رسائل ماجيستير
English
2024
Aroma profile characterization of selected types of Omani honey by gas chromatography-mass spectrometry electronic nose
Yusra Saleh Ali Al-Busaidiyah , Zahir Humaid Al-Attabi
كلية العلوم الزراعية والبحرية-جامعة السلطان قابوس · عمان
Honey is a supersaturated natural solution of sugars produced by bees from floral nectar. Throughout history, certain types of honey—especially monofloral varieties—have been valued for their unique flavor, medicinal properties, and cultural significance. Volatile organic compounds (VOCs) play a key role in defining honey’s aroma and in identifying its botanical origin. Understanding the chemical composition and sensory characteristics of honey is essential for ensuring its quality and authenticity in the marketplace.
In this study, six types of Omani honey (Sumer, Sidr, Luban, Eatam, Talh, and Rub’ Al-Khali) were analyzed for their physicochemical properties—including moisture, total soluble solids (TSS), ash, protein, sugars, pH, hydroxymethylfurfural (HMF), and CIELAB color parameters—as well as their aroma profiles using an electronic nose (E-nose) and solid-phase microextraction gas chromatography–mass spectrometry (SPME-GC-MS). This study represents the first attempt to analyze the headspace aroma profile of Omani honey.
The physicochemical analysis showed that Rub’ Al-Khali honey had the highest moisture content (16.39%), while Talh honey exhibited the highest TSS (79.17 °Brix). Sumer honey showed the highest ash (1.18%), protein (1.77%), and total sugar content (65.27%). Sidr honey had the highest pH level (5.55). The highest HMF concentration was found in Talh honey (305.61 mg/kg), while HMF contents in all other honey samples were within the Gulf Standard Organization (GSO) recommended limit (0–44.37 mg/kg), confirming that the tested honeys were free from any heat treatment.
All six honey types had moisture contents within the safe range for storage and consumption (14.39–16.39%) and pH values ranging from 2.97 to 5.55. Total sugar content exceeded 60% in all samples except Talh honey (59.67%). Based on CIELAB color analysis, all samples—except Talh honey—were classified as light-colored honey.
Aroma profile analysis demonstrated the effectiveness of the E-nose in distinguishing between different honey types and classifying them into groups based on botanical origin. In E-nose analysis, Linear Discriminant Analysis (LDA) provided better classification than Principal Component Analysis (PCA). Moreover, the Artificial Neural Network (ANN) achieved an accurate classification rate of 91.11%.
GC-MS analysis identified a total of 185 volatile organic compounds (VOCs), with 31, 50, 42, 57, 45, and 126 VOCs detected in Sumer, Sidr, Eatam, Talh, Rub’ Al-Khali, and Luban honeys, respectively. While some VOCs were common across all samples—ten compounds were detected in every sample—several VOCs were unique to specific honey types, serving as potential markers. Notably, 71 compounds were found exclusively in Luban honey.
These findings highlight the significant variation in aroma profiles associated with different floral sources. The observed differences underscore the critical role of botanical origin in shaping the sensory attributes of honey, contributing to a deeper understanding of honey quality and consumer preferences.