• Korean Journal of Food Science and Technology
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• v.26 no.4
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• pp.382-388
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• 1994

Because of its restrictive harvest from spring to summer, It is necessary to preserve raw ascidians, Halocynthia roretzi, for the purpose of processing regardless of season. We evaluated low Temperature tolerance of ascidian and conditions for cold storage to secure the quality of the stock. To retard the browning of meat rapidly occurred after sucking, ascidians were blanched for 10 seconds in 10% boiling salt solution or dipped for 60 seconds in 0.2% $NaHSO_3$ solution, respectively. The samples were stored in ice, at $-17^{\circ}C$ or $-35^{\circ}C$ for 85 days, respectively. Changes in VBN, glycogen, brown pigment formation, total carotenoid, nucleotides and their related compounds during the storage were determined, and sensory evaluation of quality was also practiced. VBN and brown pigment formation were rapidly increased. Glycogen was gradually decreased and then not detectable after 85 days in case of ice storage. Lipophilic brown pigment was higher than hydrophilic and rapidly increased during storage. The result of sensory evaluation showed that the ascidian treated in 0.2% $NaHSO_3$ was good for 85 days of storage at $-35^{\circ}C$ . Judging from the results of chemical experiment and sensory evaluation, the quality of ascidian treated in 0.2% $NaHSO_3$ and stored at $-35^{\circ}C$ was better than that of other samples.

• Journal of Mushroom
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• v.7 no.3
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• pp.115-121
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• 2009

Recently sawdust cultivation of Shiitake mushroom (Lentinula edodes ) is getting increased because log cultivation is getting difficult to get oak logs. It is important to make mycelia browning on the substrate surface in sawdust cultivation. This browned surface plays an important role like as artificial bark of the oak log, which protects the other pests and suppresses water evaporation in the substrate. The period for mycelia browning is so long that the sawdust cultivation of Shiitake mushroom can not spread well into the mushroom farms. In this article we would like to discuss about the effect of environmental condition to the mycelial browning during sawdust bag cultivation for the To reduce the period required for browning of substrates, sawdust substrates was illuminated light with difference intensity. One hundred Lux light illumination was needed for producing normal yield of fruit body but fruit body yield was low and abnormally shaped fruit body was produced when cultured under the dark condition of incubation. Illumination over 200lux is necessary for the successful browning of substrates during incubation. Optimum incubation temperature for browning of substrates and fruiting was $25^{\circ}C$. The treatment of cotton plug with different size to identify the effect of aeration on the browning of substrates and fruiting showed rapid mycelial growth and reduced the periods for browning as the size of cotton plug was bigger. However, yield of fruit body was the highest at 16mm diameter cotton plug as compared to 20mm of that. $CO_2$ content in vessel of substrates was low as the size of cotton plug was bigger during incubation. $CO_2$ content during incubation of substrate was highest in periods between 8 week and 14 week after inoculation of shiitake when substrate was changed color into brown. $C_2H_4$ content in vessel with substrates was highest at 8mm diameter cotton plug and it was increased by order of 12, 16, 20, 0, 4 mm diameter cotton plug during substrate incubation. Sawdust substrate was soaked in cold water for different time to identify soaking effect of sawdust substrate on fruit body yield and activities of enzymes in these substrates were investigated. The fruit body yield was increased up to 40% by soaking substrates in comparison with unsoaked substrates. The soaked substrates showed 165, 175g/1,000ml at treatment of 4 and 15 hours, respectively. Cellulose activities in soaked substrates were not changed with soaking time, but activities of laccase, lignin degradation enzyme, were drastically increased up to 4 times in comparison with unsoaked substrates.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.3
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• pp.214-220
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• 1993

