Understanding the potential of Black garlic as an antibacterial agent by quantifying volume scattering function

Abstract

Abstract Static light scattering examines the scattered light intensity concerning the angular distribution of small particles that are of sub-micron size. The information on size and molecular weight of any scattering particle can be obtained easily by the intensity profile of scattered light. The scattered intensity depends on factors like size, scattering angle, wavelength of light interacting with the particle, relative refractive index of the particle and the medium. The information obtained from the scattering profile provides vital information that may be used to characterize these particles. The current research explores the antibacterial properties of Black garlic (Allium sativum L.) by using biochemical methods and light scattering tools. This tool offers complementary insights into antibacterial activity. In our investigation, we specifically examined the antibacterial activity of Black garlic against Escherichia coli (E. coli) ATCC-9637, a common bacterial strain, through a biochemical method. This biochemical assay provided initial evidence of the antibacterial effects of Black garlic, demonstrating its potential as a natural antibacterial agent. Following these tests, we further validated our findings using Static Light Scattering (SLS) techniques. It is an efficient tool used in analysis of various materials such as polymers, nanoparticles, metal oxides, aerosols etc. Since the measurement of accurate size, shape etc. depends on the scattering intensity, the scattering profiles carries vital information about the morphology of the particles. The SLS instrument generally consists of a laser source, goniometer scale and detectors. The detectors measure the scattering intensity over the angular range of 10° to 170°. SLS is an effective technique of quantifying the morphology of particles and its volume scattering function. Therefore, it is advantageous over biochemical methods which are usually adopted for such characterizations. The antibacterial activity was carried out for black garlic inoculated with Escherichia coli sample processed at different temperatures, that is, 37, 65, and 100 $$^\circ \text{C}$$ ∘ C . The light scattering measurements of Black garlic were conducted at 37, 65, and 100 $$^\circ \text{C}$$ ∘ C temperature. The investigations on antibacterial activity of black garlic on Escherichia coli bacterial strain exhibited different zone of inhibition, which proves the difference in magnitude of antibacterial activity. This may be attributed to the alterations in the morphology of the bacterial cell due to the antibacterial effect of black garlic against the bacterial strain. The observation was also supported by the unique scattering signatures exhibited by the similar samples at three different temperatures. The scattering profiles have revealed the distinctiveness of each sample associated with its morphology and composition. This ensures the application of light scattering equipment as a substitute approach for examining the bioactivity of Black garlic without utilizing a biochemical approach. In this work, the interpretation of the antibacterial activity of Black garlic was confirmed by the light scattering technique for the first time. SLS proved to be an efficient tool in understanding the role of black garlic as antibacterial agent by quantifying volume scattering function at different temperatures. The highest antibacterial activity was observed at 37 $$^\circ \text{C}$$ ∘ C .

Keywords

• Light scattering
• Black Garlic
• Mueller matrix
• Volume scattering function
• Antibacterial activity