Technical Yearbook 2024

performed on different types of wines with pea and potato proteins. The performance of PVI/PVP is shown in comparison. Reduction of astringency Potato proteins react better with astringent tannins than pea proteins. Clarification tests performed on different wines confirmed this effect, as shown in Figure 7. The performance of hydrolysed gelatine is shown for comparison.

Oxidation management Pea proteins are better suited than potato proteins for reducing browning. This effect can be monitored by measuring the decrease in optical density at the wavelength of 420 nm, as shown in Figure 5. In this case, protein size does not seem to influence this property. Pea proteins are also found to be the best in reducing the concentration of iron, a metal with an oxidation catalyst effect, as shown in Figure 6. Reduction of astringency Potato proteins react better with astringent tannins than pea proteins. Clarification tests performed on different wines confirmed this effect, as shown in Figure 7. The performance of hydrolysed gelatine is shown for comparison. In Figure 8, the appropriate hydrolysis level on pea proteins allows them to increase their effectiveness in reducing astringency. Reduction in protein instability Protein-unstable white wines clarified with plant-based proteins and subsequently heat-tested show less change in turbidity, as seen in Figure 9. Such behaviour would suggest a stabilising effect by plant proteins. No noteworthy differences occurred with HPLC analysis of the concentration of unstable proteins (chitinases and thaumatins). Further research is needed to investigate the reason for It is well known that high dosages of plant-based proteins can impart ‘plant notes’ to the wines. Application trials of many products on the market have confirmed that the choice of product and its use at the correct dosage is important to avoid this effect. The numerous wine samples treated with pea, potato and animal proteins during our clarification trials were subjected to GC analysis, analysing the main categories of this phenomenon. Sensory impact

0 1 2 3 4 5 6 7 8 9 10

ASTRINGENCY (1-10)

Sagrantino

Brunello di Montalcino

Nebbiolo

CONTROL

PEA PROTEIN POTATO PROTEIN HYDROLYSED GELATINE

FIGURE 7. Astringency values of wines clarified with plant-based proteins and hydrolysed gelatine. In Figure 8, the appropriate hydrolysis level on pea proteins allows them to increase their effectiveness in reducing astringency. FIGURE 7. Astringency values of wines clarified with plant-based proteins and hydrolysed gelatine.

0 1 2 3 4 5 6 7 8 9 10 0 1 2 3 4 5 6 7 8 9 10

ASTRINGENCY (1-10)

Cabernet Sauvignon Brunello di Montalcino

Sagrantino

Nebbiolo

ASTRINGENCY (1-10) CONTROL

PEA PROTEIN

Cabernet Sauvignon Brunello di Montalcino PEA PROTEIN MODERATE HYDROLYSIS

PEA PROTEIN HIGH HYDROLYSIS

Sagrantino

Nebbiolo

FIGURE 8. Astringency values of wines clarified with pea protein at different degrees of hydrolysis. Reduction in protein instability Protein-unstable white wines clarified with plant-based proteins and subsequently heat tested show less change in turbidity, as seen in Figure 9. Such behaviour would suggest a stabilising effect by plant proteins. No noteworthy differences occurred with HPLC analysis of the concentration of unstable proteins (chitinases and thaumatins). Further research is needed to investigate the reason for this phenomenon. FIGURE 8. Astringency values of wines clarified with pea protein at different degrees of hydrolysis. FIGURE 8. Astringency values of wines clarified with pea protein at different degrees of hydrolysis. Reduction in protein instability Protein-unstable white wines clarified with plant-based proteins and subsequently heat tested show less change in turbidity, as seen in Figure 9. Such behaviour would suggest a stabilising effect by plant proteins. No noteworthy differences occurred with HPLC analysis of the concentration of unstable proteins (chitinases and thaumatins). Further research is needed to investigate the reason for this phenomenon. CONTROL PEA PROTEIN PEA PROTEIN MODERATE HYDROLYSIS PEA PROTEIN HIGH HYDROLYSIS

10 12 14 16 10 12 14 16

0 2 4 6 8 0 2 4 6 8

Δ NTU

Δ NTU

CONTROL

5 g/hl PEA PROTEIN + 50 g/hl BENTONITE

50 g/hl BENTONITE 70 g/hl BENTONITE

FIGURE 9. ΔNTU values of heat test (30 minutes at 80°C) performed on Traminer . Sensory impact It is well known that high dosages of plant-based proteins can impart ‘plant notes’ to the wines. Application trials of many products on the market have confirmed that the choice of FIGURE 9. ΔNTU values of heat test (30 minutes at 80°C) performed on Traminer . Sensory impact It is well known that high dosages of plant-based proteins can impart ‘plant notes’ to the wines. Application trials of many products on the market have confirmed that the choice of product and its use at the correct dosage is important to avoid this effect. The numerous wine samples treated with pea, potato and animal proteins during our FIGURE 9. ΔNTU values of heat test (30 minutes at 80°C) performed on Traminer . CONTROL 5 g/hl PEA PROTEIN + 50 g/hl BENTONITE 50 g/hl BENTONITE 70 g/hl BENTONITE

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TECHNICAL YEARBOOK 2024