Foster Sarah C, Cheung Cynthia, Tipton Laura, Baker Jonathan D, Keahi-Wood Kahoalii K, Perrault Uptmor Katelynn A
Nontargeted Separations Laboratory, Chemistry Department, William & Mary, Williamsburg 23185, Virginia, United States.
Laboratory of Forensic and Bioanalytical Chemistry/Forensic Sciences Unit, Chaminade University of Honolulu, Honolulu 96816, Hawaii, United States.
ACS Omega. 2025 May 15;10(20):20754-20762. doi: 10.1021/acsomega.5c01820. eCollection 2025 May 27.
Taro (Colocasia esculenta L.) is a plant originating from Southeast Asia now prevalent throughout the Pacific Islands. Growing taro was and remains an important facet of the Hawaiian culture. Poi is a food product prepared from steamed taro that has been macerated and allowed to ferment. While poi is commonly prepared at home, it can also be found commercially from select Hawaiian brands. The general fermentation process of poi produces volatile organic compounds (VOCs) such as alcohols, aldehydes, ketones, organic acids, esters, and heterocycles, among others, through microbial and enzymatic reactions. The VOCs found in poi are a class of compounds traditionally analyzed through gas chromatography (GC)-mass spectrometry (GC-MS) but have not previously been characterized in the literature. This study aimed to identify a core VOC profile of commercial poi products to better understand sample composition. Changes in fresh to aged poi were observed as well as its brand specific profiles. Analysis was conducted using comprehensive two-dimensional GC-quadrupole mass spectrometry with flame ionization detection (GC×GC-qMS). Samples were prepared according to package instructions, extracted via headspace SPME Arrow, and analyzed in replicates of 10. A total of 56 analytes were identified across three brands of commercial poi, ranging from 11 different compound classes. All brands showed a clear distinction between fresh and aged samples. Fresh samples across all brands contained 4,4-dimethoxy-3-methylbutan-2-one while aged samples all contained 2,5-dimethylfuran. Within the fresh state, the VOC profiles from each brand appeared to be distinct from one another. Taro brand poi was the least similar to Hanalei brand poi and He Mea Ono brand poi. He Mea Ono and Hanalei had some overlap in VOCs, but a substantial portion of their VOC profile was unique to the individual brand. In the aged state, there was a significant overlap among all three brands, which indicates that fermentation caused the VOC profiles to become more similar to one another. Visual distinctions in chromatographic plots were supplemented by principal component analysis and box plots, identifying distinguishing compounds. Investigating the profile of poi via GC×GC-qMS enhanced our understanding of its unique qualities, historical context, and contemporary use.
芋头（Colocasia esculenta L.）是一种原产于东南亚的植物，如今在整个太平洋岛屿都很常见。种植芋头过去是且现在仍然是夏威夷文化的一个重要方面。芋泥是一种由蒸熟的芋头制成的食品，经过浸渍和发酵而成。虽然芋泥通常是在家里制作的，但也可以从一些特定的夏威夷品牌购买到。芋泥的一般发酵过程通过微生物和酶促反应产生挥发性有机化合物（VOCs），如醇类、醛类、酮类、有机酸、酯类和杂环化合物等。芋泥中发现的挥发性有机化合物是一类传统上通过气相色谱（GC）-质谱（GC-MS）分析的化合物，但此前在文献中尚未有过特征描述。本研究旨在确定商业芋泥产品的核心挥发性有机化合物谱，以更好地了解样品组成。观察了新鲜芋泥到陈化芋泥的变化以及其品牌特定谱。使用全二维气相色谱-四极杆质谱联用火焰离子化检测（GC×GC-qMS）进行分析。样品按照包装说明制备，通过顶空固相微萃取箭形纤维进行萃取，并进行10次重复分析。在三个商业芋泥品牌中总共鉴定出56种分析物，分属于11个不同的化合物类别。所有品牌的新鲜样品和陈化样品之间都有明显区别。所有品牌的新鲜样品都含有4,4-二甲氧基-3-甲基丁-2-酮，而陈化样品都含有2,5-二甲基呋喃。在新鲜状态下，每个品牌的挥发性有机化合物谱似乎彼此不同。芋头品牌的芋泥与哈纳雷品牌和He Mea Ono品牌的芋泥最不相似。He Mea Ono和哈纳雷在挥发性有机化合物方面有一些重叠，但它们的大部分挥发性有机化合物谱是各个品牌独有的。在陈化状态下，所有三个品牌之间有显著重叠，这表明发酵使挥发性有机化合物谱彼此变得更加相似。色谱图中的视觉差异通过主成分分析和箱线图得到补充，从而识别出有区别的化合物。通过GC×GC-qMS研究芋泥的谱增强了我们对其独特品质、历史背景和当代用途的理解。
