Search Results (72)

Okara, the soybean residue generated during soymilk and tofu production, is nutrient-rich but underutilized due to its high moisture content and perishability. This study established a sustainable solid-state co-fermentation strategy using Rhizopus oligosporus (BCRC 31631) and Yarrowia lipolytica (BCRC 21252) to enhance the bioactive value of black soybean okara from two Taiwanese cultivars—Tainan No. 3 (TN.3) and Tainan No. 5 (TN.5). Co-fermentation markedly enhanced β-glucosidase activity, reaching 0.75 U/g DW at 30 °C after 48 h in TN.3 and 0.68 U/g DW after 24 h in TN.5, approximately 3.5-fold higher than single-strain fermentation. Near-complete (97–100%) hydrolysis of daidzin, glycitin, and genistin occurred within 24–48 h, producing 672.9 µg/g DM of total aglycone-type isoflavones—an ~11-fold increase compared with unfermented okara (61.5 µg/g DM), where most isoflavones (~740 µg/g DM) remained glycosylated. Varietal structure affected conversion efficiency: TN.3 exhibited stronger enzymatic responsiveness and higher aglycone yield, whereas TN.5 showed faster but less extensive transformation. The process also revealed a bioactive–pigment trade-off, as enhanced isoflavone activation coincided with anthocyanin degradation. These findings demonstrate that ambient-temperature solid-state co-fermentation effectively boosts β-glucosidase activity and isoflavone bioconversion, transforming low-value okara into a high-value functional ingredient consistent with circular bioeconomy and sustainable food system goals. Full article

Drying critically shapes tofu’s texture, structure, and final appearance, whether it occurs during cooking or is applied intentionally in reprocessing. This study aimed to characterize the drying kinetics of tofu through experimental analysis and through modeling. Tofu samples were dried at temperatures ranging from 40 °C to 90 °C using a convective drying tunnel and an oven. Shrinkage and color changes were analyzed. Empirical models, a shrinking-core model and a newly developed oven-cooking model were tested against experimental data. The drying kinetics exhibited a constant and a decreasing rate phase, which were separated by a water content threshold of 2.56 ${\mathrm{kg}}_{\mathrm{W}}/{\mathrm{kg}}_{\mathrm{DS}}$. Tofu undergoes non-enzymatic browning and exhibited total shrinkage of 0.38. These physical changes were more significant at lower drying temperatures when the product was dried below a water content of 1.39 ${\mathrm{kg}}_{\mathrm{W}}/{\mathrm{kg}}_{\mathrm{DS}}$. The logarithmic model provided the best fit (${\mathrm{R}}^2\ge 0.9920$) to the experimental data. However, the cooking model shows good results as well (${\mathrm{R}}^2=0.9678$) and offers physical validity. This study provides evidence that the drying mechanisms of tofu are not temperature-dependent within the studied range. It also emphasizes the importance of drying time over drying temperature in the physical changes of the product. The successful fit of the cooking model highlights the link between drying and cooking processes, suggesting potential applications in both areas. Full article

This study presents a comprehensive assessment of tofu production from whole chickpeas as a plant-based protein alternative for sustainable food systems and humanitarian use. A novel process comprising soaking, wet milling, starch sedimentation, thermal coagulation, and optional drying yielded tofu with 56.2% protein (dry basis). Byproducts, including starch and okara, were also recovered and characterized. Nutrient recovery analysis, relative to seed nutrient content, showed that tofu retained most of the protein (59.1%) and fat (43.2%), okara accounted for the majority of fiber (34.5%) with residual protein (13.5%) and fat (16.7%), while the starch fraction primarily contained net carbohydrates (21.6%). Techno-economic modeling showed that fresh tofu can be produced with minimal inputs and an estimated thermal requirement of 0.798 kWh/kg, while tofu powder required 4.109 kWh/kg; both represent idealized values assuming no heat loss or system inefficiency. Theoretical energy minima were estimated under idealized assumptions, and broader environmental and food security implications are discussed as perspectives. Unlike soy, chickpeas carry a low allergenic risk, which may enhance suitability for population-wide feeding interventions. Broader implications for sustainable development goals (hunger, health, climate action) and humanitarian applications are discussed as perspectives. Chickpea tofu may represent a viable shelf-stable protein platform for local and emergency food systems. Full article

