Fermentation and Quality Characteristics of Yogurt Treated with Bifidobacterium longum.

The fermentation and quality characteristics of yogurt were investigated according to the inoculation concentration of Bifidobacterium longum. The total sugar content of yogurt decreased as the fermentation time increased, and with an increased concentration of B. longum treatment the fermentation time decreased rapidly. As fermentation progressed, the lactose content decreased rapidly at the beginning and gradually decreased as the pH decreased. Depending on the B. longum treatment concentration, the lactose content varied from 0.29 ± 0.01 to 0.47 ± 0.01% and was 0.5% or less in all experimental groups. The experimental group inoculated with 0.0015% of B. longum displayed the best results in all categories, including pH, total acidity, lactic acid content, solid non-fat content, and total lactic acid bacteria count, which are factors that determine the quality of yogurt. In summary, the experimental group inoculated with 0.0015% of B. longum was determined to be the highest quality yogurt.

Physicochemical Properties of Soft and Hard-type Rice Flour According to Moisture Content and High Hydrostatic Pressure Treatment.

This study investigated the effects of high hydrostatic pressure (HHP) treatment on the physicochemical properties of rice flour according to its moisture levels in order to develop new materials for processed rice foods. The rice varieties used were the Samkwang variety (normal and hard type) and the Shingil variety (processing and soft type). The moisture content of the rice flour was adjusted to 35-55% and it was treated with the HHP treatment at 400-600 MPa. The water absorption capacity, solubility, and swelling power of the rice flour increased as the moisture levels and pressure increased. The 600 MPa enzymatic hydrolysis-treated rice flour showed similar results to the heat-treated rice flour. Scanning electron microscopy showed few cavities, resulting in a dense structure. X-ray diffraction confirmed that the 23° peak, which indicates the degree of gelatinization, decreased with increasing moisture levels and pressure. The HHP treatment of the rice flour changed its physicochemical properties according to the moisture levels and pressure applied. These results can provide important information on the development and production of various foods.

Antioxidative and antidiabetic effects of germinated rough rice extract in 3T3-L1 adipocytes and C57BLKS/J-db/db mice.

BACKGROUND: To overcome disadvantages of germinated brown rice, we germinated rough rice and tested effects of its useful ingredients on prevention of diabetes. OBJECTIVE: This study investigated the in vitro antioxidant and in vivo antidiabetic effects of rough rice (Oryza sativa L.) with hulls, before and after germination. Rough rice was germinated for 4 days and extracted with water at 120°C. DESIGN: This study measured antioxidants and antioxidative effects and inhibitory activities against α-amylase and α-glucosidase of rough rice before and after germination and investigated antidiabetic effects of rough rice through animal experiments. RESULTS: All these factors increased after germination. Also, α-amylase and α-glucosidase inhibition and glucose uptake by 3T3-L1 adipocytes were significantly increased after germination. Oral administration of the germinated rough rice extract for 8 weeks significantly increased insulin levels and decreased blood glucose levels in a C57BLKS/J-db/db mice model. Immunohistochemical analysis showed that germinated rough rice effectively protected against liver, kidney, and pancreatic tissue damage. DISCUSSION: Useful ingredients in germinated rough rice could be used to prevent diabetes. CONCLUSIONS: These results suggest that germinated rough rice extract had a beneficial effect on diabetes by increasing the antioxidant activity and further purification studies are necessary to elucidate the mechanism of the extract's antidiabetic activity.

Changes of phenolic-acids and vitamin E profiles on germinated rough rice (Oryza sativa L.) treated by high hydrostatic pressure.

This study was performed to investigate changes in the phenolic acid and vitamin E profiles of germinated rough rice following high hydrostatic pressure treatment (HPT). Rough rice was germinated at 37°C for two days and subjected to 0.1, 10, 30, 50, and 100MPa pressures for 24h. The total phenolic acid content increased from 85.37µg/g at 0.1MPa to 183.52µg/g at 100MPa. The highest gallic acid (4.29µg/g), catechin (9.55µg/g), p-coumaric acid (8.36µg/g), ferulic acid (14.99µg/g), salicylic acid (14.88µg/g), naringin (6.18µg/g), trans-cinnamic acid (45.23µg/g), and kaempferol (40.95µg/g) contents occurred in the sample treated at 100MPa after germination. The maximum vitamin E content of about 2.56 (BG) and 4.34mg/100g (AG) were achieved at 30MPa. These result suggest that a combination of HPT and germination are efficient method for enhancement of functionality in rough rice, and clarify the influence of HPT conditions on the vitamin E and phenolic acid in germination rough rice.

