Influences of Technological Parameters on Cross-Flow Nanofiltration of Cranberry Juice.

The paper focused on the influence of operative conditions on the separation of benzoic acid from 10 °Brix cranberry juice by cross-flow nanofiltration with a plate and frame pilot scale (DDS Lab Module Type 20 system). Six kinds of commercial nanofiltration membrane were investigated. The results showed that the rejection of benzoic acid was significantly lower than that of other components in cranberry juice, including sugars and other organic acids. In a range of 2-7.5 L/min, feed flow rate slightly affected the performance of nanofiltration. Higher temperatures resulted in higher permeate flux and lower rejection of benzoic acid, whereas rejection of sugar and organic acid was stable at a high value. In a range of 2.5-5.5, pH also significantly affected the separation of benzoic acid and negative rejection against benzoic acid was observed at pH 4.5 with some of the membranes. This implies that pH 4.5 is considered as an optimum pH for benzoic acid separation from cranberry juice. The lower permeate flux caused a lower rejection of benzoic acid and negative rejection of benzoic acid was observed at the low permeate flux. Pretreatment by ultrafiltration with CR61PP membranes could improve the permeate flux but insignificantly influenced the efficiency of separation. The results also indicated that NF99 and DK membranes can be effectively used to separate benzoic acid from cranberry juice.

Distribution of radioactive cesium ((134)Cs plus (137)Cs) in rice fractions during polishing and cooking.

We investigated the distribution of cesium-134 ((134)Cs) and cesium-137 ((137)Cs) during polishing and cooking of rice to obtain their processing factors (Pf) and food processing retention factors (Fr) to make the information available for an adequate understanding of radioactive Cs dynamics. Polishing brown rice resulted in a decreased radioactive Cs concentration of the polished rice, but the bran and germ (outer layers) exhibited higher concentrations than brown rice. The Pf values for 100% polished rice and outer layers ranged from 0.47 to 0.48 and 6.5 to 7.8, respectively. The Fr values for 100% polished rice and outer layers were 0.43 and 0.58 to 0.60, respectively. The distribution of radioactive Cs in polished rice and outer layers was estimated at approximately 40 and 60%, respectively. On the other hand, cooked rice showed significantly lower levels of radioactive Cs than polished rice, and transfer of radioactive Cs into wash water was observed. The Pf and Fr values for cooked rice were 0.28 and 0.65 to 0.66, respectively. From these results, we can calculate that if the radioactive Cs concentration in brown rice is 100 Bq/kg, the concentrations of Cs in polished rice and cooked rice will be 47 to 48 Bq/kg and 13 Bq/kg, respectively.

Distribution of radioactive cesium ((134)Cs Plus(137)Cs) in a contaminated Japanese soybean cultivar during the preparation of tofu, natto, and nimame (Boiled Soybean).

We investigated the fate of radioactive cesium ((134)Cs plus (137)Cs) during the production of tofu, natto, and nimame (boiled soybean) from a contaminated Japanese soybean cultivar harvested in FY2011. Tofu, natto, and nimame were made from soybean grains containing radioactive cesium (240 to 340 Bq/kg [dry weight]), and the radioactive cesium in the processed soybean foods and in by-product fractions such as okara, broth, and waste water was measured with a germanium semiconductor detector. The processing factor is the ratio of radioactive cesium concentration of a product before and after processing. For tofu, natto, nimame, and for the by-product okara, processing factors were 0.12, 0.40, 0.20, and 0.18, respectively; this suggested that these three soybean foods and okara, used mainly as an animal feed, can be considered safe for human and animal consumption according to the standard limit for radioactive cesium of soybean grains. Furthermore, the ratio of radioactive cesium concentrations in the cotyledon, hypocotyl, and seed coat portions of the soybean grain was found to be approximately 1:1:0.4.

Dynamics of radioactive cesium (134Cs and 137Cs) during the milling of contaminated Japanese wheat cultivars and during the cooking of udon noodles made from wheat flour.

The fate of radioactive cesium ((134)Cs plus (137)Cs) during the milling of contaminated Japanese wheat cultivars harvested in FY2011, and during the cooking of Japanese udon noodles made from the wheat flour, was investigated. Grain samples containing various radioactive cesium concentrations (36.6 to 772 Bq/kg [dry weight]) were milled using a laboratory-scale test mill to produce eight fractions: three break flours (1B, 2B, and 3B), three reduction flours (1M, 2M, and 3M), bran, and shorts. The concentrations of radioactive cesium were found to be highest in the bran fractions of all the samples tested, with 2.3- to 2.5-fold higher values than that of the whole grain. Shorts contained radioactive cesium levels similar to that of the whole grain. In contrast, radioactive cesium concentrations in other fractions were found to be less than half the concentration in whole grain. The average processing factor (PF) value calculated for patent flour (0.401 ± 0.048), made from the mixture of 1B, 2B, 1M, and 2M for human consumption, or for low-grade flour (0.467 ± 0.045), made from the mixture of 3B and 3M, was found to be less than 0.5; whereas the average PF value (2.07 ± 0.232) for feed bran (mixture of bran and shorts), which has been used mainly as livestock feed in Japan, was over 2.0. Boiling udon noodles (made from patent flour) resulted in a substantial reduction (>70 % of initial amount) of radioactive cesium. Moreover, radioactive cesium was reduced further (<10 % of the initial amount) in the subsequent rinsing process, and the PF value of boiled noodles was recorded as 0.194. These results demonstrated that patent flour containing radioactive cesium can be made safe for human consumption by adopting the standard limit for radioactive cesium in wheat grain and that radioactive cesium in udon noodles is substantially reduced by cooking.

