β-Cyclodextrin-Mediated Beany Flavor Masking and Textural Modification of an Isolated Soy Protein-Based Yuba Film

The application of β-cyclodextrin (CD) to remove unattractive volatile compounds has been applied in various food products. This study investigated the effect of CD concentration (1–4%) on the beany flavor masking and textural modification of yuba film prepared by isolated soy protein (ISP) in the presence of (+CD), or after removing, the flavor-entrapped CD (−CD). Based on gas chromatography–mass spectrometry (GC–MS), the addition of CD caused a decrease in 1-octen-3-ol, benzaldehyde, hexanal, and 2-heptanone, which are characterized as the major beany flavor compounds. Regardless of presence or removal, the use of CD was effective in reducing beany flavor in yuba film. Scanning electron microscopy (SEM) observation indicated that the CD present in yuba film was distributed on the lower surface and matrices of the films. In yuba film containing 4% CD, the CD crystals were concentrated on both the upper and lower surfaces of the film. The textural properties of the yuba film were affected by the presence or removal of CD, and better puncture strength was obtained when yuba was made after removing the CD. Therefore, this study indicates that the addition of CD was a good approach to mask the beany flavor of soy protein-based products, and textural properties could be improved by removing CD from the product formulation.

Production, Quality, and Acceptance of Tempeh and White Bean Tempeh Burgers

The food industry has been challenged to develop new healthy food products. Tempeh, originating in Indonesia and produced by fungal fermentation, would be an alternative healthy food for the Brazilian population. This study was designed to produce white bean (cv BRS Ártico) tempeh burger, to determine and compare its nutritional and sensory properties with conventional soybean-based tempeh burger. The production and the analyses of proximal composition and microbiological contamination were determined in the tempeh, following reference methods. For the sensory analysis, a nine-point hedonic scale test was performed with 82 untrained evaluators, and at the end, a question of purchase intent was answered. The results indicated significant differences in the nutritional value of the tempehs, which is justified by the difference in the composition of the raw materials used. The samples did not present a risk of microbiological contamination for consumption. The white bean tempeh burgers showed similar appearance and crispy consistency, but received lower scores for flavor, compared to the soybean burgers, probably due to their residual beany flavor. The beany flavor could be minimized by increasing the cooking time of the beans. White bean tempeh can be a good alternative for healthy eating, and its manufacture could promote the production of new products made from beans, giving a new focus to the Brazilians’ traditional food. It is still necessary to improve the techniques of production and test new ingredients for the preparation of tempeh burgers to obtain higher acceptability.

Efeito do inibidor de protease Kunitz sobre níveis de lipoxigenases em sementes de soja

As lipoxigenases (LOX) são responsáveis pelo "beany flavor", sabor característico da soja [Glycine max. (L.) Merrill], que é o maior obstáculo ao consumo da soja nos países ocidentais. O inibidor de tripsina Kunitz (KTI) é responsável por 80% da inibição da atividade tríptica, além de provocar hiperplasia pancreática em animais monogástricos. Essas duas características são muito importantes em programas de melhoramento que visam à melhoria da qualidade da soja. Objetivou-se, neste trabalho verificar o efeito do inibidor de protease (KTI), sobre níveis de LOX em sementes de soja, nos seguintes genótipos: KTI+/LOX+, KTI+/LOX-, KTI-/LOX+ e KTI-/LOX-. As LOXs foram identificadas por teste colorimétrico, atividade enzimática e eletroforese em gel de poliacrilamida. O teor de proteína foi quantificado pelo método do ácido bicinconínico para determinação da atividade específica de LOX. Observou-se que, para o genótipo KTI+/LOX+, a atividade específica de LOX 1 foi alta, variando de 177,92 a 206,94 UA/mg de proteína e para LOX 3 variou de 17,90 a 19,85 UA/mg de proteína; para KTI+/LOX- e KTI-/LOX- não foi detectada atividade de LOX e que para o genótipo KTI-/LOX+ a atividade específica para LOX 1 variou de 117,24 a 124,64 UA/mg de proteína, e de 17,35 a 20,29 UA/mg de proteína para LOX 3. Houve uma redução de 40% na atividade específica de LOX1 e de 1% para LOX 3, no genótipo KTI-/LOX+, quando comparados ao KTI+/LOX+. Esses resultados comprovam uma associação negativa entre o inibidor de tripsina Kunitz e a atividade de lipoxigenases.