Viscosity of evaporated soymilk prepared in the laboratory using normal and 11S-lacking soybean seeds.

BACKGROUND: Soymilk is utilized not only as a beverage but also as an alternative to bovine milk, including products such as yoghurt and cream. Evaporated soymilk is expected to be utilized as condensed milk. Raw and heated soymilk samples prepared in our laboratory were evaporated and then subjected to viscosity measurement. The soymilk samples were made from two different varieties: Fukuyutaka, which contains 7S and 11S globulin proteins; and an 11S-lacking soybean (Nanahomare). RESULTS: Raw Fukuyutaka soymilk had a lower viscosity and could be concentrated to a solids content of over 300 g kg-1 compared to heated soymilk (around 250 g kg-1 ), but the viscosity changes of Nanahomare soymilk showed an opposite trend. Only 7S globulin was denatured during evaporation at 75 °C and likely affected the interaction between proteins and oil bodies. This tendency was remarkable in the Nanahomare soymilk. The strange viscosity change behavior of evaporated Nanahomare soymilk, number of protein particles, intrinsic fluorescence and flow behavior suggest that thermally denatured 7S globulin accelerates the interactions between oil bodies, whereas 11S globulin, which is probably in its native state, suppresses the acceleration by denatured 7S globulin. CONCLUSION: Raw soymilk containing native globulins shows a slower increase in viscosity during evaporation. However, denatured 7S globulin accelerates the increase in viscosity during evaporation through interactions between oil bodies. The effect of the denatured state of individual proteins on interactions is expected to be useful in understanding the interaction between proteins and in controlling their properties and functions. © 2022 Society of Chemical Industry.

Immunobiotic Feed Developed with Lactobacillus delbrueckii subsp. delbrueckii TUA4408L and the Soymilk By-Product Okara Improves Health and Growth Performance in Pigs.

Lactobacillus delbrueckii subsp. delbrueckii TUA4408L is able to differentially modulate the innate immune response of porcine intestinal epithelial cells triggered by TLR4 activation. This strain also has a remarkable ability to grow on plant substrates. These two immunological and biotechnological characteristics prompted us to evaluate whether the soymilk by-product okara fermented with the TUA4408L strain can serve as an immunobiotic feed with the ability to beneficially modulate the intestinal immunity of piglets after weaning to improve their productivity. Our in vivo studies demonstrated that the administration of immunobiotic TUA4408L-fermented okara feed significantly increased piglet growth performance and meat quality. These positive effects were associated with the ability of the TUA4408L-fermented okara feed to beneficially modulate both intestinal microbiota and immunity in pigs. The immunobiotic feed improved the abundance of the beneficial bacteria Lactobacillus and Lactococcus in the gut of pigs, reduced blood markers of inflammation, and differentially regulated the expression of inflammatory and regulatory cytokines in the intestinal mucosa. These findings indicate that the immunobiotic TUA4408L-fermented okara feed could be an economical and environmentally friendly option to improve the growth performance and immune health of pigs.

Genomic Characterization of Lactobacillus delbrueckii TUA4408L and Evaluation of the Antiviral Activities of its Extracellular Polysaccharides in Porcine Intestinal Epithelial Cells.

In lactic acid bacteria, the synthesis of exopolysaccharides (EPS) has been associated with some favorable technological properties as well as health-promoting benefits. Research works have shown the potential of EPS produced by lactobacilli to differentially modulate immune responses. However, most studies were performed in immune cells and few works have concentrated in the immunomodulatory activities of EPS in non-immune cells such as intestinal epithelial cells. In addition, the cellular and molecular mechanisms involved in the immunoregulatory effects of EPS have not been studied in detail. In this work, we have performed a genomic characterization of Lactobacillus delbrueckii subsp. delbrueckii TUA4408L and evaluated the immunomodulatory and antiviral properties of its acidic (APS) and neutral (NPS) EPS in porcine intestinal epithelial (PIE) cells. Whole genome sequencing allowed the analysis of the general features of L. delbrueckii TUA4408L genome as well as the characterization of its EPS genes. A typical EPS gene cluster was found in the TUA4408L genome consisting in five highly conserved genes epsA-E, and a variable region, which includes the genes for the polymerase wzy, the flippase wzx, and seven glycosyltransferases. In addition, we demonstrated here for the first time that L. delbrueckii TUA4408L and its EPS are able to improve the resistance of PIE cells against rotavirus infection by reducing viral replication and regulating inflammatory response. Moreover, studies in PIE cells demonstrated that the TUA4408L strain and its EPS differentially modulate the antiviral innate immune response triggered by the activation of Toll-like receptor 3 (TLR3). L. delbrueckii TUA4408L and its EPS are capable of increasing the activation of interferon regulatory factor (IRF)-3 and nuclear factor κB (NF-κB) signaling pathways leading to an improved expression of the antiviral factors interferon (IFN)-ß, Myxovirus resistance gene A (MxA) and RNaseL.

