Laser-induced sound pinging for the rapid determination of total sugar or sweetener content in commercial beverages

• Published in: Talanta (Oxford) Vol. 240; p. 123034
• Main Authors: Bhawawet, Nakara, Larm, Nathaniel E., Adhikari, Laxmi, Polo-Parada, Luis, Gutiérrez-Juárez, Gerardo, Baker, Gary A.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.04.2022
• Subjects: Beverages; Beverages - analysis; Dietary Carbohydrates; Fructose; Lasers; Photoacoustic; Quality control; Speed of sound; Sugar; Sweetener; Sweetening Agents - analysis; Photoacoustic; Sweetener; Speed of sound; Beverages; Sugar; Quality control
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2021.123034

We recently reported on fixed-path length laser-induced sound pinging (FPL-LISP) as a rapid photoacoustic technique employing an inexpensive benchtop tattoo-removal laser for reliably determining the speed of sound in low-volume fluids. In this contribution, we demonstrate the capacity of FPL-LISP to analyze representative commercial beverages for their natural or artificial sweetener contents. As a benchmark, the speed of sound was determined for solutions of sugars (glucose, fructose, sucrose), mock high fructose corn syrup (HFCS-55), and 12 household sweeteners (culinary sugars, syrups, honey, molasses) across the concentration range of 1–20% w/v in water, simulating the typical sweetener range found in commercial soft drinks. The setup was then employed to estimate sweetener contents of 26 popular commercial beverages using the HFCS-55 standard curve as a training data set. Our results are remarkably consistent with the label values for these representative commercial beverages, in spite of the fact that some beverages clearly employ a sweetener other than HFCS-55 or a proprietary blend, suggesting the excellent potential of the FPL-LISP setup as a quick screening tool well-suited to quality control and real-time assessment in the beverage and fermentation industrial sectors. The proposed approach represents a significant improvement over many existing methods on the basis of measurement time (down to 1 s, which can be considered real time for many applications), lenient sample requirements (tens of microliters to 1 mL), robust and user-friendly analysis, practical considerations (e.g., economical, minimal service and maintenance concerns), and prospects for advancing both online monitoring and fully portable versions of this instrumentation. [Display omitted] •Laser-induced sound pinging for determination of sweetener content in beverages.•Rapid, non-destructive, low-volume, and inexpensive photoacoustic analysis.•Potential for online monitoring and fully portable quality control applications.