GCMS Investigation of Volatile Compounds in Green Coffee Affected by Potato Taste Defect and the Antestia Bug

Abstract

Potato taste defect (PTD) is a flavor defect in East African coffee associated with Antestiopsis orbitalis feeding and 3-isopropyl-2-methoxypyrazine (IPMP) in the coffee. To elucidate the manifestation of PTD, surface and interior volatile compounds of PTD and non-PTD green coffees were sampled by headspace solid phase microextraction and analyzed by gas chromatography mass spectrometry. Principal component analysis of the chromatographic data revealed a profile of surface volatiles distinguishing PTD from non-PTD coffees dominated by tridecane, dodecane, and tetradecane. While not detected in surface volatiles, IPMP was found in interior volatiles of PTD coffee. Desiccated antestia bugs were analyzed by GCMS, revealing that the three most prevalent volatiles were tridecane, dodecane, and tetradecane, as was found in the surface profile PTD coffee. Coffee having visible insect damage exhibited both a PTD surface volatile profile and IPMP in interior volatiles, supporting the hypothesis linking antestia bug feeding activity with PTD profile compounds on the surface and IPMP in the interior of the beans.

Analysis of volatile profiles of green Hawai'ian coffee beans damaged by the coffee berry borer (Hypothenemus hampei)

“…Notably, Jackels et al . used GC–MS and PCA to identify differences in green coffee bean volatile profiles after damage by the variegated coffee bug (A. thunbergii ) . The study differentiated between samples exhibiting the ‘potato taste defect’ that occurs in infested beans as a result of A. thunbergii by quantitatively tracking the variation in GC–MS traces.…”

“…Others have used PCA in volatile assessment to categorize coffee beans based upon quality, damage, or regional identity. In a study by Jackels et al ., GC–MS profiles were used with PCA to differentiate between undamaged green coffee beans and beans that had been damaged by another insect pest, Antestiopsis thunbergii (Gmelin) (= A. orbitalis (Westwood)) (Hemiptera: Pentatomidae), which is responsible for potato taste defect . Similarly, Toci and Farah used solid‐phase microextraction (SPME) and GC to develop a ‘volatile fingerprint’ for Brazilian coffees with varying degrees of damage and over a range of ripeness .…”

Relationship Between the Different Aspects Related to Coffee Quality and Their Volatile Compounds

“…Compounds from a wide variety of chemical classes, such as aldehydes (2‐butenal, 2‐methylpropanal*, 3‐methylbutanal, and 2‐methylbutanal*), acetic acid, ethers (1‐methoxy‐3‐methylbenzene and 2,4,6‐trichloroanisole), alcohols (dimethyl‐3‐octenol, 2‐methylisobutanol, 2‐methyl‐1‐propanol, 3‐methyl‐1‐butanol, 1‐octen‐3‐ol, 2‐nonanol, hexan‐1‐ol, 4,8a‐dimethyl‐decahydronaphthalen‐4a‐ol (geosmin), and 1,2,7,7‐tetramethylbicyclo[2.2.1]heptan‐2‐ol (2‐methylisoborneol), pyrazines (3‐isopropyl‐2‐methoxypyrazine* and 3‐isobutyl‐2‐methoxypyrazine*), ketones (1‐octan‐3‐one*, pentadecan‐2‐one), phenols (3‐methyl‐1‐methoxyphenol), thiols (dimethyl disulfide, and 2‐furfurylthiol*), hydrocarbons (methylbenzene, 1,3‐bis‐1,1‐dimethylethylbenzene, 7‐methyl‐3‐methylene‐1,6‐octadiene), and an ester (2,6‐bis‐(1,1‐dimethylethyl)‐4‐acetate) have been identified as responsible for negative notes in coffee. However, none of compounds mentioned has been associated with characteristic defects listed in the Official Brazilian Classification (COB), related to the type of drink or to microbial development in the seeds (Guyot and others ; Spadone and others ; Borjesson ; Cantergiani and others ; Morais and others ; Ribeiro and others ; Iamanaka and others ; Jackels and others ).…”

“…According to Toledo and Barbosa () and Bee and others (), only slight changes in sensory aspects of the beverage such as acidity and bitterness were noticed, but the sensory impact of the presence of 1‐(2‐methyl‐phenyl)‐ethanone in raw seeds should be thoroughly investigated after the roasting of the seeds. However, the odiferous compounds 3‐isopropyl‐2‐methoxypyrazine* and 3‐isobutyl‐2‐methoxypyrazine*, which results in a flavor defect known as potato taste, has been associated with the Antestia Bug ( Antestiopsis orbitalis ) infestation in East African coffee (Jackels and others ).…”

Metabolic Profiling of Wastes from Raw and Ripe Mango Seeds to Comprehend Its Beneficial Medicinal and Cosmetic Properties for Commercialization

“…In fact NMR and GC-MS/LC-MS are the most widely used tools in metabolomics analysis (Chen et al, 2014;Coen et al, 2008;Grosch et al, 2013;Jackels et al, 2014;Nobakht et al, 2016;Scalbert et al, 2009;Smolinska et al, 2012;Sumner et al, 2003;Ulrich et al, 2008;Zekeya et al, 2014). NMR spectroscopy offers a readily usable technique, which has sensitivity at nM concentrations.…”