Browning of ascidian, Halocynthia roretzi, meat occurres very rapidly when skinned off or cut during processing and it resulted the quality loss of fresh frozen, dehydrated or fermented products. In this study, the causes of color development and prevention of browning were experimented. The browning of ascidian meat may be occurred enzymatically by a tyrosinase contained in meat and viscera which acted specifically on L-tyrosine as a substrate rather than on catechol. Activity of the enzyme in viscera was three times higher than in meat. The optimum pH and temperature on the tyrosinase activity of crude enzyme obtained from ascidian was 6.0 and $30{\sim}35^{\circ}C$, respectively. The enzyme was inactivated heating at $80^{\circ}C$ for 3 minutes or $90{\sim}100^{\circ}C$ for 1 minute and it was inhibited by $0.1{\sim}0.5mM$ solutions at ascorbic acid, sodium hydrogen sulfite, cystein, citric acid, cyanide but only sodium hydrogen sulfite treatment was effective to retard such a high content of enzyme as in case of viscera. In practical use for processing of ascidian meat browning was retarded by dipping the viscera removed ascidian meat in 0.2M citric acid for 5 minutes or $0.2\%$ sodium hydrogen sulfite solution for 1 minute resulting in sulfur dioxide residue less than 100 ppm.

• Food Industry
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• s.34
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• pp.47-49
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• 1976

• Current Research on Agriculture and Life Sciences
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• v.1
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• pp.141-150
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• 1983

This report decribes the changes of internal browning and PPO in apples, when the method of storage was changed in the condition of low temperature. Internal browning was found more Fuji harvested in November than Fuji in October. The degree of internal browning was the highest during the storage of 0.09mm 2% and 0.06mm 2%, 0.06mm 20% was followed. In the subatmospheric storage with complete remove of $CO_2$ internal browning was not observed. During the storage of P.E. film bag, Fuji havested in November was higher than in October, and Fuji on 0.09mm 2% was higher than in 0.06mm, and Fuji during the storage of P.E. film bag was increased in PPO activity and PPO specific activity. During the subatmospheric storage with complete remove of $CO_2$, PPO activity of Fuji was little changed, but it's PPO specific activity was continuously decreased. PPO activity of Ralls was more higher than PPO activity of Fuji. PPO activity and PPO specific activity during the early stage of storage and the end stage of storage were little changed. Internal browning of Fuji was more effected $CO_2$ injury than chilling injury. There is no relation between internal browning and degree of PPO activity was effected by $CO_2$ and slightly related with internal browning.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.9
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• pp.1347-1355
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• 2015

In this study, the physicochemical properties, antioxidant capacities, and volatile flavor compounds of oriental melon wine prepared by freeze concentration after heat treatment (HA), ascorbic acid treatment (AAT), and heat and ascorbic acid treatment (HAAT) were investigated. During fermentation period, the melon wine by HAAT showed greater reduction of soluble solids and reducing sugar contents compared to other treatments. In addition, the melon wine treated with HAAT also showed a higher L value and lower browning index compared to other treatments. After aging, free sugar including fructose, and organic acids including citric acid, succinic acid, and malic acid were detected in all samples. For antioxidant activities and contents, HAAT treated wine showed greater antioxidant activities and total phenolic contents than those of others. In GC/MS analysis, a total of 33 volatile flavor compounds were identified. In the principal component analysis of volatile flavor compounds, principal components 1 and 2 represented 88.15% of the whole date distribution and showed opposite tendencies. Taken together, HAAT enhanced the antioxidant activities and sensory properties of oriental melon wine. Moreover, freeze concentration gave the different volatile flavor characteristics in oriental melon wine.

