What is Acidity Regulator E330?

Introduction to E330

Acidity regulator E330, commonly known as citric acid, is a versatile food additive that plays a crucial role in the food and beverage industry.

Uses of E330

E330 has a pleasant sour taste, providing a refreshing and tart flavor without an aftertaste. It is safe, non-toxic, and widely used as an acidulant in food and beverages. E330 can form complexes with divalent or trivalent cations and is used as a chelating agent in metal processing and as a detergent in cleaning products (as a water-softening agent). It can also be derivatized to produce various compounds, making it useful in the organic chemical industry. Therefore, it finds extensive applications in the fields of food and beverage, pharmaceutical and chemical manufacturing, cleaning and cosmetics, organic materials, and more. It is currently the most widely demanded organic acid in the world, with no substitute that can fully replace its acidulant properties.

What Foods Commonly Engage with It?

1. Carbonated beverages: E330 is often used in soft drinks, energy drinks, and carbonated water to provide a tangy and refreshing taste.

2. Fruit juices: Many packaged fruit juices, especially those with a longer shelf life, may contain E330 as a flavor enhancer and preservative.

3. Jams, jellies, and fruit preserves: E330 helps maintain the pH balance and preserve the freshness of these products.

4. Candy and confectionery: Sour candies, gummies, and certain types of confectionery items may contain E330 to give them a tangy flavor.

5. Sauces and dressings: E330 is commonly added to sauces, dressings, and marinades to provide acidity and enhance the flavor profile.

6. Canned and preserved fruits: E330 is used to preserve the color and texture of canned fruits and prevent browning.

7. Ready-to-drink teas and flavored water: E330 can be found in flavored teas and enhanced waters to add acidity and improve the taste.

8. Bakery products: Some baked goods, such as certain bread, cakes, and pastries, may include E330 to enhance flavors and act as a dough conditioner.

9. Dairy products: E330 is sometimes used in cheese-making processes to regulate acidity and aid in coagulation.

10. Processed meats: E330 can be added to processed meats, like sausages and cured meats, to improve their flavor and extend shelf life.

Production Techniques

The production methods of E330(citric acid) can be divided into three main categories: fruit extraction, chemical synthesis, and biofermentation. Currently, biofermentation is the predominant method for E330(citric acid) production. Biofermentation can further be classified into solid-state fermentation and submerged deep-tank fermentation. Solid-state fermentation requires less energy but involves more labor and occupies larger space, making it less suitable for large-scale production. Submerged deep-tank fermentation employs stainless steel tanks with mechanical stirring and aeration, ensuring uniform distribution of microorganisms in the liquid phase. It does not generate spores during fermentation, and all microbial cells are used for E330(citric acid) metabolism. This method achieves high fermentation rates and allows for mechanization or automation, facilitating large-scale production.

Operational Process

• Raw Material Processing

According to the fermentation requirements, the processing of potato raw materials involves the following methods: direct crushing, grinding, slurry preparation, liquefaction, and continuous sterilization. During the production of potato raw materials, the potatoes are transported from storage to the preparation workshop. The raw materials are passed through a magnetic separator to remove iron impurities and protect the equipment. Then they undergo coarse crushing, where the potatoes are crushed into small pieces of 1-3 cm to improve the efficiency of the grinding machine and facilitate material transportation. After coarse crushing, the potatoes are conveyed by a bucket elevator to the intermediate powder silo. From there, they are discharged into the grinding machine for further pulverization. Once pulverized, the material is stored in a powder silo and then sent to the batching tank through metering. In the batching tank, water is added to form a slurry, and amylase enzyme and heating solution are added for liquefaction. After liquefaction is completed, the slurry is sent to the continuous sterilization unit and then to the fermentation workshop.

• Fermentation Process

The liquid feed provided by the preparation workshop, which has undergone continuous sterilization and cooling, is pumped into the sterilized fermentation tanks. The tanks are inoculated with E330(citric acid) bacteria that have been cultivated in advance, using differential pressure or flame sterilization methods. The fermentation or cultivation process takes place under ventilation and agitation. During fermentation, parameters such as temperature, pressure, airflow, and stirring speed are continuously monitored and recorded. Regular checks are conducted on sugar consumption, bacterial growth, pH value, foam formation, and other changes. Based on the requirements of the fermentation process, adjustments are made to optimize the fermentation rate or bacterial activity. Typically, fermentation is carried out for about 66 hours (with the inoculum tank taking approximately 25 hours). Once the residual sugar index and acid production meet the criteria, the large tanks can be emptied. After the inoculum tank’s bacterial activity and population reach the required standards, it can be used for inoculation. If any abnormal conditions are detected during regular testing in the fermentation or inoculation process, appropriate actions should be taken promptly. For early to mid-stage contamination, increasing the inoculum size can establish a dominant growth advantage for the main bacterial population, or immediate sterilization and re-inoculation can be performed with suitable nutrient sources. In the later stages, stricter monitoring and early emptying of the tanks are recommended. In the case of tank overturning, sterilization, and discharge should be carried out, and the causes should be thoroughly investigated to strengthen the various aspects of sterilization operations.

