Abstract:
Chitosan is a polysaccharide derived from chitin by N-deacetilation, which has the
property of gel formation. The objective was to develop a chocolate milk beverage using
modified (hydrogel) chitosan as a thickening agent, and to make a sensory and rheological
evaluation of this beverage. In the sensory evaluation an acceptability and comparative
test with 50 local consumers was carried out, with the developed beverage and samples
from the Brazilian market, with the attributes overall acceptability and viscosity. The
hybrid hedonic scale was used. The rheological evaluation was carried out with a
rotational rheometer (Rheotest) with the H1 probe. A controlled rate test – ramp (0- 500,
and 500-0 L s-1, 120 seconds, up and down), at 25ºC was used. There was no difference
(P> 0.05) among the beverages in the overall acceptability. In spite of that, the developed
beverage had a better score (7.12) in comparison with a market beverage (6.4). The
beverages differed in viscosity (P< 0.05); the score of the developed beverage was 7.06 and
the score of the market beverage was 5.87. The market beverage fitted to the Ostwald-deWaele,
Bingham, and Casson models, and the developed beverage fitted better to the
Ostwald-de-Waele model. The consistence index (K) of the market beverage was 0.150 Pa
s
n
, while that of the developed beverage was 1.590 Pa sn
, showing a high difference in the
consistence characteristic of the samples. The flow index (n) of the market beverage was
0.625 and that of the developed beverage was 0.435. All market beverages showed
thixotropic behavior. The hydrogel chitosan was effective as a thickening agent and
furnished a good acceptability of the beverage.
Keywords: Chitosan, Chocolate products, Food development, Food structure, Hydrocolloid.
