Chemical analysis and acetylcholinesterase inhibitory effect of anthocyanin-rich red leaf tea (cv. Sunrouge)

BACKGROUND: The purpose of this study was to evaluate the effects of leaf order or crop season on anthocyanins and other chemicals in the anthocyanin‐rich tea cultivar ‘Sunrouge’ (Camellia sinensis x C. taliensis) by using high‐performance liquid chromatography, and to study the effect of ‘Sunrouge’ extract on acetylcholinesterase (AChE) activity in human neuroblastoma SK‐N‐SH cells. RESULTS: The total anthocyanin content was higher in the third (3.09 mg g^?1) than in the second (2.24 mg g^?1) or first crop season (1.79 mg g^?1). The amount of anthocyanins contained in the stem was high (1.61 mg g^?1). In the third crop season, the concentrations of delphinidin‐3‐O‐β‐D ‐(6‐(E)‐p‐coumaroyl)galactopyranoside (DCGa), cyanidin‐3‐O‐β‐D ‐(6‐(E)‐p‐coumaroyl)galactopyranoside, delphinidin‐3‐O‐β‐D ‐galactopyranoside, delphinidin‐3‐O‐β‐D ‐(6‐O‐(Z)‐p‐coumaroyl)galactopyranoside, cyanidin‐3‐O‐β‐D ‐galactoside, and delphinidin‐3‐O‐β‐D ‐glucoside were 1.57 mg g^?1, 0.52 mg g^?1, 0.40 mg g^?1, 0.22 mg g^?1, 0.14 mg g^?1, and 0.11 mg g^?1, respectively. DCGa accounted for about 50% of the anthocyanins present. The suppressive effect of ‘Sunrouge’ water extract on AChE activity in human neuroblastoma SK‐N‐SH cells was the strongest among the three tea cultivars (‘Sunrouge’, ‘Yabukita’ and ‘Benifuuki’). CONCLUSION: These results suggested that ‘Sunrouge’ might protect humans from humans from AChE‐related diseases by suppressing AChE activity. To obtain sufficient amounts of anthocyanins, catechins and/or caffeine for a functional food material, ‘Sunrouge’ from the third crop season should be used. Copyright © 2012 Society of Chemical Industry     

Heat treatment for the control of Bacillus cereus spores in foods

The effect of heat treatments on food products related to soybean curd contaminated with Bacillus cereus spores was investigated for the purpose of preventing food-poisoning outbreaks by B. cereus. In the case of B. cereus strains isolated from foods, heating foods inoculated with the spores for 20 min at 70 degrees C, 5 min at 75 degrees C, 2 min at 100 degrees C, or 10 sec with a microwave oven plus reheating after standing for 2 hr at 25 degrees C reduced the number of surviving cells within the foods to less than one-hundredth. In the case of a heat-resistant strain isolated from a food poisoning outbreak, heating for 20 min at 70 degrees C plus reheating after standing for 1.5-2 hr at 35 degrees C, heating for 10 min at 75 degrees C plus reheating after standing for 1.5-2 hr at 35 degrees C, or heating for 2 min at 100 degrees C plus reheating after standing for 4 hr at 25 degrees C was effective. There was not much difference between the flavor components in foods with and without heat treatment at 70 degrees C, as analyzed by gas chromatography-mass spectrometry. These results indicate that these heat treatments are available to control B. cereus spores, without affecting the sensory quality of the foods.     

Application of femtosecond laser ablation for detaching grown protein crystals from glass capillary tube

We developed a novel technique for detaching protein crystals from glass capillary tube using the counter diffusion crystallization technique by femtosecond laser irradiation. X-ray diffraction analysis demonstrated that femtosecond laser irradiation has little effect on crystallinity. This technique will contribute to progress in structural genomics as a powerful tool.     

Moisturizing effect of vesicles formed from monoglycerides on human skin

The moisturizing effect of vesicles formed from monoglycerides on human skin was studied by measurement of conductance on and transepidermal waterloss from the skin surface. Although sonication of the monoglycerides in water with Ca2+ gave multilamellar vesicles, the lamellar structure of the vesicles disappeared during their storage without any other additive. With the addition of poly(vinylpyrrolidone) after the sonication, the stability of the vesicles increased and their lamellar structure was maintained for 3 months at 40 degrees C. These vesicles led to a significantly higher water content of the stratum corneum of human skin compared with non-lamellar monoglyceride, and consequently they improved rough human skin.     

