Desenvolvimento de doce de leite sem adição de sacarose e sem lactose

Abstract

Doce de leite (DL) is the one most popular concentrated dairy product in Brazil. However, the high-calorie, sugar content and/or the presence of lactose limit its spread among consumers. Therefore, the development of dairy products to restrictive diets, especially lactose intolerance and the reduced-calorie is a great challenge for the dairy industry and a market opportunity. Thus, the aim of this work was the development and characterization of DL with no added sucrose and lactose (SL) and without the addition of sucrose (SA) as well as, to evaluate the sensory acceptability and the purchase intent by consumers. Three sort of DL were produced, the traditional one (TR), SL and SA samples. For the preparation of the DL SL, the milk was hydrolyzed by β-galactosidase enzyme and the hydrolysis degree was accompanied by the cryoscopic index. The production took place in open pan with soluble solids concentration of 61-68 °Brix. DL were analyzed regarding lactose hydrolysis by Fluorophore-Assisted Carbohydrate Electrophoresis (FACE), and characterized as regards chemical composition, color, crystals presence and microbiological requirements. Sensory analysis was performed using acceptance test in hedonic scale (1 to 9) and the purchase intent analysis (1 to 5). The results were evaluated by ANOVA and a posteriori comparison of average by the Student's t test with confidence interval of 95%. The milk samples used in the DL production showed centesimal composition, freezing point and acidity values within the current legal standards. Lactose hydrolysis was achieved with 80 minutes at 40 ° C, with concentration of 0.7 g/L, confirmed in the DL SL sample by FACE analysis through glucose and galactose electrophoretic bands. The prepared DL showed compositional features in accordance with the Technical Regulation of Identity and Quality (RTIQ), even though different from each other.. Regarding color, the DL SA sample exhibited lighter color (L = 44.09 ± 0.73). The number of crystals per gram of doce de leite in the DL TR and SA sample was 2.63 x 104 ± 19.00 and 4.63 x 106 ± 298.22, with crystal size of 29.78 ± 27.84 µm and 24.83 ± 1.04 µm, respectively. As for sensory acceptance, DL TR obtained the highest scores in the most judge attributes and in the purchase intent analysis. Lactose crystals were not perceived in the DL SL sample, most likely as a result of the lactose hydrolysis and their acceptance was equal (p>0.05) or greater (p<0.05) when compared to color, texture and consistency of the DL TR sample. The DL SA sample was the least accepted by consumers.