Effect of Response Surface Methodology-Optimized Ultrasound-Assisted Pretreatment Extraction on the Composition of Essential Oil Released From Tribute citrus Peels

Abstract

The traditional hydrodistillation (HD) and ultrasound-assisted pretreatment extraction (UAPE) methods were proposed to obtain essential oil (EO) from Tribute citrus (TC) peels. The Box-Behnken design was employed to optimize the HD and UAPE procedures. Moreover, gas chromatography-mass spectrometry (GC-MS) and electronic nose (E-nose) were applied to identify the discrepancy of the extraction methods. The yield of EO extracted by UAPE (114.02 mg/g) was significantly higher than that by HD (85.67 mg/g) (p < 0.01) undergoing 40 min short time-consuming UPAE. A total of 28 compounds were extracted from the TC peels as terpenes were the predominant components. d-Limonene was the most vital compound in the T. citrus essential oil (TCEO), accounting for 86.38% of the total volatile concentration in HD and 86.75% in UAPE, respectively, followed by α-pinene, sabinene, γ-myrcene, and β-phellandrene. The chart of radar and graphic of the principal component analysis by E-nose displayed no significance, which was similar to the GC-MS results. This study demonstrated that UAPE is an efficient and short time-consuming method for TCEO extraction, which provides a promising method for the separation of EO from aromatic plant materials.

Recent advances in the implementation of ultrasound technology for the extraction of essential oils from terrestrial plant materials: A comprehensive review

“…Interestingly, extraction time also significantly impacts EOs yield across all conditions. Analogous reports have been documented by G. Li et al [6] on the extraction of EOs from Tribute citrus peels. The authors compared the HD and UAP methods and applied the Box-Bhenken design to optimize both processes.…”

“…These properties have led to the widespread application of EOs in food, medicine, and agriculture. While elucidating the mechanisms behind these properties is challenging, numerous researchers have endeavored to explore and expound upon these mechanisms [6] , [15] , [59] . The evaluation of EO antibacterial activity predominantly relies on two key methods: MIC and the measurement of the zone of inhibition (mm) in the agar-well diffusion technique [50] .…”

“…In the cosmetics industry, EOs play a role as fragrance components in perfumes, contribute to aromatherapy in skincare, and are incorporated into various products such as lip balms, massage oils, skincare products, and hair care products. EOs' versatility makes them valuable in these sectors, adding a wide range of flavor, aroma, and therapeutic properties to products [6] , [53] . Fig.…”

“… The highest extraction yield of 115.072 mg/g of EOs was obtained through the UAP at 40 min time. [6] UAP Lime peel US power = 100 W, frequency = 40 kHz, time = 30, 60, 90 and 120 min and Temp = 30 °C The EOs extraction yield increased by 7.69, 16.67, 37.66, and 23.38 % for peels subjected to ultrasound treatment for 30, 60, 90, and 120 min, respectively. [43] UAP Kumquat peel US power = 150, 210, 240, and 270 W, and time = 15, 20, 30, and 40 min.…”

“…These are volatile, concentrated liquids primarily comprised of diverse compounds, including terpenes, aldehydes, ketones, alcohols, esters, and oxides [1] , [2] , [3] , [4] . The secondary metabolites of plants are mainly derived from various plant materials, encompassing leaves, peels, seeds, flowers, barks, fruits, stems, and roots [5] , [6] , [7] . EOs have strong and pleasant smells because of their aromatic nature, distinguishing fragrances and scents for plants [8] , [9] , [10] .…”