Tofu Whey Research Articles

Characterization of a new style tofu coagulated by fermentation of Lactobacillus plantarum SJ-L-1.

A new style of tofu coagulated through the fermentation of Lactobacillus plantarum SJ-L-1 was produced. L. plantarum SJ-L-1 with a high growth rate and excellent acid production ability was isolated and identified from naturally fermented soy yellow whey. The gene annotation indicated the potential outstanding isoflavone conversion capacity of L. plantarum SJ-L-1. Furthermore, fermentation tofu was prepared using L. plantarum SJ-L-1 and Lactobacillus rhamnosus 1-16 as the starter microbiota. Compared to traditional MgCl2 tofu and fermented soy whey tofu, SJ-L-1 tofu exhibited a slight increase in hardness and better structure uniformity. SJ-L-1 tofu also possessed the highest levels of total isoflavone content (76.33µg/g) and volatile compounds (561.54µg/kg) among the four styles of tofu. This research indicated that this new type of tofu coagulated through a combination of heat and fermentation of L. plantarum SJ-L-1 represents a promising candidate for future functional foods.

Identification of Fouling Occurring during Coupled Electrodialysis and Bipolar Membrane Electrodialysis Treatment for Tofu Whey Protein Recovery.

Tofu whey, a by-product of tofu production, is rich in nutrients such as proteins, minerals, fats, sugars and polyphenols. In a previous work, protein recovery from tofu whey was studied by using a coupled environmental process of ED + EDBM to valorize this by-product. This process allowed protein recovery by reducing the ionic strength of tofu whey during the ED process and acidifying the proteins to their isoelectric point during EDBM. However, membrane fouling was not investigated. The current study focuses on the fouling of membranes at each step of this ED and EDBM process. Despite a reduction in the membrane conductivities and some changes in the mineral composition of the membranes, no scaling was evident after three runs of the process with the same membranes. However, it appeared that the main fouling was due to the presence of isoflavones, the main polyphenols in tofu whey. Indeed, a higher concentration was observed on the AEMs, giving them a yellow coloration, while small amounts were found in the CEMs, and there were no traces on the BPMs. The glycosylated forms of isoflavones were present in higher concentrations than the aglycone forms, probably due to their high amounts of hydroxyl groups, which can interact with the membrane matrices. In addition, the higher concentration of isoflavones on the AEMs seems to be due to a combination of electrostatic interactions, hydrogen bonding, and π-π stacking, whereas only π-π stacking and hydrogen bonds were possible with the CEMs. To the best of our knowledge, this is the first study to investigate the potential fouling of BPMs by polyphenols, report the fouling of IEMs by isoflavones and propose potential interactions.

Tofu Whey-Based Media for Probiotic Lactiplantibacillus plantarum D4 as a Halal Starter Culture

In recent years, the development of probiotic-based fermented products with halal status has been a concern. The use of growth medium has relied on de Man Rogosa and Sharpe (MRS) as a relatively expensive standard medium, and its halal status is still uncertain. Extensive research has been carried out to investigate the development of low-cost halal alternative media for the cultivation of probiotic lactic acid bacteria (LAB). This study aimed to develop a probiotic halal and low-cost culture medium using a tofu whey-based medium. This study used three tofu whey-based media – A (tofu whey 100%), B (tofu whey 94.5%, molasses 3%, skim milk 2.5%), C (tofu whey 92.5%, molasses 3%, cheese whey 2.5%, tomato extract 2%), and MRS broth as a standard medium. Bacterial populations, total sugars utilized, total lactic acids produced, low pH (2.0) tolerance, and high bile salt concentration (oxgall 1.5%) were assayed. The highest bacterial population after 48 h of incubation was shown by medium B compared to medium MRS (12.34 ± 0.87 and 11.48 ± 0.3 log CFU/mL). Total sugars utilized by 48.28 ± 2.89, 38.89 ± 6.94, 39.14 ± 4.24, and 76.00 ± 1.41 %; on the other hand, total lactic acids produced by 0.16 ± 0.12, 0.03 ± 0.04, 0.31 ± 0.03, and 2.25 ± 1.48 % in A, B, C, and MRS, respectively. Probiotic tolerance at low pH and the presence of bile salts of Lactiplantibacillus plantarum D4 consistently showed a high survival rate in medium B compared to MRS. Based on these results, the components and proportions used in medium B were suitable for the growth of L. plantarum D4 as a halal probiotic starter candidate.