Background: The relationship between sports participation and food preferences in adults, as well as the influence of gender, is still unclear. Objective: The objective of this study was to investigate the association between sports participation and individual food preferences and to explore potential gender differences among sports participants in a large group of Italian adults. Methods: This cross-sectional study involved 2665 adults (aged ≥ 18 years) who lead normal lives and underwent a routine lifestyle and dietary assessment at a clinical centre specialising in nutrition, metabolic health, and lifestyle counselling in Rome. Participants completed an online questionnaire on food preferences (19 foods) and sports practice. Multivariate logistic regression models, adjusted for age, sex, and smoking, were used to assess associations. Results: Sports participation was defined as engaging in structured physical activity at least once per week and was reported by 53.5% of subjects (men: 60.1%; women: 49.0%; p < 0.0001). After adjustment, active individuals were significantly more likely to prefer plant-based drinks, low-fat yoghurt, fish, cooked and raw vegetables, fruit, whole grains, tofu, and dark chocolate (all p < 0.05) and less likely to prefer cow’s milk (p = 0.018). Among sport participants, males were more likely to prefer meat (general, white, red, processed) and eggs, while females preferred plant-based drinks. No significant gender differences were observed for dairy products, legumes, or fish. Differences in food preferences were also observed according to the type of sport, with bodybuilders showing higher preference for tofu and dark chocolate. The strongest associations were found in the 25–44 age group. Conclusions: Sports participation is independently associated with specific food preferences, characterised by greater preference for plant-based and fibre-rich foods, and gender differences in food choices persist even among active adults. These findings highlight the need to consider both sports participation and gender when designing nutritional interventions. Full article

Tofu quality is critically influenced by coagulants, though their impact on protein digestibility remains underexplored. This study aimed to investigate the effects of calcium sulfate (CaSO₄), magnesium chloride (MgCl₂), and their combination (CaSO₄ + MgCl₂) on the physicochemical properties and protein digestibility of tofu. Water-holding capacity, cooking loss, texture, protein composition, and protein digestibility were analyzed. The results showed that the CaSO₄ + MgCl₂ combination yielded a water-holding capacity of 99.16%, significantly higher than CaSO₄ tofu (93.73%) and MgCl₂ tofu (96.82%), while reducing cooking loss to 2.03% and yielding the highest hardness (897.27 g) and gumminess (765.72). Electrophoresis revealed distinct protein retention patterns, with MgCl₂ (0.6% w/v) forming denser gels that minimized protein leakage into soy whey. During in vitro digestion, MgCl₂-coagulated tofu exhibited superior soluble protein release (5.33 mg/mL after gastric digestion) and higher intestinal peptide (5.89 mg/mL) and total amino acid (123.06 μmol/mL) levels, indicating enhanced digestibility. Conversely, the CaSO₄ + MgCl₂ combination showed delayed proteolysis in electrophoresis analysis. These findings demonstrate that coagulant selection directly modulates tofu’s texture, water retention, and protein bioavailability, with MgCl₂ favoring digestibility and the hybrid coagulant optimizing physical properties. This provides strategic insights for developing nutritionally enhanced tofu products. Full article

