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Showing posts from October, 2019

Oregano essential oils prime plant immunity to fight downy mildew

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By Lucinda Heyns

In this study, researchers wanted to better understand how essential oils (EO) can help to protect grapevines against downy mildew. Essential oils (EO) are considered promising compounds for use in plant protection as studies have indicated their antibacterial, antiviral and antifungal properties on numerous crops. The challenge is that their efficiency is dependent on factors such as timing of application, application methods and interaction between the host, the pathogen and the essential oil (EO).
PROJECT LAYOUT: Researchers wanted to determine: Whether continuous fumigation of grapevines with EO can control downy mildew. Through fumigation, some of the challenges regarding direct application could be avoided. What mechanisms were triggered inside the plant and the pathogens when exposed to EO. Whether EO represses downy mildew oomycetes or primes plant resistance.A custom-built chamber was used. This chamber allowed for continuous fumigation of potted vines with d…

New frontiers in quantifying smoke taint in vineyards

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By Lucinda Heyns

The aim of this projects was to start development of a non-destructive, in field method to detect what the extent of smoke taint is in grapevine canopies, after exposure to smoke from fires.
PROJECT LAYOUT: Seven cultivars were exposed to smoke under controlled conditions in two sites over two seasons. Sauvignon Blanc, Pinot Gris, Chardonnay and Pinot Noir in a commercial vineyard in Adelaide Hills region was used and Shiraz, Cabernet Sauvignon and Merlot in a vineyard in Adelaide. In the first part, physiological measurements were taken inside the canopy to determine degree of smoke contamination after exposure to smoke: Stomatal conductance was measured and infrared thermal images were acquired. Using machine learning modelling based on pattern recognition, which is based on predictable changes in stomatal conductance patterns as determined from infrared thermal image analysis, a model was developed to detect the degree of smoke contamination in canopies.
In the seco…

The effect of music on wine tasting

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By Karien O'Kennedy

Italian researchers did a study on the effect of music on the taste of wine. The motivation for such a study is valid since it is well documented and researched that taste can be a multi-sensory phenomenon. However, how these scientists went about researching this phenomenon is rather entertaining.
Disclaimer: This article is an opinion piece and the opinions expressed in this article are my own (Karien O’Kennedy) and may or may not represent the general opinions of Winetech.
EXPERIMENTAL LAYOUT Eleven women and 19 men with a mean age of 29.8 years were used as tasters of two different wines while two different types of music (or no music) played.These participants were unaware of the purpose of the experiment.The one wine was a Chardonnay and the second wine was a homemade Merlot (made apparently by using a crusher).The wines were served to the participants in plastic cups (Eish!)BOTH white and red wine (40 ml per tasting) was served at 5°C. Three music variable…

The effect of berry shrivelling on Shiraz wine composition and sensory characteristics

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By Karien O'Kennedy

The aim of the study was to determine the effect of late-season Shiraz berry dehydration (berry shrivel) on the chemical and sensory properties of the resulting wine.
PROJECT LAYOUT Shiraz grapes were harvested on 25 February 2016 from a commercial vineyard (8 – 10 t/ha) in New South Wales, Australia. Grape bunches were manually sorted into two groups: shrivelled and non-shrivelled. Grape bunches with 80% or more shrivelled berries were classified as shrivelled. The individual shrivelled berries in the non-shrivelled bunches were manually removed. 25 kg of grapes were fermented in triplicate for each treatment in 100L stainless steel tanks. pH was adjusted with tartaric acid to 3.6 three times during the winemaking process.Fermentation was conducted with EC 1118 between 24 and 28°C. The must was inoculated one day after the start of alcoholic fermentation with MLF culture: Enoferm Alpha. YAN was adjusted to 250 mg/L with DAP and Fermaid A after the onset of fermen…