Growth and metabolic behavior of probiotic Bifidobacterium longum subsp. longum in minimally supplemented soy (tofu) whey

Soy (tofu) whey is a liquid side-stream from tofu production. It is a nutrient-rich substrate that can be converted into beverages by fermentation. In this study, soy whey media supplemented with various nutrients (control, glucose, glucose + cysteine-HCl (GC), glucose + cysteine-HCl + yeast extract (GCY)) were evaluated as fermentation substrates for probiotic Bifidobacterium longum subsp. longum BB536. GC and GCY facilitated strain BB536 growth leading to the production of acetic and lactic acid. However, there was no significant decrease in sugar content after fermentation, while succinic acid and selected amino acids such as cysteine showed significant decreases after fermentation. Vitamin B12 (2.12 µg/L) was found only in fermented GCY samples. Endogenous volatile compounds such as heptanal and hexenal in tofu whey were reduced to low or trace levels while short-chain fatty acids, 2,3-butanedione and volatile sulfur compounds such as hydrogen sulfide and 3-methylthiophene were produced. Iron and potassium contents in the fermented soy whey increased after fermentation. This research provides further insights into the possibility of utilizing B. longum BB536 to ferment soy whey into a novel functional beverage or ingredient.

Impact of nanofiltration pre-concentration prior to a combination of electrodialytic processes on the extraction of proteins from tofu whey

Tofu whey is a by-product of tofu production which represents a major challenge in the industry, considering treatments that must be applied before its disposal to reduce its environmental impact. Rich in nutrients, such as protein and minerals, tofu whey valorization represents an interesting alternative. In this study, the impact of a pre-concentration step by nanofiltration prior to coupled electrodialysis and electrodialysis with bipolar membrane (ED+EDBM) treatments on protein recovery was investigated. Tofu whey without concentration (1X) and volume concentration factors of 2X and 3X were used. The 3X condition allowed a protein recovery about 20 % higher than the 1X. Also, protein purity of the recovered fraction was similar for these three conditions, with an average value of 44.8 % (dry basis). The lowest relative energy consumption of 2.7 Wh/g of protein recovered was achieved with the 3X VCF; as the VCF increased, up to 3.5 times less energy was required to isolate the same amount of protein. The NF+ED+EDBM was efficient to recover the proteins with the highest molecular weights. Although the pre-concentration step improved protein recovery, yields are still low and should be increased by further optimization step.

The Use of Tofu Whey from Food Industry Waste in Podological Care

The aim of the study was to create cosmetic formulations used for washing and conditioning based on natural whey derived from tofu. Tofu whey used in the production of hair cosmetics turns out to be valuable waste that replaces water. Whey is an ingredient rich in proteins, oligosaccharides and isoflavones. When trying to follow the principles of sustainable development, we need also to be responsible for protecting water resources. Using whey, we limit water consumption to the necessary minimum. Hence, we also support no water waste trend. Tofu whey, which is a valuable waste that replaces water, was used in the production of podology products. The research was conducted following the approval of the Bioethics Committee, resolution number 223/22. Tests confirming or excluding the properties and performance of tofu whey declared by the Ordering Party were carried out at probands’ homes and in the Dermatology Center (Centrum Dermatologii Sp. z o.o.) in Poznan. The probands were volunteers. A group of 30 people was selected for the study according to the indications for the use of the product submitted for experiments. The selection of probands was carried out after a preliminary assessment of the condition of feet and health. Due to the purpose of the product, the study involved people who declared a desire to improve the appearance and condition of their feet. The study used the imaging method with the participation of a microcamera.

Protein Recovery from Tofu Whey Wastewater Using a Column Reactor: Preliminary Results

