## 3 Results and Discussion
### Analysis of Volatile Components in NFC Goji Juice  
The ion peaks of all volatile compounds in freshly pressed and processed NFC goji juice were summarised to construct a fingerprint of volatile organic compounds using the Gallery plugin in GC-IMS LAV. This analysis identified differences in volatile compounds between freshly pressed and processed NFC goji juice. As shown in Figure 7, 49 volatile substances were detected by GC-IMS, including ten alcohols (four monomers and dimers), 17 aldehydes (six monomers and dimers), nine ketones (three monomers and dimers), five esters, two furans, one olefin, one ether, and four alkanes (one monomer and dimer). The results indicated significant differences in the volatile substances between freshly pressed and processed goji juice, highlighted in red and green boxes. Volatile compounds in the red box were present in both juices before and after processing (Table 9: 1-36). Compared with fresh wolfberry juice, the relative contents of 2-hexenaldehyde-M, hexaldehyde-M, and 2-methylbutylraldehyde in NFC wolfberry juice increased by 0.07%, 0.08% and 0.18%, respectively. It may be due to the release of aldehydes promoted by processing. Esters such as ethyl propanoate and methyl acetate, which have a fruity aroma, increased by 0.03% and 0.22%, respectively, after processing. The relative contents of alcohols such as butanol and ethanol-D increased by 0.09% and 1.04%, respectively. Alcohols, important precursors of long-chain ester compounds, are mainly derived from the reduction of amino acids and oxidation of fats [39], serving as crucial aromatic substances. The relative content of 16 volatile compounds--1,2-dimethoxyyethane, 1-hexanol-M, (E)-2-pentenal-M, 3-hydroxy-2-butanone-M, 3-pentanone-D, 2-pentylfuran, 3-octanol, 1-pentanol-M, 1-penten-3-one-M, 1-hexanol-D, 2,3-butanedione, 3-hydroxy-2-butanone-D, 2-ethylfuran, (Z)-4-heptenal, 3-heptanol, and propanol--in the red box decreased after processing. This decrease is possibly due to the degradation of some compounds caused by changes in conditions such as cell rupture, light, oxygen, and temperature during homogenisation, ultrasonication, and sterilsisation. The compounds in the green box area--(E)-2-octenal-M, (E)-2-octenal-D, dimethyl trisulfide, 2-heptenal-M, 2-heptenal-D, heptanal-D, 1-pentanol-D, (E)-2-pentenal-D, 1-penten-3-one-D, butyl lactate, and alpha-phellandrene--had very low contents (0.1-0.37%) in the processed NFC goji juice. Among these 11 volatile substances, (E)-2-octenal (monomer, dimer), 2-heptenal (monomer, dimer), (E)-2-pentenal (dimer), and 1-pentene-3-one (dimer) are aldehydes and ketones containing unsaturated bonds, which degrade more quickly under high-temperature processing, reducing their relative content.henylacetaldehyde and 2-heptanone, which have fruity aromas, significantly increased in relative content after processing by 0.21% and 0.07%, respectively. This increase is likely due to high-temperature sterilsisation promoting the degradation and oxidation of unsaturated fatty acids, enhancing the juice's flavour. Overall, the total relative content of volatile flavour substances in NFC goji juice decreased by 19.86% after processing.