Rui Sérgio S.F. Silva

Sensory evaluation of a milk formulation supplemented with n3 polyunsaturated fatty acids and soluble fibres

Abstract The hypocholesterolemic effect of some polyunsaturated fatty acids and soluble fibres has been demonstrated mostly in epidemiological studies. Two types of fatty acids (eicosapentaenoic-EPA 20:5n-3 and docosahexaenoic-DHA 22:6n-3) and soluble fibres (oat flour and guar gum), were mixed in different proportions and used in a milk formulation according to a factorial design (3 2 ) with a repetition in the central point. The 10 assays were submitted to a sensory test, using a structured hedonic scale applied to heart surgery patients ( n =240), in order to evaluate the general acceptability of each mixture. Some of these ( n =137) answered a questionnaire, which was used to identify the target public for this product, using multivariate analysis and the correspondence technique. Response surface methodology (RSM) was used to model the polynomial quadratic regression which predicts the “sensory acceptability ( y )” as a function of variation from selected factors: x 1 =(n3 polyunsaturated fatty acids or n3PUFA)g/kcal and x 2 =(soluble fibres or SF)g/kcal. The concentrations used in the mixtures were: 0.1–0.8 and 0.1–0.3 g/100 kcal, respectively. The coefficient of determination ( R 2 ) was 95.76%, indicating the good fit of the model to the experimental data. The high level of n3PUFA and SF significantly decreased the sensory quality of the product, limiting the maximum expression of the functional properties of these two factors. The contour plots obtained from the quadratic model permitted determination of the acceptability of the milk formulation, which was estimated in each possible combination of n3PUFA acid and SF. These procedures were essential for developing a good product with functional properties for human consumption.

MISTURAS DE FARINHA DE AVEIA E AMIDO DE MILHO COM ALTO TEOR DE AMILOPECTINA PARA PRODUÇÃO DE "SNACKS"

The potential application of modified starch to enhance properties of oat flour extruded products was investigated. The process was performed using a single screw extruder, applying a 25 factorial design with 3 repetitions on the central point. The independent variables were: feed moisture, extrusion temperature, screw speed, die diameter and modified starch level and depended studied variables were: specific volume, hardness and fracturability. Based on results of the experiments a new experimental design was proposed to optimize product characteristics. The best combination of variables to obtain snacks with good expansion and texture was: 17% feed moisture, 183°C temperature, 100rpm screw speed, 4mm die diameter and 30% waxy starch. The product obtained presented 7.2mL/g specific volume, 5.41N hardness and 2.02N fracturability, therefore their characteristics were similar to those of commercial corn products.

Estudo de custo-rendimento do precessamento de queijos tipo minas frescal com derivado de soja e diferentes agentes coagulantes

O desenvolvimento de alimentos e uma constante nas industrias, nas universidades e nos institutos de pesquisa visando otimizar processamentos, agregar diferentes ingredientes em produtos ja existentes, entre outros fatores. Apos o desenvolvimento de um produto, informacoes adicionais podem ser obtidas pela determinacao do rendimento e do custo do produto final. O objetivo deste trabalho foi estimar o rendimento e o custo de queijos Minas frescal tradicionais e adicionados de extrato hidrossoluvel de soja desengordurado (EHS) processados com coalho bovino e com coagulante microbiano (Aspergillus niger var. awamori). A introducao de 8% do EHS (em relacao ao teor de solidos totais do leite) no queijo Minas frescal processado com coalho bovino proporcionou rendimento em gramas de solidos totais por litro de leite (g ST/L) superior de 16,67% em relacao ao queijo Minas frescal tradicional processado com o mesmo coalho. O queijo tipo Minas frescal processado com coagulante microbiano e com 8% de EHS apresentou rendimento (g ST/L) superior de 16,54%, quando comparado ao seu tradicional. O custo das formulacoes-base (kg de queijo/100L de leite) processadas com coalho bovino e com coagulante microbiano foi US

Influence of high osmotic pressure on sorbitol production by Zymomonas mobilis

36,75 e US

Combined sensory optimization of a prebiotic cereal product using multicomponent mixture experiments

37,50, respectivamente, ao passo que os queijos tradicionais processados com os mesmos agentes coagulantes apresentaram custo equivalente a US

Gel textural characteristics of corn, cassava and yam starch blends: A mixture surface response methodology approach

35,12 e US

Effect of soybean oil and Tween 80 on the production of botryosphaeran by Botryosphaeria rhodina MAMB-05

35,36.

Expansion and hydration properties of cassava starch extruded with emulsifier

The objective of the present work was to study the variation on the sorbitol production in relation to the concentration of sugars, (metabolizable or not) and the cultivation time. A full factorial design was used considering the factors such as sucrose and maltose concentration and cultivation time. The addition of sugars caused increases on the sorbitol production up to the concentration of 300g/L however, decreases on the sorbitol production were observed when the concentration reached values above this. Increasing the time of fermentation was statistically significant to sorbitol production, however, little increase the production was noticed after 36h.