Soymilk Improves Muscle Weakness in Young Ovariectomized Female Mice.

Estrogens play a key role in an extensive range of physiological functions in various types of tissues throughout the body in females. We previously showed that estrogen insufficiency caused muscle weakness that could be rescued by estrogen administration in a young female ovariectomized (OVX) mouse model. However, long-term estrogen replacement therapy increases risks of breast cancer and cardiovascular diseases. Soymilk contains plant-based protein and isoflavones that exert estrogen-like activity. Here we examined the effects of prolonged soymilk intake on muscle and its resident stem cells, called satellite cells, in the estrogen-insufficient model. Six-week-old C57BL/6 OVX female mice were fed with a dried soymilk-containing diet. We found that prolonged soymilk intake upregulated grip strength in OVX mice. Correspondingly, cross-sectional area of tibialis anterior muscle was significantly increased in OVX mice fed with soymilk. Furthermore, soymilk diet mitigated dysfunction of satellite cells isolated from OVX mice. Thus, these results indicated that prolonged soymilk intake is beneficial for improving muscle weakness in an estrogen-insufficient state in females.

Isoflavone and protein constituents of lactic acid-fermented soy milk combine to prevent dyslipidemia in rats fed a high cholesterol diet.

A high cholesterol diet induces dyslipidemia. This study investigated whether isoflavone aglycones in lactic acid-fermented soy milk (LFS) improve lipid metabolism in rats fed a high cholesterol diet. Male Sprague-Dawley rats aged seven weeks were fed an AIN-93G diet, a 1% cholesterol diet (a high cholesterol diet), a high-cholesterol diet containing 4% isoflavone extract of LFS (LFS extract diet), a high-cholesterol diet containing 19.4% ethanol-washed LFS (ethanol-washed LFS diet, isoflavone-poor diet), or a high cholesterol diet containing 23.2% intact LFS (intact LFS diet) for five weeks. The plasma total cholesterol (TC) level was increased in the rats fed the LFS extract diet compared with those fed the high cholesterol diet. The TC level was decreased by the intact LFS and ethanol-washed LFS diets. The cholesterol-lowering effect was stronger in the rats fed the intact LFS diet than those fed the ethanol-washed LFS diet. The plasma triglyceride (TG) level was unchanged in the rats fed the LFS extract diet, but it decreased in rats fed the intact LFS and ethanol-washed LFS diets. Although, compared with the high cholesterol diet, the LFS extract and ethanol-washed LFS diets did not reduce hepatic cholesterol and TG, both levels were remarkably lowered by the intact LFS diet. These results suggest that the improvement in lipid metabolism of rats fed a high-cholesterol diet containing LFS isoflavone aglycones is not due to an independent effect but due to a cooperative effect with soy protein.

Lactobacillus delbrueckii TUA4408L and its extracellular polysaccharides attenuate enterotoxigenic Escherichia coli-induced inflammatory response in porcine intestinal epitheliocytes via Toll-like receptor-2 and 4.

SCOPE: Immunobiotics are known to modulate intestinal immune responses by regulating Toll-like receptor (TLR) signaling pathways, which are responsible for the induction of cytokines and chemokines in response to microbial-associated molecular patterns. However, little is known about the immunomodulatory activity of compounds or molecules from immunobiotics. METHODS AND RESULTS: We evaluated whether Lactobacillus delbrueckii subsp. delbrueckii TUA4408L (Ld) or its extracellular polysaccharide (EPS): acidic EPS (APS) and neutral EPS (NPS), modulated the response of porcine intestinal epitheliocyte (PIE) cells against Enterotoxigenic Escherichia coli (ETEC) 987P. The roles of TLR2, TLR4, and TLR negative regulators in the immunoregulatory effects were also studied. ETEC-induced inflammatory cytokines were downregulated when PIE cells were prestimulated with both Ld or EPSs. Ld, APS, and NPS inhibited ETEC mediated mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) activation by upregulating TLR negative regulators. The capability of Ld to suppress inflammatory cytokines was diminished when PIE cells were blocked with anti-TLR2 antibody, while APS failed to suppress inflammatory cytokines when cells were treated with anti-TLR4 antibody. Induction of Ca²âº fluxes in TLR knockdown cells confirmed that TLR2 plays a principal role in the immunomodulatory action of Ld, while the activity of APS is mediated by TLR4. In addition, NPS activity depends on both TLR4 and TLR2. CONCLUSION: Ld and its EPS have the potential to be used for the development of anti-inflammatory functional foods to prevent intestinal diseases in both humans and animals.

