DBP, and DINP in food and food additives to ensure safety and regulatory compliance.

Information on 23 phthalate compounds

Detection and Analysis of Plasticizers in Fish Oil

Regular testing for plasticizer contamination plays a pivotal role in safeguarding the integrity of products, particularly in industries where plastic materials are utilized. The importance of such testing cannot be overstated, and it extends across various sectors, including food production, healthcare, pharmaceuticals, and consumer goods manufacturing.

The Life Sciences Analytical Division of Standard Testing Group Co., Ltd. offers comprehensive services for the detection of over 18 phthalate plasticizers, delivering tailored research and technology development solutions.

As a distinguished third-party analytical testing and research and development (R&D) entity, Standard Analytical Division boasts a wide-ranging suite of analytical instruments, including Liquid-Mass Triple Quadrupole, High-Resolution Liquid-Quadrupole (HRLQE), Gas Chromatograph (GC), Liquid Chromatograph (LCH), Amino Acid Auto Analyser (AAA), Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), Nuclear Magnetic Resonance (NMR), and various other cutting-edge tools.

The unwavering commitment is to address the unique challenges faced by our clients by continuously enhancing the life sciences research infrastructure and refining technical methodologies. We proudly offer an array of professional scientific research services, delivering analytical testing expertise and technical support to esteemed scientific research institutions, universities, hospitals, and biotechnology research and development enterprises worldwide.

Best Practices for Preventing Plasticizer Contamination During Fish Oil Processing and Storage

Preventing plasticizer contamination during fish oil processing and storage is of paramount importance to uphold product quality and safety. Implementing best practices in handling, storage, and quality control is essential in minimizing the risk of plasticizer introduction:

Proper Handling:

1. Supplier Vetting: Begin by carefully selecting reputable suppliers of raw materials. Ensure they adhere to industry standards and regulations concerning plasticizer content in packaging materials.
2. Material Inspection: Conduct a rigorous inspection of incoming materials, including containers, pipes, and packaging materials. Verify that they are compliant with established quality and safety standards.
3. Hygienic Practices: Enforce strict hygiene protocols in processing facilities. Contaminants can transfer from hands, clothing, and equipment, so proper sanitation is crucial.
4. Material Compatibility: Opt for food-grade materials in contact with fish oil. Materials such as stainless steel and food-grade are less likely to leach plasticizers into the product.

Storage Recommendations:

1. Temperature Control: Maintain stable and controlled storage temperatures for both raw materials and finished products. Elevated temperatures can accelerate the release of plasticizers from materials.
2. Air Quality: Ensure good ventilation in storage areas to minimize the concentration of airborne contaminants. Proper airflow can help disperse potential plasticizer emissions.
3. Proper Packaging: Use packaging materials that are known to be resistant to plasticizer migration. Glass, sanitary stainless steel or high-quality food-grade plastics can be effective choices.
4. Sealed Storage: Seal containers and tanks to prevent contamination from external sources, such as dust or fumes, which could carry plasticizers.

Quality Control Measures:

1. Routine Testing: Implement a rigorous testing regimen for plasticizer levels in both raw materials and finished products. This allows for early detection of contamination.
2. Batch Tracking: Maintain meticulous records and batch tracking systems. This facilitates quick identification and recall of any contaminated products.
3. Employee Training: Continuously train staff on proper handling procedures and the importance of vigilance in preventing plasticizer contamination.
4. Regular Audits: Conduct regular audits of suppliers, manufacturing processes, and storage conditions to ensure compliance with quality and safety standards.
5. Environmental Monitoring: Monitor the environment for potential sources of contamination, such as air quality and nearby industrial activities that may release plasticizers into the atmosphere.

Incorporating these best practices into your fish oil processing and storage procedures can significantly reduce the risk of plasticizer contamination. By maintaining strict control over materials, storage conditions, and quality assurance, you can uphold the purity and safety of your fish oil products, fostering consumer trust and ensuring compliance with regulatory standards.

Removing Plasticizers: Traditional & Advanced Technologies

Heat treatment and distillation as traditional approaches.

CN107790066A describes the removal of most of the plasticisers from fats and oils by the addition of carboxylate salts to the fats and oils under negative pressure and high temperature with the introduction of water vapour.

However, the removal temperature of this process is very high, the removal time is very long, and the amount of water added has a significant effect on the removal rate of plasticisers.

Cutting-edge Technologies for Plasticizer Removal

Short-Path Molecular Distillation:

• This technique operates under molecular high vacuum distillation conditions, where components like VEs, sterols, and flavonoids share similar volatility with PAEs (phthalate plasticizers).
• These substances condense together at the condensing surface, entering the light fraction phase.
• Higher boiling point unsaturated fatty acids remain unaffected and do not evaporate.
• Multi stages molecular distillation significantly reduces free fatty acid content in fish oil. which decreased from 5.69% to 1.20% after primary molecular distillation and to 0.33% after secondary sub-sequential distillation.
• It effectively removes high concentrations of plasticizers while preserving the fatty acid composition of fish oil, and it did not produce trans fatty acids.

Supercritical Fluid Extraction (SFE):

• SFE, though efficient, can be cost-prohibitive and inefficient for large-scale production due to solvent consumption and equipment investments.
• Ethanol, while effective in removing large molecular weight plasticizers like DEHP, can impact the flavor profile of fats and oils.

