Vol. 1 No. 1 (2023)

Food is the foundation for human survival and healthy development. People need to eat every day, and obtain the essential nutrients from food in order to promote body growth and development through biochemical process such as digestion, absorption and metabolism. With the increasing concern about health and nutrition, people gradually realize that the nutrients contained in food are critical to our physical functions and overall well-beings. To formulate a proper diet plan, prevent diseases and keep good health, it is critical for us to have a thorough understanding of the nutritional ingredients, functions and chemical interactions of food. Food Nutrition Chemistry is a comprehensive interdisciplinary science, focusing on the nutrients contained in food and their impact on human health, which plays an important role in the field of life and health.

Globally, humans are at risk of increasing incidence of metabolic diseases, the occurrence of which is closely linked to people’s daily diet. Fruits and vegetables are among the important daily food types for people. Varieties of plants’ secondary metabolites are contained in fruits and vegetables, including phenolic acids, flavonoids, anthraquinones, terpenoids, alkaloids, steroidal saponins, and polysaccharides. These metabolites usually have multiple bioactive functions, such as antioxidant, antitumor, hypoglycemic, hypolipidemic, neuroprotection, anti-inflammatory, antibacterial, and disease prevention, which are of great importance in preventing the occurrence of human metabolic diseases. However, the composition, content, bioactive functions, and mechanisms of action of these metabolites in different types of fruits and vegetables vary greatly. The progress of the research on the main bioactive components of fruits and vegetables and their multi-functions is reviewed in this paper to promote people’s understanding and utilization of the functional components of fruits and vegetables.

Fruits and vegetables are an indispensable part of a healthy diet due to their rich nutrients. However, fruits and vegetables are not suitable for preservation after harvest, and their losses account for nearly half of the total global food losses. One of the most important reasons is that ethylene is still biosynthesized after fruits and vegetables are picked, accompanied by the respiratory climacteric of fruits and vegetables. As a plant hormone, ethylene can cause fruits and vegetables to overripe, soften, and rot after harvest. Therefore, the control of ethylene in the environment where fruits and vegetables are stored is of great significance to prolong the shelf life of fruits and vegetables and reduce economic losses. This paper reviewed the research progress of ethylene resistance control methods and their applications in the regulation of fruit and vegetable preservation and provides a reference for the further development of green, efficient, safe, and economical ethylene resistance control methods and technical applications.

Arsenic speciation in food and diet was assessed for human exposure through dietary approaches because it seems as a critical public health issue all over the world. Globally, rice is a vital commodity in world hunger and vastly important for survival of human race. Rice is widely used for the formulation of baby formulas, breakfast cereals, bread, cookies, cakes, rice drinks and other foodstuff. Arsenic is concentrated at higher rates in rice grains and containing more than 85% of total arsenic forms that poses serious health aliments o human as well as animal life on the planet. Meanwhile, Arsenic contaminated water and soil may induce hazardous affects to humans through water-soil-plant pathway.

Nicotinamide mononucleotide (NMN) is an endogenous substance in humans with high safety and thermal stability, and its application in cosmetics, medical health, and functional foods has received widespread attention. However, the synthesis process of NMN has problems, such as high cost, time-consuming process, and low yield, which limits the large-scale industrial application of NMN to a certain extent. Nicotinamide phosphoribosyl transferase (Nampt) is a critical enzyme in the technical route of the biological synthesis of NMN, which can catalyze the synthesis of NMN using nicotinamide and phosphoribosyl pyrophosphate. The screening and expression of Nampt with excellent enzymatic properties and stability is the key to the synthesis of NMN via this method. At present, the main problems in the technical route of NMN production using Nampt are that the catalytic activity of Nampt is low and the sources of Nampt are limited. In this study, we isolated Enterobacter chengduensis 2021T4.7, a microorganism with a high NMN production, and optimized its fermentation condition. The yield of NMN was up to 67.66 μM. In addition, we synthesized Nampt and constructed related recombinant high-yield engineered bacteria. We semi-rationally designed a Nampt structure derived from mice and obtained mutant mNampt-V365L with NMN yield as high as 135.99 μM, which increased by 62% from that of the wild type. Here, we screened high-NMN-yield natural strains and obtained high-NMN-yield strains through the semi-rational design optimization of Nampt enzymes, which provided new chassis microorganisms and new ideas for the conversion rate of NMN.