## 3 Results and Discussion  
### Vitamin C Content  
Vitamin C plays an important role in the process of collagen synthesis in humans. Because humans are unable to synthesize vitamin C, fresh fruit and vegetables are needed as a supplement of vitamin C [1]. As a result, soybean sprouts have attracted people's attention for their high content of vitamin C. Figure 1 presents the vitamin C content in soybean sprouts that have been treated with chitol oligosaccharidesadriades of different molecular weights at different concentrations. It can be found that chitol oligosaccharidesadriade could effectively promote the vitamin C accumulation in soybean sprouts, and all the different chitol oligosaccharidesadriade treatments revealed higher vitamin C content than the control. The vitamin C content of soybean sprouts was increased by 45.84% with 0.001% of 1 kDa chitol oligosaccharidesadriade. When the concentration of chitol oligosaccharidesadriade increased to 0.01%, the vitamin C content reached the maximum, 33.33 mg/100 g fresh weight, about 2.11-fold in comparison with the control of 15.83 mg/100 g fresh weight. However, after treatment with 0.1% and 1% of 1 kDa chitol oligosaccharidesadriade, the vitamin C content decreased to 29.17 mg/100 g and 24.67 mg/100 g, which were still more than the control. There was a similar trend for the treatment with 2 kDa and 3 kDa chitol oligosaccharidesadriade. After treatment with 0.01% of 2 kDa and 3 kDa chitol oligosaccharidesadriade, the vitamin C content of soybean sprouts increased to 30.83 mg/100 g fresh weight and 27.35 mg/100 g fresh weight, respectively.  
As an important bioactive component, vitamin C does not exist in soybeans but increases after germination. This is owing to a response in the environmental factors [16]. Chitosan and chitol oligosaccharidesadriade are well documented plant defense elicitors and are recognized as stress signals by plant cells [22]. It has been discovered that the size and dosage of chitol oligosaccharidesadriade are crucial in determining their  
Figure 1: Vitamin C content of soybean sprouts under different chitol oligosaccharidesadriade treatments. The treatments were conducted with chitol oligosaccharidesadriades of three molecular weights (1, 2, and 3 kDa) at four different concentrations (0.001 to 1%). The control treatment (0%) included the same solutions without chitol oligosaccharidesadriades. Vertical bars represent the standard error of three replicates. Different letters indicate statistically significant difference (\(p<0.05\)).  
In the present study, the vitamin C content (15.83 mg/100 g fresh weight) of the control was similar to that (15.82 mg/100 g fresh weight) reported by NO and others. However, after treatment with 0.01% of 1 kDa chitooligosaccharide, the highest vitamin C content of soybean sprouts increased to 33.33 mg/100 g fresh weight, which was significantly higher than their treatment with 0.1% of 493 kDa chitosan (17.01 mg/100 g fresh weight) [13]. This result was in accordance with previous studies, which showed that the antiviral activity of chitosan increased as its molecular weight decreased. The highest activity was exhibited by the fractions with Mw = 2.2 and 1.2 kDa [23].