# Biochemical Composition of Eggplant Fruits: A Review
## 5 Minerals in Eggplant  
Eggplants are rich sources of biologically essential minerals, such as Na, K, Ca, Mg, P, Fe, Cu, and Zn, for which contents are similar to those reported in tomatoes and higher than those found in carrots, potatoes, or onions. [PERSON] et al. [39] carried out a study to evaluate the variability in mineral content (K, Mg, Fe, Cu, and Zn) among five Indian commercial varieties of eggplant (Punjab Sadabahar, Pusa Ankur, Pusa Purple Long, Pusa Upkar, and Pusa Kranti) and to identify mineral-rich genotypes [39]. The mean values recorded for K, Mg, Fe, Cu, and Zn in these eggplant cultivars were 193, 9.91, 0.342, 0.0721, and 0.135 mg/100 g, respectively. [PERSON] and [PERSON] [40] also conducted a study to determine the mineral composition (Na, K, Ca, P, Fe, Cu, Zn) of raw, boiled, and steamed gboma eggplant (_Solanum macrocarbon_) Eiervrug leaves. The study found the raw samples contained higher mineral content (naturally-occurring abiogenic substances) than the boiled samples (Table 4) [40]. The minerals (sodium, potassium, magnesium, calcium, phosphorous, iron, copper, and zinc) were evaluated according to the official analysis methods defined by the Association of Official Analytical Chemists (AOAC). Further, it was observed that the percentage loss in zinc was the highest (35.29%) when compared to other minerals, and the values of mineral content for both samples were significantly distinct (\(p\leq 0.05\)).  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Minerals (mg/100 g)** & **Raw** & **Boiled** & **Steamed** \\ \hline Na & 16.60 & 13.80 & 15.40 \\ K & 175.00 & 164.00 & 168.00 \\ Ca & 31.24 & 27.69 & 29.56 \\ P & 25.48 & 21.77 & 23.54 \\ Fe & 1.16 & 1.06 & 1.12 \\ Cu & 31.06 & 28.74 & 29.69 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Mineral composition of raw, boiled, and steamed eggplant (_Solanum macrocarbon_) leaves in mg/100 g [40].  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Vitamins** & **Common Name** & **mg/100 g** \\ \hline Vitamin A & Retinol & 0.8 \\ Vitamin B complex & - & 18–22 \\ Vitamin B1 & Thiamine & 0.039 \\ Vitamin B2 & Riboflavin & 0.037–0.11 \\ Vitamin B3 & Nica & 0.649 \\ Vitamin B5 & Pantothenic acid & 0.281 \\ Vitamin B6 & Pyridoxine & 0.084–0.1 \\ Vitamin B9 & Folate & 18–22 \\ Vitamin C & Ascorbate & 1.8–2.2 \\ Vitamin E & Tocopherol & 0.2–0.3 \\ Vitamin K & Menaquinone & 2.9–3.5 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Vitamins and their content in eggplant (mg per 100 g) [10].  
Significant variations in the concentrations of these macro- and micro-minerals were observed among different varieties, with differences up to 156.3% in the concentration of Ca and 142.2% in the concentration of Fe [32]. It was further reported that, on average, landscapes possessed a higher total concentration of macro-minerals (283.8 mg/100 g) than commercial cultivars of eggplant (270.3 mg/100 g) or hybrids between different landscapes (257.9 mg/100 g). Moreover, the global mean concentrations of the three micro-nutrients (Fe, Cu, and Zn) were: 0.168 mg/100 g\({}^{-1}\) for Fe, 0.062 mg/100 g\({}^{-1}\) for Cu, and 0.136 mg/100 g\({}^{-1}\) for Zn. According to [PERSON] et al. [18], the Hindu cultivar exhibited the highest values for concentrations of K (191.18 mg/100 g), Ca (59.63 mg/100 g), P (33.52 mg/100 g), Mg (28.96 mg/100 g), Zn (0.78 mg/100 g), and Mn (0.44 mg/100 g); whereas the Philippine cultivar reported the highest concentrations of Fe (3.13 mg/100 g). No significant differences were found for Cu concentration among the five cultivars (Table 5) [18].