What are the alternative solutions for meat colorants?

Nitrate, nitrite as meat products coloring agent, which plays an important role in the production of cured meat production process, is conducive to improving the color of meat products, so that meat products show bright rose red, can effectively inhibit the growth of certain spoilage bacteria and pathogenic bacteria (Staphylococcus aureus and Clostridium botulinum) [1].
Although nitrates and nitrites are nationally recognized and permitted food additives, it plays an important role in the preparation of meat products [2]. However, the acute and chronic hazards it brings cannot be ignored. Nitrates are unstable and easily oxidized to nitrites, and excessive nitrites entering the bloodstream can make the tissues hypoxic, with a short latency period, and in severe cases, death due to respiratory failure [3].
In 1954, after Barnes and Magee found that dimethyl nitrosamine is a serious carcinogen to humans, FAO/WHO set the ADI for nitrite at 8 mg/60 kg body weight [4]. The strong carcinogenicity of traditional meat colorants has made the search for new, safe meat colorants with reduced toxicity to humans a focus of attention. So far, nitrite substitutes have been sought in the following two ways. First, the search for additives that can replace nitrite (e.g., coloring agents, polyvalent chelating agents, antioxidants, bacteriostatic agents and their compounds);
Second, adding substances that can block nitrosamine formation (e.g., sorbic acid, ascorbic acid, sorbitol, and their complexes) in the case of adding traditional coloring agents [5].
Natural food substitutes i. Egg yolk powder Egg yolk powder is one of the new meat coloring agents. Firstly, Chen Baomei [6] invented the use of egg yolk powder instead of nitrite as a meat product coloring agent and applied to fish and livestock meat. The egg yolk powder used is made from fresh eggs, which is freeze-dried or spray-dried and other processes to make a powder (containing a large amount of hydrogen sulfide, and its coloring mechanism is believed to be that hydrogen sulfide in egg yolk powder has a similar function to nitrite (easy to combine with myoglobin), and it shows a bright red color.
The 5%~15% egg yolk powder, moderate amount of salt, ascorbic acid, etc. in the pickle solution impregnated with 3~50 h, can make the meat products coloring good, bright color. Add appropriate amount of salt, sugar, ascorbic acid, sorbitol, etc. to promote coloring and shorten the impregnation time; due to the size of the form of the product, the purpose is different, select the appropriate impregnation time.
The color of pork cured in a pickle solution made from 9% egg yolk powder and appropriate amounts of ascorbic acid, salt, sorbitol, and water was similar to that of ham cured with 250 mg/kg of sodium nitrite, but there was no nitrite residue. However, the sodium nitrate residue of cured meat using sodium nitrite was 35 mg/kg, making it obvious that curing with egg yolk powder is safe and feasible [7]. Second, celery powder celery contains a variety of vitamins, minerals and flavonoids, is a kind of natural nitrate resource base, nitrate content of 2100 mg/kg. Ren Xiaoqing et al [8] studied three kinds of fermented celery powder instead of nitrite to produce air-dried sausage, and the results showed that in the production of air-dried sausage, the fermented celery powder can be used instead of nitrite for the coloring and antioxidant effects.
The research team of Tianjin Agricultural College studied more on celery powder, Liu Caihong et al [9] found that the three celery powders FCPmlz, FCP506, and FCP504 can play a good antioxidant role and inhibit the production of volatile saline nitrogen. All the celery powders blocked the synthesis of N-nitrosamines and the difference between the color of meat products and the use of nitrate coloring was almost negligible.
Sebranek J G et al [10] found that celery powder contains about 3% nitrate, will be 0.2% to 0.4% of celery powder added to meat products can maintain good color and flavor of cured meat products, excess will produce off-flavors, it can be seen that celery powder can be used as an alternative to nitrites for meat products coloring, bacteriostatic and antioxidant effects. Third, natural seasoning onion, garlic, onion is a natural seasoning. Ginger has anti-fat oxidation effect, the active ingredient is curcumin and hexahydrocurcumin, which can prevent the oxidation of fats and oils. The chemical component S – chain allyl cysteine sulfoxide in garlic and its sulfur-containing components, such as diallyl disulfide and diallyl trisulfide can inhibit the growth of nitrate-reducing bacteria [11].
Garlic produces allicin (an antifungal compound) when sliced. Turmeric inhibits Staphylococcus aureus & Clostridium botulinum and has powerful antioxidant properties comparable or even superior to nitrite and ascorbic acid [12].
Pigment substitutes I. Erythroxanthin pigments Erythroxanthin pigments, or erythrochromes, are secondary metabolites of Aspergillus oryzae. Red yeast pigment is a safe, non-toxic and efficient pigment with excellent properties such as high temperature resistance, oxidation resistance, pH stability and unique protein coloring effect.
It has good antibacterial and antimicrobial effects in fermented sausage production, and is effective in the development of low-nitrogen meat [13]. Yao Bo et al [14] directly used the red currant pigment as a coloring agent instead of nitrite for curing preserved sausage, and the results showed that the effect was similar to that of adding sodium nitrite at a mass concentration of 0.15 g/kg when adding red currant pigment at 0.03 g/kg.
