• Horticultural Science & Technology
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• v.19 no.4
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• pp.545-549
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• 2001

The relationship between ethylene action and flesh softening in post-storage persimmon fruits was investigated by treating the fruits with 1-MCP. The patterns of firmness change caused by various treatments with 1-MCP and ethylene were similar to those of changes in cell wall-degrading enzyme activities, including cellulase, PG, PME, and ${\beta}$-galactosidase. Moreover, the activities of these enzymes were inhibited by 1-MCP treatment. These results show that the cell wall-degrading enzymes influenced by ethylene account for the flesh softening process of post-storage persimmon fruit. The ethylene production of fruits, as measured by ACC content and ACC oxidase activity, nevertheless, was not influenced by 1-MCP treatments. It is suggested that the flesh softening phenomena in post-storage persimmon fruits is correlated to the ethylene responsiveness of tissue rather than the ethylene production rate per se.

• Korean Journal of Food Science and Technology
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• v.25 no.1
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• pp.78-82
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• 1993

This study was carried out to develop a new processing method for the production of yeast autolyzate (YA) by which the yield and the quality could be improved, compared to the conventional method. The result indicated that 85.3% of yeast cell walls treated with glucanase and protease was ruptured by homogenizing at 10,000 psi. Alkali treatment, however, was not effective in disintegrating yeast cell walls. Optimum conditions for autolysis of ruptured yeast cells, obtained with help of response surface methodology (RSM), were pH 7.0, $30^{\circ}C$, ethanol 4% and salt 3%. YA produced by the developed method had significantly higher yield and better sensory quality than that produced by the conventional method.

• Korean Journal Plant Pathology
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• v.3 no.2
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• pp.124-130
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• 1987

The optimum conditions for protoplast formation and regeneration from Pyricularia oryzae Cav. were selected as follows. As a basic solution, 0.02M potassium phosphate buffer solution plus 0.6M KCl adjusted to pH 5.2 with 1N HCl was used. A mixture of enzyme combinations with 20mg Cellulase R-l0/ml, 5mg Macerozyme R-l0/ml and l0mg Driselase/ml used as a lytic enzyme showed better lytie effect than any single enzyme treatment for protoplast formation. Two-day-old mycelia of P. oryzae grown in the mixture of three lytie enzyme solution at $30^{\circ}C$ for 3 hr showed best condition for protoplasts formation. For regeneration from the protoplasts of P. oryzae, potato dextrose agar containing 0.02M potassium phosphate plus 0.6M KCl used as a stabilizer was best for regeneration medium.

• Korean Journal of Food Science and Technology
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• v.41 no.3
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• pp.345-349
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• 2009

This study measured the amounts of uronic acid, total sugars, non-cellulosic neutral sugars, phenolic compounds as well as antioxidants activity in cell wall materials (CWM) derived from different parts of deodeok (Codonopsis lanceolata). The values of the uronic acid (UA): neutral sugars (NS) ratio in polymers extracted from the CWM of the flesh and skin were 4 and 6, respectively. The total sugar contents of the flesh and skin were 788.6 and 824.9 ${mu}g/mg$ of CWM, respectively. Galactose and arabinose were the main noncellulosic neutral sugars. The chemical structure of five phenolic compounds from the CWM were analyzed and identified as vanillic acid, p-OH-benzaldehyde, vanillin, ferulic acid, and 8-O-4' diferulic acid by HPLC spectral data. Among them, p-OH-benzaldehyde, vanillin, and 8-O-4' diferulic acid were the first compounds identified from the deodeok. The content of 8-O-4' diferulic acid in the skin CWM was 56.1 ${mu}g/g$ AIR (alcohol insoluble residue). The ethanol-NaOH fractions from CWM had the highest oxygen radical absorbance capacity (ORAC) activities, followed by the AIR fractions and ethanol fractions.

• Korean Journal of Food Science and Technology
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• v.27 no.6
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• pp.934-938
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• 1995

Water soluble fractions (WSF) of wheat bran treated with thermal processes such as autoclaving, microwaving and extrusion were characterized to investigate the structural response of plant cell wall to thermal and mechanical energy. From the chemical analysis and gel filtration chromatography of WSF, gelatinization of starch was found to be the primary solubilizing mechanism of wheat bran, followed by the structural disintegration of fibrous non-starch cell wall materials. It was also found that extrusion process resulted in degrading relatively higher molecular weight non-starch polysaccharides from the cell wall. GC analysis of water soluble non-starch polysaccharides indicates that the arabinoxylan residues of cell wall are the most susceptible site to thermal treatments studied. In particular, the degrading degree of cell wall of wheat bran is the most significant for extrusion accompanying both high temperature and high shear.