This study investigated the quality evolution of soybean products (soymilk, tofu, dried bean curd) through mixed-strain fermentation with Lacticaseibacillus rhamnosus CICC 6151 and Saccharomyces cerevisiae AS2.400 under optimized conditions (7% inoculum, pH of 5.2, 85 °C/50 min thermal treatment). Physicochemical, structural, and microbial dynamics were systematically analyzed. Key results demonstrated that probiotic tofu exhibited superior water-holding capacity (82% WHC vs. 65% in traditional variants) and enhanced protein retention (Δ + 2.4% during storage), linked to microbial-mediated structural stabilization. Mixed fermentation induced substrate competition (S. cerevisiae biomass: OD₅₆₀ of 1.2 at 10 h vs. L. rhamnosus OD₆₀₀ of 1.0 at 25 h; ANOVA p < 0.001), driving pH-dependent protein network formation (isoelectric precipitation at pH of 4.8 ± 0.1) and volatile profile divergence (PCA explained 82.2–89.1% of variance). Probiotic variants maintained chromatic stability (ΔE < 15 vs. traditional ΔE > 23) and textural integrity (23% lower deformation under compression), correlated with secondary structure preservation (β-sheet increased by 10% in FTIR analysis). These findings establish synergistic microbial–metabolic regulation as a strategy for developing functional bean products with enhanced nutritional and sensory properties. Full article

Okara, the soybean residue from soy milk and tofu production, offers significant potential as a sustainable, fiber-rich ingredient for starch-based and gluten-free food systems. This study investigates the comparative effects of whole okara and its extracted dietary fiber (DF) on the retrogradation, rheological properties, and nanostructural organization of rice starch (RS) gels. Rice starch suspensions were blended with 5–20% (dry basis) of either whole okara or DF, thermally gelatinized, and analyzed using dynamic rheology, synchrotron-based Wide-Angle X-ray Scattering (WAXS), and Fourier Transform Infrared (FTIR) spectroscopy. DF markedly reduced the gelation temperature and enhanced storage modulus (G′), indicating earlier and stronger gel network formation. WAXS analysis showed that DF more effectively disrupted long-range molecular ordering, as evidenced by suppressed crystallinity development and disrupted molecular ordering within the A-type lattice. FTIR spectra revealed intensified O–H stretching and new ester carbonyl bands, with progressively higher short-range molecular order (R_1047/1022) in DF-modified gels. While whole okara provided moderate retrogradation resistance and contributed to network cohesiveness via its matrix of fiber, protein, and lipid, DF exhibited superior retrogradation inhibition and gel stiffness due to its purity and stronger fiber–starch interactions. These results highlight the functional divergence of okara-derived ingredients and support their targeted use in formulating stable, fiber-enriched, starch-based foods. Full article

Currently, workers in the ribbed smoked sheet (RSS) rubber production industry face increasing health risks, primarily due to their direct involvement in converting fresh latex into raw rubber sheets. This process involves the manual addition of appropriately diluted commercial formic acid and acetic acid to induce coagulation, resulting in a tofu-like consistency, which is subsequently processed into rubber sheets. Previous studies have indicated that the use of commercial formic and acetic acids poses significant health hazards to workers and contributes to environmental pollution. Therefore, this study explores the feasibility of replacing commercial formic and acetic acids with wood vinegar derived from para-rubber wood, bamboo, and eucalyptus in the RSS production process. Wood vinegar samples from the three biomass sources were analyzed for their organic compound compositions using gas chromatography and subsequently used as coagulants in the preparation of raw rubber sheets. The drying kinetics and antifungal properties of the resulting sheets were then evaluated. The results revealed that wood vinegar derived from para-rubber wood contained the highest concentration of acetic acid (41.34%), followed by bamboo (38.19%) and eucalyptus (31.25%). Rubber sheets coagulated with wood vinegar from para-rubber wood and bamboo exhibited drying kinetics comparable to those obtained using acetic acid, with the two-term exponential model providing the best fit. Conversely, rubber sheets coagulated with eucalyptus-derived wood vinegar, which had a relatively high concentration of phenolic derivatives (22.08%), followed drying behavior consistent with the Midilli et al. model, similar to sheets treated with formic acid. In terms of antifungal properties, five fungal genera—Aspergillus, Penicillium, Fusarium, Trichoderma, and Paecilomyces—were identified on the rubber sheets. Fungal growth was most pronounced in the control samples (untreated with wood vinegar), whereas samples treated with wood vinegar exhibited significantly reduced fungal colonization. These findings indicate that wood vinegar is effective in inhibiting fungal growth on the surface of rubber sheets and may serve as a safer and more environmentally friendly alternative to commercial acid coagulants. Full article

