• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.52 no.2
• /
• pp.180-184
• /
• 2019

Aerobic bacteria, coliforms, Escherichia coli, and pathogenic bacteria were investigated in laver Porphyra sp. samples from various regions of Korea. The mean bacterial counts were $6.9{\pm}0.87log\;CFU/g$ (range 4.0 to 7.7) log CFU/g in dried laver, $2.83{\pm}4.36log\;CFU/g$ in roasted laver, and $4.93{\pm}1.43log\;CFU/g$ in seasoned laver. Coliforms were most abundant (mean count: $2.1{\pm}1.01log\;CFU/g$) in dried laver. No pathogenic bacteria, including Staphylococcus aureus, Salmonella spp. Vibrio parahaemolyticus, or Listeria monocytogenes, were detected in any of the samples. Aerobic microorganisms were the most diverse microorganisms in dried laver. Staphylococcus spp. were predominant, but S. aureus was not detected. Standardization of laver production is necessary to ensure a hygienic product because laver products are often ingested without heating or cooking, and the production process is simple.

• Environmental Analysis Health and Toxicology
• /
• v.12 no.3_4
• /
• pp.67-73
• /
• 1997

This study was carried out to investigate the contents of heavy metals such as iron, copper, lead, cadmium, magnesium, platium in connection with water pollution in sea weed (dried laver) collected from the west, south, south- west, and east coasts of Korea. The results of the study are as follows; Iron was shown the highest value (1.280ppm) in the wild laver from the south coast. Copper was detected in larger qauntities (0.169 ppm) in green laver than in any other kinds of laver observed in this study. Lead was detected in larger quantities (0.195ppm) in the usual laver and green laver from the south-west coast as compared with the other coasts. Although cadmium and platium was also detected from every kind of laver, the concentrations were not over the allowance of the residual.

• Journal of Nutrition and Health
• /
• v.29 no.3
• /
• pp.278-285
• /
• 1996

Contents of insoluble(IDF), soluble dietary fiber (SDF), and total dietary fiber(TDF) of 30 foods which are consumed commonly by 80 Koeran male college students were determined by Prosky and colleagues' enzymatic-gravimentric method. Foods with highest intake frequency were rice, Kimch'i, and red pepper powder. TDF, IDF, and SDF contents of rice were 0.96, 0.59 and 0.37g/100g wet wt., respectively and tose of Kimch'i were 3.07, 2.19 and 0.88g/100g wet wt., respectively. Red pepper powder contained high amount of TDF(39.37) and IDF (33.13g/100g wet wt.). The TDF content of the 30 foods ranged from 0.70 to 39.37g/100g wet wt. Red pepper (39.37), dried laver(31.36), and dried sea mustard (37.77g/100g wet wt.) contained high amounts of TDF. The IDF content of the 30 foods ranged from 0.13 to 33.13g/100g wet wt. Red pepper powder (33.13), dried laver(15.55) and sesame(15.43g/100g wet wt.) contained high amounts of IDF. SDF of the 30 foods ranged from 0.01 to 25.66g/100g wet wt. Dried sea mustard(25.66), dried laver(15.81), coffee powder (13.17), and garlic(8.72g/100g wet wt.) were good sources of SDF. % ratio of SDF to TDF of the 30 foods was lower than 50% except soybean curd(94.27%), coffee powder (88.93%), garlic(86.17%), dried sea mustard(67.94%), and dried laver(50.41%). It is recommended to increase intake of seaweeds in order to supply TDF adn SDF properly.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.55 no.5
• /
• pp.662-669
• /
• 2022

The purpose of this study is to test the effects of electrolyzed water treatment on dried-laver Pyropia sp. processing facilities to control microbial contamination. Following the progression of the process to the next step, as well as during the lapse between process operating hours, the contamination level of total viable cell counts (TVC) and total coliform (TC) of laver increased. The TVC increased during the aging step, and after the molding-drying steps were completed, it increased by approximately 2.0 log CFU (colony forming unit)/g. Freshwater used for processing in April had a TVC of 4.31 log CFU/mL, which was more polluted than 2.61 log CFU/mL of seawater. Electrolyzed water was used to treat the sponge used in the laver-molding process, which resulted in a 2 log CFU/mL decrease.The TVC of dried-laver decreased by 1 to 2 log CFU/g when electrolyzed water was applied to the process. In conclusion, application of electrolyzed water in dried-laver processing was shown to be effective in reducing the microbiological contamination of the final product.

• Korean Journal of Food Science and Technology
• /
• v.46 no.6
• /
• pp.677-681
• /
• 2014

The effects of toasting, simulated gimgui (dried and toasted laver) manufacturing, on lipid oxidation and antioxidant and pigment contents of dried laver (Porphyra spp.) were evaluated by peroxide value (POV) and conjugated dienoic acid (CDA) value measurement, HPLC, and spectrophotometry. Dried laver was toasted for 40 or 300 s at $120^{\circ}C$, or for 2 or 5 s at $250^{\circ}C$. The POV and CDA contents were significantly higher in the toasted samples (0.60-0.69 mmol/kg and 2.17-4.20%, respectively) except in samples toasted at $120^{\circ}C$ for 40 s, compared to those in the non-toasted samples (0.43 mmol/kg and 1.21%, respectively). Chlorophyll was the most stable pigment during toasting (>90% retention), followed by carotenoids (50-77% retention) and phycocyanins and phycoerythrins (13-73% retention). Porphyran was the most stable antioxidant (>95% retention), and polyphenols, the most unstable antioxidant (24-75% retention). Despite the degradation of pigments and antioxidants during toasting, the dried laver still contained health-benefiting components after toasting.