Antioxidant combination inhibits reactive oxygen species mediated damage.

We examined the preventive activity of naturally occurring antioxidants against three reactive oxygen species using a protein degradation assay. The hydroxyl, hypochlorite, and peroxynitrite radicals are typical reactive oxygen species generated in human body. Previously, we found that hydrophobic botanical antioxidants exhibited specific antioxidant activity against hydroxyl radicals, whereas anserine and carnosine mixture, purified from chicken extract and vitamin C, exhibited antioxidant activities against hypochlorite and peroxynitrite radicals respectively. Since ethanol, used as a solvent in the experiments, also showed an antioxidant action against the hydroxyl radical, we re-assessed antioxidant activities using aqueous solutions of botanical antioxidants. Among the seven hydrophobic antioxidants examined, ferulic acid exhibited the strongest antioxidant activity against the hydroxyl radical. An antioxidant preparation of anserine-carnosine mixture, vitamin C, and ferulic acid prevented oxidative stress by reactive oxygen species. Loss of deformability in human erythrocytes and protein degradation caused by reactive oxygen species were completely inhibited.

Scanning Near-field Optical/Atomic Force Microscopy detection of fluorescence in situ hybridization signals beyond the optical limit.

Fluorescence in situ hybridization (FISH) is widely used in molecular biological study. However, high-resolution analysis of fluorescent signals is theoretically limited by the 300-nm resolution optical limit of light microscopy. As an alternative to detection by light microscopy, we used Scanning Near-field Optical/Atomic Force Microscopy (SNOM/AFM), which can simultaneously obtain topographic and fluorescent images with nanometer-scale resolution. In this study, we demonstrated high-resolution SNOM/AFM imaging of barley chromosome (Hordeum vulgare, cv. Minorimugi) FISH signals using telomeric DNA probes. Besides detecting the granular structures on chromosomes in a topographic image, we clearly detected fluorescent signals in telomeric regions with low-magnification imaging. The high-resolution analysis suggested that one of the telomeric signals could be observed by expanded imaging as two fluorescent regions separated by approximately 250 nm. This result indicated that the fluorescent signals beyond the optical limit were detected with higher resolution scanning by SNOM/AFM.

Nano-scale imaging of chromosomes and DNA by scanning near-field optical/atomic force microscopy.

Nano-scale structures of the YOYO-1-stained barley chromosomes and lambda-phage DNA were investigated by scanning near-field optical/atomic force microscopy (SNOM/AFM). This technique enabled precise analysis of fluorescence structural images in relation to the morphology of the biomaterials. The results suggested that the fluorescence intensity does not always correspond to topographic height of the chromosomes, but roughly reflects the local amount and/or density of DNA. Various sizes of the bright fluorescence spots were clearly observed in fluorescence banding-treated chromosomes. Furthermore, fluorescence-stained lambda-phage DNA analysis by SNOM/AFM demonstrated the possibility of nanometer-scale imaging for a novel technique termed nano-fluorescence in situ hybridization (nano-FISH). Thus, SNOM/AFM is a powerful tool for analyzing the structure and the function of biomaterials with higher resolution than conventional optical microscopes.

Atomic force microscopy study of chromosome surface structure changed by protein extraction.

We applied atomic force microscopy (AFM) to investigate the surface structure of barley chromosome in combination with a chemical treatment method. As a result, we have obtained high-resolution topographic images of granular structures with a diameter of ca. 50 nm on the surface of critical-point dried metaphase chromosomes. Treatment with 2M NaCl significantly modified the chromosome surface structure: surface roughness was increased and chromosome thickness was decreased. The NaCl treatment extracted two major proteins with molecular weights of 4000 and 20,000 Da. These proteins might be belonging to non-histone protein families that do not contain any aromatic amino acid. The results demonstrate the advantage of the combined method of high-resolution AFM imaging and chemical treatments for understanding nano-scale surface structures of the chromosome.

Simultaneous collection of topographic and fluorescent images of barley chromosomes by scanning near-field optical/atomic force microscopy.

The present study investigated the applicability of scanning near-field optical/atomic force microscopy (SNOM/AFM) to observations of YOYO-1 stained barley chromosomes. Using this technique, topographic and fluorescent images in the same portion were obtained simultaneously, thus enabling the precise analysis of fluorescent structures in relation to the morphology of chromosomes. In YOYO-1 stained chromosomes, the fluorescent intensity roughly reflected the local amount and/or density of DNA in chromosomes. R-banding of chromosomes stained with YOYO-1 and methyl green was also observed clearly as bright spots of various sizes by this microscope. Thus, the SNOM/AFM is expected to become a useful tool for analysing the structure and function of chromosomes more precisely than before.

Imaging of chromosomes at nano-meter scale resolution using scanning near-field optical/atomic force microscopy.

Topographic and fluorescent images of whole barley chromosomes stained with YOYO-1 were observed simultaneously by scanning near-field optical/ atomic force microscopy (SNOM/AFM). The chromosome was relatively smooth and flat in the topographic images and no significant difference in height was present between regions of high fluorescent and low fluorescent intensity in the chromosomes. The telomeric region, labeled by fluorescence in situ hybridization (FISH) method, was also observed by SNOM/AFM at high resolution, and fluorescent signals of the telomeric region were clearly defined on the topographic image of chromatin fibers on the chromosome at the nano-meter scale level. Although the telomeric signals were usually visualized as a single fluorescent region at the end of sister chromatids by conventional light microscopy, they were observed separately as two fluorescent regions, less than 100-200 nm distance, using the SNOM/AFM. The SNOM/AFM offers great potential in identifying particular single gene location on chromosomes in the near future.