Emerging Applications of Hyaluronic Acid

Hyaluronic acid (HA) is a glycosaminoglycan composed of D-glucuronic acid and N-acetylglucosamine, with unique molecular structure and physicochemical properties. Hyaluronic acid is widely present in human joint cavity, skin, vitreous body and other tissues. However, with the increase of age, its content in the human body gradually decreases, which can lead to many problems such as arthritis, skin aging, increased wrinkles, blurred vision, etc.

Research results analysis

01 Revealing the potential of HA: exploring its physicochemical properties, modification and its role in food applications

Background

Hyaluronic acid (HA) is a glycosaminoglycan composed of D-glucuronic acid and N-acetylglucosamine, with unique molecular structure and physicochemical properties. It has been shown to be non-immunogenic, biocompatible and biodegradable. In food processing, HA exhibits hygroscopicity, viscoelasticity, film-forming ability and antioxidant properties. These remarkable properties make it a very promising candidate for enhancing the functional properties of food.

Scope and approach

This paper reviews the physicochemical properties, solution properties, synthesis and degradation of HA. In addition, this review also provides an in-depth discussion of the research progress in HA modification, focusing on the research progress in chemical modification, enzymatic modification and physical modification of HA functional groups. In addition, the review also explores the various applications of HA in the food industry.

Key findings and conclusions

HA is well known for its unique physical and chemical properties and is widely used in non-food technology fields. Recently, its application has been extended to the food industry. There are many options for creating new derivatives by modifying the functional groups of HA, changing its conformation, or combining with biopolymers. Currently, HA has been approved by many countries as a new food ingredient, additive, health food or dietary supplement. In addition, the study also explores the application of HA in food, including nutritional supplementation, food safety testing, food packaging, food delivery system and food quality improver. Overall, HA shows great potential in the food industry in terms of enhancing the functional properties of food.

Conclusion

In the past few decades, research on HA has achieved remarkable success due to its unique biodegradability, biocompatibility, viscoelasticity and water absorption properties. With the continuous emergence of new technologies, various modification methods provide a wide range of options for the synthesis of new HA derivatives with different physicochemical properties. Due to its multifaceted properties, it has been approved as a functional food, food ingredient, additive or dietary supplement and has been widely used in many countries. Therefore, the research scope of the Drug Administration has expanded to the fields of nutritional supplementation, food inspection, food packaging materials, food delivery systems, and food quality improvement. However, the potential value of HA remains largely untapped. In order to fully realize its potential, further research and technological advances are needed to develop new HA derivatives, design food and drug delivery systems, explore the physicochemical stability mechanism of HA in food processing, improve the biocompatibility of HA, and thoroughly evaluate the safety and efficacy of HA products.

02 Conformational entropy of hyaluronic acid helps enhance taste

Abstract

Natural flavor/flavor enhancers are essential ingredients to potentially address the overconsumption of condiments. This study reports that hyaluronic acid (HA) can modulate taste, which is controlled by the dynamic interaction between taste compounds, mucins, and HA. Various conformations of HA affect taste perception. The high molecular weight (Mw) of 1090 kDa HA inhibited taste perception due to its increased viscosity and hindered Na+ penetration into the mucin layer. Both medium and low molecular weight (100, 400 kDa) HA enhanced taste perception. Isothermal titration calorimetry confirmed that mucins bound HA more strongly. As the molecular weight increased from 8 kDa to 400 kDa, the strength of their interaction increased. The quartz crystal microbalance with dissipative properties further showed that the rigid conformation of 100 kDa HA facilitated Na+ binding to taste receptors, thereby enhancing taste perception. The flexible conformation of 400 kDa HA may hide taste receptor cells and reduce taste enhancement. This work promotes the understanding of the conformational entropy of natural mucus adhesion and mucus penetration polymers, which lays the foundation for their potential application as taste enhancers.

Conclusion

HA with low molecular weight (such as 100 and 400 kDa) can effectively enhance salty and sweet taste characteristics and prolong the taste perception time. The rigid rod-like conformation of 100 kDa HA has a stronger binding affinity to mucin, allowing more Na+ to contact taste buds, while the elastic random coil conformation of 400 kDa HA has the opposite effect. The inhibition of taste may be related to the higher molecular weight of HA, such as 1090 kDa. Higher viscosity and chain entanglement will hinder the penetration of Na+ ions through the mucin layer. The experiment focused on the interaction between mucin and HA in complex food systems and gastrointestinal environments in vivo. In summary, the experiment demonstrated the importance of conformational entropy for studying HA interactions and improving taste from a basic and applied perspective. These results lay the foundation for the use of natural mucus and mucus permeable polymers as taste enhancers.

