Synthesis of Antibacterial Bioactive Compounds Using Linoleic Acid Extracted from Melon Seeds Oil and Evaluation of Its Waste Meal Ash for Fried Oil Regeneration

Abstract

This work aimed to use linoleic acid extracted from melon seed oil for the development of biological compounds, and to use the ash of melon seed cake for fried oil treatment. Eight active compounds were developed using linoleic acid and the elucidation of their structure was established according to elemental analysis and spectral data. The developed compounds were tested for their antibacterial activity. The melon seed cake was carbonized for the treatment of fried oils. The melon seed oil was rich in linoleic acid (61.4%) and it contains several fatty acids including lauric, myristic, palmitic, palmitoleic, stearic, oleic, linolenic, arachidic, and paulinic in concentrations of 0.2%, 0.73%, 11.7%, 0.11%, 10.3%, 14.1%, 0.49%, 0.19%, and 0.1%, respectively. The extracted linoleic acid showed a high refractive index (1.471), iodine value (122.3 g I2/100 g), saponification (184.42 mg KOH/g), low peroxide value (3.9 meq/kg oil), polymer content (1.00%), polar contents (1.95%), and moisture content (42 g/kg). The melon seed ash was rich in several metals including magnesium (743.5 mg/kg), calcium (137 mg/kg), sodium (12.95 mg/kg), potassium (1040 mg/kg), chromium, manganese, iron, copper, zinc, cadmium, and mercury in concentrations of 0.072, 40.88, 19.29, 3.334, 8.21, 0.005, 0.005 mg/kg, respectively, as well as arsenic (0.09 mg/kg), lead (0.044 mg/kg), phosphorus (1222 mg/kg) and selenium (0.13 mg/kg) which they improved the physic-chemical properties of fried oils. Linoleic acid was used for the development of 9 compounds with antimicrobial activity against Gram-positive and Gram-negative bacteria. Additionally, the melon seed ash improved the chemical characteristic of used cotton and sunflower oils. Therefore, the linoleic acid extracted from melon seed oil is a promising source for the development of antibacterial agents and the leftover cake is promising for the production of adsorbent material suitable for fried oils treatment. Graphical Abstract: [Figure not available: see fulltext.]