• Journal of the East Asian Society of Dietary Life
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• v.25 no.1
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• pp.146-152
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• 2015

Seasoned laver is the highest consumed item among processed laver foods. However, it easily undergoes quality deterioration during processing and storage by lipid oxidation. The purpose of this study was to develop onion seasoned laver with strengthened functional properties through evaluation of storage characteristics. Proximate composition, color index, acid value, thiobarbituric acid (TBA) production, and sensory evaluation of seasoned laver with 0, 15 and 30% onion powder were analyzed during storage periods of 0, 12 and 24 weeks. The lightness, redness, and yellowness of 30% onion seasoned laver significantly increased according to storage period. The acid value and TBA production significantly increased in control laver without onion powder, with no significant difference in 30% onion seasoned laver according to storage period. Sensory preference of onion seasoned laver was better than that of control laver in terms of taste, texture, and overall acceptability. To sum up these results, seasoned laver with 30% onion powder showed superior color degree, acid value, TBA production and sensory preference in proportion to added amount.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.2
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• pp.156-164
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• 2020

To develop a seasoned laver from cooking oyster effluent (C-COE), this study optimized the C-COE concentration, roasting temperature and time using response surface methodology (RSM). The optimal C-COE concentration, roasting temperature and time for producing seasoned laver from C-COE were 31.0%, 182.2℃ and 21.1 sec, respectively. The proximate composition of the seasoned laver prepared with C-COE under the conditions was 5.2% moisture, 37.4% crude protein, 8.2% crude lipid, 11.1% ash, 38.1% carbohydrate. The water activity of the prototype seasoned laver was 0.038. The prototype had stronger taste and flavor intensities than a commercial product. There was no difference (P>0.05) in the Hunter color value between the prototype and the commercial product. The peroxide (POV) and acid values (AV) of the prototype were 6.0 meq/kg and 1.4 mg KOH/g, respectively, which are considered acceptable. The results suggest that the seasoned laver with C-COE developed can be industrialized.

• Fisheries and Aquatic Sciences
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• v.18 no.1
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• pp.21-26
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• 2015

Seasoned laver Pyropia spp. is a traditional Korean seafood that has gained popularity worldwide because of its unique taste, texture, and health benefits. It is prepared by roasting a sheet of dried laver, to which vegetable oils have been applied, at an ultra-high temperature (UHT) of $300^{\circ}C$. Therefore, the oxidative stability of the oils is the most important factor in determining the shelf life of seasoned laver products. In this study, we investigated changes in the thermal oxidative stability of six major vegetable oils (sesame, perilla, sunflower, rice bran, canola, and olive) during the seasoned laver processing. The oxidation induction time of each oil from the seasoned laver products was decreased compared with the fresh oil. These results indicate that the UHT treatment ($300^{\circ}C$, 10 s) induced thermal oxidation of the oils. Among the six seasoned laver oils, the induction times of olive (OL, 8.02 h) and sesame (SE, 5.31 h) oils were significantly higher than the other oils. The acid values (AVs) of OL and SE oils from the seasoned laver were 0.49 and 0.79, respectively. On the other hand, perilla oil had the overall worst thermal oxidative properties (induction time: 0.35 h, AV: 2.82). Our results provide useful information about seasoned laver products for researchers or manufactures.

• Fisheries and Aquatic Sciences
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• v.18 no.1
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• pp.27-33
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• 2015

Seasoned laver Pyropia spp. is one of the most well-known Korean traditional seafoods, and is becoming more popular worldwide. Various mixed oils are used in the preparation of seasoned laver; however, there is no information available regarding the effects of the blending ratio of oils on the quality of seasoned laver. In this study, the effects of the blending ratio of corn, sesame, and perilla oils on the oxidation and sensory quality of seasoned laver were monitored and optimized using a response surface methodology. An increase in the proportion of corn and sesame oils resulted in an excellent oxidation induction time, whereas a high ratio of perilla oil reduced the thermal oxidative stability of the mixed oil. In the sensory test, the seasoned laver with the highest proportion of sesame oil was preferred. The optimal blending ratio (v/v) of corn, sesame, and perilla oils for both oxidation induction time ($Y_1$) and sensory score ($Y_2$) was 92.3, 6.0, and 1.7%. Under optimal conditions, the experimental values of $Y_1$ and $Y_2$ were $4.41{\pm}0.3h$ and $5.58{\pm}0.8$points, and were similar to the predicted values (4.34 h and 5.13 points). Our results for the monitoring and optimization of the blending ratio provide useful information for seasoned laver processing companies.

• Preventive Nutrition and Food Science
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• v.19 no.1
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• pp.40-48
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• 2014

Laver is one of the most consumed edible red algae seaweeds in the genus Porphyra. Laver is primarily prepared in the form of dried, roasted, and seasoned products. We investigated the total polyphenol and flavonoid contents of laver products, and evaluated the in vitro antioxidant properties of solvent extracts from commercially processed laver products. Significant differences in the concentration of phenolic compounds were found among differently processed laver. The total phenolic content for laver extracts ranged from 10.81 mg gallic acid equivalent (GAE)/g extract to 32.14 mg GAE/g extract, depending on extraction solvent and temperature. Laver extracts contained very few flavonoids (0.55 mg catechin equivalent/g extracts to 1.75 mg catechin equivalent/g extracts). 2,2-Diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS), hydroxyl radical, and superoxide anion scavenging assays were used to determine the radical scavenging capacities of laver extracts. These assays revealed that the processing method and extraction condition affected the antioxidant potentials of laver. Antioxidant activity of dried laver, roasted laver, and seasoned laver increased in a concentration-dependent manner ($100{\sim}1,000{\mu}g/mL$). The radical scavenging activities of $37^{\circ}C$ and $100^{\circ}C$ water extracts were lower than that of a $37^{\circ}C$ 70% ethanol extract. The highest radical scavenging capacity was observed in the $37^{\circ}C$ 70% ethanol extracts of dried laver, roasted laver, and seasoned laver. Overall, these results support that notion that laver contains bioactive compounds, such as polyphenols and flavonoids, which may have a positive effect on health.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.4
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• pp.362-368
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• 2018