• Journal of the Korean Society of Food Science and Nutrition
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• v.15 no.2
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• pp.165-170
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• 1986

Various cell wall polysaccharides such as IAP(ionically associated pectin), CBP(covalently bounded pectin), HF(hemicellulosic fraction) and CF(cellulosic fraction) were fractionated by chemical method from hot pepper fruit cell wall during ripening and softening. And then, the composition of the polysaccharides were determined. The IAP and CBP were composed of $65{\sim}88%$ polyuronide, $4{\sim}29%$ hemicellulose and $0.3{\sim}2.1%$ cellulose. And hemicellulose also contained $8{\sim}13%$ polyuronide and $0.1{\sim}1.1%$ cellulose. The containing ratio of hemicellulose associated with the CBP was higher than IAP. All of the polysaccharides except CF decreased by the turning stage showed softening. The polyuronide made up IAP changed little but, that of the CBP increased during softening owing mainly to decrease of the hemicellulose that was bounded to the CBP and was mostly linked to galactose.

• Korean Journal of Microbiology
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• v.33 no.4
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• pp.242-246
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• 1997

The protein profile of Synechococcus sp. cyanophage was investigated employing SDS-PAGE. The phage appears to be composed of two major proteins of 97 and 52 kDa and at least seven minor proteins of 70, 65, 60, 40, 35, 28, and 6 kDa. It seems that each subunit is combined to form a multimer although any disulfide bond does not exist in the phage structure. Lytic activity of the phage particle against cell wall was detected around the 52 kDa on renaturing SDS-PAGE using heat-killed Micrococcus luteus cells as substrate. The activity has the optimal pH between 9 and 10, and slightly inhibited by EDTA.

• Journal of Applied Biological Chemistry
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• v.63 no.4
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• pp.291-295
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• 2020

In order to increase the utilization of defatted sesame meal (DSM), a by-product of sesame oil production, the conditions of extraction of insoluble proteins from DSM by enzyme treatment were investigated. As a result of comparing the treatment results of proteolytic enzymes Alcalase, Flavorzyme, Neutrase, and Protamex with control, Protamex was effective in increasing the total solid and protein content. At the reaction conditions of Protamex (50 ℃, pH 6.0), the dosage of enzymes was appropriate for 1% of DSM and 3 h of enzyme reaction time. To improve the efficiency of enzymatic treatment, the protein content extracted increased as the heat treatment temperature increased, and slightly increased above 110 ℃. As a result of investigating the effect of the combination treatment of cell lytic enzyme (Tunicase) and protease (Protamex) on protein solubilization, it was most effective to treat the cell lytic enzyme after processing the protease. After heat treatment (110 ℃, 10 min), sequential treatment of Protamex and Tunicase increased the protein content by about 3.5 times (9.85→35.58 mg/mL) of the non-heated control and 2.2 times (15.83→35.58 mg/mL) of the heat treated control.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.2
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• pp.175-179
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• 1997

Changes of protein contents and chromatogram patterns by gel filtration chromatography was investigated for the purpose of studying changes of Proteins during softening of persimmon and jujube fruits. Contents of water-soluble and salt-soluble proteins were increased during softening of persimmon and jujube fruits, but that of cell wall-bound proteins was decreased. After performing a gel filtration of water-soluble protein, one peak was separated in mature persimmon fruits and three peaks in soft persimmon fruits. In the case of jujube fruits, there were three peaks in both of mature and soft fruits. Pattern of salt-soluble and cell wall-bound proteins by gel filtration chromatography hardly changed during softening. During softening of two fruits, the contents of water- soluble and salt-soluble proteins appeared to be increased on the same fractions with the decreasing in content of cell wall-bound proteins.

• Journal of Mushroom
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• v.19 no.4
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• pp.329-335
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• 2021

This experiment was conducted to investigate the changes in freshness parameters and determine the optimal UV-B irradiation conditions for each storage period for Heuktari, an oyster mushroom cultivar, grown under LED lightNo significant changes were observed in the CO₂ and O₂ content until day 12 of storage; however, after day 15, the CO₂/O₂ ratios were higher in the UV-treated groups than in the untreated groups. No color difference was observed between the UV-treated and untreated groups. In all UV-treated groups, hardness decreased over time; however, the group irradiated for 15 minutes showed higher hardness values than those of the untreated group. The UV-irradiated group showed higher ergosterol content than did the untreated group, and scanning electron microscopy revealed that mushroom cell wall destruction increased with increased UV treatment time. Overall, these findings confirmed that UV-B irradiation increased the ergosterol content of Heuktari but decreased its freshness and negatively impacted other storage characteristics.