CoCl(2) inhibits neural differentiation of retinoic acid-treated embryoid bodies

The effects of CoCl(2) on retinoic acid (RA)-treated embryoid bodies (EBs) were investigated. Four-day EBs were treated with 5x10(-6) M of RA for 4 d, then subjected to attached culturing for 7 d in the presence of CoCl(2) at 0, 20, and 100 microM. Differentiation into MAP2- and GFAP-immunopositive cells was inhibited by CoCl(2) in a dose-dependent manner. Next, RA-treated EBs were dissociated into single cells and cultured for 7 d at an initial cell density of 1x10(3)/cm(2). The number of cells increased in a CoCl(2)-dose dependent fashion. In cultures with 100 microM of CoCl(2), more than 90% of the cells were immunopositive for nestin and nestin-immunopositive cells formed clusters, while there were few cells immunopositive for MAP2 or GFAP. These results suggest that CoCl(2) inhibits neural differentiation of RA-treated EB cells and promotes the proliferation of nestin-immunopositive cells, i.e., embryonic stem (ES)-derived neural stem-like cells.     

Contents of barbaloin-related compounds in aloe drinks and their change during storage

The contents of barbaloin (BA), isoBA, aloin-dimers A, B, C, D and aloe-emodin (AE) in aloe drinks were investigated. BA and isoBA were detected in 30 of the 31 samples at the levels of 120-570 micrograms/mL and 120-580 micrograms/mL, respectively. Aloin-dimers A, B, C and D were detected in 8 of the 31 samples at the levels of 12-38 micrograms/mL, 13-39 micrograms/mL, 11-36 micrograms/mL and 16-69 micrograms/mL, respectively. AE was detected in all of the 31 samples at the levels of 0.03-1.3 micrograms/mL. When aloe drinks were stored for 4 weeks at 5 degrees C after opening the bottle, decrease of BA and isoBA, and increase of AE and aloin-dimers A, B, C and D were observed in most cases. However, in a few aloe drinks, all of BA, isoBA, aloin-dimers A, B, C, D and AE decreased. In these drinks, the existence of aloin-trimer was elucidated by LC/MS analyses. These data suggested that BA in aloe drinks is converted to the dimer and then to the trimer during storage.     

Purification and some properties of beta-fructofuranosidase I formed by Aureobasidium pullulans DSM 2404

beta-Fructofuranosidase I (FFase I) formed by Aureobasidium pullulans DSM 2404 was purified. The enzyme had a molecular weight of about 430 kDa, was not affected by various metal ions and showed high transfructosylating activity. The yield of fructooligosaccharides production using purified FFase I was 62%.     

Detection method of injured Escherichia coli O157 in noodles and vegetables

An enrichment procedure and a polymerase chain reaction (PCR) method for the detection of injured Escherichia coli O157 in foods were examined. Freeze-injured E. coli O157 inoculated in boiled spaghetti could be detected in 6-h culture within 12 h by the PCR method. Cells injured by heating in boiled spaghetti and cells injured by chlorine treatment in raw lettuce and carrot did not grow sufficiently to be detected in 6-h culture but were detected in 18-h culture using selective agar media. The injured cells could be also detected in 18-h culture within 24 h by the PCR method. Enrichment at 42 degrees C in trypticase soy broth (TSB) was more effective than that at 42 degrees C in modified EC broth with novobiocin. These results indicated that the usage of enrichment in TSB for 18 h at 42 degrees C in combination with the PCR method is suitable for screening for E. coli O157 in boiled or chlorinated foods, even if the O157 cells are injured.     

Factors affecting the oxidative activity of laccase towards biphenyl derivatives in homogeneous aqueous-organic systems

Catalytic oxidation of biphenyl derivatives was investigated using laccase in a homogeneous aqueous-organic system. A thermostable laccase from Trametes sp. showed the highest catalytic activity for the oxidation of 4-hydroxybiphenyl (4-HB) at a reaction temperature of 60 degrees C when dimethylsulfoxide (DMSO) was employed as a co-solvent. Furthermore, the catalytic performance was successfully enhanced by the incorporation of a laccase mediator system (LMS) into the aqueous-DMSO media. The catalytic performance strongly depended on the type of mediator, and the highest activity was observed with 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) as mediator, suggesting the importance of the selection of a suitable mediator. It was verified that this mediator system is applicable to the oxidation of several biphenyl derivatives with hydroxyl groups.