Cinnamaldehyde, also known as cinnamaldehyde, cinnamaldehyde, β-benacrolein, or 3-phenyl-2-propenal, is an aldehyde organic compound found in essential oils such as cinnamon oil, rose oil, and patchouli oil.

Its chemical name is triphenyl acrolein with the molecular formula C9H8O, and at atmospheric pressure, it has a melting point of -8°C and a boiling point of 253°C, and exists as a liquid. Cinnamaldehyde has both cis and trans isomers, and all natural cinnamaldehyde is trans structure.

Cinnamaldehyde has a strong and long-lasting cinnamon oil flavor, with antibacterial and antifungal, vasodilating blood vessels and lowering blood pressure and other properties, widely used in medicine, food industry and other fields.

Physiological functions of cinnamaldehyde

Cinnamaldehyde has the effect of lowering blood glucose and blood lipids, and can be used to treat type II diabetes mellitus. Intake of cinnamaldehyde can improve the body’s utilization of glucose and esters, and achieve the purpose of lowering blood glucose and blood lipids.

Research shows that type II diabetes patients taking cinnamaldehyde, its fasting blood glucose, triglycerides, low-density lipoprotein content are significantly reduced.

Cinnamaldehyde can be used in the treatment of anti-cellular fibrosis, research shows that cinnamaldehyde can inhibit high glucose-induced proliferation of renal interstitial fibroblasts hypertrophy and interstitial collagen synthesis and secretion.

Huang Jiangyan studied high glucose-induced rats and found that cinnamaldehyde reduced the proliferation of rat cardiac fibroblasts and inhibited the synthesis and secretion of intercellular collagen.

Cai Leiqin et al. showed that cinnamaldehyde specifically activates the nuclear factor E-2-related factor pathway and promotes the healing of wounds in diabetic mice.

Some studies have shown that cinnamaldehyde can resist peptic ulcers by inhibiting the erosion of gastric mucosa by pepsin and increasing the blood flow rate of gastric mucosa; it can gently stimulate the stomach and intestines, promote the secretion of saliva and gastric juice, enhance the digestive function, promote the appetite, release the spasm of gastrointestinal smooth muscle, and relieve the spasmodic pain of intestinal tract.

Antibacterial effect of cinnamaldehyde

Cinnamaldehyde has a broad-spectrum antibacterial effect, Zhang Wenjuan et al. 22 species, 31 conditional pathogenic fungi for cinnamaldehyde antifungal experiments, the results show that cinnamaldehyde on Aspergillus flavus, Aspergillus fumigatus, Penicillium citrinum and other fungi have a better inhibition effect.

Cinnamaldehyde can make certain bacteria in the body of the reactive oxygen content, produce oxidative damage, and cause their death. Wang Fan et al. cinnamic aldehyde in the role of Escherichia coli and Pseudomonas aeruginosa found that after treatment with cinnamic aldehyde solution, the growth of Escherichia coli is inhibited, the bacteria in the body of hydrogen peroxide, malondialdehyde and other content increased significantly, Pseudomonas aeruginosa cell surface has a bacterial membrane, although not detected in the body of the accumulation of reactive oxygen species, but its growth and metabolism is also affected.

Cinnamic aldehyde can inhibit the growth of bacteria by destroying their structure and normal metabolic function. Cinnamic aldehyde contains aldehyde group, has a certain hydrophilicity, easy to adsorb on the hydrophilic group on the surface of the fungus, on the cell membrane of the chitin synthase and glucan synthase activity has a certain inhibitory effect, thereby inhibiting the generation of chitin and glucose in the cell wall, destroying the polysaccharide structure of the cell wall, inhibiting the growth of the fungus; can also be dissolved in the hydrophobic domains of cell membranes between neighboring lipoyl chains, enhance the permeability of the cell membrane, leading to the death of the fungus. ATP leakage, resulting in bacterial death.

Cinnamaldehyde can inhibit the growth of bacteria by affecting the normal expression of intracellular DNA or RNA. Xie Xiaomei et al. observed and analyzed the DNA and RNA in Aspergillus flavus and Aspergillus fumigatus by laser scanning confocal microscope, and found that cinnamaldehyde could interfere with the synthesis of DNA and the normal metabolism of RNA, which led to abnormal protein metabolism, and could not complete the normal cycle of the cell, and inhibited the growth of the mold. Cinnamaldehyde can block the expression of the key gene FKS, leading to the synthesis of polysaccharide in the cell wall of Aspergillus fumigatus, thus inhibiting the growth of the mold.

