• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.5
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• pp.433-438
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• 1985

Lipids extracted from two kinds of sun-dried laver samples, wild Porphyra suborbiculata and cultured Porphyra tenera, produced at Wan-do in Korea were studied. Dried P. suborbiculata contained $0.8\%$ total lipid(TL) which consisted of $21.4\%$ neutral lipid(NL), $53.4\%$ glycolipid(GL) and $25.2\%$ phospholipid(PL), and dried P. tenera contained $1.2\%$ TL which consisted of $30.5\%$ NL, $50.3\%$ GL and $19.2\%$ PL. Among the NL of dried P. suborbiculate and P. tenera, free fatty acid ($41.4\%,\;39.0\%$), triglyceride($25.6\%,\;28.8\%$) and free sterol ($22.1\%,\;16.7\%$) were predominant. Digalactosyl diglyceride ($34.7\%,\;46.6\%$) and monogalactosyl diglyceride ($19.2\%,\;18.0\%$) were the major components among the GL. Sulfoquinovosyl digylceride ($4.2\%$) was also identified in P. tenera only. And main lipids in the PL of P. suborbiculata and P. tenera were phosphatidyl ethanolamine ($40.3\%,\;35.7\%$) and phosphatidyl choline ($28.6\%,\;30.7\%$) and followed by phosphatidyl serine($15.1\%,\;19.2\%$) and phosphatidyl inositol ($16.0\%,\;14.4\%$). The major fatty acids in the TL of the dried P. suborbiculata were 20:5 ($29.4\%$), 16:0 ($23.4\%$) and 20:4 ($13.0\%$), and those of the dried P. tenera were 20:5 ($36.7\%$), 16:0 ($16.2\%$), 16:1 ($10.7\%$) and 18:1 ($9.7\%$). The fatty acid composition of the both samples in the NL fraction were similar to the pattern in those of the TL. The abundant fatty acids in the PL of the both dried laver were 20:5, 16:0 and 18:1. In case of the GL fraction, the main fatty acids of the dried P. suborbiculata were 16:0, 20:5, 18:1 and 20:4, while those of the dried P. tenera were 20:5, 16:0 and 18:1.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.1
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• pp.35-38
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• 2003

Nuclear 18S ribosomal RNA gene (185 rDNA) from the aquaculturable seaweed Porphya tenera (Bangiales, Rhodophyta) was amplified using the polymerase chain reaction and its sequence was analysed. Complete 185 rDNA has an 1,822 bp exon and a 510 bp intron. The G+C contents of exon and intron were $48.68\%\;and\;54,90\%,$ respectively. The exon sequence showed $99.6\%$ homology to the GebBank accession number AB029880 of the Japanese P. tenera. The intron region that is inserted upstream between 568 and 1,079 showed $43.6\%$ homology to the AB029880.

• Journal of Life Science
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• v.27 no.10
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• pp.1121-1129
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• 2017

The authors evaluated the scavenging activities of ABTS+ radical, hydroxy radical (OH), nitric oxide (NO), and ferric ion reducing antioxidant power (FRAP) from ethanol extracts of four edible alga, Enteromorpha linza, Porphyra tenera, Sargassum fusiforme, and Undaria pinnatifida. ABTS+ scavenging activity was analyzed according to the method of Brand-Williams et al. ABTS+ scavenging activity of S. fusiforme was evaluated to 61.8% at 8.0 mg/ml. ABTS+ scavenging activity of P. tenera was evaluated to 35.7% at 8.0 mg/ml. P. tenera and U. pinnatifida showed similar inhibitions of ABTS+ scavenging activity. According to the results of the OH assay in seaweed, inhibitory activities were in the order of S. fusiforme > P. tenera > U. pinnatifida > E. linza. The results showed scavenging activity for NO in the following order of potency: S. fusiforme > P. tenera > U. pinnatifida > E. linza with concentration values of 8.0 mg/ml. The NO scavenging activities of dough, which was instant noodles mixed with S. fusiforme and 3.5% salt, were 27.2% at 8.0 mg/ml. After boiling for 5 minutes, FRAP scavenging activity of instant noodles mixed with extracts of U. pinnatifida was evaluated to 31.5% at 8.0 mg/ml. S. fusiforme showed the highest inhibition activity of ABTS+, OH, NO, and FRAP among the four algae. Thus, these findings provide evidence that P. tenera, U. Pinnatifida, S. fusiforme, and E. linza extracts could become sources of natural antioxidants.

