Exploring Red Yeast Red: The "Magical Code" in Natural Pigments

     1、 Basic Overview of Red Yeast Red

   （1） Definition and Source

Hey, guys! Today we are going to unveil the mysterious veil of red yeast together.

     Red yeast is like a brilliant color gifted to us by this magical painter of nature. It is a great natural food coloring.

     It mainly comes from red yeast rice or red mold, which is like finding the source treasure of color. We can use ethanol like magic to extract liquid Monascus pigments from Monascus rice; It is also possible to obtain this precious red yeast red through a series of alchemy like operations such as extraction, crystallization, and refinement from the "treasure" carefully nurtured by Monascus in deep culture medium.

     （2） Composition analysis

     The composition of red yeast rice is complex, containing multiple pigment components, mainly including six color components belonging to different color systems, such as red erythema and red yeast rice pigment, yellow red yeast rice pigment and red yeast rice pigment, purple red erythema and red yeast rice pigment, etc. These components belong to polyketide compounds, which together form Monascus Red, giving it diverse physicochemical properties and application value.

     2、 The production process of red yeast rice

     （1） Raw material preparation

     The selection of raw materials is crucial for the production of red yeast rice, and usually indica rice is chosen as the main raw material.

     This is because indica rice has a suitable starch content and texture structure, which can provide good basic conditions for the growth and fermentation of Monascus in the future.

     In the raw material preparation stage, there are also certain requirements for the quality of indica rice, such as ensuring that its particles are full, free of mold, and have few impurities, in order to ensure a smooth fermentation process.

     Moreover, high-quality raw materials are the primary prerequisite for producing high-quality red yeast rice. The nutritional content they contain directly affects the efficiency and quality of the pigment produced by Monascus fermentation, laying a solid foundation for the entire production process. Just like building a house requires a stable foundation, good raw materials are the key starting point for the production of red yeast rice.

     （2） Fermentation process

     This is a key step in the production of red yeast rice, which requires liquid deep fermentation with Monascus fungus. First, select and isolate high-quality Monascus purpureus strains, and inoculate them into liquid culture media containing various nutrients.

     During fermentation, the conditions are strictly controlled, with a temperature maintained at around 30-32 ℃. The ventilation rate should be well controlled. In the early stage, the oxygen demand is low, and in the middle stage, the oxygen consumption of bacterial growth is high. Reducing the air volume in the later stage is beneficial for pigment generation and accumulation. It is also necessary to pay attention to parameters such as pH value and stirring speed of the fermentation broth. After a 50-60 hour fermentation cycle, preparations should be made for extracting red yeast.

     （3） Extraction and refinement

     After fermentation, it enters the extraction and refining process, with the aim of obtaining high-quality powdered natural edible pigments from the fermentation products. Extract the red yeast pigment from commonly used ethanol extraction fermentation broth, use its solubility to separate impurities, extract the filter residue multiple times with 70% -80% ethanol, and combine the filtrate.

     The refining process includes filtration, concentration and spray drying operations. Filter out insoluble impurities, concentrate and remove excess ingredients to increase pigment concentration, and spray dry the concentrated solution into powder pigment. Through these steps, Hongqu Hong can be applied in various fields with qualified form and quality.

     3、 Characteristics of Red Yeast Red

     （1） Physical and chemical properties

     1. Color presentation

     The most intuitive characteristic of red yeast rice is its unique color, usually purple red, bright red, or orange red. Its color expression will vary under different media and environmental conditions.

     For example, in neutral or alkaline aqueous solutions, red yeast red can effectively display its bright purple red color, and the color is uniform and bright, making food with added red yeast red quickly dyed with this natural and eye-catching color.

     When in an acidic environment, especially when the pH value is below 4.0, its solubility will decrease and the brightness of the color may also be affected to some extent, but the overall purple red tone can still be distinguished.

     In practical applications, such as in meat jerky and pastries, purple red yeast rice is widely used to make the product appearance more attractive; In braised cooked food, the bright red and orange red koji red can create a mouth watering color effect, greatly enhancing the appearance of the food.

