• Journal of Applied Biological Chemistry
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• v.42 no.2
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• pp.92-96
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• 1999

To study the regulatory mechanism of isoprenoid (carotenoid) biosynthesis, we have compared the expression patterns of nine isoprenoid biosynthetic genes in Korean red pepper (Capsicum. annuum cv. NocKaung). The expression of geranylgeranyl pyrophosphate synthase gene was initially induced at early ripening stage (I1) and was rather slightly decreased during pepper fruit ripening. The ex-pression of phytoene synthase gene was strongly induced at semi-ripening stage (I2) and the phytoene desaturase transcript was maximally induced at the fully ripened stage (R). Our results suggest that genes encoding two 3-hydroxy-3-methylglutaryl-CoA reductase isozymes (HMGR1 and HMGR2) and farnesyl pyrophosphate synthase might be not so critical in pepper carotenoid biosynthesis but three genes encoding geranylgeranyl pyrophosphate synthase, phytoene synthase and phytoene desaturase were induced in a sequential manner and coordinately regulated during the ripening of pepper fruit.

• Journal of the Korean Wood Science and Technology
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• v.50 no.4
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• pp.272-282
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• 2022

The essential oil extracted from Citrus × natsudaidai (Yu. Tanaka) Hayata peels is known to have various biological properties. However, the chemical composition of essential oil is influenced by the ripening stages of fruits, which then affects related biological activities. This study investigates the antioxidant activities of essential oils extracted from Citrus × natsudaidai peels at different ripening stages (immature, mature, and overripe). The essential oils were extracted using the hydro-distillation method. As a result of gas chromatography-mass spectrometry (GC-MS) analysis, d-limonene was dominant and was increased as matured. However, 𝛄-terpinene was decreased. The antioxidant properties and their total phenolic content (TPC) were influenced by the ripening stages. The TPC was highest in the immature stage of essential oil (1,011.25 ± 57.15 mg GAE/100 g). 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity was excellent in the immature stage (EC₅₀ = 15.91 ± 0.38 mg/mL). 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity was superior in overripe stage (EC₅₀ = 20.43 ± 0.37 mg/mL). The antioxidant activity measured using ferric reducing antioxidant power (FRAP) assay showed higher values for the essential oils in immaturity (1,342.37 ± 71.07 mg Fe²⁺/100 g). Comprehensively, the essential oil in the immature stage showed the best antioxidant activity. Finally, knowing the chemical composition and antioxidant activity at different ripening stages will provide data for selecting the right fruit.

• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.2
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• pp.157-163
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• 1985

Various cell wall polysaccharides and related enzyme activities in hot pepper fruit were determined at different stages of maturity. The uronic acid content of cell walls decreased between immature green and turning stage fruit and then increased by red ripe stage. In contrast, cellulose content of cell walls changed only a little during ripening. Total neutal sugar content of cell wall material decreased 50% and galactose content of the walls decreased about 80% by the turning stage. Polygalacturonase and ${\beta}-galactosidase$ activities, as well as total hemicellulose from isolated cell walls of ripening hot pepper fruit were studied using gel filtration chromatography. Polygalacturonase activity was not detectable but 5 isozymes of ${\beta}-galactosidase$ were resolved. The activities of the enzymes were relatively high and gel filtration showed that they differed in molecular weight. Hemicellulose content decreased during ripening and softening. The molecular weight profiles shifted from high molecular weight to low molecular weight polymers during ripening. The changes in cell walls that may be associated with fruit softening involve the alteration of hemicellulose prior to the degradation of wall-bound uronic acid. It is suggested that the decrease in cell wall galactose involved changes in turnover of new cell wall components.

