## 3 Discussion  
In the present study, different harvesting times of golden mulberry fruit were used to investigate their effects on the marketable percentage, appearance quality, and physical  
Figure 3: Relative content of aroma components of golden mulberry at different maturity stages. Figure 2: Common and unique aroma components in golden mulberry. and chemical qualities of the golden mulberry fruit. With the increase in maturity, the percentage of fruit drop and mold percentage was significantly increased, resulting in a significant decline in the percentage of marketable fruit. The T3 period still had 89.0% marketable fruit percentage, but the percentage of marketable fruit declined more seriously in the T4 period, accounting for only 65.7%. Therefore, from an economic perspective, it is advisable to harvest mulberry fruits before the T3 stage. The quality indices of TSSs, SSs, and total acid are important indicators for evaluating the postharvest quality and flavor of mulberry fruits [26; 27]. In the present study, further analysis of the quality indices of TSSs, total sugar, and total acid of golden mulberry fruits in different periods showed that the indices of total sugar, total acid, and SSs/TA all reached a balance in the period of T3, with total sugar and SSs/TA having the highest values and total acid the lowest value. Although the value of TSSs had reached a maximum of 26.19 \(\pm\) 0.91 at T4, the corresponding mulberry fruits at this time had a mushy texture and might not be suitable for eating. The content of TSSs, total acid, and solid-acid ratio are commonly used to evaluate the flavor of fruits [28], but none of those indicators considered the degree of contribution of specific sugar-acid fractions, and therefore did not reflect the true sweet and sour flavor of fruits, especially when the sugar content of fruits was at a high level, and fruits with appropriate acidity tended to be more accepted by consumers [29]. The sensory evaluation results (Table 3) showed that the T3 fruit received the highest scores in flavor, color, and overall sensory quality, indicating a better perceived balance between sweetness and acidity. Therefore, by comprehensively analyzing the physicochemical parameters (TSSs, total sugar, total acid, SSs/TA) and sensory evaluation results, it can be concluded that the golden mulberry fruit harvested at the T3 stage exhibited the most balanced sweet and sour flavor and optimal overall eating quality. The process of free radical scavenging in plants is complex and closely related to antioxidant activity [30; 31]. To comprehensively assess the antioxidant activity of mulberry fruits at different ripening stages, three methods, ABTS, FRAP, and DPPH, were used in the present study. The results showed that all mulberry fruits at all harvesting stages possessed antioxidant activity, with the strongest free radical scavenging capacity at T1 and non-significant differences at T2, T3, and T4. The trends of total polyphenol content and DPPH values in the present study were consistent with the study of [PERSON] et al. [32], who reported that total anthocyanin and polyphenol content in mulberry genotypes was significantly associated with higher antioxidant capacities (FRAP and DPPH) and that anthocyanins were the primary contributors to the total antioxidant activity. [PERSON] et al. analyzed the antioxidant capacity of mulberry fruit extract and found that the total phenol, flavonoid, and anthocyanin content in mulberry fruit was significantly correlated with its antioxidant capacity [31]. Polyphenols exert antioxidant activity through the structural characteristics of their phenolic hydroxyl groups. These hydroxyl groups can effectively scavenge free radicals by donating hydrogen atoms or electrons. By comparing the changes in the antioxidant capacity of mulberries at different maturity stages, this study further validated the relationship between mulberry maturity and antioxidant activity.