Degree Type

Thesis

Date of Award

2014

Degree Name

Master of Science

Department

Food Science and Human Nutrition

First Advisor

Cheryll A. Reitmeier

Second Advisor

Murlidhar R. Dharmadhikari

Abstract

The La Crescent grape, a cross of St. Pepin and an unnamed Swenson selection (Vitis riparia x Muscat Hamburg), is a cold-hardy cultivar gaining popularity throughout the Midwest. Due to its recent introduction, there is a considerable amount to be learned about the characteristics of wines made from the grape. To investigate the aromas specific to the wine, research lots of wine were produced from La Crescent juice contributed by a commercial Iowa winery over two vintages (years 1 and 2). Juice and wines were analyzed chemically by HPLC and bench-top methods. Descriptive sensory analysis was conducted by a trained sensory panel following each vintage. Samples evaluated were dry and off-dry versions of the research La Crescent wines, a commercial La Crescent wine from the contributing winery, and a commercial Moscato wine, included for comparison. Aroma and flavor attribute intensities were measured separately in year 1 and as a combined response for aroma in year 2. Sweetness and acidity were also evaluated. Six descriptors were identified in year 1, and 7 in year 2. Grapefruit, lychee, pineapple and rose attributes were common to the sensory panels for both vintages. Apricot (year 1) and peach (year 2) were also useful in describing La Crescent wines however, variations in panel make-up or training likely led to their interchangeable in the study. In year 1, grapefruit and pineapple were the most intense aromas in all La Crescent wines. In the Moscato wine, rose and lychee were the most intense aromas. Grapefruit flavors were more intense in research wines than in commercial wines, while apricot flavors were more intense in commercial wines than in research wines. Flavor ratings were affected by sweetness and acidity perceptions. In year 2, all wines were best characterized by rose and lychee. Principal component analysis (PCA) accounted for 59 and 63 percent of the variability in years 1 and 2, respectively. Wines were mainly separated by sweetness and acidity on the first principal component. Grapefruit, pineapple, rose and lychee were the most intense aromas/flavors expressed in dry, off-dry and commercial La Crescent wines and are important descriptors for these wines.

Copyright Owner

Jennifer R. Savits

Language

en

File Format

application/pdf

File Size

98 pages

Included in

Food Science Commons

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