• Journal of the Korean Applied Science and Technology
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• v.33 no.2
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• pp.304-310
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• 2016

This study shows the changes of the nucleotides and their related compounds of squid during fermentation for 8 weeks at $10^{\circ}C$ in 5% salt solution. Among nucleic acid related matters, ATP and ADP were vanished not to be detected, AMP existed only at the early stage and then rapidly decreased until the mid-stage of the ripening. Inosine and hypoxanthine were the main components of nucleotides and their related compounds. As the salt concentration was decreased and fermentation temperature raised, pH was significantly increased to the latter stage of the ripening and hence fermentations was enhanced. The titrable acidity was continuously decreased until the latter stage of the ripening. Considering the above result, it is possible to make an estimate that the suitable fermentation conditions of squids are $10^{\circ}C$ of fermentation temperature, 10% of salt concentration and 5 weeks of ripening period.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.4
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• pp.406-412
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• 2014

The influence of rainfall during the ripening stage on pre-harvest sprouting, seed viability, and seed quality was investigated in two Korean rice cultivars, Shindongjin and Hopum. When the rainfall was artificially treated in a greenhouse, HP started to pre-harvest sprouting at three days of rainfall treatment (DRT), but Shindongjin did not show pre-harvest sprouting at 40 DAH treatment and just 0.3~0.8% at 50 DAH, which was much lower than 15.3~25.8% of Hopum in the same treatment. After harvest, the seed germination of Hopum decreased about 10~25% compared to non-treated seeds, but that of Shindongjin decreased much little rate than that of Hopum. The seed longevity tested by accelerated aging decreased with prolonged rainfall period in both cultivars, but the varietal difference was clear; Shindongjin could withstand longer accelerated aging than Hopum. Shindongjin maintained its germination (>50%) ability after 15 days of accelerated aging regardless of the rainfall treatment period and time, but Hopum dropped below 50% germination ability after only 5 days of accelerated aging. In conclusion, rainfall during the ripening stage induced not only pre-harvest sprouting, but also reduced seed quality and longevity during storage, which varied between two cultivars.

• Korean Journal of Food Science and Technology
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• v.53 no.1
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• pp.63-71
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• 2021

In this study, a comparative analysis was carried out between the 'Beta Tiny' and 'TY Nonari' cherry tomato cultivars harvested at the pink and red stages. Samples of the red stage were stored at room temperature for 9 days, during which physicochemical qualities, antioxidant compounds, and activities were measured. As cherry tomato ripening and storage progressed, firmness was reduced, whereas the lycopene content increased. Total phenolic content and antioxidant activity showed no significant changes as ripening and storage progressed; however, total flavonoid content of 'Beta Tiny' showed a significant increase (p<0.05). The main polyphenols in the two cultivars were identified as chlorogenic acid, rutin, and (-)-epigallocatechin gallate, among which chlorogenic acid showed a significant decrease (p<0.05) as ripening and storage progressed. A strong correlation was found between total phenolic and flavonoid content (R=0.744), and ABTS radical scavenging activity (R=0.975). Additionally, a negative correlation was shown by lycopene and chlorogenic acid (R= -0.934).

• Food Engineering Progress
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• v.22 no.4
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• pp.374-380
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• 2018

Aronia has low preference because of astringent and bitter taste. Appropriate processing is essential for eating aronia. For the processing of aronia, the aim of this study is to provide basic information on the cultivar and ripening stages. Three varieties (Viking, Nero and McKenzie) were studied. We divided the stages of maturity into four levels based on color. The physicochemical properties were analyzed. In the case of hardness, the first stage of maturity was the highest, and there was no difference between varieties. As maturation progressed, brightness and yellowness gradually decreased, and redness was highest at the second stage. The sugar content was the lowest in the Viking and significantly increased with the maturity stage. The acidity was highest in the Viking. Nero showed the highest radical scavenging ability. Total polyphenols and flavonoids were the highest in Nero. The highest level was shown at the first stage by the ripening stage.

• Horticulture, Environment, and Biotechnology : HEB
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• v.59 no.6
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• pp.787-804
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• 2018

Flavor quality is import for determining consumer perception and acceptance of tomato products. In this study, 'Fendou' tomato fruit were harvested at six ripening stages and sampled to investigate the development of flavor-relevant compounds during vine ripening. Results showed that upon the initiation of ripening there was an increase in respiration rate and concomitant ethylene evolution that was associated with increased membrane permeability. In accordance with these physiological changes, flavor-relevant compounds demonstrated different expression patterns as fruit ripened, which contributed to 'red-ripe' flavor characteristics of red-ripe fruit. Based on correlation analysis between ethylene evolution and the flavor-relevant compounds during 'Fendou' tomato ripening and the other researchers' reports, the activation of System 2-dependent autocatalytic ethylene production plays an important role in the development of most flavor-relevant compounds during tomato vine ripening. Overall, our results suggested that most flavor-relevant compounds that accumulated the most during tomato fruit ripening at red stage could be under ethylene regulation and were among the most important contributors to the 'red-ripe' flavor. Due to the development of these compounds, the flavor quality at late ripening stages is different from that of fruit at early ripening stages.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.229-229
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• 2017

