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Takahashi M, Kumari P, Li C, Mikami K. Low temperature causes discoloration by repressing growth and nitrogen transporter gene expression in the edible red alga Pyropia yezoensis. MARINE ENVIRONMENTAL RESEARCH 2020; 159:105004. [PMID: 32662437 DOI: 10.1016/j.marenvres.2020.105004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 04/25/2020] [Accepted: 04/26/2020] [Indexed: 06/11/2023]
Abstract
The reduced availability of nitrogen sources in seawater leads to discoloration of the edible red seaweed Pyropia yezoensis and induces the expression of genes encoding ammonium, nitrate and urea transporters. In the present study, we demonstrate that low temperatures can also cause discoloration of this economically important seaweed. Thus, we addressed regulatory mechanisms of cold-inducible discoloration. When P. yezoensis thalli were incubated at 0, 5 and 10°C, the thalli exhibited retarded growth and discoloration, along with reduced phycoerythrin contents. Fertilization with nitrogen sources did not recover this discoloration at 0°C, suggesting that defects in nitrogen absorption cause low temperature-induced discoloration. The expression levels of many nitrogen transporter genes were reduced at low temperature. We propose that low temperature-mediated repression of ammonium, nitrate and urea transporter gene expression promotes the reduced absorption of nitrogen sources in P. yezoensis, thereby leading to discoloration. This process is different from the well-known mechanism underlying discoloration in P. yezoensis under nitrogen-deficient conditions at normal culture temperature.
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Affiliation(s)
- Megumu Takahashi
- Faculty of Bio-Industry, Tokyo University of Agriculture, 196 Yasaka, Abashiri, 099-2493, Japan
| | - Puja Kumari
- Faculty of Fisheries Sciences, Hokkaido University, 3-1-1 Minato-cho, Hakodate, 041-0821, Japan
| | - Chengze Li
- Graduate School of Fisheries Sciences, Hokkaido University, 3-1-1 Minato-cho, Hakodate, 041-0821, Japan
| | - Koji Mikami
- Faculty of Fisheries Sciences, Hokkaido University, 3-1-1 Minato-cho, Hakodate, 041-0821, Japan.
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Lee EJ, Ramakrishnan SR, Kim GR, Kwon JH. Storage stability of soluble pigments, chlorophylls, and carotenoids in electron-beam-irradiated edible lavers (Porphyra umbilicalis) with impact on microbial safety and sensory characteristics. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2019; 99:3860-3870. [PMID: 30680730 DOI: 10.1002/jsfa.9608] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 12/31/2018] [Accepted: 01/22/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND In this study, we investigated whether electron beam (e-beam) irradiation can inactivate microbial populations, including aerobic bacteria plate count, fungi, and coliforms, in two types of lavers (dried and roasted). The impact of e-beam doses of 4 and 7 kGy on microbial populations, color values, total soluble pigments, chlorophylls, and carotenoid content immediately and after storage at 4, 15, 25, and 35 °C for 4, 8, and 12 weeks was also evaluated. RESULTS The initial microbial load of approximately 106 and 105 CFU g-1 in both dried and roasted lavers was reduced to 104 and 101 CFU g-1 , respectively, after irradiation at 7 kGy. No further proliferation was observed in irradiated dried lavers during 4 weeks of storage at 4 and 15 °C. When stored at low temperature, the shelf-life was extended for up to 12 weeks in 7 kGy irradiated dried and roasted lavers. High amounts of soluble pigments and carotenoids were observed during storage in the 7 kGy irradiated dried laver samples at the end of 12 weeks irrespective of temperature. Although the chlorophyll content decreased under the storage conditions, it was comparatively stable in the 7 kGy-irradiated dried laver. Maximum degradation of color was observed in laver samples subjected to the roasting process. CONCLUSION Overall, this study indicated that e-beam irradiation of laver at 7 kGy maintains microbial safety as well as quality attributes during storage for up to 12 weeks. Further, dried laver had more essential compounds than roasted laver. © 2019 Society of Chemical Industry.
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Affiliation(s)
- Eun-Jin Lee
- School of Food Science and Biotechnology, Kyungpook National University, Daegu, South Korea
- Food Analysis Division, Institute of Health and Environment, Daegu, South Korea
| | | | - Gui-Ran Kim
- School of Food Science and Biotechnology, Kyungpook National University, Daegu, South Korea
| | - Joong-Ho Kwon
- School of Food Science and Biotechnology, Kyungpook National University, Daegu, South Korea
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Sasuga K, Yamanashi T, Nakayama S, Ono S, Mikami K. Discolored Red Seaweed Pyropia yezoensis with Low Commercial Value Is a Novel Resource for Production of Agar Polysaccharides. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2018; 20:520-530. [PMID: 29696549 DOI: 10.1007/s10126-018-9823-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 04/03/2018] [Indexed: 06/08/2023]
Abstract
The red seaweed Pyropia yezoensis has been demonstrated to be a novel resource for the production of high-quality agar. P. yezoensis is grown for the food industry in large-scale Japanese mariculture operations. However, discolored P. yezoensis is mostly discarded as an industrial waste, although it has some kind of utility values. Here, we evaluated the utility of discolored P. yezoensis as a resource for agar production. The quality of agar from the discolored seaweed was comparable to that from normal seaweed. In addition, as a distinguishing characteristic, agar yield was higher from discolored seaweeds than from normal types. Moreover, we successfully used agar from discolored P. yezoensis for bacterial plate media and DNA electrophoresis gels without agarose purification. Thus, our results demonstrate that discolored P. yezoensis is suitable for agar production and use in life science research. Diverting discolored P. yezoensis from disposal to agar production provides a solution to the current industrial waste problem in mariculture, as well as a secure source of agar for research purposes.
