The effects of AC electric field on wine maturation

A pilot plant scale innovative technique applying AC high voltage electric field to accelerate wine aging of Young Cabernet Sauvignon is reported in this paper. The design principles, equipment configuration and its effect on wine taste and flavour are presented. Results from a sensory evaluation group demonstrated that there were various effects on the wine quality under different conditions, some positive while others negative. An optimum treatment, with electric field 600 V/cm and treatment time 3 min, was identified to accelerate wine aging, which made the harsh and pungent raw wine become harmonious and dainty. HPLC and GC/MS combined with routine chemical analysis methods were used to identify the differences between the treated and untreated samples. It was found that the contents of higher alcohols as well as aldehydes in volatile compounds decreased to a large number, meanwhile, the contents of esters and free amino acids slightly increased while others remained unchanged through all treatments. The results of this study show that the technology of accelerating wine aging by high voltage electric field is a feasible method to shorten wine maturing process times and to improve the quality of a young wine, if favourable process conditions are chosen. The application of physical treatment methods other than heat, such as electric field, magnetic field, ultrasonic wave and microwave, etc., for green processing of foods, is becoming popular. AC electric current is of continuous wave form, thus being seldom used in food processing. However, numerous previous studies about the effect and mechanisms of accelerating wine aging with high voltage AC electric field have been conducted in the Laboratory of South China University of Technology. This manuscript presents the effect of high intensity AC electric field on young wine's physicochemical properties and sensory quality. The results presented in this paper show that it is a promising and novel technology to shorten the young wine's aging period. Recently, a few of the Chinese winery companies have already started to set up the plant scale equipment.