Experimental Determination of Guava Leaf Drying Technology
Nguyen Thanh Phong and Le Anh Duc*
Faculty of Engineering and Technology, Nong Lam University Ho Chi Minh City, Ho Chi Minh City, Vietnam
*Corresponding Author: Le Anh Duc, Faculty of Engineering and Technology, Nong Lam University Ho Chi Minh City, Ho Chi Minh City, Vietnam.
Published: January 08, 2025
Abstract
Psidium guajava L., commonly known as guava, belongs to the Myrtle family and is cultivated in tropical and subtropical climates. Guava leaves have been used for medicinal purposes due to their numerous health benefits in several countries. This study presents the results of determining the drying methods and drying conditions for guava leaves through various techniques: the sun drying, shade, the hot air drying, the heat pump drying, and the vacuum drying. The drying methods were conducted at three temperature levels: 45°C, 50°C, and 55°C. Moisture reduction rate, tannin content, and sensory evaluation of the color and flavor of the dried guava leaves were the basis for selecting the appropriate drying method and conditions. The results identified heat pump drying at 45°C for 210 minutes as the most suitable method, producing dried guava leaves with a standard moisture content of 11 ± 0.5%. The dried guava leaves had a tannin content of 7.75%, with the characteristic color and aroma of guava leaves, making them suitable for processing into medicinal products such as guava leaf powder or tea. The equation predicting the moisture content of guava leaves over drying time during the drying process has been established.
Keywords: Guava leaves; heat pump dryer; Tannin; hot air drying; sun drying
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