Identification and quantification of short oligomeric proanthocyanidins and other polyphenols in boysenberry seeds and juice

Proanthocyanidins and other polyphenols in the seeds and juice of boysenberry were quantitatively analyzed. Polyphenolic extracts were prepared from the waste seeds and commercial juice by chromatographic fractionation. Compositional analysis revealed that both extracts contained six polyphenolic classes: flavanol monomers, proanthocyanidins, anthocyanins, ellagic acid, ellagitannins, and flavonol glycosides. Ellagitannins were the most abundant polyphenols in both extracts. Proanthocyanidins were present as short oligomers consisting of dimeric and trimeric procyanidins and propelargonidins, with the most abundant component being procyanidin B4 in both extracts. Quantification by high-performance liquid chromatography-mass spectrometry (HPLC-MS) revealed that the seeds contained a 72-fold higher amount of proanthocyanidins than the juice. These results indicate that boysenberry fruits contain short oligomeric proanthocyanidins along with flavanol monomers and the seeds represent a good source of short oligomeric proanthocyanidins.     

Differential detection of shrimp and crab for food labeling using polymerase chain reaction

Shrimp and crab are well-known as allergenic ingredients. According to Japanese food allergy labeling regulations, shrimp species (including prawns, crayfishes, and lobsters) and crab species must be differentially declared when ≥10 ppm (total protein) of an allergenic ingredient is present. However, the commercial ELISA tests for the detection of crustacean proteins cannot differentiate between shrimp and crab. Therefore, two methods were developed to discriminate shrimp and crab: a shrimp-PCR method with postamplification digestion and a crab-PCR method that specifically amplifies a fragment of the 16S rRNA gene. The sensitivity and specificity of both PCR methods were verified by experiments using DNA extracted from 15 shrimp species, 13 crab species, krill, mysid, mantis shrimp, other food samples (cephalopod, shellfish, and fish), incurred foods, and commercial food products. Both PCR methods could detect 5 pg of DNA extracted from target species and 50 ng of genomic DNA extracted from incurred foods containing 10 ppm (μg/g) total protein of shrimp or crab. The two PCR methods were considered to be specific enough to separately detect species belonging to shrimp and crab. Although false-positive and false-negative results were obtained from some nontarget crustacean species, the proposed PCR methods, when used in conjunction with ELISA tests, would be a useful tool for confirmation of the validity of food allergy labeling and management of processed food safety for allergic patients.     

Responses of leaf photosynthesis and plant growth to altered source–sink balance in a Japanese and a Dutch tomato cultivar

We investigated the effects of altered source/sink ratio by leaf or fruit pruning on leaf photosynthetic characteristics and whole-plant growth of ‘Momotaro York’, a Japanese cultivar, and ‘Dundee’, a Dutch cultivar and verified a hypothesis for sink-limitation of plant growth proposed by Tanaka and Fujita (1974). Plants were grown hydroponically with a high-wire system in a greenhouse for 11 weeks. Light-saturated photosynthesis of young, fully expanded leaves measured at atmospheric CO₂ partial pressure of 37 Pa and at an intercellular CO₂ partial pressure of 20 Pa was not influenced by alteration of source/sink ratio for either cultivar. Although soluble sugars were accumulated in leaves under high source/sink conditions, the amount of ribulose-1,5-bisphosphate carboxylase/oxygenase, a rate-limiting factor for CO₂-limited photosynthesis, was not affected by the altered source–sink balance. Net assimilation rate of a whole plant increased with decreasing source/sink ratio, but this can be accounted for by the changes in light interception per unit leaf area, without taking the source–sink relationship into consideration. It was concluded that the altered source/sink ratio did not change leaf photosynthetic capacity and the sink-limitation hypothesis cannot be applied to either cultivar under the conditions of the present study.     

Synthesis of morphiceptin (Tyr-Pro-Phe-Pro-NH(2)) by dipeptidyl aminopeptidase IV derived from Aspergillus oryzae

Morphiceptin (Tyr-Pro-Phe-Pro-NH(2)), tetrapeptide, was synthesized using dipeptidyl aminopeptidase IV (DP IV, EC 3.4.14.5) derived from Aspergillus oryzae RIB 915 as a catalyst. Tyr-Pro-OEt was incubated with Phe-Pro-NH(2) in the presence of DP IV under various conditions of temperature, concentrations of ethylene glycol, pH, reaction time, and others. Morphiceptin was obtained at 40% yield under the optimal reaction conditions: substrate, 4 mM Tyr-Pro-OEt.HCl and 20 mM Phe-Pro-NH(2).HCl; enzyme, DP IV, 0.275 nkat; solvent, 60% ethylene glycol containing 20 mM phosphate buffer at pH 7.0; amine, 4.2 mM diisopropylamine at 4 degrees C for 24 h. Amino group protection was unnecessary for synthesis of morphiceptin by DP IV.     

Paraticulate metals in waters of a typical irrigation river: The River Sakuragawa,Japan

The particulate metallic elements in waters of a water system of the River Sakuragawa and Lake Kasumigaura were measured by the multielement analyses using particle-induced X-ray emission. The heavy metal particulates for environmental standards were less than 0.0001 ppm for Cd, 0.00037 ppm for Cr, and 0.00078 ppm both for Hg and Pb in the river waters. The predominant metal particles in the waters were Fe, Mn, and Zn.     

