IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Influence of successive oxygen saturations of a grape juice, supplemented or not with laccase, on its color and hydroxycinnamic acids concentration

Influence of successive oxygen saturations of a grape juice, supplemented or not with laccase, on its color and hydroxycinnamic acids concentration

Abstract

Aim: This work studies how successive O2 saturations affects the color and hydroxycinnamic
acids concentration in the absence and presence of laccase from B. cinerea with the aim of better understanding the browning processes.

Materials and methods: Grapes of Muscat of Alexandria were harvested and pressed with a vertical press to extract 60% of their juice. Aliquots of 30 mL of this must were placed in 60 mL flasks equipped with a pill (PreSens Precision Sensing GmbH) for measuring oxygen by luminescence (Nomasense TM O2 Trace Oxygen Analyzer). These flasks were added or not with SO2 (50 mg/L) and with 2 UA/mL of laccase from B. cinerea (Giménez et al., 2022). All operations were carried out with a continuous nitrogen stream to protect the grape juice from air oxygen. The grape juices were then saturated in O2. The flasks were kept at 20±2 °C and O2 was monitored (Diéval et al., 2011). Once O2 was completely consumed, this operation was repeated twice to reach a total of three O2 saturations. Absorbances at 420, 320 and 280 nm were determined in all the samples. Hydroxycinnamic acids and GRP were analyzed by RP-HPLC-DAD-ESI-MS (Lago-Vanzela et al., 2013).

Results and discussion: Samples without SO2 and laccase consumed O2 after the 2st saturation in around 1 hour with an initial O2 consumption rate (OCR) of 0.262±0.009 mg of O2/minute. Surprisingly, no significant differences were found in the OCR of the samples supplemented with laccase in the 1st saturation (0.266±0.075). However, the OCR decreased significantly for the 2nd and 3rd saturations in the case of the samples without laccase (0.128±0.003 and 0.101±0.011 respectively) whereas no significant decrease was observed when laccase was present (0.268±0.013 and 0.238±0.049 respectively). The supplementation with SO2 almost completely inhibited OCR in both cases, without and with laccase (0.006±0.002 and 0.011±0.003 respectively). The A420 nm (yellow color) increased after each saturation and this augmentation was significant higher in the samples supplemented with laccase. In contrast, the A320 nm (hydroxycinnamic acids) and A280 nm (total phenolic compounds) do the opposite. Finally, caftaric and cutaric acids and in a minor extent fertaric acid concentrations decreased after each saturation and this decrease was very similar in the samples supplemented or not with laccase. In contrast, the samples supplemented with SO2 hardly showed changes in the different absorbances or in the hydroxycinnamic acids.

Conclusions:

These results confirm that SO2 is very effective to prevent browning even in the presence of laccase. This data also indicate that the presence of laccase provokes higher browning even consuming the same O2 than without its presence, probably because can use more substrates than natural grape tyrosinase

References

Diéval, J.B., Vidal, S., & Aagaard, O. (2011). Measurement of the oxygen transmission rate of co-extruded wine bottle closures using a luminescence-based technique. Packaging Technology and Science, 24, 375–385.
Giménez, P., Anguela, S., Just-Borras, A., Pons-Mercadé, P., Vignault, A., Canals, J.M., Teissedre, P.L., Zamora, F. (2022) Development of a synthetic model to measure browning caused by laccase activity from Botrytis cinerea. LWT – Food Science and Technology 154 (2022) 112871. 
Lago-Vanzela, E.S., Rebello, L.P.G., Ramos, A.M., Stringheta, P.C., Da-Silva, R., García-Romero, E., Gómez-Alonso, S. and Hermosín-Gutiérrez, I. (2013) Chromatic characteristics and color-related phenolic composition of Brazilian young red wines made from the hybrid grape cultivar BRS Violeta (‘BRS Rúbea’ × ‘IAC 1398-21’). Food Research International 54, 33–43.

