Gelatine, casein and potassium caseinate as distinct wine fining agents: different effects on colour, phenolic compounds and sensory characteristics

Abstract

<p style="text-align: justify;"><strong>Aims</strong>: Describe and compare some characteristics, such as molecular weight (MW) distribution and surface charge density of commercial protein fining agents and to enhance the understanding of their effect on wine chemical and sensory characteristics.</p><p style="text-align: justify;"><strong>Methods and results</strong>: Protein (casein, potassium caseinate and gelatine) MW distribution was characterised by electrophoresis. These proteins were added to a red and a white wine, in order to evaluate its effect on colour, phenolic compounds and sensory attributes.</p><p style="text-align: justify;"><strong>Conclusion</strong>: A band at 30.0 kDa characterised casein and potassium caseinate. Gelatines showed polydispersion on the MW distribution, gelatine GSQ on the higher MW (> 43.0 kDa) and gelatine GL on the lower MW (< 43.0 kDa). Despite the fact that casein and potassium caseinate had similar MW distribution, casein decreased essentially the monomeric ((+) - catechin and (-) - epicatechin) while the potassium caseinate showed a lower influence on these compounds. Also, among the two gelatines used, a different behaviour was observed. The gelatine characterised by a polydispersion below 43.0 kDa depleted more the polymeric tannin fractions than the gelatine characterised by a polydispersion above 43.0 kDa. That gelatine has also decreased colour intensity and coloured anthocyanins of red wine but the hue remains unchanged. Addition of fining agents did not affect greatly the concentration of monomeric anthocyanins. Sensory analysis showed that wines fined with the different proteins presented distinct characteristics.</p><p style="text-align: justify;"><strong>Significance and impact of study</strong>: The knowledge of the physico-chemical characteristics, such as MW distribution and surface charge density, is important for wine fining optimisation and consequently for the wine quality.</p>

Fining of red wines with gluten or yeast extract protein

“…The Ip of proteins were determined according to Braga et al. (2007) using the PCD 03 pH particle charge detector (Mütek, Herrsching, Germany).…”

“…The MWs of gelatin influence their interaction with condensed grape tannins (Maury et al. , 2001; Braga et al. , 2007; Cosme et al.…”

Evaluating potential alternatives to potassium caseinate for white wine fining: Effects on physicochemical and sensory characteristics

“…Additionally, it has been shown that wines treated with fining agents at commercial concentrations and made according to standard processes do not appear to present a risk to allergic individuals, and no detectable amounts of fining agent remain in the wines (Fischerleitner & Eder, 2007;Kirschner, Belloni, Kugler, Ring, & Brockoe, 2009;Lifrani et al, 2009;Weber et al, 2007). The wine industry is currently finding it difficult to replace casein, a fining agent with fully characterised effects on wine physicochemical and sensory characteristics (Amati, Galassi, & Spinabelli, 1979;Braga, Cosme, Ricardo-da-Silva, & Laureano, 2007;Cosme, Ricardo-da-Silva, & Laureano, 2008;Jouve et al, 1989;Sims, Eastridge, & Bates, 1995). The effects of potential new allergen free alternatives on wine chemical and sensory properties, such as pea protein, have been insufficiently studied.…”

Effect of Polyphenol Concentrations on Astringency Perception and Its Correlation With Gelatin Index of Red Wine

“…Gelatin index (Ribéreau‐Gayon and Glories 1986) approximates astringency by measuring the extent of tannin precipitation with gelatin. This is an in vitro method, which was selected because gelatin is used to reduce harshness (astringency) and improve clarity (Braga et al . 2007).…”