Poultry manure application enhances the phytochemical contents, antioxidant, and fixed oil of Momordica charantia L

Due to its rich sources of bioactive compounds, Momordica charantia (bitter melon) is used as a food and natural medicine, resuting in many beneficial health effects. Poultry manure is a valuable source of organic fertilizer used to enrich soil fertility to obtain high yields from agricultural products. It contains high levels of essential macro and micronutrients. The present study aimed to determine the effects of chicken and turkey manure applications on the protein content, extract content, antioxidant activity, total phenolic and flavonoid contents, and mineral matter productivity of bitter melon fruits. In addition, the study evaluated the chicken and turkey manure applications on the fixed oil quality of bitter melon seeds. In this context, different doses of chicken (T_1:10, T_2:12.5, T_3:15, T_4:17.5 t/ha) and turkey (T_5: 10, T_6: 12.5, T_7:15, T_8:17.5 t/ha) manures were applied by sowing. The crude protein contents values of the bitter melon fruits ranged from 4.79 to 7.80 %, and a maximum crude protein content of bitter melon fruits was obtained from T₈ application. The highest DPPH activity was observed with the T₇ (88.43 %) and T₄ (86.23 %) applications, while the highest FRAP value was obtained from T₄ application (73.52 mg TE/g). In addition, the highest total phenolic content (21.13 mg GAE/g) and total flavonoid amount (11.44 mg QE/g) of bitter melon fruits were obtained from T₆ application. Maximum capric acid (50.40 %) was recorded in the seed oil after applying the T₁, while the highest concentration of lauric acid (30.09 %) were reflected by applying the T₅. The highest Fe, Cu and Mn concentrations were found in the T₄, while the highest concentration of Zn and B recorded in the fruit extract appeared after applying the T₆. The PCA analysis showed 56.2 % of total variation. Thus, the results suggest that the application of poultry manure could be employed to get maximum benefits regarding protein and extract contents, antioxidant activity, total phenolic and flavonoid contents, fixed oil component and mineral content values.