## 3 Results and Discussion
### Organic Acid Content  
The organic acid compositions of the 'Warrior' and 'Albion' parsnip cultivars in both edible and inedible parts are shown in Tables 3 and 4. Seven organic acids were identified: oxalic acid, malic acid, lactic acid, acetic acid, citric acid, succinic acid, and fumaric acid. Malic acid content in the cortex, pH, and skin was measured at 137.32 \(\pm\) 19.58, 203.94 \(\pm\) 12.42, and 362.99 \(\pm\) 9.71 mg/100 g FW, respectively. These results suggest that malic acid, along with lactic acid, is the predominant organic acid in the edible parts of the 'Warrior' cultivar. On the other hand, fumaric acid had the lowest content in all parts, and acetic acid was not detected. The main organic acids identified in the edible parts of 'Albion' were oxalic acid and malic acid, with oxalic acid showing the highest content of 887.95 \(\pm\) 1.21 mg/100 g FW (cortex), 393.27 \(\pm\) 1.02 mg/100 g FW (pith), and 1669.34 \(\pm\) 6.34 mg/100 g FW (skin), respectively. Fumaric acid was the lowest, similar to the 'Warrior', and lactic acid was not detected. The main organic acid in the inedible parts of 'Warrior' cultivar stem and leaf was identified as malic acid, and the contents of malic acid in stem and leaf were 597.48 \(\pm\) 1.42 and 937.71 \(\pm\) 6.71 mg/100 g FW, respectively, which were high compared to other organic acids. The main organic acid in the inedible parts of 'Albion' was identified as oxalic acid, with 3329.11 \(\pm\) 1.76 (stem) and 1715.34 \(\pm\) 8.02 (leaf) mg/100 g FW, respectively. Moreover, the 'Warrior' cultivar was found to contain oxalic acid, lactic acid, citric acid, succinic acid, and fumaric acid, while the 'Albion' was found to have several organic acids, including malic acid, acetic acid, citric acid, succinic acid, and fumaric acid. Detailed information including the HPLC chromatograms is reported in Supplementary Figure S1. Organic acids are critical in determining the taste, flavor, and pH of fruits and vegetables, with significant impacts on their overall quality and consumer acceptance. These acids, such as citric, malic, and ascorbic acids, contribute to the sourness, balance sweetness, and influence the preservation of produce. For example, citric acid is known for its sharp sourness, common in citrus fruits, which enhances flavor complexity by balancing sweetness and adding freshness [21; 22]. Moreover, organic acids play roles beyond taste, \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Cultivar** & **Firmness (N)** & **SSC (°Brix)** & **pH** & **Water Content (\%)** \\ \hline ’Warrior’ & 7.84 \(\pm\) 0.03  & 9.83 \(\pm\) 0.15  & 6.69 \(\pm\) 0.16  & 81.71 \(\pm\) 0.83  \\ ’Albion’ & 7.18 \(\pm\) 0.17  & 12.49 \(\pm\) 0.90  & 5.80 \(\pm\) 0.05  & 73.28 \(\pm\) 2.67  \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Firmness, soluble solid content (SSC), pH, and water content of parsnip (_Pastinaca sativa_). including extending shelf life and offering health benefits. For instance, malic acid not only contributes to flavor but also helps in preserving fruit by inhibiting bacterial growth, while ascorbic acid acts as a potent antioxidant, enhancing the nutritional value and post-harvest life of fruits and vegetables [22]. In particular, malic, citric, and oxalic acids are known to be involved in the processes when plants acquire nutrients and detoxify heavy metals [23]. Organic acid content can vary not only by cultivars or plant parts, but also by growing conditions such as soil and climate. Some organic acids are increased by external environmental stressors [24]. Interestingly, acetic acid was not detected in the 'Warrior' cultivar and lactic acid was not detected in the 'Albion' cultivar in both the edible parts. In addition, acetic acid and succinic acid were not detected in the inedible parts of 'Warrior' cultivar and lactic acid was not detected in the inedible parts of of 'Albion' cultivar, which is similar to the study by [PERSON] et al. [25] in that organic acid composition may differ between cultivars.