Assessment of Ultrasound-Assisted Extraction of Caffeine and its Bioactivity

Abstract

This research focused on using spent coffee grounds as a source of caffeine by ultrasound-assisted extraction technique. Two types of ultrasound techniques (ultrasonic bath and ultrasonic probe) were studied to extract caffeine. The effect of the sonication type sonication power, extraction time, and extraction temperature on the extraction efficiency was investigated. The results demonstrated that extraction by an ultrasonic probe is superior to ultrasonic bath extraction. The highest caffeine recovery was obtained at 55 °C by using an ultrasound bath where caffeine concentration was 795.74 mg/L after 60 min. The bioactivity of extracted caffeine was also studied and compared with the bioactive of standard caffeine against candida albicance yeast. The results showed that the minimum inhibition concentration for natural caffeine was 100 mg/L which is half of the minimum inhibition concentration of standard caffeine.

Caffeine Extraction from Spent Coffee Grounds by Solid-liquid and Ultrasound-assisted Extraction: Kinetic and Thermodynamic Study

“…However, these organic compounds give spent coffee grounds a toxic nature, whereas when untreated spent coffee grounds are disposed of in the environment, their decomposing can produce greenhouse gases such as carbon dioxide and methane contributing to global warming. Furthermore, its disposal can alter the acidity of the landfill and the surrounding area's soils, which can affect the environment negatively [7].…”

استخلاص الكافيين من مخلفات القهوة بعملية الاستخلاص الصلب-سائل

“…It is produced by soluble coffee industries, domestic coffee consumption, restaurants and cafes coffee consumption 2 . Although spent coffee grounds contain organic compounds, which makes them valuable, these compounds harm the environment, where they can be a source of greenhouse gases when decomposing and maybe change the acidity of the landfill and surrounding soil which can contribute to increasing soil pollution which is an important environmental concern [3][4][5] Caffeine (1, 3, 7-trimethyl-3, 7-dihydro-1H-purin-2, 6-dion) is the most substantial component that can be obtained mainly from coffee leaves and beans 6 . Also, it can be found in many plants, among other organic health-effective materials [7][8][9] , such as tea leaves and cocoa beans 10 .…”