# Identification and Quantification of Valuable Compounds in Red Grape Seeds
## 4 Discussion  
All four ascertainments, the determination of the total content of polyphenols, the determination of antioxidant and antiradical activity, as well as the determination of phenolic compounds were performed on all seven grape varieties. The grapes came from plantations in Romania, more precisely from the Banat area. The analyses were performed after extraction, in three periods, on the first day after their drying, on the 14 th day and on the 30 th day of storage of the grape seed extract. To eliminate as many errors as possible, such as those related to equipment, human errors, temperature or humidity, we decided to analyze three samples from each grape extract on each day of analysis. According to the obtained results, in the case of determining the total content of polyphenols, antioxidant and antiradical capacity, a slight decrease of these contents was found in the three days of analysis. This decrease was slight in all seven grape samples. The highest values were obtained in the case of the Novac variety. This is also demonstrated by the analysis of phenolic compounds because this variety has high values for all identified components. Merlot seeds have the lowest values in all three determinations, analysis of total polyphenol compounds, antioxidant and antiradical analysis. Using the HPLC method, we identified several phenolic compounds contained in the analyzed seeds. In all seven samples, the following proportion has the highest proportion: syrginic acid, gallic acid and vanilic acid. Syrginic acid is an excellent compound to be used as a therapeutic agent and possesses antioxidant, antimicrobial, anti-inflammatory and antiendotoxic capabilities [53]. Gallic acid has various properties, including antifungal, antimicrobial, and anticancer capabilities [54]. Vanillic acid reduced collagen accumulation  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Compound**} & \multicolumn{6}{c}{**Composition (mg/L ppm (Parts per Million))**} \\ \cline{2-9}  & **Cabernet** & **Merlot** & **Pinot noir** & **Burgund** & **Cadarca** & **Syrah** & **Novac** \\  & **Sauvignon** & & & & & & & \\ \hline Catechin & 8.17 \(\pm\) 0.01 & 7.28 \(\pm\) 0.01 & 6.98 \(\pm\) 0.01 & 7.15 \(\pm\) 0.01 & 8.12 \(\pm\) 0.01 & 8.46 \(\pm\) 0.01 & 8.78 \(\pm\) 0.01 \\ Epicatism & 5.11 \(\pm\) 0.01 & 5.12 \(\pm\) 0.01 & 5.16 \(\pm\) 0.01 & 4.82 \(\pm\) 0.01 & 4.43 \(\pm\) 0.01 & 5.98 \(\pm\) 0.01 & 6.17 \(\pm\) 0.01 \\ Epicatechin gallate & 2.15 \(\pm\) 0.01 & 2.18 \(\pm\) 0.01 & 2.26 \(\pm\) 0.01 & 1.95 \(\pm\) 0.01 & 2.24 \(\pm\) 0.01 & 2.02 \(\pm\) 0.01 & 2.46 \(\pm\) 0.01 \\ Gallic acid & 26.34 \(\pm\) 0.05 & 0.71 \(\pm\) 0.01 & 31.46 \(\pm\) 0.05 & 31.02 \(\pm\) 0.05 & 32.46 \(\pm\) 0.05 & 33.80 \(\pm\) 0.05 & 35.46 \(\pm\) 0.05 \\ P-hydroxybenzoic acid & 1.85 \(\pm\) 0.05 & 1.23 \(\pm\) 0.05 & 1.77 \(\pm\) 0.05 & 2.04 \(\pm\) 0.05 & 2.09 \(\pm\) 0.05 & 2.22 \(\pm\) 0.05 & 2.30 \(\pm\) 0.05 \\ Vanilic acid & 18.02 \(\pm\) 0.01 & 15.57 \(\pm\) 0.01 & 16.15 \(\pm\) 0.01 & 13.24 \(\pm\) 0.01 & 18.65 \(\pm\) 0.01 & 18.45 \(\pm\) 0.01 & 20.08 \(\pm\) 0.01 \\ Syrginic acid & 122.87 \(\pm\) 0.25 & 130.13 \(\pm\) 0.25 & 129.40 \(\pm\) 0.25 & 129.81 \(\pm\) 0.25 & 133.20 \(\pm\) 0.25 & 134.26 \(\pm\) 0.25 & 134.12 \(\pm\) 0.25 \\ M-hydroxybenzoic acid & 4.58 \(\pm\) 0.01 & 4.60 \(\pm\) 0.01 & 4.20 \(\pm\) 0.01 & 3.69 \(\pm\) 0.01 & 3.44 \(\pm\) 0.01 & 5.32 \(\pm\) 0.01 & 5.26 \(\pm\) 0.01 \\ Caffe acid & 1.01 \(\pm\) 0.01 & 1.08 \(\pm\) 0.01 & 0.96 \(\pm\) 0.01 & 1.19 \(\pm\) 0.01 &and hydroxyproline content [55]. According to the results obtained from this determination, we notice that the seeds of the Novac variety contain the highest amounts of syringe acid, gallic acid and vanillic acid, and the seeds of the Merlot variety have a low content of vanillic acid and gallic acid. These values justify the results obtained in the case of determining the antioxidant and antiradical capacity.