micro-oxygenation in contemporary winemaking - Cape Wine ...

Micro-oxygenation in Contemporary Winemakingneeds to be based on current best practice and tasting panels need to be properlyconstituted and analysed correctly. Another significant problem in these studies is thetiming of when the endpoints are evaluated. Significant differences that are foundimmediately after the micro-oxygenation treatment may not persist after subsequentoenological manipulation and maturation which means, in fact, that that impact of thetreatment on the final product delivered to the consumer is negligible.7.3 DESCRIPTION OF IDENTIFIED STUDIESThe key characteristics of the 19 English language scientific evaluations of microoxygenationI identified are summarised in Table 18. All of these studies were published inthe last decade and there is clearly a rapidly growing literature on the subject since morethan half of the articles were published in the last two years.A wide range of different grape varietals were used in the trials and this is certain toinfluence the results obtained (Pérez-Magariño et al., 2009). It is encouraging that two ofthe papers (du Toit et al., 2006a; de Beer et al., 2008) are from South African researchersusing local varietals. All of the study designs included a control wine for comparison thoughthe nature of that control differed between studies. Earlier research tended to compareMOX-treated wines against untreated controls whereas the more recent investigationshave used more realistic comparison groups.The timing, dose and duration of micro-oxygenation employed was quite variable. Anumber of the initial studies investigated MOX treatment after malolactic fermentation (postMLF) whereas, in keeping with current practice, later investigations have used pre-MLFMOX, or treatments both before and after malolactic fermentation. Again, this variationmakes it extremely difficult to compare the findings of different studies.The vast majority of the identified studies focused on changes in colour and phenoliccomposition of treated wines. There are only three reported studies which haveinvestigated the effect on aroma compounds, three which measured wine anti-oxidantstatus, and only one which has evaluated the impact on microbiological stability with anyrigour (Table 18). At present in the literature there are only five studies which havescientifically evaluated the impact of MOX using sensory panels. Most of the reportedstudies did have replicates and undertook some statistical analyses although this wasusually fairly limited.60