ABSTRAK Industri tahu menghasilkan air limbah pekat atau whey (dadih), yang memiliki pH rendah dan bahan organik yang tinggi, sehingga dapat menyebabkan pencemaran lingkungan jika tidak diolah dengan baik. Di sisi lain, salah satu kandungan limbah tahu pekat yaitu protein dapat dimanfaatkan kembali untuk mengurangi potensi pencemaran lingkungan dan diolah lebih lanjut menjadi produk yang bernilai ekonomis. Penelitian ini bertujuan untuk mendapatkan data awal untuk menilai kelayakan penggunaan metode fraksinasi busa untuk pemulihan protein dari limbah tahu pekat. Limbah tahu pekat dalam penelitian kami memiliki konsentrasi protein awal 3.115 mg/l. Percobaan dilakukan dengan menggunakan reaktor fraksinasi busa berbentuk kolom dalam mode semi-curah. Kombinasi tiga laju alir udara (10, 30, dan 60 l/jam) dan tiga konsentrasi limbah tahu pekat (10, 50, dan 100%) diuji. Hasil percobaan menunjukkan bahwa konsentrasi protein awal mempengaruhi pemulihan protein, sehingga diperlukan konsentrasi protein awal sekitar 3.000 mg/l. Rasio pengayaan tertinggi 1,0 ± 0,5, setara dengan pemulihan protein 6 ± 4%, dicapai pada laju alir 10 l/jam dan konsentrasi limbah tahu pekat 100%. Peningkatan laju alir hingga 30 l/jam tidak mengubah rasio pengayaan (0,9 ± 0,2), tetapi meningkatkan pemulihan protein hingga 71 ± 14%. Penelitian lebih lanjut diperlukan untuk parameter-parameter lain seperti konsentrasi protein awal, komposisi limbah tahu pekat, laju aliran udara, ukuran gelembung, holdup cairan, dan desain reaktor. ABSTRACT The tofu industry generates highly-polluted wastewater called whey, which has a low pH and high organic matter, and therefore can cause environmental pollution when not treated properly. On the other hand, one of the whey constituents namely protein can be recovered from the wastewater to reduce its environmental potency and to be further processed as a product that has an economic value. This study aimed to obtain preliminary data to assess the feasibility of using the foam fractionation method for the recovery of protein from tofu whey wastewater. Tofu whey in our study had an initial protein concentration of 3115 mg.L-1. The experiment was performed using a column foam fractionation reactor in a semi-batch mode. Combinations of three air flow rates (10, 30, and 60 L.h-1) and three tofu whey concentrations (10, 50, and 100%) were tested. Our results show that initial protein concentration influenced protein recovery, with a protein concentration of approximately 3000 mg.L-1 required. The highest enrichment ratio of 1.0 ± 0.5, which corresponded to 6 ± 4% protein recovery, was achieved at 10 L.h-1 flow rate and 100% whey concentration. Increasing the flow rate to 30 L.h-1 did not change the enrichment ratio (0.9 ± 0.2), but increased the protein recovery to 71 ± 14%. Further investigation is needed for parameters such as initial protein concentration, whey composition, air flow rate, bubble size, holdup time, and reactor design.

Lactobacillus amylolyticus L6 produces a novel maltogenic amylase with stable catalytic activity

Lactobacillus amylolyticus is rich in starch hydrolases, but the maltogenic amylase (MA), an anti-staling additive in the food baking industry, was not characterised. Herein, we investigated the MA from L. amylolyticus L6 (LAMA), a strain isolated from the naturally acidified tofu whey, the LAMA gene was firstly obtained by PCR amplification, and subsequently the recombinant enzyme was expressed, purified, and its catalytic activity was finally characterised. The optimum pH and temperature were 5.5–6 and 37–48 °C, respectively, the temperature range broad (40–65 °C), the pH stability high (pH 4.5–8.5), and the half-life long (444 h). Fe3+ and Triton X-100 improved enzyme activity to some extent, but enzymatic activity was not dependent on metal ions. Cyclodextrin was the preferred substrate, and hydrolytic activity was ranked β-cyclodextrin > α-cyclodextrin > γ-cyclodextrin. Molecular docking simulations verified the preference of LAMA and revealed the binding poses and sites of both substrates and LAMA. Among them, Tyr41 and Asn40 may be the key to influencing the binding ability of both substrates. Thus, L. amylolyticus L6 containing LAMA may have a bright future in application on bakery products.

"The Use of Tofu Whey from Food Industry in the Cate of the Scalp and Hair"

"The Use of Tofu Whey from Food Industry in the Cate of the Scalp and Hair"