• Korean Journal of Food Science and Technology
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• v.3 no.1
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• pp.29-36
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• 1971

When a low-temperature treatment was given to a small sweet pepper variety Zairaisisi, the seed browning effect appeared soon. This change attracted the studies to determine and discuss the browning metabolites, polyphenolic compounds, and changes in their between-step components. (1) Chlorogenic acids were found as a polyphenolic compound in seed, whereas no flavanol-type polyphenol was observed. (2) There was sharp increase in total polyphenol content and chlorogenic acid with a low-temperature treatment. The contents of these substrates dropped below that of room-temperature treatment after the browning effect took place. (3) A marked increase in between-step metabolites phenylalanine, tyrosine, shikimic acid contents, and thus assumed activated shikimate pathway in this process. (4) It was suggested by determining the effect of specific metabolic inhibition and respiratory inhibitor administrations on enzymes that active biosynthesis of polyphenolic compounds takes place in shikimate pathway with combination of phosphoenolpyruvate and erythrose-4-phosphate connected to TCA cycle jaming after an active EMP pathway was gone through with sugars in pepper seeds at a low-temperature. (5) It was also suggested from the observation of increased K ion flow-out in pepper seeds with a low-temperature treatment that there is an abnormality in the plasma membrance.

• Korean Journal of Food Science and Technology
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• v.3 no.1
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• pp.37-43
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• 1971

(1) Relatively active polyphenol oxidase influence was seen at $0{\circ}C$, and the optimal pH level for the enzyme from the seeds of a small type sweet pepper Zairaisisi is 6.5. (2) The starting stage of the brown coloration with low-temperature injuries showed a strong activity of polyphenol oxidase, and the activity drops to 0 as the entire seed became brownish. (3) The browning effect with enzyme solution of polyphenol extracts suggested that the brown coloration continues in vitro even if polyphenol oxidase activity is nil. (4) Although cytochrome oxidase activity dropped when an abnormality occurrs in electron pathways of respiration at the starting stage of the browning with low temperature injuries, there was no marked influence of it on the total respiration, indicating the fact that polyphenol oxidase can take place of terminal oxidase in the compensatory respiration process.

• Journal of Bio-Environment Control
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• v.22 no.3
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• pp.202-208
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• 2013

This study was conducted to investigate the effect of delayed controlled atmosphere (CA) storage on fruit quality and the incidence of storage disorders during CA storage of 'Fuji' apples (Malus x domestica Borkh.). In the first year of experiment, 'Fuji' apples showed 40% of watercore disorder at the commercial harvest time (Oct. 22). Twenty days delayed CA storage caused to develop the incidence of flesh browning while 30 days delayed CA storage did not. In the second year of experiment, watercore was increased with delaying harvest time. As the estabilishment of delayed CA storage was delayed, the incidence of flesh browning increased at 10 to 30 days delayed CA storage but 40 days delayed CA storage did not have any flesh browning incidence. Respiration rate increased with extending the storage duration. Delayed CA storage reduced respiration rate but was not different compared to the rapid CA. Ethylene production rate was lower in delayed CA storage than in cold storage but higher in delayed CA storage, compared to rapid CA storage. Titratable acidity was lower in delayed CA storage as CA storage progressed. Firmness was not different between rapid CA storage and delayed CA storage after 8 months of CA storage. Therefore, the results indicate that delayed CA storage should be a promising approach to reduce the risk development of flesh browning and watercore during CA storage of 'Fuji' apples.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.2
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• pp.143-148
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• 1998

This study was carried out in order to investigate oxidative deterioration during dehydration at $40^{\circ}C,\;50^{\circ}C$ and $60^{\circ}C$ of sea mussel and baby clam. Moisture content was decreased with drying temperature and time. Sea mussel was dehydrated more rapidly than baby clam that had Harder muscle tissue. Both samples were not reached to Aw 0.62 in case of 10 hrs drying at $40^{\circ}C$, But it reached within 8 hrs in sea mussel and 10 hrs in baby clam at $50^{\circ}C$, respectively. Even if $60^{\circ}C$ could speed up drying, it caused to form more free fatty acid, peroxide, thiobarbituric acid and brown pigments. Lipophilic brown pigment was 10 times higher than hydrophilic and actively increased in all samples. fluorescence intensity was also increased with drying temperature and time. Particularly, it was higher sea mussel than baby clam more or less.