• Journal of Food Hygiene and Safety
• /
• v.14 no.2
• /
• pp.134-139
• /
• 1999

The relationship between storage stability and chlorophyll contents of dried laver(DL), roasted laver(RL) and roasted seasoned laver(RSL) according to packaging during storage at 20$\pm$0.5$^{\circ}C$ were investigated by measuring the acid value(AV) and the peroxide value(POV). There results are as follows; 1.The storage stability was decreased in the rank of 0 < 3< 6 < 9 months by storage term, RL < DL < RSL by the kind of laver products and PP/PE/AL/PE/LLDPE(Al) < PP/PE(PP) y packaging. 2. When the silica gel was added to RSL, the storage stability was improved. The more the addition level of silica gel was increased, the more the storage stability was improved. The rank order was 2g < 4g in RSL. 3. Reduction of the total chlorophyll content in RSL were deacreased to 10% when packed with Al and 24% when packed with PP.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.51 no.3
• /
• pp.221-229
• /
• 2018

Various types of dried laver Pyropia yezoensis have been produced in response to increasing demand and other laver goods manufactured using different processing methods are continuously being developed. The dried laver used in this experiment was initially heated at $165^{\circ}C$ for 3 seconds, followed by second heating at a high temperature ($340-350^{\circ}C$) to increase the storage period and enhance taste and flavor. Nutrient analysis of each sample heated under three conditions revealed that the protein and lipid contents were highest in samples from D company, while the carbohydrate contents remained relatively stable. After storage for 10 weeks at room temperature, changes in the composition were evaluated. The results showed decrease in protein (30%-49%) and essential amino acid contents. During storage, the major unsaturated fatty acids contained in dried laver slightly changed to 53.4%-56.0% in the form of EPA, while saturated fatty acids slightly increased to 18.4%-22.6% in the form of palmitic acid. The variables derived from fatty acid composition, such as atherogenic and thrombogenic, and hypocholesterolemic/hypercholesterolemic dietary indices, and polyunsaturated fatty acids/saturated fatty acids ratio, also indicated reasonable levels of stability. However, the laver should be consumed within 2 months.

• Korean Journal of Food Science and Technology
• /
• v.35 no.6
• /
• pp.1017-1021
• /
• 2003

The chemical properties of porphyran from dried laver (Porphyra yezoensis) and decolored laver were measured. Dried laver contained 12.5% porphyran while decolored laver contained 12.3%. The chemical components of porphyran extracted from dried and decolored laver were examined. The content of total sugar was 64.5% and 63.7% on dry base, respectively, while that of sulfate was 17.6% and 16.9%, respectively. The content of 3,6-anhydrogalactose was 18.8% and 18.1%, respectively.

• Preventive Nutrition and Food Science
• /
• v.18 no.2
• /
• pp.139-144
• /
• 2013

Laver, a red algae belonging to the genus Porphyra, is one of the most widely consumed edible seaweeds. The most popular commercial dried laver species, P. tenera and P. haitanensis, were collected from Korea and China, respectively, and evaluated for proximate composition, amino acids, minerals, trace heavy metals, and color. The moisture and ash contents of P. tenera and P. haitanensis ranged from 3.66~6.74% and 8.78~9.07%, respectively; crude lipid and protein contents were 1.96~2.25% and 32.16~36.88%, respectively. Dried lavers were found to be a good source of amino acids, such as asparagine, isoleucine, leucine, and taurine, and ${\gamma}$-aminobutyric acid. K, Ca, Mg, Na, P, I, Fe, and Se minerals were selected for analysis. A clear regional variation existed in the amino acid, mineral, and trace metal contents of lavers. Regular consumption of lavers may have heath benefits because they are relatively low in fat and high in protein, and contain functional amino acids and minerals.

• Journal of Marine Bioscience and Biotechnology
• /
• v.14 no.2
• /
• pp.69-75
• /
• 2022

The micro-Kjeldahl method, a common technique for analyzing crude proteins, is time-consuming and dangerous due to the employment of reagents such as sulfuric acid and sodium hydroxide. However, a Fourier transform near-infrared (FT-NIR) spectrophotometer analysis can be completed in under a minute after simple pre-processing if data has been gathered using sufficient reference material in advance. Furthermore, the use of safe reagents in this technique ensures the safety of the experimenter and the environment. In addition, a portable FT-NIR spectrophotometer enables real-time measurement at processing or distribution sites and has recently gained popularity. The standard errors of calibration and regression (r²) for the calibration result for estimating the crude protein content of dried laver were 0.9775 and 1.2526, respectively. The standard error of prediction was 1.1814, and the r² was 0.9303 in the validation results, which was a good level. In the present study, a method for predicting the crude protein content of dried laver using an FT-NIR spectrophotometer in the range of 29%-40% crude protein content has been reported.