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BACKGROUND: In this study, soy protein isolate/sugar beet pectin (SPI/SBP) emulsion gelswere prepared through an enzymatic gelation process. The effects of emulsifier (SBP, SPI or SPI/SBP complex) and emulsification process on the microstructure, texture, breakdown properties and aroma release behavior of resulting emulsion gels were investigated. RESULTS: Oil emulsification by SBP/SPI complex resulted in a higher amount of emulsifier absorbing on the oil-water interface than by SBP and SPI alone, indicating that a more compact interfacial network was formed. Flocculation of oil droplets was observed and corresponding emulsion gels exhibited lower fracture force and strain when the oil was emulsified by SPI and SBP/SPI complex. Moreover, emulsion gels with small droplets produced a greater quantity of small fragments after mastication. However, microstructure did not have a significant effect on breakdown properties of emulsion gels. Headspace gas chromatography analysis showed that the release rate of ethyl butyrate before and aftermasticationwas significantly lower in emulsion gel with more compact network, but the release of aroma compounds with higher hydrophobicity did not show a significant influence of the microstructure and texture of emulsion gel. CONCLUSION: This finding provides a useful application for designing semi-solid foods with desirable flavor perception. [ABSTRACT FROM AUTHOR]

In this study, sugar beet pectin and soy protein were used to prepare the double-network ( DN) modified-tofu by sequential laccase and microbial transglutaminase treatments. The mechanical properties of modified-tofu were analysed by uniaxial compression test and texture profile analysis. The DN modified-tofu exhibited greater mechanical toughness than the corresponding single-network modified-tofu, while the ratio of soy glycinin to soy protein isolate reached and exceeded 50%. The enhancement of mechanical toughness may be mainly ascribed to the hierarchical microstructure which is observed in DN modified-tofu by scanning electron microscopy. DN modified-tofu provided a distinctive mechanical and sensory tough texture as compared to other tofu samples. In addition, the oral processing measurements indicated that DN modified-tofu required higher jaw-closing muscle activities, a greater number of chews and longer chewing duration to be processed. Furthermore, the chewing pattern of DN modified-tofu was different from other tofu samples. [ABSTRACT FROM AUTHOR]