As a coloring agent for meat products, the high production cost of erythrocyanidin, the purification and light stability of erythrocyanidin, as well as the potential hazards in erythrocyanidin (oryzanamycin) are the main roadblocks affecting the expansion of the application of erythrocyanidin. Therefore, in-depth research on the deep fermentation process of Aspergillus oryzae to improve the content of functional red currant active ingredients and the light stability of red currant red pigment is an urgent problem to be solved in the red currant industry [15]. Second, beet red beet red, also called beet red, is a natural pigment, the main components of beet anthocyanin and beet flavin. Tests have shown that the addition of beet red 32 mg/kg of samples, and the addition of 50 mg/kg nitrite sample control color is similar, but the flavor is slightly worse; can be optimized by adding a certain amount of ascorbic acid. However, beet red is not heat stable, so tea extract and ascorbic acid need to be added to improve its heat stability [16].
Sebranek J G et al [17] used spray dried Swiss chard powder as a natural source of nitrite with the advantage of being allergen free. Beet powder is similar to celery powder and should be used in a certain concentration; excess can lead to contradictory effects. Third, lycopene lycopene is a natural carotenoid present in tomatoes, watermelon, peppers and other fruits and vegetables with deep red crystals, high safety, natural coloring hue, and a variety of health functions, such as antioxidant, lipid-lowering, immunity enhancement, cancer prevention, etc [18-19].
Lycopene, with its color-presenting and antioxidant effects, is at the same time easy to oxidize and isomerize, with poor stability, which severely limits its application. And lycopene-rich tomato paste, tomato powder, tomato peel and other tomato products than lycopene pure product is much more stable, and tomato products are acidic, can slow down the growth of microorganisms, improve the storage stability of the product and improve the good flavor and good color, and therefore, the lycopene and its products for the study of nitrite substitutes to provide a possible. Fourth, cochineal red cochineal red is extracted from the rind of the cochineal tree red-orange-yellow natural pigments. Carmine red is stable to heat, light and oxygen, safe and non-toxic, without any mutagenic, carcinogenic and genotoxic effects. Some studies have found antimicrobial activity of cochineal extract against Clostridium perfringens and Clostridium botulinum strains with inhibitory effect [20-21];
Zarringhalami S et al [22] found that the use of cochineal partially replaced nitrite as a sausage coloring agent in sausages, and the test found that samples containing 60% cochineal had the best color, but did not show any advantage in microbiological and sensory aspects. V. Nitrosohemoglobin Nitrohemoglobin is the use of hemoglobin of livestock blood, synthetic production of nitrosohemoglobin. Huang Qun et al [23] found that: nitrosohemoglobin heat insensitive, but sensitive to light, oxidants, divalent iron ions; change the pH value of nitrosohemoglobin has a certain degradation; most of the metal ions, food additives and nitrosohemoglobin does not react.
Nitrosohemoglobin as a coloring agent to replace nitrite added to meat products, can realize the development of low-nitrogen, nitrate-free meat products. At the same time, animal blood (containing protein, vitamins, biological enzymes, trace elements, etc.) can be effectively utilized, making the products high-quality and nutrient-rich. Therefore, nitrosohemoglobin as meat coloring agent is undoubtedly a hot research topic at home and abroad [24].
Other substances
I. Carbon monoxide is widely used at home and abroad as a new type of gas coloring agent, especially for the processing of red meat such as livestock and poultry. The color of meat mainly depends on the myoglobin content and the form of its existence [25].CO is extremely stable after combining with myoglobin, which results in better coloring and color protection.
At present, the use of CO direct or indirect treatment of animal products so that the product color is good, the main way to use gas-conditioned packaging, meat to be processed placed in the bag color, such as meat into the gas-conditioned bags containing CO, can make the product effective preservation period from the original 3 ~ 7 d to 15 ~ 30 d, the technology has been applied in a large number of beef products. Second, tea polyphenols tea polyphenols have excellent antioxidant function, is an excellent natural food antioxidant. Sun Jingxin et al [26] added salt, nitrite, tea polyphenols, Vitamin C to partially replace nitrite in chicken breast, to study the effect of color protection under different conditions. The results showed that the combination of nitrite, vitamin C and tea polyphenols could promote the color development of chicken meat products and effectively protect its color; however, its color development and color protection effects were still affected by some factors, such as temperature, light, oxygen, cooking and heating or not, and other processing or storage conditions.
Yao Hongliang et al [27] investigated the effect of different combinations of coloring agents (ascorbic acid, tea polyphenols, egg yolk powder, red color pigment and other coloring (auxiliary) agents to form a certain combination) on the sensory and sodium nitrite residue of Cantonese-style bacon. The results showed that the addition of 0.3% tea polyphenol, 7% egg yolk powder, 0.04% red yeast red formula group of bacon coloring and very low sodium nitrite residue. Visible. Tea polyphenols and other additives can enhance the mixed use of its color protection and color effect. Third, amino acids add 0.3% of the amino acids and peptides of the conjugate and with 10 × 10-6 of sodium nitrite or 0.5% of lysine salt and arginine mixture in equal amounts, can make the meat products with good color. It can be seen that amino acids have the potential to significantly reduce the amount of sodium nitrite.
