Nitrate and nitrite, as long-standing additives used in food industry and particularly prevalent in meat products, are often perceived negatively by consumers due to their potential to produce carcinogenic nitrosamines. Within the past decades, the importance of nitric oxide (NO) has been established for human health, including cardiovascular health, immunizing and defending system, skeletal muscle contraction and relaxation, nervous system, and cognitive function. Gradually, nitrate and nitrite, as the main NO donors, have also been demonstrated to have numerous health benefits in clinical studies. Likewise, NO has showed positive effect on postharvest fruits and vegetables. In view of different controversies, this review comprehensively discussed the effect of nitrate, nitrite on meat products and NO on fruits and vegetables, the intake of nitrate and nitrite by diet, the physiological functions, synthesis and metabolism of nitrate, nitrite, and NO in human body. It is hoped to provide some new understanding for nitrate, nitrite, and NO in food preservation and human health.

In this study, gelatin type A microspheres (GAMs) and gelatin type B microspheres (GBMs) loaded with sodium nitrite (NaNO₂) were prepared by emulsification cross-linking method, their physical and chemical characteristics were characterized, and their effect on the quality preservation of beef jerky and pork jerky was explored. The results showed that the particle size of the microspheres was 25–40 μm. With the increase of TGase concentration, the elastic modulus and viscous modulus of the microspheres increased, showing a viscoelastic internal structure like a solid. At the same time, it was found that the microspheres had a good preservative effect on beef jerky and pork jerky, and GAMs was more effective than GBMs, which may be closely related to the high encapsulation rate of NaNO₂ and the release of NO from GAMs.