• Environmental Analysis Health and Toxicology
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• v.14 no.3
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• pp.75-79
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• 1999

Due to increasing marine pollution there is a great possibility that seaweed is contaminated with polycyclic aromatic hydrocarbons (PAHs). To investigate the effect of processing on PAM removal from Porphyra tenera (laver) contaminated PAH, laver was contaminated with fluoranthene known to have a strong photoinduced toxicity, followed by washings and drying, which are usual processes for dried laver preparation. Sample at each step was collected and its toxicity was evaluated using cultured animal cells as well as analyzing PAH contents. Fluoranthene level in laver was significantly lowered by sequential washings with sea water and distilled water, but not by drying. Fluoranthene content in raw laver right after contamination was 221 ppm and decreased to 130 ppm by washings with seawater plus distilled water while its level was not lurker lowered by drying process. Cytotoxicity and photoinduced cytotoxicity in mammalian cells were significantly elevated in laver extracts containing fluoranthene. Cellular arylhydrocarbon hydroxylase (AHH), one of the biomarkers for cellular accumulation of PAH, was greatly induced by laver extract contaminated with fluoranthene. These results suggest that photoinduced toxicity and AHH activity can be used to monitor contamination of seafood by PAHs. Fluoranthene accumulated in laver was efficiently removed by sequential washings with seawater and tap water for 24 hrs and 12 hrs, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.1
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• pp.193-195
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• 2001

A radiation-resistant bacterium was isolated from gamma irradiated dried laver (Porphyra tenera) and its microbiological characteristics were examined. As a result of resistance test to gamma irradiation, the isolate was survived $10^{3}$ CFU/mL even at 30 kGy and significant shoulder line zone was shown until 20 kGy. The $D_{10}$ value was 11.27 kGy. The isolate was gram-positive, non-motile coccus and catalase-positive. n culture, the red-pigmented smooth colony was observed. The biochemical test in API (analytical profile index) system showed that the isolate fermented glucose and fructose as the carbon source. Therefore, a radiation-resistant bacterium isolated from laver was potentially identified as Micrococcus roseus sp.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.6
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• pp.1166-1172
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• 1998

A method for the isolation and purification of DNA from a red algae, Porphyra was innovated. The innovation of the method consists mainly of three steps that include sodium acetate treatment, chloroform extraction, and 0.2 volume isopropanol precipitation step. The sodium acetate treatment was designed to remove polysaccharide contamination, and the isopropanol step to remove proteins and salts contaminents. Genomic DNA,s of several species(for example, P. tenera, P. yezoensis, P. seriata, and P. pseudolinearis) was successfully isolated by the innovated method. The amount of DNA purified from one g of sample material with the innovated method was 53 g in average. The resulting DNA was characterized to include high molecular weight and showed no nuclease activity. The DNA was pure enough to be digested directly by various restriction enzymes without any difficulties. Porphyra DNA was pure enough and adequate for amplification reaction through the polymerase chain reaction (small nuclear rDNA PCR amplification).

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.8
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• pp.1270-1276
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• 2013

Laver, a red algae belonging to the genus Porphyra tenera, is one of the most widely consumed edible seaweeds in Korea, China, and Japan. Lavers are usually consumed in dried, roasted, and seasoned forms to improve their palatability. We evaluated the composition of amino acids, minerals, and trace heavy metals in these three differently cooked forms of laver. The moisture and ash contents of three differently cooked lavers ranged from 1.49~9.69% and 6.07~10.31%, respectively. The crude protein and lipid content ranged from 17.24~36.88% and 0.52~42.42%, respectively. Dried laver was found to be a good source of amino acids such as taurine, alanine, and glutamic acid (871.10 mg, 833.53 mg, and 719.77 mg per 100 g dry weight, respectively). Laver was a good source of macro and micro minerals such as K, Ca, Mg, Na, P, I, and Fe, although laver more extensively cooked (roasted and seasoned) contained less minerals compared to the dried form. Mercury levels in the three differently cooked forms of laver were all less than 100 ng/g dry weight (the limit of detection with our methodology). The levels of arsenic were the most abundant elements in the differently cooked laver. There was a clear variation, depending on the cooking process, in terms of amino acid, mineral, and trace metal contents of laver.

