Current state of knowledge and challenges in wine clarification

Abstract

Clarity in wine is an essential quality attribute that is recognised and valued by consumers. Despite advances made in recent times to improve technological aspects of clarification processes, the inherent compositional variability of wine still affects these processes. This paper reviews the complex interactions of wine constituents, for example protein, polysaccharides and phenolic substances, and the physical chemistry and current knowledge relating to wine clarification. Furthermore, it discusses potential areas of fundamental research into the mechanisms and interactions that lead to successful clarification that are required to improve the clarification process and may lead to increased process capacity and wine quality.

Effect of Different Clarification Treatments on the Volatile Composition and Aromatic Attributes of ‘Italian Riesling’ Icewine

“…The first requirement for wine fining is to decrease turbidity or increase transmittance, thus, to get a crystal clear and translucent wine with good stability, whiles minimizing the influence on other parameters of the wine [2]. As can be seen from Figure 1A, both fining agents and mechanical clarification caused a significant increase in wine transmittance.…”

“…Nowadays, wine stabilization and limpidity can be enhanced by centrifugation, filtration, fining or other clarification technologies [1]. The aim of this process is to decrease turbidity by removing suspended and colloidal particles in wine, meanwhile, macromolecules such as unstable proteins, which can later be denatured or aggregated and cause stability problems can also be removed [2,3].…”

A New Extract from Pomegranate (Punica granatum L.) By-Products as a Potential Oenological Tannin: Preliminary Characterization and Comparison with Existing Commercial Products

“…The International Organization of Vine and Wine (OIV) authorized the use of oenological tannins to facilitate the clarification of wines and musts as long as they do not change the olfactory properties and the color of the wine [ 1 ]. Beyond this authorized use, nowadays oenotannins are commonly used in winemaking for other properties, classifiable in 5 main groups [ 2 ]: (i) impact on oxygen/metals: protection of wine from oxidation, anti-laccase activity, superoxide radicals scavenger, direct consumption of dissolved oxygen, iron-chelating ability and capability of preventing oxidative damages through Fenton-based reaction [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 ]; (ii) impact on color/pigments: improvement and stabilization of color in red wine, triggering for formation of new pigments and co-pigmentation effect [ 12 , 13 , 14 , 15 ]; (iii) protein interaction and preventing protein haze [ 16 , 17 ]; (iv) sensory/mouthfeel properties: capability of improving wine structure and mouthfeel (particularly bitterness and astringency) and of eliminating reduction odors [ 18 , 19 ]; (v) bacteriostatic effects [ 20 ].…”

Clarifying effect of different fining agents on mulberry wine

“…To some extent, the clarification of fruit wine can be achieved through filtration, enzymatic treatment, membrane techniques and clarifying agent addition (El Rayess & Mietton-Peuchot, 2016;Mierczynska-Vasilev & Smith, 2016). Enzymes are generally applied to clarify and filter the must and wine (Armada, Fern andez, & Falqu e, 2010).…”

“…Fruit wines generally contain some dispersed entities of colloidal size, which significantly affected the storage and consumption of wine. The procedure of clarification can remove suspended and colloidal particles in the fruit wine that create turbidity and also to remove unstable proteins or other macromolecules that can later aggregate and cause the wine to appear hazy (Mierczynska‐Vasilev & Smith, ).…”