Comparative study of the use of chitosan in the clarification of the must with traditional substances

Abstract

Chitosan is a universal, of natural origin, nonallergic and biodegradable sorbent, capable of binding a large spectrum of organic and non-norganic substances, making it widely used throughout the wine production process. The process of must clarification was studied in this research, using the fungal origin biopolymer, chitosan, in comparison with the use of the most commonly used fining substances in winemaking practice, the pectolytic enzymes and bentonite. The physicochemical composition of clarified musts and of dry white wines obtained from these musts, produced in micro-winemaking conditions, within IȘPHTA, was studied. The dynamics of the alcoholic fermentation process of the clarified must with the use of the studied substances was also studied. The research carried-out proves that the treatment with chitosan contributes to a better clarification of the must compared to pectolytic enzymes or bentonite. Dry white wines obtained correspond to the quality requirements, stipulated in the normative documents in force, and the higher quality of must clarification by chitosan treatment also has a positive effect on the organoleptic indices of the wine. Tests on the susceptibility to various physical-chemical changes have shown that treating must with chitosan enables the production of dry white wines that are stable to protein breakdown and oxidative browning. As a result of the research, recommendations were given for the clarification of the grape must in order to obtain quality dry white wines.