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Affiliation(s)
- Keiji Sasuga
- Graduate School of Fisheries Sciences, Hokkaido University, 3-1-1 Minato-cho, Hakodate, 041-8611, Japan
- Suzuyo Research Institute, Co. Ltd., 11-26 Tsukiji-cho, Shimizu, Shizuoka, 424-0944, Japan
| | - Tomoya Yamanashi
- Suzuyo Research Institute, Co. Ltd., 11-26 Tsukiji-cho, Shimizu, Shizuoka, 424-0944, Japan
| | - Shigeru Nakayama
- Suzuyo Research Institute, Co. Ltd., 11-26 Tsukiji-cho, Shimizu, Shizuoka, 424-0944, Japan
| | - Syuetsu Ono
- Miyagi Prefecture Fisheries Cooperative Association, 1-27 Kaisei, Ishinomaki, 986-0032, Japan
| | - Koji Mikami
- Faculty of Fisheries Sciences, Hokkaido University, 3-1-1 Minato-cho, Hakodate, 041-8611, Japan.
- College of Fisheries and Life Science, Shanghai Ocean University, 999 Huchenghuan Road, Lingang New City, Pudong District, Shanghai, 201306, China.
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Tanaka R, Ishimaru M, Hatate H, Sugiura Y, Matsushita T. Relationship between 4-hydroxy-2-hexenal contents and commercial grade by organoleptic judgement in Japanese dried laver Porphyra spp. Food Chem 2016; 212:104-9. [PMID: 27374512 DOI: 10.1016/j.foodchem.2016.05.166] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 05/26/2016] [Accepted: 05/26/2016] [Indexed: 11/24/2022]
Abstract
To evaluate the correlation between the commercial grade determined by organoleptic judgment panel and chemical substances in dried laver Porphyra spp., we analyzed the contents of free amino acids, 5'-nucleotides, total lipids, fatty acids, α-tocopherol, lipophilic pigments, and aldehydes in several grades of laver that had been classified by an organoleptic judgment panel. Compared with the lower-grade laver samples, the excellent-grade laver samples contained higher concentrations of free amino acids, 5'-nucleotides, total lipids, α-tocopherol, chlorophyll a, and β-carotene and lower concentrations of aldehydes such as 4-hydroxy-2-hexenal (HHE), propanal, butanal, and 1-hexanal, which are formed during lipid peroxidation of n-3 or n-6 polyunsaturated fatty acids. In addition, the HHE content was strongly correlated with the propanal content in the analyzed laver (r(2)=0.9123). These results showed that the commercial grade assigned by an organoleptic judgment panel was correlated with chemical substances associated with color, taste, and the prevention of lipid oxidation.
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Affiliation(s)
- Ryusuke Tanaka
- Department of Marine Biology and Environmental Sciences, Faculty of Agriculture, University of Miyazaki, Gakuen-kibanadai-nishi-1-1, Miyazaki 889-2192, Japan.
| | - Mami Ishimaru
- Department of Marine Biology and Environmental Sciences, Faculty of Agriculture, University of Miyazaki, Gakuen-kibanadai-nishi-1-1, Miyazaki 889-2192, Japan
| | - Hideo Hatate
- Department of Marine Biology and Environmental Sciences, Faculty of Agriculture, University of Miyazaki, Gakuen-kibanadai-nishi-1-1, Miyazaki 889-2192, Japan
| | - Yoshimasa Sugiura
- Department of Food Science and Technology, National University of Fisheries, 2-7-1 Nagata-Honmachi, Shimonoseki, Yamaguchi 759-6595, Japan
| | - Teruo Matsushita
- Department of Food Science and Technology, National University of Fisheries, 2-7-1 Nagata-Honmachi, Shimonoseki, Yamaguchi 759-6595, Japan
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Oh S, Shin M, Lee K, Choe E. Effects of water activity on pigments in dried laver (Porphyra) during storage. Food Sci Biotechnol 2013. [DOI: 10.1007/s10068-013-0247-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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KOHATA S, MATSUNAGA N, HAMABE Y, YUMIHARA K, SUMI T. Photo-stability of Mixture of Violet Pigments Phycoerythrin and Phycocyanin Extracted without Separation from Discolored Nori Seaweed. FOOD SCIENCE AND TECHNOLOGY RESEARCH 2010. [DOI: 10.3136/fstr.16.617] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Affiliation(s)
| | - Toshiyuki ISOBE
- Graduate School of Social and Cultural Studies, Kyushu University
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Current awareness in phytochemical analysis. PHYTOCHEMICAL ANALYSIS : PCA 2004; 15:415-422. [PMID: 15595457 DOI: 10.1002/pca.751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
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Cheng JA, Chen CH, Yang H. The study of the sublimable six-coordinated aluminum quinolate with sulfonamide substitutents. Chem Phys Lett 2004. [DOI: 10.1016/j.cplett.2004.08.132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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