# Advances in the Study of Bioactive Compounds and
## 2 Nutritional Composition of Goji Berry
Prebiotics are non-digestible food components that selectively stimulate the growth or activity of beneficial gut bacteria. The fiber in goji berries may serve as a substrate for these beneficial bacteria, potentially contributing to improved gut health and overall well-being. **Variation in nutritional composition due to geographical origin and cultivation practices. ** While the nutritional profile of goji berries is generally impressive, it is important to note that significant variations can occur based on geographical origin, cultivation practices, and processing methods. These variations can affect both the macronutrient and micronutrient compositions of the berries, as well as their content of bioactive compounds. Geographical origin plays a significant role in determining the nutritional composition of goji berries. For instance, [PERSON] et al. [27] analyzed Goji berries from Inner Mongolia, Ningxia, and Xizang using non-targeted LC-qTOF-MS metabolite profiling. The Inner Mongolia goji berries were characterized by significantly higher levels of several flavonoid glycosides, including quercetin and kaempfer glycosides, as well as isomers of dicaffeoylquinic acid and phenolic acids such as coumaric acid. These compounds were the most discriminative metabolites for the Mongolian variety, which also appeared as the most distinct group in the PCA analysis. Chinese goji berries, on the other hand, were found to contain higher levels of citric acid, chlorogenic acid isomers, and N-hydroxy-L-tyrosine (Figure 3). In our previous study [28], the electrochemical behavior of 2-O-(\(\beta\)-D-glucopyranosyl) ascorbic acid, a vitamin C analog, was investigated using a glassy carbon electrode. The study established an analytical method for detecting 2-O-(\(\beta\)-D-glucopyranosyl) ascorbic acid based on its electrochemical oxidation signal. This method allowed for linear detection in the range of 100 nM to 300 \(\mu\)M, with a detection limit of 30 nM (S/N = 3), demonstrating higher sensitivity compared to previously reported HPLC methods. The oxidation potential of 2-O-(\(\beta\)-D-glucopyranosyl) ascorbic acid was found to be 0.84 V, significantly higher than that of ascorbic acid, indicating its greater stability. The study also revealed that the oxidation process was controlled by diffusion, with the current increasing proportionally with the scan rate. The results suggested that 2-O-(\(\beta\)-D-glucopyranosyl) ascorbic acid could serve as a reliable indicator for the quality of goji extracts. Additionally, a pesticide compound, acetamiprid, was detected predominantly in the Chinese goji berry extracts, highlighting a unique aspect of their chemical profile. Tibetan goji berries exhibited variability between the two regions studied. The Tibetan T1 variety was characterized by metabolites such as acetyl tryptophan, 10-deoxygeniposidic acid, and ferulic acid hexose. The Tibetan T2 variety, meanwhile, contained late eluting compounds like myristic acid and other low-molecular-weight short-chain fatty acids. Our previous study explored the feasibility of using electrochemical fingerprinting techniques to identify the geographical origin of goji [29]. We collected samples from various locations and different varieties, including Ningqi-1 and Ningqi-7. They recorded electrochemical fingerprints using differential pulse voltammetry (DPV) in two buffer solutions, phosphate buffer saline (PBS) and acetate buffer saline (ABS). The results showed that while the electrochemical behaviors of a single variety grown in different regions were similar due to genetic control, subtle differences in the fingerprints allowed for geographical differentiation. For instance, the Ningqi-7 samples from Qinghai Province exhibited higher electrochemical responses, indicating a greater accumulation of electrochemically active substances compared to samples from other regions.