# Variation of Nutritional Quality Depending on Harvested Plant Portion of Broccoli and Black Cabbage
## 3 Results and Discussion
### Vegetables Nutritional Quality
#### 3.2.2 Broccoli's Head and Stem Nutritional Quality  
In Figure 1, FRAP analysis showed contrasting results: in fact, Roja and Santee possessed the highest concentration of antioxidant in stem, while in Roja-II head was the plant part with the highest antioxidant capacity (9.91 \(\pm\) 0.16 mM Trolox/kg fw), thus highlighting that with maturation there is a greater accumulation of nutritional substances in this part of plants. Similar FRAP results were obtained by [PERSON] et al. [26] (on heads) and [PERSON] et al. [27] (on whole material). The total average of different plant parts showed that stem possessed a higher FRAP value than head. In the literature, [PERSON] et al. [8] found an opposite trend in turnip, reporting that flower buds possess the highest antioxidant capacity, followed by leaves and stems, where flavonoids were the most represented compound. In the analyzed broccoli, the range of phenol concentration varied from 891.26 to 2574.77 mg GA/kg of fw (Figure 2). Total phenol content, that is responsible for the 80% of total antioxidant capacity, resulted to be highest in the broccoli heads, with an average value of 1499.35 mg GA/kg of fw. This trend was confirmed in all the analyzed genotypes, where TPH of heads were always statistically higher than the corresponding stems. Roja-II had a higher content of phenols in head and stem than Roja (first harvest), probably due to stage of development; this confirms that the late harvesting has a positive effect on the quality of the product, as reported by [PERSON] et al. [28] and [PERSON] [25]. Our study confirms that total phenolic content is influenced by genotype and plant developmental stage, in accordance with previous studies [26; 29]. \begin{table}
\begin{tabular}{c c c c} \hline \multirow{2}{*}{**Vegetables**} & **TEAC 1** & **TPH 2** & **ACY 3** \\  & **(mM TE/kg fw)** & **(mg GA/kg fw)** & **(mg CYA-3-GLU/kg fw)** \\ \hline
**Black Cabbage Leaves** & 5.68 \(\pm\) 0.21 2  & 1444.60 \(\pm\) 23.82 3  & 3.25 \(\pm\) 0.24 4  \\
**Black Cabbage Seeds** & 8.39 \(\pm\) 0.53 5  & 1767.79 \(\pm\) 12.67 6  & 16.87 \(\pm\) 0.24 \\ \hline  & & & \(n\) = 8 \\ \hline
**Santee 4** & 4.65 \(\pm\) 0.13  & 1038.74 \(\pm\) 26.48  & 18.15 \(\pm\) 2.33  \\
**Roja 5** & 4.31 \(\pm\) 0.15  & 1046.20 \(\pm\) 28.73  & 23.42 \(\pm\) 2.75  \\
**Roja-II 6** & 8.86 \(\pm\) 0.24  & 2021.17 \(\pm\) 117.64  & 72.61 \(\pm\) 9.05  \\ \hline \end{tabular}
\end{table} 
Table 3: Average values of total antioxidant capacity, phenolics and anthocyanins content of the different vegetables analyzed. Figure 1: Average values and standard deviation of total antioxidant capacity measured by Ferric Reducing Antioxidant Power (FRAP) of Broccoli analyzed: Roja, Santee and Roja-II harvest divided into head and stem, and their average. Values with the same lowercase letter were not significantly different (Test SNK \(p\leq 0.05\), \(n=3\)). Lowercase letters refer to Roja, Santee and Roja-II harvest divided into head and stem. Values with the same uppercase letter were not significantly different (Test SNK \(p\leq 0.05\), \(n=9\)). Uppercase letters refer to head and stem average values. Figure 2: Average values of Total Phenol Content (TPH) with standard deviation of different cultivars and type of tissues of Broccoli: Roja, Santee and Roja-II harvest divided into head and stem, and their average. Values with the same lowercase letter were not significantly different (Test SNK \(p\leq 0.05\), \(n=3\)). Lowercase letters refer to Roja, Santee and Roja II harvest divided into head and stem. Values with the same uppercase letter were not significantly different (Test SNK \(p\leq 0.05\), \(n=9\)). Uppercase letters refer to head and stem average values. the same tissue; this result was probably due to the capacity of FRAP method to detect other antioxidant compounds over phenols, such as ascorbic acid, carotenoids, vitamins, and others, although the phenolics content represented 80% of the total antioxidant capacity as reported by [PERSON] [30].