Optimizing Garlic Oil Extraction: A Comparison of Microwave Heating and Traditional Drying Method

Abstract

Pre-treatment, such as drying, is important in producing high-quality essential oil from plants. Due to a lack of pre-processing treatment, heavy losses are incurred in terms of both the quality and quantity of garlic oil. These losses could be attributed to respiration, transpiration, or microbiological spoilage. This study aimed to investigate the effect of oven drying and microwave heating on the oil yield of garlic. The nutraceutical industry is currently keen on obtaining garlic extracts using mild extraction processes to recover high levels of labile allicin. Therefore, the oil is extracted using a modern method, microwave-assisted extraction (MAE). In this study, MAE was conducted to determine the optimum extraction conditions, including extraction time and sample-to-solvent ratio, to achieve the highest yield of garlic oil. MAE can significantly reduce extraction time and solvent consumption compared to conventional methods such as solvent extraction and maceration. Based on the results obtained, garlic heated using a microwave yielded a higher oil yield than oven-dried garlic, with percentages of 11.18% and 6.78%, respectively. The best extraction time using MAE was found to be 20 minutes, and the optimal sample-to-solvent ratio was 1:1.5. Moreover, the efficiency of extraction obtained from microwave-heated garlic exceeded that of oven-dried garlic, with percentages of 31.94% and 12.91%, respectively.