• ALGAE
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• v.18 no.4
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• pp.321-331
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• 2003

Cryopreservation of sporothalli of the red alga Porphyra (P. seriata, P. yezoensis, P. tenera, P. pseudolinearis and P. dentata) was performed by the two-step cooling method in liquid nitrogen. The algal samples were suspended in various cryoprotective solutions, and slowly cooled to -40$^{\circ}C$ in 4 hours using a programmed freezer. After the first slow cooling the suspensions with cryoprotectants were immediately immersed in liquid nitrogen. The suspension from the programmed freezer was thawed quickly by agitation of the vial in a water bath at 40°C. When ice in the suspension of cryogenic vial was mostly melted, the vial was transferred to an ice bath for complete melting of the residual ice. The cryoprotectants in the vial were washed off by gradual dilution with seawater. The viability of the cell was assessed with neutral red staining. The viability of Porphyra samples ranged 54.6-70.9% when the mixed suspension of 10% dimethylsulfoxide and 0.5 M sorbitol in 50% seawater used as a cryoprotectant.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.10
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• pp.1514-1519
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• 2005

This study was performed to investigate the effects of Porphyra tenera (PT) on cytotoxicity and quinone reductase (QR) activity in the cancer cells. PT was extracted with methanol and further fractionated into five different types: hexane (PTMH), ethyl-ether (PTMEE), ethylacetate (PTMEA) butanol (PTMB) and aquous (PTMA) partition layers. We determined the cytotoxic effect of these layers on C6, HepG2, MCF-7, and HT-29 cell lines by MTT assay. Among the various fractions, hexane (PTMH) of PT showed the strongest cytotoxic effect on C6, HepG2 and MCF-7 cell lines. PTMH displayed very low level of cytotoxicity at the lower concentration levels and at 300 $\mu$g/mL. PTMH resulted in 87.5$\%$ growth inhibition on C6 cell 70 $\%$ on the HepG2 cell and 89$\%$ on the MCF-7 cell, which were significantly high compared to other fractions. A 400 $\mu$g/mL PTMH concentration level, 99$\%$, 94.5$\%$ and 99$\%$ of cell growth inhibition were resulted on the same cell lines. On HT-29 cell line, both hexane (PTMH) and aqueous (PTMA) fraction of PT showed cytotoxic effects, but the Percentage was not as high as previous results tested on other cell lines such as C6 HepG2 and MCF-7 cell lines. Also, we observed quinone reductase (QR) inducing-effects in all fractions of PT on HepG2 cells. The QR inducing effects of the PTMH on HepG2 cells at 150 $\mu$g/mL concentration was 6.6 times higher than the control. Although further studies are needed, the present work suggests that PT was a potential to be used as a chemopreventive.

• Food Science and Preservation
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• v.23 no.1
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• pp.139-143
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• 2016

This study investigated the effect of electron beam (EB) treatment on the microbial reduction of dried laver (Porphyra tenera) and identified EB-resistant bacteria from the treated dried laver. After EB treatments of 4 kGy and 7 kGy, the numbers of total bacteria and EB-resistant bacteria were measured using tryptic soy agar and mannitol salt agar, respectively. The morphological and biochemical characteristics of each isolated EB-resistant bacteria were investigated and these bacteria were identified. Compared to the control ($1.5{\pm}0.2){\times}10^6CFU/g$, the total bacterial number was significantly decreased to ($5.4{\pm}0.5){\times}10^4CFU/g$ and ($1.1{\pm}0.6){\times}10^4CFU/g$ after EB treatments of 4 kGy and 7 kGy, respectively. With a higher EB dosage, the number of red colonies was almost same, whereas the number of yellow colonies was significantly decreased to ($3.3{\pm}1.2){\times}10^3CFU/g$ and 0 CFU/g for 4 kGy and 7 kGy, respectively. All red and yellow colonies were gram-positive cocci, catalase-positive, and resistant to 3% and 5% NaCl media. From the 16S rDNA sequence analysis, yellow and red colonies were identified as either Micrococcus flavus or M. luteus, with 99% similarity for the yellow colonies, and Deinococcus proteolyticus and D. piscis, with 99% and 97% similarity for the red colonies, respectively.