The present study investigates the effect of heat treatment on the stability and antimicrobial activity of Aloe vera L. extracts obtained from both in vivo grown and in vitro regenerated plants. Whole leaf and inner gel extracts were prepared using ethyl acetate and subjected to different temperature treatments (25°C, 50°C, 75°C, and 100°C) for 30 minutes. The antimicrobial efficacy of treated and untreated extracts was evaluated against a wide range of human pathogenic microorganisms, including bacteria, fungi, and yeast, using the disc diffusion method. The results demonstrated that heat treatment up to 75°C did not significantly affect the antimicrobial activity of the extracts, indicating strong thermal stability. However, exposure to 100°C resulted in a significant reduction in inhibitory activity, although it did not completely eliminate the antimicrobial properties. Both in vivo and in vitro derived extracts exhibited broad-spectrum antimicrobial activity against tested pathogens such as Escherichia coli, Staphylococcus aureus, Candida albicans, and Aspergillus species. Comparatively, inner gel extracts showed higher antimicrobial efficacy than whole leaf extracts. Statistical analysis using ANOVA confirmed that differences observed at higher temperatures were significant (p < 0.05). The findings suggest that Aloe vera L. extracts retain considerable bioactivity even after moderate heat exposure. This study highlights the potential application of Aloe vera L. extracts as natural antimicrobial agents in food preservation and pharmaceutical formulations. Their notable thermal stability enhances their suitability for industrial processing, contributing to extended shelf life and improved safety of products.
Neelofar Khanam*1,2,3, G. K. Sharma3 (Fri,) studied this question.