There is increased consumer demand for roasted seasoned laver Pyropia yezoensis, processed in various ways. The antioxidative activity of roasted seasoned laver was evaluated at different storage times and the quality of the roasted seasoned laver was improved. The laver was also heated at different temperatures for 3 seconds: $340^{\circ}C$ (SH340), $345^{\circ}C$ (SH345), $350^{\circ}C$ (SH350) and commercial roasted seasoned laver (D) was used as standard. The samples were stored in a transparent acrylic case ($39{\times}27{\times}18cm$) at room temperature for 10 weeks. The total phenolic content began to decrease after 7 weeks of storage and was 395.2, 386.4, 395.8 and $416.4{\mu}g/100g$ for SH340, SH345, SH350 and D, respectively. The respective DPPH (1,1-diphenyl-2-picryl-hydrazyl) radical scavenging activity after 7 weeks of storage were 48.6%, 49.5%, 47.7% and 46.1%. The ferric reducing antioxidant power (FRAP) decreased rapidly after 7 weeks of storage due to the influence of sulfate groups. Therefore, the appropriate storage period and packaging method should be established based on these results.

• Journal of the Korean Home Economics Association
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• v.17 no.3
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• pp.53-59
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• 1979

Vitamin contents of three grades of Korean laver high, medium and low were measured. They were cooked by different methods to examine changes in their vitamin content. Results of this experiment are as follows ; 1. Vitamin contained in loogr of laver amount to 13,200 I.U, for high grade, 16,100 for mediium grade, and 16,400 for low grade . The low -grade laver, which is interwoven with green laver, showed the highest vitamin content. 2. When laver was broiled sheet by sheet, its vitamin loss rate was 11% for high grade, 19% for medium grade, and 20% for low grade. Thus , the one with a higher vitamin content showed a higher vitamin loss rate. When two sheets of laver, which were put upon each other, were broiled, their vitamin loss rates were 2.3% for high grade, 1.73 % for medium grade, and 2.64% for low grade. Thus broiling laver at the unitof two to three sheets together is a way of decreasing the vitamin loss rate. 3. When laver was broiled with salt applied on its surface , its vitamin loss rate was 8.3% for high grade, 13% for medium grade, and 10.9% for low grade. When laver was broied at the unit of two sheets together after salt and sesame oil were added, its vitamin loss rate was 2.2% for high grade, 5.2% for medium grade, and 8.2% for low grade . The one with a higher vitamin content showed a higher vitamin loss rate. 4. When laver was mixed seasoned soysauce, its vitamin loss rate increased in process of time. In 48 hours after laver was mixed with seasoned soysauce , its vitamin loss rate read 24.2%, 27.1% and 35% respectively, for the three grades of laver. Thus the laver mixed with seasoned soysauce has to be used right after so cooked so as to obtained the highest possible vitamin content.

• Journal of the East Asian Society of Dietary Life
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• v.13 no.4
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• pp.326-333
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• 2003

The purpose of this study was to investigate the effect of various cooking methods(roasted, salad, deep-fried seasoned-roasted and commercial laver) on mineral contents, color and sensory evaluation of laver. The contents of mineral of dried laver by various cooking methods were analyzed using the Inductively Coupled Plasma(ICP) system. The results were summarized as follows : The content of crude protein, moisture, ash and crude fat in dried laver were 35.1％, 10.6％, 9.7％ and 0.8％, respectively. Among the minerals of dried laver, the content of poassium was the highest (2268.0mg/100g d.w.) and those of calcium and iron were comparatively high (495.1mg/100g, 13.5mg/100g). Ca/P ratio of dried laver was about 1:1 levels. Among various laver dishes, the total mineral content was the highest in the roasted laver, but low in the deep-fried laver. Among color values by cooking methods, "L(lightness)" and " - a(greenness)" values were the highest in the roasted laver, and "b(yellowness)" was the highest in the deep-fried laver. The seasoned-roasted laver was highly scored by the sensory evaluation.

• Journal of Food Hygiene and Safety
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• v.14 no.2
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• pp.134-139
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• 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
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• v.52 no.4
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• pp.321-327
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• 2019

This study aimed to compare on sensory and nutritional characteristics between seasoned Laver Pyropia yezoensis with concentrates of octopus Octopus vulgaris cooking effluent (SL-COCE) and commercial seasoned laver (C-SL). Proximate composition of SL-COCE was significantly higher in moisture and ash, lower in lipid than those of C-SL. However, there was no differences in protein between seasoned lavers (P<0.05). The SL-COCE was stronger in sensory appearance, taste, flavor and texture than the C-SL. The SL-COCE was higher in mineral (Ca, P, K, Fe and Zn) than the C-SL. Total amino acid content of SL-COCE was slightly higher than that of C-SL. The major amino acids of SL-COCE were aspartic acid, glutamic acid and alanine. Mineral content based on the 100 g of SL-COCE was 272.3 mg in calcium, 392.2 mg in phosphorus, 1,025.8 mg in potassium, 10.6 mg in iron, 4.4 mg in zinc, which was higher than C-SL. Total content of fatty acid per the 100 g of SL-COCE was 35,098 mg, which was lower than C-SL (39,679 mg). The major fatty acids of SL-COCE were 16:0, 18:1n-9 and 18:2n-6.