Hypocholesterolemic effects of lactic acid-fermented soymilk on rats fed a high cholesterol diet.

The effect of fermented soymilk on rats fed a high cholesterol diet was investigated to clarify the cholesterol-lowering function. Male Sprague-Dawley rats aged 7 weeks were fed a control diet (1% cholesterol, high cholesterol diet), high cholesterol diet containing 11.7% fermented soymilk diet (5% soy protein as final concentration, F-5), or high cholesterol diet containing 23.4% fermented soymilk diet (10% soy protein as final concentration, F-10) for 5 weeks. The liver weight and fat mass were decreased by the ingestion of fermented soymilk. The hepatic triglyceride and cholesterol levels in the F-5 and F-10 groups were significantly lowered compared to those in the control group. The plasma total cholesterol level of the F-10 group was significantly decreased. The expression of SREBP-2, a cholesterol synthesis-related gene, was significantly decreased in liver of the F-5 group, but the expression of CYP7a1, a cholesterol catabolism-related gene, was significantly increased. These results suggest that fermented soymilk can modulate the cholesterol metabolism in rats fed a high cholesterol diet.

Characterization of a cellular immunostimulating peptide from a soybean protein fraction digested with peptidase R.

An immunostimulating glutamine-rich peptide was purified from a soybean protein fraction digested with Peptidase R produced by Rhizopus oryzae (Ro-digest) by a combination of SP-Sepharose column chromatography and reversed-phase high-performance liquid chromatography. The purified peptide was supposed to be located at or near the glutamine-rich region 202 to 222 of the glycinin G4 subunit. The peptide significantly increased the number of CD8(+), CD11b(+), and CD49b(+) cells in C3H/HeN mouse spleen cell cultures, while 2 chemically synthesized glutamine-rich peptides corresponding to residues 202 to 213 (QQQQQQKSHGGR) and residues 214 to 225 (KQGQHQQEEEEE) of the glycinin G4 subunit increased the number of interleukin (IL)-12(+)CD11b(+) cells. The peptide 202-213 also significantly increased the number of CD49b(+), IL-2(+)CD4(+), and interferon-gamma(+)CD4(+) cells and stimulated the cytotoxic activity of spleen cells toward the human erythroleukemia cell line K562. These results indicate that the glutamine-rich region of the soybean glycinin G4 subunit stimulates the cellular immune system in mouse spleen cell cultures.

Soybean protein fraction digested with neutral protease preparation, "Peptidase R", produced by Rhizopus oryzae, stimulates innate cellular immune system in mouse.

A soybean protein fraction was prepared from defatted soybean seed flour and digested with 29 kinds of commercially available protease originating from preparations of animals, plants, and microorganisms. Some digests, in particular, Ro-digest prepared using a Rhizopus oryzae neutral protease preparation (Peptidase R), displayed strong mitogenic activity toward C3H/HeN mouse spleen cells. The number of spleen CD11b+, CD49b+, interleukin (IL)-12+CD11b+, and interferon (IFN)-gamma+CD49b+ cells significantly increased when cultured with Ro-digest. Similarly, the number of spleen IFN-gamma+CD4+ cells significantly increased in the presence of Ro-digest while that of spleen IL-4+CD4+ cells was largely unchanged. Additionally, 5-week-old male C3H/HeN mice were given diets consisting of ovalbumin (OVA) alone (control diet) or a mixture of OVA and Ro-digest (Ro-digest-added diet) as a protein source for 5 weeks, and the immune properties of the mice were investigated. The number of IL-12+CD11b+ cells was greater in spleens from mice given the Ro-digest-added diet than in those given the control diet. The cytotoxic activity of spleen cells toward the human erythroleukemia cell line, K562, was significantly higher in mice given the Ro-digest-added diet than in those given the control diet. Furthermore, in a microarray analysis of mRNAs extracted from mice Peyer's patch cells, gene expression related to innate immune responses was increased in mice given the Ro-digest-added diet. These results indicate that the Ro-digest might stimulate cellular immune systems, in particular, an innate immunity in mice.