Quantitative determination of geosmin in red beets (Beta vulgaris L.) using headspace solid-phase microextraction

Area of Science:

• Analytical Chemistry
• Food Science
• Agricultural Science

Background:

• Geosmin is an earthy-smelling compound that can affect the flavor of root vegetables like red beets.
• Accurate quantification of geosmin is crucial for maintaining the quality and consumer acceptance of red beet products.

Purpose of the Study:

• To develop and validate an improved analytical method for determining geosmin concentrations in red beets.
• To assess the suitability of headspace solid-phase microextraction (HSPME) for routine geosmin analysis in red beet matrices.

Main Methods:

• Utilized headspace solid-phase microextraction (HSPME) with a polydimethylsiloxane/divinylbenzene fiber for volatile extraction from red beet juice.
• Employed gas chromatography (GC) for the separation and quantification of extracted geosmin.
• Optimized extraction time and desorption conditions for efficient geosmin recovery.

Main Results:

• The developed HSPME method demonstrated high relative recovery (99.2%) and a low relative standard deviation (7.48%).
• Achieved a practical detection limit of 1 microg/kg in beet root tissue, suitable for quality control.
• Geosmin concentrations varied among four red beet cultivars, ranging from 9.69 +/- 0.22 to 26.7 +/- 0.27 microg/kg.

Conclusions:

• Headspace solid-phase microextraction (HSPME) is a reliable and efficient technique for the determination of geosmin in red beets.
• The method's high accuracy and sensitivity enable effective quality assessment of different red beet cultivars.
• This analytical improvement supports the food industry in managing off-flavors and ensuring product consistency.