     2. Solubility

     Red yeast has its own characteristics in terms of solubility. It is easily soluble in neutral and slightly alkaline aqueous solutions, and can quickly disperse uniformly in such solutions to form a color stable liquid, which is convenient for use and blending in food processing and other fields

     For example, when coloring some beverages or liquid foods, simply add an appropriate amount of red yeast rice to a suitable aqueous solution, stir slightly, and it can dissolve well and play a coloring role.

     However, in acidic environments, its solubility will significantly decrease. For example, in fruit juices or acidic sauces with low pH values, if red yeast red is directly added, incomplete dissolution or even a small amount of precipitation may occur. Therefore, in such application scenarios, it is necessary to consider adjusting the pH of the solution appropriately or using special addition methods to ensure that red yeast red can be fully dissolved and exert its effect.

     At the same time, red yeast rice is easily soluble in ethanol, propylene glycol, propylene glycol, and their aqueous solutions, but insoluble in fats and non-polar solvents. This means that in oily foods or applications that require avoiding contact with fats, attention should be paid to the use and dosage of red yeast rice to prevent problems such as inability to dissolve or uneven distribution.

     3. Stability

     The stability of red yeast rice is reflected in various aspects. In terms of temperature, temperatures below 130 ℃ are more heat-resistant and color stable, while temperatures above 150 ℃ are prone to decomposition and color loss. When processing food at high temperatures, temperature control is necessary, and low-temperature processing may be necessary.

     In terms of lighting, alcohol solutions are less affected by ultraviolet rays, but direct sunlight and prolonged exposure to natural indoor light can affect their color stability. Storage and use of products containing red yeast red should avoid light. In terms of pH value, it is relatively stable within the range of 3-10, and stability decreases beyond this range. When preparing solutions or processing foods with different pH values, attention should be paid to the influence of pH value.

     In addition, red yeast rice has good stability against common metal ions, oxidants, and reducing agents. However, Cu ² ⁺ and Fe ³ ⁺ may cause discoloration and precipitation in specific situations, which should be noted in practical applications.

     （2） Biological activity

     Red yeast rice has various biological activities, which give it more functional value in many fields of application.

     Firstly, it has antibacterial and bactericidal effects. It has a strong inhibitory effect on harmful bacteria such as Bacillus subtilis and Staphylococcus aureus. When applied in the food industry, it not only has a coloring effect, but also helps to inhibit the growth of harmful microorganisms that may exist in food, extending the shelf life of food. For example, when using red yeast rice instead of some nitrite as a coloring agent in meat products, it has been found to have a significant "toxic" effect on Clostridium botulinum, which can rupture nutrient cells and improve food safety while ensuring food color.

     The antioxidant properties are also one of the important biological activities of red yeast rice. It can eliminate free radicals and has potential positive significance in human health, such as helping to reduce the damage of free radicals to cells and prevent the occurrence of some chronic diseases; In food processing, it can also delay the oxidation and deterioration process of food to a certain extent, maintaining the quality and color stability of food.

     In addition, red yeast rice also shows potential anti-cancer, anti obesity, and lipid-lowering effects. Some of its components, such as Monacolin K, can inhibit cholesterol synthesis, regulate blood lipid levels, and reduce low-density lipoprotein cholesterol (LDL-C) levels in the blood, thus playing a positive role in the prevention of cardiovascular diseases. These biological activities make Monascus not only a simple coloring agent, but also a natural substance with health benefits, further enhancing its application value in fields such as food and medicine.

     4、 Application Fields of Monascus Red (II) Pharmaceutical Field

     （1） Food sector

     Application of meat products

Red yeast rice is widely used in meat products such as sausages and ham. It can replace nitrite as a coloring agent, providing a stable natural red color. It also has antibacterial effects, can inhibit harmful microorganisms, and extend shelf life. Research has shown that using it in fermented sausages can reduce the amount of nitrite used, without affecting sensory and storage properties, allowing consumers to eat healthily.

     Seasoning application

     Red yeast rice plays an important role in soy sauce production, as it can increase the redness index and improve the flavor. Adding saccharified and aroma enhancing yeast rice containing red yeast rice can improve the utilization and yield of raw materials, resulting in a better color and taste of soy sauce.

