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

Abstract

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.

Beneficial Effects of Soybean-Derived Bioactive Peptides

“…The prediction of cost and supply for SPs is much easier than that for milk protein products, which makes cost management easy and increases the profitability of products. Highquality SPs may be used as financial substitutes for casein, milk protein concentrate, skim milk powder, whole milk powder, and whey protein-derived peptide material [149,150].…”

Changes of Soybean Protein during Tofu Processing

“…At a certain temperature, GDL slowly hydrolyzes the gluconic acid and releases protons, which is a suitably gradual process for forming a continuous soy protein network structure through hydrophobic and electrostatic interactions [70]. Excessive gel rate can result in gel with an uneven structure and low strength [71]. Kaoru et al [60] showed that the gelation process of GDL is similar to that of salt-based coagulants, and its gelation curve conforms to first-order reaction kinetics.…”

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

“…SDS-PAGE analysis of tofu gels treated with different temperatures was performed to investigate the influence of thermal treatment on the soy protein aggregation. The 7S (β-conglycinin) and 11S (glycinin) globulins are the two main storage proteins, accounting for more than 70% of the total soybean protein content (Zheng et al, 2020). In general, 7S is composed of three subunits: α, α 0 , and β, and 11S is consisted of an acidic (A) polypeptide and a basic (B) polypeptide linked by a disulfide bond (Wu et al, 2018).…”

“…shelf life of RTE firm tofu (Zheng, Regenstein, Teng, & Li, 2020). The tofu-based product obtained can be capable of being stored at room temperature.…”