Effects of high hydrostatic pressure treatment on the enhancement of functional components of germinated rough rice (Oryza sativa L.).

This study was performed to evaluate the enhancement of functional components of germinated rough rice. Rough rice was germinated at 37 °C for 6 days, and subjected to a high hydrostatic pressure treatment (HPT) at 30 MPa for 24 h (HP24) and 48 h (HP48). Germinated rough rice without HPT (HP0), HP24, and HP48 were analysed for their functional components. The highest γ-aminobutyric acid, total arabinoxylan, and tricin 4'-O-(threo-ß-guaiacylglyceryl) ether contents were 121.21 mg/100g, 10.6%, and 85.82 µg/g, respectively, after HP48 for 2 days. γ-Oryzanol contents increased from 23.19-36.20 mg/100g (at HP0) to 31.80-40.32 mg/100g (at HP48). The highest vitamin B (60.99 mg/100g) and E (4.07 mg/100g) contents were observed after HP24 for 5 and 2 days, respectively. These results suggest that a combination of HPT and germination efficiently enhances the functional characteristics of rough rice.

Analysis of peroxiredoxin decreasing oxidative stress in hypertensive aortic smooth muscle.

To determine the role of peroxiredoxin (Prx) in response to oxidative stress and during hypertension in the vasculature, we identified Prx proteins and analyzed their antioxidant effects. Rat aortic smooth muscle contains all six Prxs (I-VI). Prx I, II, and VI shifted to its acidic site on two-dimensional polyacrylamide gel electrophoresis after exposure to H(2)O(2). The total expression of Prx I and VI was increased in response to H(2)O(2). The expression of Prx I, but not that of Prx II and VI, increases and the acidic form of Prx I and the sulfonic acid form of Prx (SO(3)H-Prx) are more strongly expressed in the aortic smooth muscle of hypertensive rats than in that of normotensive control rats. Prxs were also found in the mesenteric artery, heart, and kidney. The expression levels of Prx I and VI were increased in mesenteric artery, but not heart and kidney, from hypertensive rats compared with that from normotensive rats. These results suggest that Prxs play a crucial role against oxidative stress in vascular smooth muscles during hypertension.

Serotonin depolarizes the membrane potential in rat mesenteric artery myocytes by decreasing voltage-gated K+ currents.

We hypothesized that voltage-gated K+ (Kv) currents regulate the resting membrane potential (Em), and that serotonin (5-HT) causes Em depolarization by reducing Kv currents in rat mesenteric artery smooth muscle cells (MASMCs). The resting Em was about -40 mV in the nystatin-perforated patch configuration, and the inhibition of Kv currents by 4-aminopyridine caused marked Em depolarization. The inhibition of Ca2+-activated K+ (KCa) currents had no effect on Em. 5-HT (1 microM) depolarized Em by approximately 11 mV and reduced the Kv currents to approximately 63% of the control at -20 mV. Similar 5-HT effects were observed with the conventional whole-cell configuration with a weak Ca2+ buffer in the pipette solution, but not with a strong Ca2+ buffer. In the presence of tetraethylammonium (1mM), 5-HT caused Em depolarization similar to the control condition. These results indicate that the resting Em is largely under the regulation of Kv currents in rat MASMCs, and that 5-HT depolarizes Em by reducing Kv currents in a [Ca2+]i-dependent manner.

c-Jun N-terminal kinase contributes to norepinephrine-induced contraction through phosphorylation of caldesmon in rat aortic smooth muscle.

