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To promote the use of waxy barley bran, an underutilized resource, samples of waxy barley were divided into three parts: polished waxy barley powder (PWBP), inner bran layer powder (IBLP), and outer bran layer powder (OBLP). The color and appearance, general properties, minerals, vitamins, β-glucan, antioxidant properties, and aroma of each part were compared. In terms of appearance and color, IBLP and OBLP appeared more yellow than PWBP; general components that were more abundant in IBLP and OBLP compared with PWBP were protein, fat, and ash. IBLP and OBLP had characteristically high values of Mg and Zn, monounsaturated and polyunsaturated fatty acids, vitamin B1, total polyphenol content, H-ORAC, and DPPH. In particular, the vitamin B1 content of OBLP was approximately 10 times higher than that of PWBP, and Mg and Zn content was more than five times higher than in PWBP. The β-glucan content of IBLP and OBLP was lower than that of PWBP, but relatively high. GC–MS analysis revealed that hexanal was the aroma component common to all three samples, and the peak areas were in the order of PWBP > OBLP > IBLP. [ABSTRACT FROM AUTHOR]

Vesicomyid clams, which inhabit deep-sea hydrothermal vents and hydrocarbon seeps, are nutritionally dependent on symbiotic, chemoautotrophic bacteria that produce organic matter by using hydrogen sulfide. Vesicomyid clams absorb hydrogen sulfide from the foot and transport it in their hemolymph to symbionts in the gill. However, mechanisms to cope with hydrogen sulfide toxicity are not fully understood. Previous studies on vent-specific invertebrates, including bathymodiolin mussels, suggest that hypotaurine, a precursor of taurine, mitigates hydrogen sulfide toxicity by binding it to bisulfide ion, so as to synthesize thiotaurine. In this study, we cloned cDNAs from the vesicomyid clam Phreagena okutanii for the taurine transporter that transports hypotaurine into cells and for cysteine dioxygenase and cysteine-sulfinate decarboxylase, major enzymes involved in hypotaurine synthesis. Results of reverse-transcription polymerase chain reaction indicate that mRNAs of these three genes are most abundant in the foot, followed by the gill. However, hypotaurine and thiotaurine levels, measured by reverse-phase high-performance liquid chromatography, were low in the foot and high in the gill. In addition, thiotaurine was detected in hemolymph cells. Hypotaurine synthesized in the foot may be transported to the gill after binding to bisulfide ion, possibly by hemolymph cells. [ABSTRACT FROM AUTHOR]

Taurine and hypotaurine are abundantly present in molluskan tissues; however, the pathways for their biosynthesis have not yet been well investigated. In this study, we established a method for simultaneous detection of taurine-related compounds, including taurine, hypotaurine, cysteic acid, cysteine sulfinic acid (CSA), cystathionine, γ-aminobutyric acid, and β-alanine along with 17 free amino acids, using phenylthiocarbamyl derivatization in ammonia-containing solution, followed by injection into reversed-phase high-performance liquid chromatography. Using this method, we analyzed the major tissues (gill, mantle, adductor muscle, foot, and digestive gland) of the hydrothermal-vent-specific mussel Bathymodiolus septemdierum. The gill and digestive gland were suggested to be the major organs for taurine/hypotaurine biosynthesis because taurine and hypotaurine levels tended to be high, and their precursors, i.e., cysteine, cysteic acid, and CSA (only in digestive gland), were detected in these two tissues. Cystathionine was detected at relatively high level in digestive gland and in other tissues at low levels, suggesting its role as storage material for taurine/hypotaurine biosynthesis. Adductor muscle was found to be rich in free amino acids, mainly due to abundance of non-sulfur-containing amino acids. [ABSTRACT FROM AUTHOR]