Compound formulation alternatives I. Sodium carbonate and five-carbon sugar Kou Deyun [28] found that the addition of sodium carbonate and five-carbon sugar (xylose), adding 10% to 30% nicotinic phthalic acid or Vitamin C as a coloring aid in pork, beef and poultry ham; as amino acids can accelerate the speed of the coloring reaction, which contains sulfur-containing amino acids are the most effective. Therefore, the addition of sulfur-containing amino acids to help color and ease the phenomenon of discoloration, the color effect of the products obtained with nitrite, nitrate similar, and high security. Second, ethyl malt phenol and iron citrate ethyl malt phenol is the use of starch fermentation prepared by a flavor enhancer, iron citrate is a nutritional enhancer. In meat processing, do not add nitrite, but in a process to add ethyl maltol, iron citrate, the effect of the same color with the use of nitrite, and can be long-term color protection. The reaction of maltol with amino acids increased the flavor of meat. Liu Dengyong et al [29] found that iron citrate and maltol applied as a coloring agent for the inner meat of roasted leg of lamb had a good and stable coloring effect. Third, L – ascorbic acid and nicotinamide L – ascorbic acid and nicotinamide are more commonly used food coloring additives. In the processing of meat products add nitrite at the same time, add L – ascorbic acid and its sodium salt, nicotinic phthalamide mixed use, can make the meat products show good color. The amount of ascorbic acid used is usually 0.02% to 0.05% of the raw meat, and the amount of nicotinic phthalamide added is 0.01% to 0.02%, or the raw meat can be immersed in an aqueous solution of 0.02% of the mixture during marination [4]. Fourth, other Yao Hongliang et al [27] test confirmed that tea polyphenols, egg yolk powder, red currant red compound use can obtain good coloring effect. Some tests have confirmed that nitrite, tea polyphenols, vitamin C can partially replace nitrite, and the product coloring effect is consistent.
Liang Chengyun et al [30] by adding red currant red pigment, sorghum red pigment and sodium nitrite complex to the sausage. The results showed that the use of three pigments: sorghum red pigment 0.08 g/kg, red currant red pigment 0.03 g/kg, and sodium nitrite 0.01 g/kg had the best coloring effect of the formula used and reduced the use of sodium nitrite in sausages to achieve the processing of low nitrate meat products.
Biological coloring agent Biological coloring agent has gradually become a research hot spot in recent years. At present, biological coloring agents mainly include salt-resistant lactic acid bacteria and lactobacilli and staphylococci. Lactobacilli are non-spore producing G+ bacteria that can utilize Cm(H2O)n and produce lactic acid, and their application in food has become popular in recent years [31], and the application of lactobacilli as additives in meat products include ham, luncheon meat, and grilled sausage.
Salt-tolerant lactic acid bacteria applied to cured meat processing can inhibit the growth of spoilage bacteria, effectively improve the storage performance of meat products, reduce the generation of nitrite, and good coloring, but also to the cured meat products bring a unique flavor. Therefore, the addition of lactic acid bacteria as a coloring agent in meat processing has a certain degree of research.
Streptococcus lactis (Nisin) is a peptide, as a preservative, with natural, efficient, non-toxic characteristics, for food spoilage bacteria in the Gram-positive bacteria have a good bacteriostatic effect, but its antimicrobial spectrum is narrow, so it can not be a single alternative to nitrite. Staphylococcus meat is widely used in fermentation of meat products, with nitrate reductase activity, at 15~200 ℃ can be nitrate reduced to nitrite, 300 ℃ when the conversion efficiency is higher. Staphylococcus meatus can convert high iron myoglobin into red myoglobin derivatives in both culture medium and meat substrate. Some scholars have inoculated staphylococci in sausages to partially replace nitrite and observe the color of sausages, and the color of sausages obtained is good.
Conclusion The study of alternatives to nitrite in meat products has been carried out by a large number of researchers. However, so far no single substance has been found to replace the role of nitrite in cured meat products, and the current research results are limited to a single replacement of nitrite’s bacteriostatic effect or coloring effect. The effect of composite additives is relatively better than that of single substance.
Based on natural flavors, natural pigments, biological bacteria (staphylococci, salt-resistant lactic acid bacteria) in part to replace nitrite as meat coloring agent is feasible, the future of meat coloring agent research can try to natural flavors, natural pigments and biological bacteria compound use or to find other new meat biological bacteria and their metabolites as a coloring agent, with a view to achieving the coloring, low-nitrogen, safety, and even to reduce the cost of meat production, increase the cost of meat products. To achieve the purpose of coloring, low nitrate, safety, and even to reduce the production cost of meat products, increase the taste and flavor of the product.