     Alcohol application

     Red yeast rice is widely used in alcoholic beverages such as red yeast rice wine, making it attractive in color, rich in aroma, mellow in taste, unique in flavor, and rich in nutrients. It is highly loved by people like Danxi red yeast rice wine.

     Application of pickled vegetables

     When pickling vegetables, red yeast rice can be used as an external pigment, which can penetrate into the inside of the vegetables through physical adsorption to change color and enhance appearance. For example, when pickling carrots, it can make them more vibrant.     

     Noodle products application

     Red yeast rice is commonly used and has good effects in bread, biscuits, pastries and other flour products. Adding red yeast extract to bread production can improve its color, aroma, and taste. In the production of biscuits and pastries, red tones can be added to the product to enhance visual effects.

     （2） Medical field

     Red yeast rice is not only used for coloring in medicine, but also contains ingredients that have health benefits such as regulating cholesterol and protecting cardiovascular health. For example, Monacolin K can inhibit cholesterol synthesis, regulate blood lipids, and reduce low-density lipoprotein cholesterol levels, which has a positive effect on the prevention of cardiovascular diseases. It is used in some drug assisted treatments for related diseases and has unique value.

     （3） Cosmetics field

     In the cosmetics industry, red yeast rice can be used as a coloring agent to add natural and healthy colors to cosmetics. It is derived from the fermentation product of natural Monascus, which is more in line with consumers' pursuit of natural and safe cosmetic ingredients than chemical synthetic pigments. It can be used in lipstick, powder blusher and other cosmetics to produce unique colors, reduce the risk of skin allergy, and has good application potential.

     5、 The health benefits and potential risks of red yeast rice

     （1） Health benefits

     Red yeast rice has multiple benefits for human health. In terms of regulating blood lipids, Monacolin K can inhibit cholesterol synthesis, reduce low-density lipoprotein cholesterol levels, and help prevent cardiovascular diseases. Moderate intake of red yeast red foods by middle-aged and elderly people can maintain cardiovascular health. In terms of antioxidant properties, it has strong antioxidant activity, can eliminate free radicals, reduce cell damage, protect overall health, and delay skin aging. It also has anti-inflammatory effects, which can assist in relieving discomfort symptoms in people with chronic inflammation, and traditional medicine has the effects of harmonizing qi and blood, promoting blood circulation, and removing blood stasis.

     （2） Potential risks

     Red yeast has potential risks. Excessive intake can cause gastrointestinal discomfort and some people may develop allergies. Long term excessive intake can increase the burden on the liver and damage it. Eating foods containing red yeast should be consumed in moderation, paying attention to food labels, monitoring bodily reactions, and seeking medical attention promptly if feeling unwell. Special populations should be cautious and seek medical advice if necessary.

     6、 Storage and usage precautions for red yeast rice

     （1） Storage conditions

     Red yeast requires a low-temperature, dry, and dark environment for storage. Low temperature can maintain chemical stability if stored in a cool indoor area below 25 ℃ or in a refrigerator (around 2-8 ℃). A dry environment is crucial, as high humidity can cause clumping, affect the effectiveness of use, and even breed microorganisms. Sealed storage cabinets with desiccants can keep them dry. Dark storage should not be ignored. Exposure to direct sunlight or prolonged natural light can affect color stability. Using opaque packaging materials or placing in a dark place can avoid adverse effects of light exposure.

     （2） Key points for use

     The use of red yeast requires precise adjustment of dosage, with different usage requirements in different scenarios. Excessive or insufficient dosage can be problematic. To ensure sufficient dissolution, it is easy to dissolve in neutral and slightly alkaline aqueous solutions. It can be dissolved in warm water or suitable solvents. The solubility decreases in acidic environments. When encountering strong acidic media, the acidity or alkalinity should be adjusted or special addition methods should be used. In addition, external factors such as light and temperature affect the color. During production and processing, it is necessary to avoid light and control the temperature well. High temperature processing can use methods such as low-temperature frying to ensure stability.