Shelf life prediction and food safety risk assessment of an innovative whole soybean curd based on predictive models

Loss of immobilized water and intense protein aggregation responsible for quality deterioration of ready to eat firm tofu

The influence of high-temperature treatment (100-120°C, 15 min) on the texture, color, and water-holding capacity of tofu gels was investigated. As the temperature increasing, the hardness and chewiness as well as the values of redness a and yellowness b increased gradually, while the water content and the lightness L value reduced progressively, and these variations were more pronounced at 115 or 120°C. Low field nuclear magnetic resonance showed that the loss of T₂₂ water led to the decrease of the water content. Scanning electron microscope revealed that the micropore in gels decreased after heating, and almost entirely disappeared at 120°C. Further analysis by SDS-PAGE indicated the soy protein aggregation formed via disulfide linkage was observed in the thermal treated tofu gels, and nondisulfide linkage might also be occurred as temperature reached 110°C or higher. The quality deterioration may be attributed to immobilized water loss combined with the protein aggregation.

Tofu products: A review of their raw materials, processing conditions, and packaging

Tofu is a traditional product made mainly from soybeans, which has become globally popular because of its inclusion in vegetarian, vegan, and hypocaloric diets. However, with both commercial production of tofu and scientific research, it remains a challenge to produce tofu with high quality, high nutrition, and excellent flavor. This is because tofu production involves multiple complicated steps, such as soybean selection, utilization of appropriate coagulants, and tofu packaging. To make high-quality tofu product, it is important to systematically understand critical factors that influence tofu quality. This article reviews the current research status of tofu production. The diversity of soybean seeds (the raw material), protein composition, structural properties, and nutritional values are reviewed. Then, selection of tofu coagulants is reviewed to provide insights on its role in tofu quality, where the focus is on the usage of mix coagulants and recent developments with new coagulants. Moreover, a comprehensive summary is provided on recent development in making high-fiber tofu using Okara (the major by-product during tofu production), which has a number of potential applications in the food industry. To help encourage automatic, environmental friendly, and high-efficient tofu production, new developments and applications in production technology, such as ultrasound and high-pressure process, are reviewed. Tofu packaging, including packaging materials and techniques, is evaluated as it has been found to have a positive impact on extending the shelf life and improving the quality of tofu products. Finally, the future research directions and potential areas for new developments are discussed.