# Variation of Nutritional Quality Depending on Harvested Plant Portion of Broccoli and Black Cabbage
## 1 Introduction  
Italy is known in the world for its high-quality horticulture; among these, _Brassica_ vegetables cover an important part of the market, with a total production of 420,630 t in 2020 ([[https://www.fao.org/faostat/en/#data/QCL](https://www.fao.org/faostat/en/#data/QCL)]([https://www.fao.org/faostat/en/#data/QCL](https://www.fao.org/faostat/en/#data/QCL)), accessed on 12 March 2022). _Brassica_ Italian crops production registered an increase of about 70,000 t since 2010.  
A lot of studies showed a relation between the high consumption of _Brassica_ vegetables and the reduction in the risk of age-related chronic illness, such as cardiovascular and other degenerative diseases [1]; they also reduce the risk of several types of cancer [2]. Broccoli and black cabbage are among the vegetable food with the highest antioxidant potential [3]. The antioxidant and antiradical activity in _Brassica_ vegetables is mainly represented by the large group of polyphenols, constituted by flavonoids (mainly flavonoids and anthocyanins) and hydroxycinnamic acids [4]. These secondary metabolites have several functions in the plant, such as UV protection, pigmentation, and disease control, such as glucosinolates [5]. In _Brassica_ genus, the main represented flavonoids are quercetin, kaempfer, and isorhamtein. Anthocyanins, in addition to conferring the blue and red pigmentation in broccoli sprouts and red cabbage, possess high antioxidant capacity [6], among them, cyanidin-3-glucoside is the most represented in _Brassica_ crops [7].  
Several studies described the variation of the antioxidant activity and phenolics content in the plant portion: for example, in turnip plants, flower buds are the most active portion,followed by leaves and stems, while roots seem to have minor phenolic concentration [8]. [PERSON] et al. [9] revealed that kale seeds have higher antioxidant potential than kale leaves, but leaves are the richest in phenolics. In _Brassica rapa_, [PERSON] et al. [10] reported that phenolic compounds content is higher in leaves harvested during the vegetative period than fructiferous stems (composed of flower, buds, and surrounding leaves), and flavonoids are the main represented compounds. These findings were confirmed by the same group [11], which found that total phenolic content is higher in green turnip than in turnip top. On the contrary, [PERSON] et al. [12] reported that harvest period has only a minimal influence on flavonoid concentration in kale. Broccoli cultivars register an increase in phenolic compounds concentration during the inflorescence's development, with an interesting antioxidant capacity in flower, stem, and leaves [13; 14].  
The aim of this work was to analyze the content of phytochemical compounds in different edible plant portions of _Brassica_ species at different developmental stages. In particular, in broccoli heads and stems were analyzed, while black cabbage leaves and seeds were evaluated.  
To investigate the interaction between genotype and plant portion, two different cultivars of broccoli were compared. The effect of plant developmental stage on phytochemicals amount was also considered, comparing broccoli of the cultivar Roja from first and second harvest period.