Efeito de enzimas comerciais e naturais utilizadas na hidrólise da mandioca sobre a qualidade sensorial da tiquira

Abstract

The amilaceous materials need to be hydrolyzed for the release of fermentable sugars and this process may be carried out by chemical or enzymatic way. The latter is the most efficient way for the starch conversion, however a limiting factor to the usage of commercial enzymes is the high cost. In this context, a substitute for the enzymes aiming the saccharification of starch should be searched for. This study evaluated the physico-chemical and sensory characteristics of aged tiquiras (cassava spirits) produced from the hydrolysis of cassava with commercial enzymes and with sweet potato, comparing to the traditional cachaça (sugar cane spirit), in two alcoholic strengths (33 and 38% v/v). Initially, an optimization of the hydrolysis process of the cassava was carried out, in order to verify the best concentrations of cassava, sweet potato for liquefaction and saccharification, water volume and commercial enzymes, in the laboratory scale, based on the results of yield in reducing sugar/g cassava. Physico-chemical analysis of the tiquiras produced was taken according to the parameters required by legislation. For the sensory analysis, the quantitative descriptive method and the acceptability and purchase interest tests were used. The utilization of sweet potato for the cassava hydrolysis (liquefaction and saccharification) has showed yields in reducing sugars significantly higher than those obtained with commercial enzymes. The proportion among cassava/sweet potato/water utilized in the semi-industrial scale for the tiquira production, established in the optimization step, was 20% cassava (m/v); 7.5% sweet potato (m/v) for liquefaction; 7.5% sweet potato (m/v) for saccharification; and 65% distilled water. The tiquiras presented physico-chemical characteristics in accordance with the Brazilian specifications, exception for the tiquira produced with sweet potato for the alcoholic strength, which was slightly below vii the minimum required. The sensory attributes which described the spirits by the quantitative descriptive analysis were based on appearance, aroma, flavor and texture, utilizing fourteen descriptive terms. According to the results, there were no significant differences (p≥0,05) for the majority of the attributes, but for yellowish coloration, wood aroma and flavor, whose values were higher for the cachaça. There was a greater acceptance and purchase interest for the cachaça and for the tiquira produced with commercial enzymes, showing that that the replacement of the commercial enzymes by the sweet potato enzymes did not result in a better sensory quality of the beverage, although better yields in reducing sugars were obtained with the hydrolysis treatments with sweet potato.