Characterization of corrinoid compounds from a Japanese black tea (Batabata-cha) fermented by bacteria

A Japanese fermented black tea (Batabata-cha) contained a considerable amount of vitamin B(12) (456 +/- 39 ng per 100 g dry tea leaves and 2.0 +/- 0.3 ng per 100 mL of tea drink). A corrinoid compound was partially purified and characterized from the tea leaves. The patterns of the purified compound by the silica gel 60 thin-layer chromatography and C18 reversed phased high-performance liquid chromatography were identical to those of authentic vitamin B(12). When 20 week old vitamin B(12) deficient rats, which excreted substantial amounts (about 250 mg/day) of methylmalonic acid in urine as an index of vitamin B(12) deficiency, were fed the tea drink (50 mL/day, 1 ng of vitamin B(12)) for 6 weeks, urinary methylmalonic acid excretion (169 +/- 29 mg/day) of the tea drink-supplemented 26 week old rats decreased significantly relative to that (250 +/- 32 mg/day) of the deficient rats. The results indicate that the vitamin B(12) found in the fermented black tea is bioavailable in mammals.     

Humus composition of soils under forest, coffee and arable cultivation in hilly areas of south Sumatra, Indonesia

To understand the effect of land use changes on the composition of humus in tropical soils, samples from land under primary forest, secondary forest, coffee plantation, and arable crops were investigated at three sites in south Sumatra, Indonesia. Total carbon and total nitrogen contents were 1.7 to 4.3 times and 1.1 to 2.8 times greater in the topsoil under primary forest than under the other types of land use. Following change from primary forest to other uses, the proportion of humic acids in the organic matter of the topsoils decreased while that of the fulvic acid fraction increased. Within the range of land uses, differences in the yields of humic acids and fulvic acid fractions were, respectively, larger and smaller than those in total carbon content. The humic acids were classified into the low and middle classes in the degree of humification. Absorption due to the green fraction of humic acids, Pg, was detected in the UV‐visible spectra of almost all the humic acids. No relation was observed between the degree of humification of humic acids or the strength of Pg absorption in their spectra and land use change. The fulvic acid fractions were fractionated on insoluble polyvinylpyrrolidone (PVP) into the adsorbed fractions consisting of humic substances and the non‐adsorbed fractions consisting of non‐humic substances. A positive correlation between the amount of the fulvic acid fraction and the percentage of the PVP‐adsorbed fraction within it indicated that the variation in the amount of the fulvic acid fraction was attributable to acid‐soluble humic substances. The ionization difference spectra of solutions between pH 12 and pH 7 suggested that the chemical structures of the PVP‐adsorbed fulvic acids have been altered by land use change.     

Contribution of Parker and Product indexes to evaluate weathering condition of Yellow Brown Forest soils in Japan

Soil weathering is recognizable through study on physico-chemical characteristics of soil. In this study, Parker, ([(Na)_a / 0.35] + [(Mg)_a / 0.9] + [(K)_a / 0.25] + [(Ca)_a / 0.7]) × 100, and Product, [SiO₂ / (TiO₂ + Fe₂O₃ + SiO₂ + Al₂O₃)] × 100, weathering indexes, originally developed for study on rocks, were tested on Yellow Brown Forest soils from two different regions in Japan. The results showed that the contribution of the mentioned indexes can be used for study on soils weathering. In other word, in a two-dimensional coordination system where the axes are Parker and Product indexes, regarding to the chemical bases of the indexes, initial and lateral products of weathering can be tracked at the same time.

Additionally, the indexes relations with soil color were studied after exposing the samples at a high temperature. Remarkable relationships between a* / b* ratio–parameters of psychometric chromaticness of color in CIE color standard system–and these two weathering indexes demonstrated that a* / b* ratio can be applied reliably to estimate the quantities of Parker and Product indexes in Yellow Brown Forest soils.     

Characteristics of Raindrop Acidification by Co-Washout of SO2(G)-H2O2(G)-HNO3(G)

In order to investigate the acid rain formation under the coexistence of SO₂(g), H₂O₂(g), and HNO₃(g) in the air, a mathematical model has been built and some numerical simulations have been carried out with use of the model. The simulation reveals that SO₂(g) absorbed into a raindrop is released and then re-absorbed as the fall distance increases. The desorption and re-absorption processes of SO₂(g) are caused by: (1) the fact that the equilibrium concentration of H₂O₂(aq) and HNO₃(aq) in raindrops are much higher than that of SO₂(aq), and (2) the fact that the oxidation reaction rate of HSO₃ ^? with H₂O₂(aq) increases with H⁺ concentration in raindrops. The degree of acidification of the rainwater has been estimated by introducing a raindrop size distribution. The acidification is mainly caused by the adsorption of SO₂(g) in the usual case where the atmospheric concentration of SO₂(g) is much higher than that of HNO₃(g). With the increase in the atmospheric concentration of HNO₃(g), the concentration of H⁺ generated from SO₂(g) decreases and the contribution of HNO₃(g) to the generation of H⁺ becomes dominant.