Vascular smooth muscle contraction is mediated by activation of extracellular signal-regulated kinase (ERK) 1/2, an isoform of mitogen-activated protein kinase (MAPK). However, the role of stress-activated protein kinase/c-Jun N-terminal kinase (JNK) in vascular smooth muscle contraction has not been defined. We investigated the role of JNK in the contractile response to norepinephrine (NE) in rat aortic smooth muscle. NE evoked contraction in a dose-dependent manner, and this effect was inhibited by the JNK inhibitor SP600125. NE increased the phosphorylation of JNK, which was greater in aortic smooth muscle from hypertensive rats than from normotensive rats. NE-induced JNK phosphorylation was significantly inhibited by SP600125 and the conventional-type PKC (cPKC) inhibitor Gö6976, but not by the Rho kinase inhibitor Y27632 or the phosphatidylinositol 3-kinase inhibitor LY294002. Thymeleatoxin, a selective activator of cPKC, increased JNK phosphorylation, which was inhibited by Gö6976. SP600125 attenuated the phosphorylation of caldesmon, an actin-binding protein whose phosphorylation is increased by NE. These results show that JNK contributes to NE-mediated contraction through phosphorylation of caldesmon in rat aortic smooth muscle, and that this effect is regulated by the PKC pathway, especially cPKC.

Cdc42 contributes to phorbol ester-induced Ca2+-independent contraction of pulmonary artery smooth muscle.

We determined the contribution of the Rho family of low molecular GTP-binding proteins to phorbol ester-induced contraction in swine pulmonary artery smooth muscle. In Ca2+-free medium containing 1 mM EGTA, 12-deoxyphorbol 13-isobutyrate (DPB, 1 microM), a protein kinase C (PKC) activator, elicited sustained contractions, which were not inhibited by treatment with verapamil, a voltage-dependent Ca2+ channel antagonist, and Y27632, a Rho-associated kinase inhibitor. Immunoblot analysis showed three PKC isoforms (alpha, epsilon, and zeta) and two Rho GTPases (RhoA and Cdc42) in both cytosolic and the membrane fractions from quiescent strips. DPB (1 microM) significantly induced PKCalpha and epsilon to translocate from the cytosolic to the membrane fraction in Ca2+-free medium. DPB also elicited the translocation of Cdc42, but not RhoA to the membrane fraction. Similarly, in the experiment for measurement of Rho GTPase activity by pull-down assay, DPB (1 microM) significantly increased the activity of Cdc42 in Ca2+-free medium. Norepinephrine (NE, 10 microM) stimulated the redistribution of RhoA from the cytosolic to the membrane fraction in swine pulmonary artery smooth muscle. In contrast, NE did not alter the subcellular distributions of Cdc42 and the PKC isoforms. These results indicate that phorbol ester evokes PKC-mediated Ca2+-independent contraction via a Rho GTPase pathway, especially Cdc42, in smooth muscle from swine pulmonary arteries.

Ligusticum wallichi-induced vasorelaxation mediated by mitogen-activated protein kinase in rat aortic smooth muscle.

Traditional herbal medicines have been widely used for the treatment of cardiovascular disorders in oriental countries. To determine the effects of Ch1LW, a chloroform extract of Ligusticum wallichi, on the vascular system, we studied changes in rat aortic smooth muscle in terms of magnitude of contraction and the activity of mitogen-activated protein kinases (MAPKs). Ch1LW inhibited the muscle contraction induced by norepinephrine (NE) in aortic strips. Ch1LW also abolished Ca2+-independent contraction evoked by 12-deoxyphorbol 13-isobutyrate in Ca2+-free medium containing 1 mM EGTA. Furthermore, western blotting analysis using phosphorylated MAPK antibodies showed that NE increased the activity of both extracellular signal-regulated kinase 1/2 (ERK1/2) and p38 MAPK, which were inhibited by PD98059 and SB203580, blockers of ERK1/2 and p38 MAPK, respectively. Furthermore, treatment with Ch1LW significantly abolished NE-mediated activation of ERK1/2, whereas the activity of p38 MAPK was not affected by the extract. These results suggest that Ch1LW induces vasorelaxation in rat aortic smooth muscle, which may be mediated by the inhibition of ERK1/2 pathway, but not p38 MAPK.