Sensory quality of upcycled legume water: Expectation vs. reality

Aquafaba and liluva are names used to define the processing water of food legumes. Large volumes of liluva are generated by frozen pea manufacturers (blanching water) and tofu producers (tofu whey). Studies have shown the potential of aquafaba and liluva in food applications as texture improvers and sources of bioactive substances and prebiotics. Nonetheless, no information on consumer perception of these new food ingredients is available. Therefore, this study investigated consumer expectations of steam blanching pea water (SBPW) and tofu whey (TW), correlating it with their actual sensory qualities and functional properties. Specifically, liluva was used as a source of prebiotics and hydrocolloids in 3D-printed mashed potatoes to enhance their rheology and printability. A preliminary survey showed a limited understanding of SBPW and TW as food ingredients, with only 43% and 38% of subjects willing to try TW and SBPW, respectively, with most subjects unsure on whether they wanted to or not (34% tofu whey and 49% liluva). Once the actual sensory test was conducted, TW-added mashed potato received favorable scores for all sensory attributes (appearance, aroma, taste, and texture). In contrast, SBPW-added mashed potato had a negative score on the color, as all nine focus group subjects described the color as gray. Overall, TW enhanced the printability of mashed potatoes due to its emulsifying ability and possibly coagulants derived from tofu making, and it was more appreciated sensory-wise, resulting in being the most preferred out of three samples (SBPW, TW, and control). Therefore, emphasizing consumer education may be key when expanding these innovative food ingredients to other food areas.

Study on the fermentation effect of Rhodotorula glutinis utilizing tofu whey wastewater and the influence of Rhodotorula glutinis on laying hens.

Tofu whey wastewater (TWW) is the wastewater of tofu processing, which is rich in a variety of nutrients. Rhodotorula glutinis can make full use of TWW to ferment and reproduce yeast cells, produce carotenoids and other nutrients, improve the utilization value of TWW, and reduce environmental pollution and resource waste. In this study, the nutrient composition changes of TWW treated by Rhodotorula glutinis were analyzed to reformulate TWW medium, and the optimal composition and proportion of TWW medium that can improve the biomass and carotenoids production of Rhodotorula glutinis were explored. Meanwhile, the Rhodotorula glutinis liquid obtained under these conditions was used to prepare biological feed for laying hens, and the effect of Rhodotorula glutinis growing on TWW as substrate on laying performance and egg quality of laying hens were verified. The results showed that the zinc content of TWW after Rhodotorula glutinis fermentation increased by 62.30%, the phosphorus content decreased by 42.31%, and the contents of vitamin B1, B2 and B6 increased to varying degrees. The optimal fermentation conditions of Rhodotorula glutinis in the TWW medium were as follow: the initial pH was 6.40, the amount of soybean oil, glucose and zinc ions was 0.80 ml/L, 16.32 g/L, and 20.52 mg/L, respectively. Under this condition, the biomass of Rhodotorula glutinis reached 2.23 g/L, the carotenoids production was 832.86 μg/g, and the number of effective viable yeast count was 7.08 × 107 cfu/ml. In addition, the laying performance and egg quality of laying hens fed Rhodotorula glutinis biological feed were improved. In this study, we analyzed the composition changes of TWW, optimized the fermentation conditions of Rhodotorula glutinis in TWW medium, explored the influence of Rhodotorula glutinis utilizing TWW on laying layers, and provided a new idea for the efficient utilization of TWW.

Effect of Coagulant and Treatment Conditions on the Gelation and Textural Properties of Acidic Whey Tofu.

This study aimed to investigate the properties of acidic whey tofu gelatin generated from two acidic whey coagulants by pure fermentation of Lactiplantibacillus paracasei and L. plantarum, as well as the characteristics of acidic whey tofu. The optimal holding temperature and the amount of coagulants added were determined based on the pH, water-holding capacity, texture, microstructure, and rheological properties of tofu gelation. Then, the differences in quality between tofu produced by pure bacterial fermentation and by natural fermentation were investigated under optimal tofu gelatin preparation conditions. The tofu gelatin presented the best texture at 37 °C with a 10% addition of coagulants fermented by both L. paracasei and L. plantarum. Under these conditions, the coagulant produced by the fermentation of L. plantarum resulted in a shorter formation time and stronger tofu gelatin compared with that produced from L. paracasei. Tofu produced by the fermentation of L. paracasei had higher pH, less hardness, and a rougher network structure, whereas tofu produced by the fermentation of L. plantarum was closer to tofu produced by natural fermentation in terms of pH, texture, rheology, and microstructure.