The rising global production of tofu and soymilk has led to an increase in okara byproduct generation, creating a need for sustainable valorisation strategies to reduce environmental burdens. This study aims to understand the environmental impacts of seven okara valorisation scenarios compared to conventional disposal methods, such as landfilling and incineration, by conducting screening Life Cycle Assessments (LCAs). The results show that uncontrolled landfilling causes the highest environmental burden (37.2 EF-µPt/kg_okara), driven by methane and ammonia emissions that contribute to climate change, acidification, eutrophication, and particulate matter formation. Controlled landfilling (10.2 EF-µPt/kg_okara) and incineration (2.5 EF-µPt/kg_okara) lower these impacts but offer no circularity benefits. Biological treatments, such as anaerobic digestion (19.6 EF-µPt/kg_okara), composting (25.4 EF-µPt/kg_okara), and black soldier fly treatment (21.6 EF-µPt/kg_okara), provide climate benefits through energy recovery and feed production but introduce ammonia and organic dust emissions. In contrast, supercritical fluid extraction (−32.3 EF-µPt/kg_okara) and conventional protein hydrolysate production (−23.4 EF-µPt/kg_okara) deliver the greatest environmental savings by displacing soy protein and food-grade oil production. Animal feed use (−5.5 EF-µPt/kg_okara) emerges as a low-impact circular option, reducing climate change, land use, and eutrophication. The results show that regional weighting of emissions (e.g., ammonia, leachate) and uncertainties in substitution effects significantly influence outcomes. This study highlights the value of screening LCAs in identifying key environmental trade-offs in valorisation strategies and supports context-specific decision-making for circular processes. Full article

Mao-tofu is famous for its unique flavour and texture in Anhui Province, China. The physicochemical properties and microbial diversity of Mao-tofu during different fermentation periods were studied. The pH of the tofu was acidic, the moisture gradually decreased, and the hardness, viscosity, and chewiness gradually increased, while the elasticity gradually decreased. Among these, changes in volatiles and synergistic effects of proteins, peptides, and free amino acids (FAAs) affect the flavour of Mao-tofu. Histamine had the highest concentration among all biogenic amine (BA) during the whole fermentation process. A microbial community analysis showed that Lactobacillus and Trichosporon were the most important strains throughout the fermentation process. Bacterial abundance and diversity also showed a gradual increase, while fungal abundance and diversity showed a gradual decrease. A comprehensive analysis of the physicochemical changes associated with microbial succession can help to gain insights into the maturation process of texture and flavour during the production of Mao-tofu. Full article

Enhancing the sustainability of manufacturing systems requires reducing product defects through effective management of risks that impact product quality. A crucial component in minimizing defects is the adoption of robust risk management strategy. This study examines risk mitigation in the tofu production process to reduce product defects, by employing the House of Risk (HOR) framework to prioritize mitigation efforts. Data were collected through observations, in depth interviews, and focus group discussions, following the two-step HOR methodology. The analysis identified 12 risk events and seven risk agents, along with six prioritized mitigation strategies, based on the Aggregate Risk Potential (ARP) ranking of the identified risk agents. The highest-priority strategy involves developing standardized work instructions for the tofu production process. This study offers practical insights for companies seeking to lower defect rates, thereby supporting the sustainability of their manufacturing systems. Full article

