Antimicrobial activity and phytochemical analysis of orange (Citrus aurantium L.) and pineapple (Ananas comosus (L.) Merr.) peel extract

Orange (Citrus aurantium L.) and pineapple (Ananas comosus (L.) Merr.) are major fruit crops, cultivated in India. Peels represent between 50 to 65 % of total weight of the fruits and remain as the primary byproduct. Orange and pineapple fruits are majorly used for juice extraction in industrial leads to cause huge amounts of residues. If these residues are not processed further, it becomes waste and produce serious environmental pollution. The present study was aimed to extract the metabolites from waste peels, using ethanol and methanol solvent system and checked for the presence of various biomolecules and secondary metabolites like carbohydrates, proteins, steroid, lavonoid, alkaloids, tannins, saponines and tritepinoids. The ethanol solvent was showing most of the positive test as compared to methanol solvent in both the samples. Further, the antimicrobial properties of orange and pineapple peels were checked against pathogenic bacterial strains. The antimicrobial activity was performed, using agar well diffusion method against pathogenic bacterial strains (Klebsiella pneumonia K2044, Pseudomonas aeruginosa MTCC4676, Bacillus subtillis Py79 and Xanthomonas axonopodis pv. malvacearum LMG859). From the results, it was clearly observed that both orange and pineapple peel sample dissolved in ethanol, showing maximum zone of inhibition, against all the test pathogens. Methanol extract of both the samples, showing lower zone of inhibition in all the test pathogen as compared to ethanol extract samples. When both the samples, ethanol and methanol extracts were combined in equal amount and test against the pathogenic bacteria, they were showing maximum or equal zone of inhibition as the individual samples zone of inhibition. Finally, we can conclude that orange and pineapple fruits can be used as a antimicrobial agents for the protection from selected plant and animal pathogens, but the use of a standard method for investigation is essential. Similarly, the concentrations or dilutions used, must be appropriate with proper information about its safety.