Composition of proteins in fresh whey as waste in tofu processing

Tofu whey is a pale-yellowish liquid with specific aroma/taste which remains as the byproduct/waste after tofu squeezing and represents an environmental problem for direct disposal. Understanding the fresh tofu whey protein composition and the activity of bioactive peptides could be useful for the application of tofu whey as a functional food additive. Tofu whey was obtained during the tofu production from six soybean genotypes by hydrothermal processing in combination with chymosin-pepsin rennet. Basic 7S globulin (14.28–19.13%), γ-conglycinin (7.73–9.31%) and β-conglycinin (10.59–12.90%) were registered of the total extracted proteins. Glycinin was present with a dominant share of acidic (24.64–27.55%) versus basic polypeptides (12.18–14.61%) in the total extracted proteins. High content of total protein (22.67–28.00%), balanced content (9.76–13.33% of the total extracted proteins) and residual activity (1.95–3.76%) of trypsin inhibitors and low lectins content (5.04–5.48% of the total extracted proteins) indicate good nutritional value of the tofu whey samples. Tofu whey can be potentially useful for application as a cheap, nutritional and functional food additive and can enable sustainable production through the recycling of waste.

The effect of salinity and tofu whey wastewater on the growth kinetics, biomass, and primary metabolites in Euglena sp.

The effect of salinity and tofu whey wastewater on the growth kinetics, biomass, and primary metabolites in Euglena sp.

Tofu Whey Wastewater as a Beneficial Supplement to Poultry Farming: Improving Production Performance and Protecting against Salmonella Infection.

Tofu whey wastewater (TWW) is a by-product of the tofu production process, and contains high amounts of organic products and Lactobacillus ap. However, no studies have been reported on whether naturally fermented TWW can be used as a beneficial additive for poultry production. This study analyzed the main nutritional components and microbial flora of naturally fermented TWW from rural tofu processing plants and their effect on chick production performance, role in modulating the biochemical and immune parameters, and protection against Salmonella enteritidis (S. enteritidis) infection. It was observed that the average pH of TWW was 4.08; therefore, the total viable count was 3.00 × 109 CFU/mL and the abundance of Lactobacillus was 92.50%. Moreover, TWW supplementation increased the total weight gain and feed intake, reduced the feed/gain ratio, increased the length and relative weight of the gut, and reduced the colonization and excretion of S. enteritidis in chickens. Additionally, TWW decreased oxidative damage and pro-inflammatory cytokine secretion caused by S. enteritidis infection. In addition, TWW supplementation ensured the structure of the intestine remained relatively intact in S. enteritidis-infected chicken. Furthermore, TWW markedly promoted the intestinal barrier integrity and up-regulated the relative abundance of Lactobacillus, counteracting the changes in gut microbiota caused by S. enteritidis infection in chicken. In conclusion, our data demonstrated that TWW could be used as a beneficial addition to poultry production, providing a research basis for the further development of TWW as a health care application in in food-producing animal.

Antimicrobial activity of tofu whey and steam blanching pea water for enhancement of shelf-life of 3D printed mashed potatoes

Using naturally-occurring antimicrobials against the resistance of foodborne pathogens towards antibiotics and chemicals, as well as their insensitivity is a promising research field. Water extracts of legumes have been proven to inhibit microbial development due to the presence of phenolic compounds, protein-derived peptides, saponins and defensin. This study examined the antimicrobial effects of two types of legume water, such as tofu whey (TW) and steam blanching pea water (SBPW), by adding into three-dimensional (3D) printed mashed potato. Composition, moulding, microbial growth assessment and the inhibition zone analysis were conducted. TW and SBPW contained 4 g/100 ml of solid matter, consisting of protein, soluble carbohydrates, minerals and saponins. Results have shown decreased microbial spoilage and enhanced Lactobacillus growth of mashed potato formulated with legume water. Limited inhibition zone (1 mm) was present on TW saponin extract against Staphylococcus aureus and Lactobacillus spp. TW and SBPW addition to 3D printed mashed potatoes encouraged the development of probiotic bacteria, which can be applied to extend shelf-life of food products as well as to develop fermented foods.

Phenotypic and comparative genomic analysis of two Lactobacillus amylolyticus strains from naturally fermented tofu whey

SummaryThe differences in aspects of morphology, fermentation and probiotic characteristics between Lactobacillus amylolyticus L5 (Lam1.5) and L6 (Lam1.6) isolated from naturally fermented tofu whey were investigated by phenotypic and comparative genomic analysis. The results indicated that morphological difference between two strains may attribute to the mutation of ftsW and ftsK genes responsible for cell division. The optimum growth temperatures of Lam1.5 and Lam1.6 were different, and the acid‐producing ability of Lam1.6 was stronger than that of Lam1.5. And the growth rate of Lam1.6 exhibited better growth performance than that of Lam1.5 in MRS with initial pH 3.0–5.0. Besides, Lam1.5 was proved to be safe to be used in fermented food with safety evaluation. In respect of probiotic traits, Lam1.5 displayed the same performance in tolerance of intestinal juice, antimicrobial activity and adhesion properties as that of Lam1.6. However, Lam1.5 was more sensitive to simulated gastric juice than Lam1.6 at pH 2.5 and 3.0, which might be due to its long‐rod shape and lack of K+‐ATPase and Na+‐H+ antiporters. This study unveiled morphological and physiological differences between Lam1.5 and Lam1.6, raising the potential effect of ftsW and ftsK on the morphological development of lactobacilli that further affects their metabolic properties.

