Bioprotection on Chardonnay Grape: Limits and Impacts of Settling Parameters

Abstract

Background and Aims. If bioprotection has already been proven to limit the development of spoilage flora on musts, its effectiveness against oxidation depends on the winemaking process. To optimize its application, this study analyzed the evolution of the chemical composition of the bioprotected musts and wines, according to different settling routes. Their impacts on the organoleptic characteristics of wines were also studied. Methods and Results. A bioprotected must was subjected to 6 different maceration routes before AF (triplicates), varying the duration and temperature parameters. A temperature value ≤12°C was the main factor independently of the duration which allowed a good implantation of the bioprotectant. An increase of the maceration duration at 12°C led to browning of the must, without significant effect on the final color of the wine, which was felt as more “floral,” with more length in the mouth. Conclusions. The bioprotectant implantation and its effectiveness on the sensory profile of the wine was guaranteed at maceration temperature values lower than 12°C. Significance of the Study. This study participates in the improvement of the bioprotection management in white winemaking, with the guarantee of a positive impact of the prefermentation maceration without sulphites on the organoleptic profile of the wines.

Competition for Nitrogen Resources: An Explanation of the Effects of a Bioprotective Strain Metschnikowia pulcherrima on the Growth of Hanseniaspora Genus in Oenology

“…Indeed, its efficiency was demonstrated when inoculated with H. valbyensis but was not found when inoculated with H. uvarum. These results may seem surprising in view of the previous results from the field trials, in which the bioprotective strain was shown to be established and to predominate over the indigenous flora, even when a high proportion of H. uvarum was present [ 10 , 53 , 54 ]. These results need to be confirmed on other strains belonging to these species.…”

“…A wide range of commercial active dry NS yeasts are currently sold by manufacturers as bioprotective yeasts, mainly from Metschnikowia and Torulaspora genera [ 8 ]. The efficiency of bioprotection was previously proven in field trials with a reduction in indigenous yeasts growth through the addition of bioprotection [ 9 , 10 , 11 , 12 , 13 , 14 ], without a thorough investigation of the physiological mechanisms involved. Numerous interactions occur in the microbial world and fall into two main groups: direct (cell–cell contact) or indirect interactions (nutrient competition, toxic compound production, quorum-sensing, enzymatic activity, etc.)…”

Bio-protection in oenology by Metschnikowia pulcherrima: from field results to scientific inquiry

“… Main results on bio-protection obtained in field trials (From data published in journals for professionals and in Chacon-Rodriguez et al, 2020 ; Simonin et al, 2020 , 2022 ; Windholtz et al, 2021a , b,c ; Agarbati et al, 2023 ; Puyo et al, 2023 ). …”

“…In white winemaking, a M. pulcherrima strain was tested on Chardonnay must using three temperatures (7°C, 12°C and 18°C) and two settling times (36 and 72 h) in order to determine the optimal conditions for a bioprotective effect ( Simonin et al, 2022 ). The results showed a considerable impact of temperature on the bioprotectant implantation.…”

“…The implantation of M. pulcherrima during a cold static clarification of a Verdicchio must at low temperature (10°C, 24 h) and its control on indigenous wild yeast populations were confirmed by the work of Agarbati et al (2023) . However, an increase in settling temperature to 18°C did not allow the implantation of the bio-protection strain and therefore the control of indigenous flora ( Simonin et al, 2022 ). The impact of bio-protection on the organoleptic qualities of wines gave contradictory results, depending on the grape varieties tested.…”