PHILADELPHIA, PA –– Xylem’s OI Analytical brand 5380 Pulsed Flame Photometric Detector (PFPD) has aided researchers in the differentiation of sulfur volatiles in ripening strawberry crops. Xylem’s OI Analytical brand will be exhibiting in booth # 1449 at Pittcon 2013, March 18-21 in Philadelphia, Pennsylvania.

Strawberries are the second most important commercial fruit product in the state of Florida. A major portion of the U.S. supply of strawberries during winter and early spring comes from Florida. The commercial value of strawberries is affected by their state of ripening when harvested and the time required to reach consumers. Unfortunately, information on aroma profile changes during strawberry maturation is very limited.

Volatile sulfur compounds are common in food products and are generally formed by the degradation of sulfur-bearing amino acids such as cysteine and methionine, as well as some vitamins. Most sulfur volatiles are not present during early stages of strawberry maturation, so characterization of volatile sulfur compounds can help differentiate fruit that is commercially ripe, fully ripe, and overripe.

Identifying and quantifying volatile sulfur compounds is difficult because they are present at sub-microgram per kilogram levels. Some sulfur volatiles have olfactory thresholds below this level. Assessing changes in volatile sulfur compound concentrations as strawberries ripen requires an analytical technique that is highly sensitive and selective for sulfur species.

Researchers with the Citrus Research and Education Center at the University of Florida used a gas chromatograph equipped with an OI Analytical 5380 pulsed flame photometric detector (PFPD) to help identify and quantify volatile sulfur compounds in two strawberry cultivars and determined their relative concentration at five different stages of maturity. Results of the study were published in the Journal of Agricultural and Food Chemistry.¹

Nine new sulfur esters were identified in this study. The PFPD is very sensitive and selective for sulfur and detected the presence and concentration of these compounds. In some cases the concentrations were too low to produce peaks in a mass spectrometer total ion chromatogram. These previously unknown sulfur esters were identified by SIM – selective ion monitoring MS and matching retention times from PFPD chromatograms.

In addition to detecting new sulfur compounds the sulfur-specific chromatograms from the PFPD enabled the researchers to discern differences in sulfur volatile profiles between the two strawberry cultivars. The researchers observed that, “individual sulfur volatiles were profoundly different at almost every maturity stage.”

The sophisticated detection capabilities of the OI Analytical 5380 pulsed flame photometric detector when combined with the gas chromatograph, and the resulting differentiation of sulfur volatiles provides a greater understanding of strawberry crops as they ripen. This information is critical to strawberry producers, enabling a more accurate assessment of the condition of their produce as it progresses to market and ultimately to the consumer.

Xylem will showcase its analytics solutions and applications in booth # 1449 at Pittcon 2013, March 18-21 in Philadelphia, Pennsylvania.

To learn more about OI Analytical, as well as the complete range of analytics products from Xylem please visit www.xylemanalytics.com

¹ Identification of New Strawberry Sulfur Volatiles and Changes during Maturation, X. Du, M. Song, and R. Rouseff, Journal of Agricultural and Food Chemistry, 2011, 59, 1293-1300.

About Xylem Analytics

Xylem’s analytics businesses are leading manufacturers of premium field, portable, laboratory and online analytical instruments used in water and wastewater, environmental, food and beverage, pharmaceutical and life science applications. The company’s meters, sensors, analyzers and related consumables are used every day by thousands of end-users worldwide to analyze and control quality in countless industrial applications where precise measurement is required. Xylem’s analytics business has been created over the past three years with a series of acquisitions, including OI Analytical, YSI and MJK Automation, which have been added to the core businesses of WTW, SI Analytics, Aanderaa Data Instruments (AADI), Global Water Instrumentation, ebro and Bellingham & Stanley. www.xylemanalytics.com.

About Xylem

Xylem (XYL) is a leading global water technology provider, enabling customers to transport, treat, test and efficiently use water in public utility, residential and commercial building services, industrial and agricultural settings. The company does business in more than 150 countries through a number of market-leading product brands, and its people bring broad applications expertise with a strong focus on finding local solutions to the world’s most challenging water and wastewater problems. Xylem is headquartered in White Plains, N.Y., with 2012 revenues of $3.8 billion and 12,500 employees worldwide. In 2012, Xylem was named to the Dow Jones Sustainability World Index for advancing sustainable business practices and solutions worldwide.

The name Xylem is derived from classical Greek and is the tissue that transports water in plants, highlighting the engineering efficiency of our water-centric business by linking it with the best water transportation of all — that which occurs in nature. For more information, please visit us at www.xyleminc.com.