Phytochemical profile and inhibitory activity of Curcuma longa and Zingiber officinale extracts against food-borne pathogenic bacteria

Abstract

Due to the side effects associated with the use of chemical preservatives and the outbreak of food-borne diseases in developing countries, there has recently been a greater interest in naturally occurring food preservatives. The purpose of this study is to assess the phytochemical constituents and antimicrobial activity of Curcuma longa and Zingiber officinale extracts against selected food-borne disease-causing bacteria. Ethanolic extracts of Curcuma longa and Zingiber officinale were subjected to quantitative phytochemical screening using standard chemical tests. The antibacterial activity of the extracts and the minimum inhibitory concentration (MIC) was determined using the agar well diffusion method. Curcuma longa and Zingiber officinale quantitative phytochemical assays revealed higher levels of flavonoids (7.66±0.03 and 7.11±0.12) and lower levels of cardiac glycosides (0.96±0.01 and 0.84±0.02), respectively. Others in this class include saponin, phenol, tannic acid, and alkaloid. In a dose-dependent manner, crude extracts from both plants’ rhizomes demonstrated good antibacterial activity against Staphylococcus aureus, Bacillus cereus, Salmonella typhi, Pseudomonas aeruginosa, and Escherichia coli. At 1000 mg/ml, the diameter of the zone of inhibition ranged from 16.22 mm to 22.67 mm for both plant extracts. The combined ethanolic extracts of both plants had the highest antibacterial activity (23mm), with MIC values ranging from 75mg/ml to 150 mg/ml. This research discovered that plant extracts are high in phytochemicals and have inhibitory activity against common food-borne disease-causing bacteria. The study’s findings indicate that the plants could be used as natural food preservatives and for the treatment of foodborne diseases.