Cinnamaldehyde can inhibit the growth of Aspergillus fumigatus by blocking its metabolism. Dai Xiangrong et al. analyzed the optical density and malondialdehyde value of Aspergillus flavus spore extracts under different inhibition modes, and found that cinnamaldehyde could block the metabolic pathway in the growth process by inhibiting the activity of certain enzymes in the cells, which ultimately resulted in the failure of spores to germinate and grow into colonies normally. The functional group of cinnamaldehyde, aldehyde group, can react with the functional groups of proteins in the cell, such as amino group, carboxyl group, etc., which can inhibit or even inactivate the enzyme activity.

Metabolism of Cinnamaldehyde

Sushang conducted animal experiments with cinnamon oil and found that cinnamaldehyde can be rapidly metabolized to cinnamic acid in rats.Sapienza P P et al. showed that large doses of labeled cinnamaldehyde can be excreted as metabolites in the urine and to a lesser extent in the feces, with benzoic acid as the major metabolite.

Cinnamaldehyde is metabolized by several pathways, it can be oxidized to cinnamic acid by NAD-dependent aldehyde dehydrogenase and bound to other salts and excreted; it can also be further β-oxidized or reacted with reduced glutathione to form thioetherine derivatives, which are then bound to other compounds, and finally eliminated from the body, with very few residues in the human body.

Application of cinnamaldehyde in food

Because of its good antibacterial effect, cinnamaldehyde is widely used in food preservation. The main ways of use are: fumigation, preparation of film, emulsion treatment. Wen Xiaoli et al. fumigated the experimental group of shiitake mushrooms with cinnamic aldehyde and found that, compared with the control group, the microbial content of the experimental group was reduced, respiration was slowed down, oxidative damage was reduced, and the reduction of moisture content was slowed down.

All the indicators showed that cinnamaldehyde fumigation treatment could effectively maintain the quality of shiitake mushrooms and play a good preservation effect. Wang Liqiang et al. used cinnamaldehyde and calcium propionate as bacteriostatic agents, combined with potato starch, glycerol, calcium chloride and other substances to prepare an antibacterial edible film, which can effectively inhibit the growth and reproduction of microorganisms in the cooled meat, slow down the loss of moisture, and play a good preservation effect on the cooled meat.

Wang Qingkui et al. prepared cinnamaldehyde nanoemulsion with cinnamaldehyde, Tween 80, ethanol, ethyl acetate and distilled water, and used cinnamaldehyde nanoemulsion and cinnamaldehyde solution with the same concentration of four common aquatic animal pathogens to carry out bacteriostatic experiments, and the results showed that cinnamaldehyde nanoemulsion has better effect.

Li Hongliang et al. used cinnamaldehyde as a food preservative and found that on the basis of reducing the dosage of traditional preservatives, the compounded preservative of cinnamaldehyde has a better preservative and freshness preservation effect.

Cinnamaldehyde has a strong and long-lasting special flavor of cinnamon oil, which is commonly used in food additives. Adding trace amount of cinnamon oil in Chinese soup, coffee, cookies and baked food can increase the flavor of food. Adding cinnamaldehyde to chewing gum can increase the flavor of the gum itself, as well as mask bad breath and remove some oral bacteria.

Prospect

Because of its excellent broad-spectrum antibacterial properties, special aromatic odor, cinnamaldehyde in the food industry plays a preservation of freshness and preservation and improve the flavor and texture of the dual role.

Cinnamaldehyde has fast metabolism and little residue in the human body, and is recognized as a safe and non-toxic food spice by the Flavor and Extract Manufacturers Association of the United States (FEMA), and also recognized as a safe and non-toxic substance by the U.S. Food and Drug Administration (FDA).

In China, cinnamaldehyde is also recognized as a synthetic spice for food, which can be used in meat, candy, chewing gum, seasonings and so on. However, cinnamaldehyde has poor water solubility, strong volatility and strong flavor, which can easily affect the original flavor of food, thus limiting its application in food preservation and antiseptic.

Some derivatives of cinnamaldehyde have the similar properties of cinnamaldehyde, such as cinnamic acid cinnamon flavor is lighter, and has the antibacterial property; some studies have shown that cinnamaldehyde microemulsion can solve the problem of poor water solubility, and has a very good antibacterial effect. Further research and development of cinnamaldehyde derivatives and microemulsion and other related products can better expand the scope of application of cinnamaldehyde.