This research study was conducted to analyze the characteristics of different rice cultivars in abnormal temperature conditions (low temperature) for ripening period abnormalities, and to investigate the physiological causes behind the abnormalities. Four Korean high quality japonica-type rice cultivars, Jinbu (JB), Junamjosaeng (JJ), Geumyoung (GY), Hwawang (HW) were used in the experiment. The following day after flowering, they were then moved into two phytotrons under natural daylight with 65% RH but controlled at different temperatures - one at $19/29^{\circ}C$ (night/day) and the other at $13/23^{\circ}C$ as the low - temperature study on ripening. For the cultivars at $13/23^{\circ}C$ (low temperature study), JB and JJ had a ripening rate of 93% which is similar to the ripening rates of cultivars at $19/29^{\circ}C$ at 45 days after heading (DAH). In contrast, GY and HW recorded lower ripening rates of 86% and 57% respectively. However, when the cultivars at $13/23^{\circ}C$ were harvested at 61 DAH (when the accumulated temperature reached $1100^{\circ}C$), the difference in ripening rates compared to the 4 cultivars of $19/29^{\circ}C$ harvested at 45 DAH was not obvious (JB 94%, JJ 97%, GY 97%, HW 88%). Starch content showed little difference among the 4 cultivars at different temperature conditions while amylose content was higher for cultivars at $13/23^{\circ}C$ compared to those at $19/29^{\circ}C$. In addition, the enzyme activities of starch biosynthesis were about 5~10 days slower in cultivars at $13/23^{\circ}C$ compared to cultivars at $19/29^{\circ}C$. The grain-filling rate showed highly significant correlations with the enzyme activities of Sucrose synthase ($R^2=0.70^{***}$), ADP glucose pyrophosphorylase ($R^2=0.63^{***}$), UDP glucose pyrophosphorylase ($R^2=0.36^{***}$), Starch synthase ($R^2=0.51^{***}$), and Starch branching enzyme ($R^2=0.59^{***}$). Among the enzymes, Sucrose synthase activity had the highest correlation coefficient with grain-filling rate. In conclusion, the activity of enzymes such as Sucrose synthase, UDP glucose pyrophosphorylase, ADP glucose pyrophosphorylase, Starch synthase, Starch branching enzyme in starch biosynthesis is proven to be highly related to the grain filling process. Notably, the decrease in the activity of Sucrose synthase and Starch branching enzyme and the late increase in ADP glucose pyrophosphorylase activity at low temperature in the ripening stage are considered to be disadvantageous as they delay ripening and increased amylose content.

• Journal of Bio-Environment Control
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• v.29 no.1
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• pp.62-72
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• 2020

The purpose of this study was to investigate the quality characteristics of ripe fruit based on harvest date and to examine the ripening phase of 'Seolhyang' strawberry suitable for room temperature, cold-chain, and low temperature distribution. The strawberries were harvested six times between December 20 to May 9. The appropriate maturity of strawberries is characterized by the firmness of approximately 2.9-3.0 N, and SSC remained above 8.6 °Brix until March and declined after April. The quality index values that determine the maturity stage of strawberries should be red color, Hunter a value ranging from 32 to 37, and hue angle of 36-45℃. For the after-ripening experiment, the progression rate of the ripening stage determined based on strawberry color was 10%/day at room temperature, 5%/day at 10-12℃, and 3%/day at 5℃. Thus, strawberries should be harvested at 80% coloring stage for distribution at room temperature and at least 90% for low temperature storage to maintain the merchantability. Besides, strawberries harvested at 70% coloring stage at room temperature and strawberries harvested below 80% coloring stage at low temperatures below 5℃ had lost commercial value before reaching 100% coloring stage.