Membrane Filtration:

• Microfiltration membranes with a pore size of 0.1-1 micron sieve out impurities through sieve retention with high separation efficiency.
• While they allow the passage of large molecules and dissolved solids, they retain substances like suspended matter, bacteria, and large molecular weight colloids.
• Effective operation at pressures of 0.3-0.7 bar ensures the removal of contaminants.
• Controlled by the pore size and pore size distribution of the membrane, high filtration accuracy and stable reliability

Adsorption Techniques:

• After degumming, alkali refined oil is subjected to adsorption process(bleaching) with mineral adsorbents to remove plasticizers and impurities, with precise temperature controlling and dosing system.
• The oil undergoes a series of multi-filtration steps and heat exchanges.
• Adsorbents like activated white clay and attapulgite clay are chosen based on their efficiency and filtration characteristics.
• Decolourization is carried out under reduced pressure and specific temperature conditions.

Factors affecting the effectiveness of colour removal

• Oil quality and pre-treatment, the natural pigment in the oil is easy to remove, but the new pigment formed in the oil storage and production process or the pigment fixed by oxidation is difficult to remove, it is important to improve the quality of the oil and avoid oxidation during processing. The residual colloid and suspended matter in the neutralised oil will occupy part of the activated surface, which will reduce the decolourisation efficiency or increase the dosage of white clay.
• Type and dosage of adsorbent. Activated white clay is mainly composed of bentonite, the pigment, especially chlorophyll and other colloidal impurities adsorption capacity is very strong, for the alkaline group and polar group adsorption capacity is stronger. Attapulgite clay is mainly composed of silica, fine soil, and activated white clay, compared with the dosage of decolouring is small, less oil loss, cheap, but due to the more delicate filtration is more difficult.
• Operation Pressure: Atmospheric pressure Thermal oxidation side reaction is always accompanied by adsorption, due to the catalytic effect of the adsorbent, some non-conjugated fatty acids are easily converted into conjugated fatty acids increasing the chance of auto-oxidation. Therefore, decolourisation is generally carried out under reduced pressure.
• Operating temperature: The operating temperature is determined by the oil, the adsorbent species and characteristics, and the operating pressure.
• Operation time:The time is determined by the adsorption balance between the adsorbent and the pigment, the grease in contact with the adsorbent at high temperature may be fatty acid double bond conjugated with the extension of time, which will bring the grease with a bad smell (bleached earth smell) and the grease colour will rise back. Generally control in about 20 minutes, 10-15 minutes can meet the requirements of decolourisation.
• Decolourization process: adopting pre-decolourisation-re decolourisation process, establishing two adsorption equilibriums, it will have better decolorization effect.

Based on various refining processes for various oils, Plasticizers can be removed by appropriate refining processes including one or more degumming, alkali refining, filtration, dewaxing, deacidification, decolorization, deodorization, degreasing, filtration, fractionation, esterification, molecular distillation and hydrogenation.

Deodorization:

The deodorization process is integral to the removal of plasticizers from fish oil. Its principle is rooted in the distinct volatility of odorous substances compared to triglycerides in fats and oils. This process takes place under high-temperature and high-vacuum conditions, aided by water vapor distillation.

• As the deionized vapor passes through the fish oil containing odorous components, it comes into contact with the oil’s surface. The water vapor becomes saturated with volatilized odorous components based on partial pressure ratios and then escapes, effectively removing these odorous substances during the distillation process.
• Prior to deodorization, it’s crucial to deoxygenate the fish oil due to the presence of dissolved oxygen, typically at levels between one to five parts per million. The oxygen removal is achieved through a degassing process conducted under vacuum conditions.
• The volatile components distilled during deodorization primarily consist of fatty acids, unsaponifiables, and splattered oils and fats. These are typically recovered via direct spray condensation using a fatty acid trap set at approximately 60°C.
• Following the deodorization process, the fish oil undergoes additional steps, including cooling through polishing and filtration, to further refine and enhance its quality.

Silica Gel Column Chromatography:

• Silica gel column chromatography leverages differences in polarity between phthalate plasticizers and polyunsaturated fatty acid triglycerides in fish oils.
• Gradient elution with varying polarity organic solvents facilitates plasticizer removal.
• This process enhances the fish oil’s purity by eliminating most low and high polarity impurities.
• the fish oil is subjected to silica gel column chromatography to remove the plasticizers and then further deodorized to obtain a food-grade fish oil that meets the quality standard for plasticizers.
• Silica gel column chromatography is efficient, cost-effective, and amenable to large-scale industrial production.

These advanced technologies collectively contribute to the removal of plasticizers from fish oil, ensuring the final product meets stringent quality standards while minimizing the risk of contamination. Each method offers unique advantages, making them indispensable tools in the pursuit of pure and high-quality fish oil products for various applications.

Conclusion

As different process technologies are available for removing plasticizers from fish oil, including molecular distillation, supercritical fluid extraction, membrane filtration, adsorption and deodorization refining techniques, and silica gel column chromatography.

The choice of technology depends on specific needs, scale of production, cost considerations, and desired purity levels. Meanwhile, regulations and standards for plasticizer levels in food products are subject to change and vary by region. It’s imperative to stay updated with the latest regulations to ensure compliance and product safety.

Hopefully, the above content will be helpful for your business initiatives, welcome to discuss details with your inquiries and messages for us.

Reference resources:

https://www.nordic.com/faq-process

https://spo.nmfs.noaa.gov/sites/default/files/legacy-pdfs/CIRC278.pdf