# Selected Antioxidants in Organic vs. Conventionally Grown Apple Fruits
## 2 Materials and Methods
### Statistical Analyses  
The main effects of the (a) horticultural production system, (b) vegetation season, and (c) apple cultivar on the analysed apple fruit compositional parameters as well as interactions between the three factors were assessed using three-factor ANOVA (see Tables 1-3). In addition, for further explanation of the identified interactions, two-factor ANOVA, with the horticultural system and the cultivar as factors, followed by post hoc [PERSON]'s honestly significant difference (HSD) test (\(\alpha\) = 0.05), was performed separately for each of the two vegetation seasons (Table 4, Figures 3-5). All the analyses were carried out in R programme, with an 'nlme' statistical package (K \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **Dry Matter** & **Vitamin C** & **Dehydroascorbic Acid** & **L-Ascorbic Acid** \\ \hline Idared & \(13.30\pm 0.98\) & \(13.30\pm 4.21\) & \(1.30\pm 0.36\) & \(11.99\pm 4.23\) \\
**Year (YR)** & & & & \\
2017 & \(14.14\pm 1.69\) & \(8.47\pm 3.07\) & \(1.77\pm 0.93\) & \(6.70\pm 3.02\) \\
2018 & \(13.22\pm 0.80\) & \(17.23\pm 2.44\) & \(1.42\pm 0.39\) & \(15.81\pm 2.51\) \\
**ANOVA \(p\)-values** & & & & \\ SYS & 0.000 & NS & 0.001 & 0.027 \\ CV & 0.000 & 0.000 & 0.000 & 0.000 \\ YR & 0.021 & 0.000 & 0.050 & 0.000 \\ SYS \(\times\) CV & 0.000 & 0.000 & 0.000 & 0.000 \\ SYS \(\times\) YR & 0.004 & 0.000 & 0.002 & 0.000 \\ CV \(\times\) YR & 0.000 & 0.000 & 0.006 & 0.000 \\ SYS \(\times\) CV \(\times\) YR & NS & 0.000 & 0.001 & 0.000 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: _Cont_. Figure 3: Concentrations (mean and SD) of phenolic acids (sum) in Champion, Gala, and Idared apple fruits collected from organic and conventional orchards in 2017 and 2018 growing seasons. Within each season and group of compounds, bars marked with the same letters are not significantly different at \(p<0.05\). \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & **Phenolic Acids** & **Gallic Acid** & **Chlorogenic Acid** & **Caffeic Acid** & \(p\)**-Cumaric Acid** \\ \hline
**System (SYS)** & & & & & \\ Conventional & \(13.3\pm 2.3\) & \(0.94\pm 0.92\) & \(10.8\pm 1.8\) & \(0.58\pm 0.18\) & \(0.97\pm 0.52\) \\ Organic & \(17.5\pm 1.6\) & \(0.84\pm 0.53\) & \(14.8\pm 2.0\) & \(0.71\pm 0.22\) & \(1.14\pm 0.62\) \\
**Cultivar (CV)** & & & & & \\ Champion & \(16.2\pm 2.0\) & \(1.14\pm 1.08\) & \(13.4\pm 2.3\) & \(0.72\pm 0.23\) & \(0.92\pm 0.72\) \\ Gala & \(14.9\pm 1.7\) & \(0.63\pm 0.21\) & \(12.1\pm 1.6\) & \(0.62\pm 0.26\) & \(1.46\pm 0.32\) \\ Idared & \(15.2\pm 4.4\) & \(0.91\pm 0.64\) & \(12.9\pm 4.0\) & \(0.59\pm 0.08\) & \(0.80\pm 0.37\) \\
**Year (YR)** & & & & & \\
2017 & \(15.4\pm 2.7\) & \(0.50\pm 0.08\) & \(12.8\pm 2.6\) & \(0.79\pm 0.15\) & \(1.33\pm 0.31\) \\
2018 & \(15.4\pm 3.2\) & \(1.28\pm 0.90\) & \(12.9\pm 3.0\) & \(0.50\pm 0.15\) & \(0.79\pm 0.64\) \\
**ANOVA \(p\)-values** & & & & \\ SYS & 0.000 & 0.003 & 0.000 & 0.004 & 0.002 \\ CY & 0.001 & 0.000 & 0.001 & 0.000 & 0.000 \\ YR & NS & 0.001 & NS & 0.005 & 0.002 \\ SYS \(\times\) CV & 0.000 & 0.000 & 0.000 & 0.000 & 0.000 \\ SYS \(\times\) YR & NS & 0.001 & NS & NS & NS \\ CV \(\times\) YR & 0.000 & 0.000 & 0.000 & 0.000 & 0.000 \\ SYS \(\times\) CV \(\times\) YR & 0.038 & 0.000 & NS & 0.017 & 0.000 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The main effect of (and interaction between) the production system (conventional and organic), cultivar (Champion, Gala, Idared) and harvest year (2017, 2018) on the concentrations (mean \(\pm\) SD) of phenolic acids (mg/100g f.w.) in apple fruit.