## 3 Results  
### Comparison of Characterizations of Glycosylated Hydrolysates  
The browning intensity, free amino production and antioxidant properties are shown in Figure 1A-C to assess the physicochemical properties of the GPP-A and GPP-B. It was shown that two factors can be used to evaluate the degree of glycosylation: browning intensity and free amino content [22]. Meanwhile, the antioxidant activity of glycosylated hydrolysates via two pathways was determined by the DPPH radical scavenging rate in this study. The absorbance at 420 nm of browning intensity is an important indicator for judging the advanced stage of glycosylation. Figure 1A suggested that the absorbance of the WPI, GPP-A and GPP-B was 0.326, 0.718 and 0.423, respectively. It demonstrated that the browning intensity of the GPP through the two pathways was significantly higher than that of the WPI (\(p<0.05\)). There were unsaturated brown substances (such as copolymers, melanonids, nitrogenous polymers) generating during the final stage of the glycosylated reaction [23]. It suggested that glycosylation formed by the porcine-plasma protein hydrolysates and the three kinds of monosaccharides had a deeper color, compared with the porcine-plasma protein hydrolysates [24]. Meanwhile, the absorbance of GPP-A was 70.73% higher than that of GPP-B, indicating that GPP-A exhibited stronger glycosylation development. This indicated that the glycosylated hydrolysates via pathway A could form more unsaturated brown substances, causing a stronger browning intensity. A similar result was provided showing that the UV-absorbance of hydrolyzed glycosylated products was higher than glycosylated hydrolysates [25]. From Figure 1B, the free amino production of the WPI was significantly lower than that of GPP-A and GPP-B (\(p<0.05\)). It suggested that the amino N of the proteins was cross-linked with the carbonyl of galactose. The glycosylated conjugation formed by the hydrolysates of zein and chitosan showed a higher free amino content in comparison to zein [26]. Moreover, the hydrolysates of soy protein-maltodextrin consumed more free amino groups in comparison to soy protein [27]. Furthermore, the free amino content of GPP-B was significantly lower than that of GPP-A (\(p<0.05\)), exhibiting that the pathway A could consume more free amino groups, compared with pathway B. Therefore, the reactivity of GPP-A was higher, which was consistent with the consequence of the browning intensity (Figure 1A). The authors of [25] exhibited that the molecular weight of GPP-A was lower than that of GPP-B, thus consuming more of the free amino groups of GPP-B. Figure 1: Changes in browning intensity (**A**); free amino production (**B**); and DPPH radical scavenge ability (**C**) of GPP-A and GPP-B. Values with different letters are significantly different (\(p<0.05\)). Figure 1C indicates that the antioxidant properties of the WPI, GPP-A and GPP-B were 22.77, 93.37 and 84.18%, respectively. It indicated that the glycosylated hydrolyses generated by both of the two pathways could significantly increase the radical scavenging rate in comparison with the WPI (\(p<0.05\)). Moreover, the GPP-A showed stronger antioxidant properties than GPP-B. A study showed that the glycosylation reaction could produce melanosomes with strong antioxidant activities, resulting in enhancing the DPPH radical scavenging rate [28]. Moreover, there were more peptides with strong antioxidant properties generating after hydrolysis [11]. It has been demonstrated that the glycosylated products formed by the hydrolyses of chicken breast meat and xylose show stronger antioxidant activities, when compared with chicken breast meat [29]. Furthermore, the GPP-A exhibited a higher DPPH radical scavenging rate than the GPP-B in Figure 1C. It indicated that pathway A had stronger free radical scavenging activity, thus showing a stronger hydrogen supply ability.