DOI:

Publication date: June 23, 2022

Issue: IVAS 2022

Type: Article

Authors

Zamora Fernando 1, Giménez Pol1, Just-Borras Arnau1, Solé-Clua Ignasi1, Pérez-Navarro José2, Gombau Jordi1, Gómez-Alonso Sergio2 and Canals Joan Miquel1

1Departament de Bioquímica i Biotecnologia, Facultat d’Enologia de Tarragona, Universitat Rovira i Virgili, C/Marcel.li Domingo s/n, 43007 Tarragona, Spain
2Universidad de Castilla-La Mancha, Instituto Regional de Investigación Científica Aplicada. Ciudad Real, Spain

Contact the author

Keywords

Grape Juice, Oxidation, Browning, Laccase, Hydroxycinnamic Acids

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Biodiversity in the vineyard agroecosystem: exploring systemic approaches

Biodiversity conservation and restoration are essential for guarantee the provision of ecosystem services associated to vineyard agroecosystem such as climate regulation trough carbon sequestration and control of pests and diseases. Most of published research dealing with the complexity of the vineyard agroecosystems emphasizes the necessity of innovative approaches, including the integration of information at different temporal and spatial scales and development of systemic analysis based on modelling. A biodiversity survey was conducted in the Franciacorta wine-growing area (Lombardy, Italy), one of the most important Italian wine-growing regions for sparkling wine production, considering a portion of the territory of 112 ha. The area was divided into several Environmental Units (EUs), defined as a whole vineyard or portion of vineyard homogenous in terms of four agronomic characteristics: planting year, planting density, cultivar, and training system. In each EU a set of compartments was identified and characterised by specific variables. The compartments are meteorology, morphology (altitude, slope, aspect, row orientation, and solar irradiance), ecological infrastructures and management. The landscape surrounding EU was also characterised in terms of land-use in a buffer zone of 500 m. For each component a specific methodology was identified and applied. Different statistical approaches were used to evaluate the method to integrate the information related to different compartments within the EU and related to the buffer zone. These approaches were also preliminarily evaluated for their ability to describe the contribution of biodiversity and landscape components to ecosystem services. This methodological exploration provides useful indication for the development of a fully systemic approach to structural and functional biodiversity in vineyard agroecosystems, contributing to promote a multifunctional perspective for the all wine-growing sector.

Measurement of redox potential as a new analytical winegrowing tool

Excell laboratory has initiated the development of an analytical method based on electrochemistry to evaluate the ability of wines to undergo or resist to oxidative phenomena. Electrochemistry is a powerful tool to probe reactions involving electron transfers and offers possibility of real-time measurements. In that context, the laboratory has implemented electrochemical analysis to assess oxidation state of different wine matrices but also in order to evaluate oxidative or reduced character of leaf and soil. Initially, our laboratory focused on dosage of compounds involved in responses of plant stresses and we were also interested in microbiological activity of soils. These analyses were compared with the measurement of redox potential (Eh) and pH which are two fundamental variables involved in the modulation of plant metabolism. Indeed, the variation of redox states of the plant reflects its biological activity but also its capacity to absorb nutriments. The Eh-pH conditions mainly determine metabolic processes involved in soil and leaf and our goal is to determine if this combined analytical approach will be sufficiently precise to detect biological evolutions (plant health, parasitic attack…).