Purification of Soybean Oligosaccharides of Tofu Whey Using a Hybrid Process Based on Enzymatic Hydrolysis and Nanofiltration

Tofu whey, liquid waste of tofu processing, contains valuable components including protein, mono- and di-saccharide (glucose, fructose, sucrose, MDS) and soy oligosaccharide (stachyose, raffinose, SOS). Recovery of these components, therefore, is essential regarding sustainable food processing approach. Ultrafiltration (UF) has been successfully used for concentration of tofu whey protein. In this study, nanofiltration was employed to harvest and purify SOS from tofu whey UF-permeate. NF-membrane selection, hydrolysis of tofu whey UF-permeate and NF of pre-hydrolysis of tofu whey UF- permeate were performed to achieve the best condition for purification. It was found that the membrane, NF-DK-2540 was superior than that of NF-DL-2540 with the retention rate of stachyose (94%), raffinose (87%), sucrose (65%), glucose (7.8%) and fructose (4.3%). These results indicated that NF could harvest SOS and remove monosaccharide with acceptable retention. However, its sucrose retention was considerably high. Therefore, an enzymatic hydrolysis of UF-permeate was employed to convert sucrose to glucose and fructose. The results indicated that the use of NF combined with enzymatic hydrolysis could significantly remove MDS from tofu whey UF-permeate and consequently increasing the purity of SOS.

The possibility of a halal mix probiotic medium for the cultivation of Lactobacillus plantarum N16 and Saccharomyces cerevisiae

This study aimed to determine the effects of interaction between media type (halal mix preparation) and culture mixtures of Lactobacillus plantarum N16 and Saccharomyces cerevisiae (probiotics). A completely randomised factorial design (CRFD) consisting of 2 factors and three replications was used, where factor A was a mixture of Lactobacillus plantarum N16 and Saccharomyces cerevisiae at a ratio of 1:1 (A1); 1:2 (A2) and 2:1 (A3) and factor B was the type of growth media, that is, control (B1), whey tofu, molasses, and fish waste flour (B2), and coconut water, onggok flour and shrimp waste flour (B3). The variables measured were viability, cell biomass, and pH. The results showed interactions between factors A and B, which were significantly different (p <0.05) in terms of viability, cell biomass, and pH. Based on the results of the study, it can be concluded that the mixture of Lactobacillus plantarum N16 and Saccharomyces cerevisiae at a ratio of 2:1 (A3), using coconut water, onggok flour, and shrimp waste flour (B3) as medium and incubated at 36 °C for 24 hours was the best medium. It had a 2.37 viability, 42.33 mg/ml biomass cell, and a pH of 2.37.

Karakterisasi Aktivitas Fungsional Senyawa Bioaktif dari Whey Hasil Samping Produksi Tahu

Tofu whey is a by-product obtained during tofu production that contains proteins and peptides, soluble carbohydrates, soy isoflavone, and minerals. This research aimed to characterize the functional properties of whey protein from tofu through separation using membranes with different pore sizes. The permeate resulted from Whatman No. 3 filtration was subjected to acidity (pH) and protein content measurement, while its protein profile was characterized by SDS-PAGE. electrophoresis. Additionally, this permeate was further sieved using ultrafiltration membranes with 30, 10, and 5 kDa cut-off. The corresponding filtrates were analyzed for antioxidant activity, isoflavone content, and ACE inhibitor activity. The tofu whey had a pH of 3.14, crude protein of 2 g/100 g sample, and soluble protein content of 1.47mg/mL. The separation of protein bands using SDS-PAGE showed that the dominant protein or peptides in tofu whey had molecular weights below 18 kDa. The use of ultrafiltration membranes could increase the bioactivity of permeates. The filtrate resulting from the smallest membrane cut-off (i.e., 5 kDa) had a higher antioxidant activity, isoflavone content, and ACE inhibitory activity.