03 Effect of different concentrations of hyaluronic acid on the gelatinization and microstructural properties of corn starch

Abstract

Starch aging is a major issue affecting the quality of starchy foods. In order to improve the viscosity and texture of natural starch gelatinization and retrogradation, the effects of different concentrations of hyaluronic acid (HA) (2%, 4%, 6%) on the gelatinization and microstructure of corn starch (CS) were studied. The results showed that the addition of HA significantly increased the peak viscosity, solubility and water holding capacity of CS-HA blends. It also reduced the gelatinization temperature, swelling power and leaching rate of amylose. All blends showed shear thinning and rheological properties. The CS-HA blends formed thicker pseudoplastic systems and significantly enhanced shear stability. The structures of the blends were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. HA can effectively inhibit the short-term aging of starch, enhance the interaction between CS and HA, and form a dense honeycomb three-dimensional network structure. In summary, HA, as a new type of anionic hydrocolloid, has great potential in improving the retrogradation properties of starch products.

Conclusion

In this study, the effects of different concentrations of HA on gelatinization properties and CS microstructure were investigated. The addition of HA increased the peak viscosity and breakdown value during the paste process, while reducing the paste temperature and desizing value. The WHC was positively correlated with the amount of HA added, and the CS-HA blend containing 6% HA had the highest WHC, which may be due to the higher water retention capacity of HA. In addition, the coating of HA on the surface of starch granules prevented the leaching of amylose, and the hydroxyl and carboxyl groups of HA formed hydrogen bonds with amylose, effectively reducing the rate of starch retrogradation. The addition of HA did not form new covalent bonds, but the hydrogen bonds and electrostatic interactions between CS and HA improved the short-range order of starch. SEM observed the presence of a dense honeycomb network structure in the mixture, indicating that the interaction between HA, starch and water delayed the retrogradation of CS by hindering the recombination of starch. In addition, the addition of HA enhanced the solubility of the mixture and reduced the hysteresis loop area, and the effect was most significant when the HA addition was 6%. In summary, these findings provide valuable insights into the interaction between CS and HA and highlight the potential of HA as a functional additive to improve corn starch modification. However, in order to expand its application in the food industry, further research is needed on the effects of HA on human digestibility and food sensory properties.

04 Application of hyaluronic acid as a natural flavor enhancer and its mechanism

Abstract

Creating natural flavor enhancers is a promising approach to reduce excessive seasoning consumption. This study aimed to determine whether food-grade hyaluronic acid could be a viable option to reduce salt content in low-sodium foods without sacrificing saltiness. Using an artificial tongue and quartz crystal dissipation microbalance (QCM-D), the effects of hyaluronic acid (HA) with different molecular weights (100 kDa, 400 kDa) and concentrations (0.2%, 0.4%) on the perception of salinity in NaCl solutions were investigated. HA was confirmed to have a taste-enhancing effect. Furthermore, when added to pre-prepared dishes such as Sichuan fish and black pepper steak, HA was found to reduce salt addition by at least 10% to maintain the saltiness of the samples. The hydrogel artificial tongue simulation results showed that Na+ adhesion was positively correlated with the molecular weight and concentration of HA. The QCM-D results supported this finding, indicating that 100 kDa HA allowed Na+ to more easily penetrate the oral mucosal layer, thus showing a stronger salty taste perception compared to 400 kDa HA. ​​In conclusion, the adhesion and mucus permeability of HA make it a substitute for traditional seasonings and contribute to people's pursuit of healthier eating habits.

Conclusion

This study found that adding HA to steak, black pepper sauce, sour fish, and sour fish sauce packets can reduce the salt content in the formula by 10% without affecting people's perception of saltiness. This means that HA can be used to develop low-salt foods and effectively reduce salt intake without affecting taste. This study also preliminarily explored the molecular mechanism of HA in reducing salt content without reducing salt concentration, and found that the addition of HA can prolong the time Na+ stays on the oral mucosa, and 400 kDa HA has stronger adhesion than 100 kDa HA. ​​The binding force between HA and mucin is mainly hydrogen bonding and van der Waals force, which increases with the increase of molecular weight. Long-chain HA polymers provide more binding sites, resulting in stronger intermolecular interactions. Compared with flexible helical HA (400 kDa), rigid rod-shaped HA (100 kDa) has stronger binding to the mucosal layer. Therefore, this increase in affinity promotes the contact between Na+ and taste buds, effectively enhancing taste perception. As an innovative food flavor enhancer, HA has the potential to assist individuals in pursuing healthier dietary choices.