Permanent cover cropping with reduced tillage increased resiliency of wine grape vineyards to climate change

Majority of California’s vineyards rely on supplemental irrigation to overcome abiotic stressors. In the context of climate change, increases in growing season temperatures and crop evapotranspiration pose a risk to adaptation of viticulture to climate change. Vineyard cover crops may mitigate soil erosion and preserve water resources; but there is a lack of information on how they contribute to vineyard resiliency under tillage systems. The aim of this study was to identify the optimum combination of cover crop sand tillage without adversely affecting productivity while preserving plant water status. Two experiments in two contrasting climatic regions were conducted with two cover crops, including a permanent short stature grass (P. bulbosa hybrid), barley (Hordeum spp), and resident vegetation under till vs. no-till systems in a Ruby Cabernet (V. vinifera spp.) (Fresno) and a Cabernet Sauvingon (Napa) vineyard. Results indicated that permanent grass under no-till preserved plant available water until E-L stage 17. Consequently, net carbon assimilation of the permanent grass under no-till system was enhanced compared to those with barley and resident vegetation. On the other hand, the barley under no-till system reduced grapevine net carbon assimilation during berry ripening that led to lower content of nonstructural carbohydrates in shoots at dormancy. Components of yield and berry composition including flavonoid profile at either site were not adversely affected by factors studied. Switching to a permanent cover crop under a no-till system also provided a 9% and 3% benefit in cultural practices costs in Fresno and Napa, respectively. The results of this work provides fundamental information to growers in preserving resiliency of vineyard systems in hot and warm climate regions under context of climate change.

Organic recycled mulches in sustainable viticulture: assessment of spontaneous plants communities and weed coverage

In recent years, developing more efficient and sustainable viticulture management has been essential due to the impact of climate change in semiarid regions. For this reason, the use of recycled organic mulching (ROM) in the vineyard has become an interesting strategy to cope with water stress, isolated soil from extreme temperatures and improving soil humidity, control the presence of weeds and therefore reduce the inputs of herbicides and improve soil fertility. This work aimed to analyse the effect of three different organic mulches [straw (S), grape pruning debris (GPD) and spent mushroom compost (SMC)] and two traditional soil management techniques [herbicide (H) and interrow (IN)] on weed coverage and the spontaneous plant communities’ presence. Data sampling was collected throughout the vine vegetative cycle of 2021 in La Rioja, Spain. The different soil management techniques had a clear effect on weed coverage and his development during the vine vegetative cycle. SMC and H were the treatments with the highest and the lowest coverage percentage, respectively. IN had a delayed weed emergence at the beginning of the vine vegetative cycle, but finally it reached maximum values nearby SMC. GPD and S had similar effects on weed emergence, reaching 25-30% of the maximum coverage values. A total of 29 herbaceous species were identified during the vegetative cycle, some of them very isolated and occasional. Principal component analysis (PCAs) showed a good association between spontaneous species and treatments, furthermore, specific species-treatment associations were found. Moreover, three clear groups of herbaceous communities were identified by cluster analysis. This study provides interesting information about the effect of different alternative soil management on herbaceous plant coverage and weed species communities which could contribute to making more sustainable viticulture.

Leaf vine content in nutrients and trace elements in La Mancha (Spain) soils: influence of the rootstock

The use of rootstock of American origin has been the classic method of fighting against Phylloxera for more than 100 years. For this reason, it is interesting to establish if different rootstock modifies nutrient composition as well as trace elements content that could be important for determining the traceability of the vine products. A survey of four classic rootstocks (110-Richter, SO4, FERCAL and 1103-Paulsen) and four new ones (M1, M2, M3 and M4) provided by Agromillora Iberia. S.L.U., all of them grafted with the Tempranillo variety, has been carried out during 2019. The eight rootstocks were planted in pots of 500 cc, on three soils with very different characteristics from Castilla-La Mancha (Spain). In the month of July, the leaves were collected and dried in a forced air oven for seven days at 40ºC. Then, the samples were prepared for the analysis determination, carried out by X-Ray fluorescence spectrometry. The results obtained showed that in the case of content in mineral elements in leaf, separated by soil type, we can report the importance of few elements such as Si, Fe, Pb and, especially, Sr. The rootstock does not influence the composition of the vine leaf for the studied elements that are the most important in determining the geochemical footprint of the soil. The influence of the soil can be discriminated according to some elements such as Fe, Pb, Si and, especially, Sr.