• Lees Processing

After E330(citric acid) fermentation is completed, heat treatment should be carried out immediately to deactivate the fermentation, coagulate proteins, and improve the yield. To improve equipment utilization, a lees storage tank is added. The lees liquid is heated to 80°C through a heat exchanger and then enters the hot lees storage tank. From there, it is pumped into a filter press to remove solid particles and bacterial residue, resulting in clear lees liquid that is pumped into the next process.

• Extraction Process

The clarified E330(citric acid) lees liquid, pumped from the filtration section, is transferred to a neutralization tank for neutralization at 80°C. Calcium carbonate is conveyed into the workshop through a sealed conveyor and introduced into the neutralization tank through a variable-speed screw feeder to ensure uniform neutralization and precipitation reaction and prevent localized high concentrations. After passing the endpoint test, the calcium citrate suspension is discharged into a belt filter press to separate the solid calcium citrate from the suspension. To meet the dual requirements of corn and potato raw material production processes, the belt filter press is designed with specific elongation and strong washing capabilities, providing flexibility in raw material production for neutralization and sugar washing requirements as well as controlling the product specifications. The suspension is adjusted with hot water or acid solution, and concentrated sulfuric acid is pumped from the acid-alkali station into the acid-alkali tank. It reacts with calcium citrate at 80°C, forming a calcium sulfate and E330(citric acid) suspension, which is then sent to the acid dissolution belt filter press for filtration. The wash liquid, which is the acid dissolution liquid, is collected for slurry preparation. The calcium sulfate is transported to a slag yard for comprehensive utilization, while the E330(citric acid) from the acid dissolution process is sent to the refining section.

• Refining Process

1. Ion Exchange and Decolorization: The E330(citric acid) liquid is pumped from the temporary storage tank to the ion exchange purification process. It passes through cation exchange towers, anion exchange towers, and activated carbon decolorization towers to remove ions that affect product quality, coloration, and equipment corrosion. The cation and anion resins need to undergo acid and alkali-washing regeneration treatments. The purified E330(citric acid) mother liquor from the ion exchange process is then sent to the evaporation process.
2. Evaporation and Crystallization: Before entering the evaporation section, the purified solution undergoes fine filtration to remove tiny resin particles. The filtered solution is preheated by a heat exchanger and then sent to a double-effect vacuum concentrator to concentrate to a specific concentration. After concentration, it is transferred to a vacuum crystallizer or a low-temperature crystallizer for crystallization, determining the type of product (monohydrate or anhydrous). The E330(citric acid) crystals are separated from the liquid phase and the liquid phase is directed to respective mother liquor storage tanks. Depending on the impurity concentration, the liquid is sent back to the previous process for re-evaporation. The crystals are sent to a drying machine.
3. Drying and Packaging: The wet E330(citric acid) crystals separated by the centrifuge are sent to a fluidized bed dryer. Drying is carried out according to the product specifications, controlling the drying air, temperature, and cooling air volume. The exhaust is treated by a wet cyclone separator before being discharged. The dried E330(citric acid) crystals are transferred to a screening machine, where any non-conforming particles are removed. The screened particles, when dissolved, are returned to the crystallization system. The E330(citric acid) product is quantified, packaged, and stored.

Is Acidity Regulator E330 Good for Health?

Acidity regulator E330 (citric acid) is generally considered safe for consumption by regulatory authorities. It is widely used in the food and beverage industry and has undergone extensive studies regarding its safety and health effects. Classified as Generally Recognized as Safe (GRAS), acidity regulator E330 is not associated with significant toxicity or health risks when consumed in normal amounts. While excessive consumption may cause digestive discomfort in some individuals, moderate intake is generally well tolerated. However, it’s important to practice good oral hygiene as citric acid, being acidic, can have an erosive effect on tooth enamel. As with any food additive, it is advisable to consume a varied and balanced diet and consult a healthcare professional for personalized guidance.

In conclusion, E330 (citric acid) is a safe and widely utilized additive due to its simple production process, abundant sources, cost-effectiveness, and proven safety. Its versatility makes it a key ingredient in various industries, with the food industry being a prominent user.