Palm oil, widely used in various products, poses environmental and climate change risks. “Yeast oil” produced by Lipomyces starkeyi, an oil-producing yeast, is one of the sustainable alternatives for palm oil and was successfully produced as an edible substitute for palm oil. However, the high cost of the culture medium for oil production remains a challenge for practical applications. Okara is a by-product of tofu and soymilk production. Because yeast extract contributes to the high cost of the culture medium, we considered using okara, a cheap and nitrogen-rich substitute, to reduce costs. In the initial study with okara, the production of yeast oil was confirmed, but its productivity was low due to the high viscosity caused by its insoluble solids. To overcome this, we extracted and concentrated nitrogen components in okara using the membrane concentration process. Using NF (nanofiltration) membrane concentration, oil production increased 1.69 and 1.44 times compared to the unconcentrated extract solution (added 90% (v/v) in the culture medium) and yeast extract (added 5% (w/v) in the culture medium), respectively. These findings indicate the potential for a significant cost reduction in the culture medium and high oil yield in yeast oil production. Full article

Food security is one of the critical issues in facing the world food crisis. Utilizing food processing residue waste to make nutritious and healthy functional foods should follow a double-merit approach in facing the world food crisis. Oncom, an overlooked traditional fermented product based on local wisdom, might be an example of potential sustainable food to overcome hunger and support the circular economy programme. This review attempts to portray the existence and role of oncom based on a systematic study of hundreds of reports from different angles, mainly focusing on its processing, the microbes involved, its sensory characteristics, nutritional benefits, and promising bioactivities. Oncom can be produced by various raw materials such as tofu dreg (okara), peanut press cake, and tapioca solid waste, involving various microbes, mainly Neurospora sp. or Rhizopus sp., and various processing steps. The products show promising nutritional values. In terms of sensory characteristics, oncom is sensory-friendly due to its umami dominance. Many bioactivity capacities have been reported, including antioxidants, lowering cholesterol effect, and cardiovascular disease prevention, although some findings are still only preliminary. Undoubtedly, oncom has the potential to be developed as a future functional food with standardized quality and reliable bioefficacy. This kind of solid fermented product, based on agricultural residue wastes, is worthy of further development worldwide with full scientific support to create more reliable functional foods with a modern touch to achieve zero hunger. Full article

Tofu has captivated researchers’ attention due to its distinctive texture and enrichment in nutritional elements, predominantly soybean protein. Coagulants play a critical role in promoting coagulation during tofu production, directly influencing its texture, quality, and physicochemical characteristics. Currently, the impact of coagulant characteristics on coagulation, as well as the underlying mechanisms, remain unclear. This review provides a summary of research progress on salt coagulants, acid coagulants, enzyme coagulants, novel coagulants, polysaccharide additives, and various coagulant formulations. The coagulation mechanisms of various coagulants are also discussed. Accordingly, this paper seeks to offer reliable theoretical guidance for the development of novel coagulants and the realization of fully automated tofu production. Full article

Soybean breeding programs targeting tofu quality must evaluate their performance within zones of adaptation. A comprehensive study was carried out to examine soybean breeding lines from three maturity groups (MGs; MG0, MG00, and MG000) from 2018 to 2022. Several agronomic, chemical composition and tofu-related quality traits were evaluated, and the associations among traits were investigated. The results showed that genotypes in MG0 yielded higher and matured later, which confirmed that the selection of targeted genotypes for a specific maturity group was successful. Non-imbibed “stone seeds”, an important quality trait for tofu processors, were higher in MG000 lines. Tofu texture using both GDL and MgCl₂ coagulants was positively associated, indicating one coagulant might be enough for screening purposes. The MG by traits biplot showed very clear MG clustering for all genotypes tested from 2018 to 2022, signifying that the MG has a more pronounced effect on the investigated traits than the environmental effects seen in different years, regardless of the MG. Most tofu-related traits were higher and showed stronger associations in MG0 lines compared to the lines in earlier MGs, indicating a need for future effort in shorter season MGs. Overall, this study provided useful information for selecting soybean lines for tofu end-use application targeting specific MGs. Full article