Alcoholic Beverages Virtual Symposium: Wine

Join Agilent and GERSTEL for a 3-day live virtual seminar discussing how you can assure safety, authenticity, and quality of alcoholic beverages. The focus will be on sharing the latest in technology developments and capabilities, new applications, and customer stories.

Presentation 1: Comparison of Headspace GC-MS Techniques to Characterize Volatile Phenols contributing to Smoke Taint in Pinot Noir Wines

• Stephen Toth, GCMS Specialist in the Structure Elucidation Department – International Flavors & Fragrances (IFF)

A series of volatile phenols originating from smoke tainted grapes exposed to regional fires have been known to exhibit undesirable sensory characteristics such as smoky, burnt, ashy and medicinal flavoring in affected wines. This can be negatively perceived by consumers and often leads to an aftertaste of these characteristics lingering in the mouth after the wine has been swallowed. Wildfires plagued the counties in northern California and Oregon during the 2020 wildfire season from August through October. These fires severely impacted the grape harvest and challenged wine makers as many of their vineyards were either destroyed or their crops were contaminated with smoke taint. Numerous wineries opted to release limited amounts of 2020 Pinot Noir for this reason or produce rosé or white wines from affected grapes. Our research will look specifically at three different vintages (2019, 2020 and 2021) of Pinot Noir from the same vineyard in the Willamette Valley region of Oregon. It should be noted that “smoke” as an indicator of taste in wines is not always an indicator of smoke taint but can also be imparted into the wine by aging in oak barrels.

We will compare headspace based GCMS techniques to characterize these wines and profile the volatile phenol content. Solid phase micro extraction (SPME) and stir bar sorptive extraction (SBSE) will be used to analyze both free volatile content and gylcosidically bound phenolic content. The free volatiles will be acquired in unaltered wine to best represent the consumer’s initial experience. These samples will then experience a pH adjustment, sonication and heat treatment to release gylcosidically bound phenolic compounds which could potentially be released over time by aging the wine.

Our research will characterize the phenolic compounds contributing to the smoke taint odor and flavor present in the Pinot Noirs against the sugar bound compounds that can potentially release over the shelf life of the wine utilizing SPME and SBSE extraction methods. Additionally, the comparison of vintages will indicate whether the phenolic characteristics obtained by GCMS can be used to capture the smoke defect in the wine profile from 2020.

Key Learning Objectives/What attendees will learn:

1. Theory and applicability of SHS, SPME, SBSE, TF-SPME, DHS, and pyrolysis.

2. How to decide on the most optimal extraction technique based on research challenges.

Presentation 2: An Exploration of Phenolics in Red Wines: Chemical and Sensory Effects of Selected Winemaking Techniques

• Dr. L. Federico Casassa, Associate Professor, Enology, Cal Poly

This presentation discusses how the winemaker can manage winemaking elements – those over which we have control – to develop, evolve and enhance mouthfeel, with focus on phenolic compounds in grapes and wines from the Central Coast of California. The discussion then covers which elements can be leveraged and managed during the production of the wine. There are known protocols for grapes, yeast, fermentation, and aging. However, the challenge for the winemaker is to understand how our various treatments affect the end product. This presentation covers the effects of fermentation temperatures, cold soaking and how the manipulations of these elements can be used to modulate astringency and mouthfeel in the wines.

Presenter: Stephen Toth (GCMS specialist in the Structure Elucidation Department, International Flavors & Fragrances (IFF))

Stephen Toth is a GCMS specialist in the Structure Elucidation Department at International Flavors & Fragrances (IFF) in Union Beach, NJ. He has spent his lengthy career at IFF working in fragrance delivery, chromatography and ultimately in the mass spectrometry group where part of his role is scouting out new technologies. He is very active in the Agricultural and Food Chemistry Division of the American Chemical Society and currently serves as the treasurer and executive board member. He has edited multiple books and has organized several analytical and flavor chemistry symposia at national meetings. He also serves as a graduate student mentor for the division. He holds a B.S. and M.S in chemistry from Seton Hall University and a Ph.D in food science from Rutgers University.

Presenter: Dr. L. Federico Casassa (Associate Professor, Enology, Cal Poly)

Dr. Casassa’s research focus lies on the broad areas of grape and wine chemistry and biochemistry and their sensory implications, with especial emphasis on applied research. He has been involved in research projects focusing on the impact of irrigation techniques, especially Regulated Deficit Irrigation. Current and ongoing research projects include studies on the extraction of phenolics of sensory relevance during the course of different maceration techniques in red wines, coupled with other regulating factors and their sensory impact as evaluated by formal sensory evaluation techniques.