CHANGES IN QUALITY AND COMPOSITION PRODUCED IN WINE BY COBALT-60 GAMMA IRRADIATION

Journal Article · Sat Jun 01 04:00:00 EDT 1963 · Food Technology (U.S.)

OSTI ID:4160832

Singleton, V L

Glass-bottled red port, white port, dry red table wine, and dry white table wine purged with nitrogen and airsaturated dry sherry material were irradiated with and sensory evaluation showed considerable changes after irradiation. The bottle glass changed from colorless to greenish-brown. The wines were under a small positive pressure when opened, both white and red wines were bleached, and odor and flavor were changed. Analytical results showed no changes in extract, ethanol, volatile esters, or volatile acid, but a slight increase in pH and decrease in total acidity upon irradiation. Changes in spectral absorption were great; absorbance diminished at every wavelength, but not proportionately. All untreated wines showed a maximum at 265 to 85 m mu and a shoulder at about 320 m mu , and the red wines the typical maximum near 520 m mu , which was much decreased by irradiation. The absorbance at 320 m mu was greatly decreased and the shoulder disappeared, leaving only the residual absorption from the more intense but less affected peak at 265 to 85 m mu (absorption at these wavelengths is attributed largely to their content of flavonoid, polyphenolic substances). No appreciable change in the tannin (total polyphenolic) constant was seen, but paper chromatographic studies showed definite qualitative and quantitative changes in polyphenols The oxidation- reduction potential was greatly lowered by irradiation, and volatile substances reacting as aldehydes were produced in considerable amounts, confirming that definite, selective, and specific compositional changes are produced in wine by gamma irradiation at feasible dose levels. With wines flavor-rated by experienced judges with reference to standard wine types, large changes were produced by 500,000 and 1,000,000 rad. Grape aroma rating was significantly decreased in all cases by the higher levels of irradiation. A radiation-induced flavor seemed similar, regardless of the type of wine irradiated. Descriptive terms suggested by the panel for this flavor included cheesy, fishy, perfumy, leathery, sulfurish, fatty, metallic, aged-European-wine-like, whey-like, burned, mushroomy, and fruity. However, comments were favorable on the flavor and odor induced by high levels of radiation by 5 of the 14 panelists. The possibility of favorably influencing the quality of standard types of wine by irradiation near or below 100,000 rad seems worthy of further study, it was concluded. (BBB)

• Research Organization: Univ. of California, Davis
• NSA Number: NSA-18-000523
• OSTI ID: 4160832
• Journal Information: Food Technology (U.S.), Journal Name: Food Technology (U.S.) Vol. Vol: 17; ISSN FOTEA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ABSORPTION
ACIDITY
ACIDS
ALDEHYDES
CHEMICALS
CHROMATOGRAPHY
COBALT 60
COLOR
ESTERS
ETHANOL
FOOD
GAMMA SOURCES
IRRADIATION
ISOTOPE TECHNOLOGY
ODOR
OXIDATION
PHENOLS
RADIATION DOSES
RADIATION EFFECTS
REDUCTION
SPECTRA
STABILITY
TANNIC ACID
VOLATILITY
WINE