Thesis (MScAgric (Viticulture and Oenology))--University of Stellenbosch, 2007. / Biogenic amines are nitrogenous compounds of low molecular weight found in most
fermented foods, including wine. These biologically produced amines are essential at
low concentrations for normal metabolic and physiological functions in animals, plants
and micro-organisms. However, biogenic amines can have adverse effects at high
concentrations and pose a health risk for sensitive individuals. Symptoms include
nausea, hot flushes, headaches, red rashes, respiratory distress and fluctuations in
blood pressure. A number of countries have implemented upper limits for histamine in
food and wine. This development has already started to threaten commercial export
transactions and may become more serious in the near future, especially in the
competitive wine industry of today. The most important biogenic amines in wine include
histamine, tyramine, putrescine, cadaverine and phenylethylamine which are produced
from the amino acids histidine, tyrosine, ornithine, lysine and phenylalanine
respectively.
Biogenic amines are mainly produced in wine by microbial decarboxylation of the
corresponding precursor amino acid. It may be produced by yeast during alcoholic
fermentation, by lactic acid bacteria during malolactic fermentation, or potentially by
spoilage microbes such as acetic acid bacteria and Brettanomyces. However, lactic acid
bacteria are widely accepted as the main causative agents.
Inoculation with commercial malolactic fermentation starter cultures that do not
possess the relevant decarboxylase genes may inhibit the growth and activity of
decarboxylase positive indigenous bacteria and as such control the production of
biogenic amines in wine. In this study it was shown that co-inoculation of malolactic
starter cultures together with alcoholic fermentation could reduce the incidence of
biogenic amines in wine compared to conventional inoculation protocols; presumably
because undesirable activities were restrained at an earlier stage during co-inoculation.
It was also indicated in this work that in some cases the effect of co-inoculation on
biogenic amine reduction may only be visible after a period of ageing. The frequency of
biogenic amine occurrence in wines aged for a short period was generally higher in the
presence of fermentation lees than in its absence.
This work also included a preliminary investigation into the contribution of
commercial wine yeast starter cultures to biogenic amine production. Diamines and
polyamines (putrescine, spermidine and cadaverine) were produced to variable extents
by all yeasts with very little or no production of physiologically important biogenic
amines (histamine, tyramine and phenylethylamine).
Another objective of this study was to evaluate the influence of common
winemaking practices on biogenic amine production under winemaking conditions. We
have shown that biogenic amine production by lactic acid bacteria could be influenced,
amongst others, by the presence of precursor amino acids in the grape must or wine,
the time of contact between juice or wine and grape skins, the time of contact between
wine and yeast lees, the presence of microbial nutrients, wine pH, sulphite and ethanol levels, the phenolic composition of the wine and the number of decarboxylase positive
lactic acid bacteria present in the wine.
Lately, the wine industry is under increasing pressure to increase measures to
ensure food safety and security and to eliminate any compound, present even in trace
amounts that could reduce the wholesomeness of the wine. The need arises for a rapid
and inexpensive method for quality control. In this study we investigated the potential to
use Fourier transform infrared spectroscopy to rapidly screen for the presence of
elevated levels of biogenic amines. This presents a novel method for the detection and
quantification of total biogenic amines in wines.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/2688 |
| Date | 12 1900 |
| Creators | Smit, Anita Yolandi |
| Contributors | Du Toit, M., Du Toit, W. J., University of Stellenbosch. Faculty of Agrisciences. Dept. of Viticulture and Oenology. |
| Publisher | Stellenbosch : University of Stellenbosch |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Rights | University of Stellenbosch |
Page generated in 0.0022 seconds