Comparative Phytochemical Profiling of Garlics (Allium sativum L.) and Onion (Alium cepa L.)

Aims: This research aims to perform the extraction of garlic samples and onion as well as to carry out qualitative phytochemical screening by using Thin Layer Chromatography (TLC) and phytochemical analyses for the detection of carbohydrates, flavonoids, and alkaloids.

Study Design: Thin Layer Chromatography (TLC) and some preliminary qualitative phytochemical tests to detect the presence of carbohydrates and reducing sugars, flavonoids, and alkaloids were carried out to compare and identify the chemical compositions in black and white garlic as well as onion.

Place and Duration of Study: Pharmaceutical Chemistry Department laboratory, Faculty of Pharmacy Universiti Teknologi MARA Puncak Alam. The whole study was conducted and completed in 12 months.

Methodology: Black garlic (BG) is derived from raw white garlic (WG) that is modified by treating it with highly controlled temperature and humidity. In addition to the black and white garlic powder samples, this comparative study was also performed on smoked garlic and onion. The extraction of black garlic (BG), white garlic (WG), crushed smoked garlic (CSG), and onion was performed by using ethanol and ethyl acetate. The comparative phytochemical profiling was conducted by using TLC and qualitative phytochemical analyses were done using standard methods.

Results: The presence of amino acid in the ethanolic extracts of black garlic (BG), crushed smoked garlic (CSG), and onion were detected. Ethyl acetate extracts might contain triterpene. Phytochemical screening tests showed the presence of reducing sugars and alkaloids in ethanolic extracts of black garlic (BG), while white garlic (WG) contains flavonoids, alkaloids, and a trace amount of carbohydrates. Both extracts of onion showed the presence of carbohydrate, reducing sugars and flavonoids. Meanwhile alkaloids are only detected in ethanolic extract of onion.

Conclusion: The extracts of garlics and onion samples in this study had shown appreciable presence of some important phytochemical compounds in Allium species such as amino acids, flavonoids, alkaloids and carbohydrates.