• Horticultural Science & Technology
• /
• v.28 no.4
• /
• pp.545-551
• /
• 2010

The primary objective of this study was to determine the relationship between fruit quality characteristics and pithiness fruit occurrence for confirming occurrence factors of pithiness tissues in 'Niitaka' pears ($Pyrus$ $pyrifolia$ Nakai). Fruits were harvested 4 times in 1 week intervals from 160 days after full bloom (DAFB) to 181 DAFB. Harvested fruits were separated with the specific gravity by Archimedes laws. Also, with specific gravity level in pear fruit, sugar content, acidity, and texture profile analysis (TPA) were investigated. Final verifiability of pithiness fruit was approved by eye observation at 90 days after storage. Also, in ASS (Alcohol Soluble Solid) and AIS (Alcohol Insoluble Solid), calcium contents were investigated. Although the differences in sugar and organic acid content were not significant in fruits divided by gravity, flesh hardness was depressed in fruits that showed low gravity. These results were more conspicuous in late harvested fruits (at 174 and 181days after full bloom) which showed low gravity, representing less content of AIS content and calcium in ASS and AIS when compared with early harvest fruits. Fruits of lower gravity below 1.0 measured with dipping induced the progression of pithiness symptom up to 76%. Consequently, harvest timing is a more concise factor in pithiness fruit occurrence although those symptom also affected by storage condition. Furthermore, the cause of pithiness fruit occurrence by late harvest is due to the lower cell wall binding calcium.

• Food Science and Preservation
• /
• v.5 no.4
• /
• pp.350-354
• /
• 1998

This paper was investigated to changes of cell components during drying for studies on the softening of jujube fruits. The contents of alcohol-insoluble material, cell wall and water-soluble material were not changed at 6 days of drying, but alcohol-insoluble materials and cell wall were decreased at 9 days of drying, however water-soluble materials were increased. Pectin and hemicellulose were not changed at 6 days of drying. Pectin and alkali-soluble hemicellulose were remarkable decreased at 9 days of drying, but acid-soluble hemicellulose was increased. Water-soluble pectin was not changed at 6 days of drying, but increased at 9 days of drying. EDTA-soluble and insoluble pectin were decreased after 6 days of drying. The non-cellulosic neutral sugars were not changed at 6 days of drying. The contents of arabinose, galactose and total neutral suger were decreased at 9 days of drying.

• Korean Journal of Food Science and Technology
• /
• v.39 no.1
• /
• pp.7-13
• /
• 2007

The changes in phenolic compounds and pectin content were investigated during the growth of 3 cultivars (Hosui, Niitaka and Chuwhangbae) of Asian pear (Pyrus pyrifolria) fruits. The amounts of total phenolic compounds in peel, flesh and core was 20.61-22.98mg/g, 0.87-1.23mg/g and 6.39-37.96mg/g during early growth, respectively, and decreased with pear growth. Arbutin, chlorogenic acid and epicatechin were detected in each part of all three cultivars during early growth; of these, arbutin content was the highest. Caffeic acid, catechin and 4-hydroxymethyl benzoic acid were detected in the peel and core during the ripening process. The total pectin content in the flesh of Hosui, Niitaka, and Chuwhangbae cultivars decreased from 5.93mg/g, 5.99mg/g and 5.40mg/g to 1.07mg/g, 1.60mg/g and 1.63mg/g, respectively. Of the soluble pectins, the hydrochloric acid-soluble pectin content was the highest, 3.21-3.45mg/g, and decreased during growth.

• Food Science and Preservation
• /
• v.13 no.3
• /
• pp.397-403
• /
• 2006

This experiment was conducted to examine the changes in polysaccharide concentration and morphological variation of Fomitopsis pinicola mycelium during submerged-culture in the citrus peel medium (CP). On the 12 days culture, the yields of mycelium and alcohol insoluble substance were 40.21%(w/v) and 6.94%(w/w), respectively, which were much higher than 11.29%(w/v, wet basis) and 3.17%(w/w, wet basis) obtained from YM medium. A large amount of acid soluble polysaccharides was derived from YM medium while a larger amount of alkali soluble polysaccharide was produced from CP medium. Yields of the mycelium were higher when cultured in CP medium However, there was no significant difference in formation of membranous vesicle between mycelia cultured in CP medium and YM medium. It was also observed that the formation of vacuole was closely related to the activation of the multivescular body known as cytolysome. As a result activation of mycelium and cell wall biosynthesis were more accelerated in CP medium.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.9
• /
• pp.1450-1458
• /
• 2005

Quality characteristics of mul-kimchi prepared using eastern deep seawater added with $0.1\%$ chitosan-ascorbate (CA) were investigated during fermentation for 12 days at $10^{\circ}C$, in an effort to effectively utilize the eastern deep seawater in Korea. Four water sources were considered for preparation of mul-kimchi; (1)distilled water added with $1\%$ mineral salt (DW), (2) eastern deep seawater (containing $6\%$ salt) diluted to $1\%$ salt concentration with distilled water (ED), (3) DW+CA (DW-CA), and (4) ED+CA (ED-CA). Juice of mul-kimchi prepared with ED-CA as a water source showed higher PH and antioxidant activity, and lower acidity, total microbe numbers, turbidity and alcohol insoluble substance compared with those Prepared with other three water sources. The former also showed higher overall acceptability compared with the latter. This study demonstrated the possibility of use of eastern deep seawater added with chitosan-ascorbate as a water source for extension of shelf-life of mul-kimchi.

• Food Science and Preservation
• /
• v.14 no.5
• /
• pp.526-530
• /
• 2007

The effects of kwamaegi (0, 6, 12 and 18%, all w/w) on the quality characteristics of Kimchi during fermentation at $10^{\circ}C$ were investigated. The mixtures are denoted KK. The late of decrease in pH during KK fermentation was lower than that of control. The number of total microbes (T) in Kimchi controls fermented for 14 days did not differ, and were in the range of $8.64{\sim}8.68\;log\;CFU/g$, whereas the numbers of lactic acid bacteria (L) in KK were higher than in controls. The L/T(%) was 78.41 in control, 85.76 in 6% KK and $93.68{\sim}94.25%$ in the 16% or 18% KK samples. The hardness of tissue ($2.98{\sim}3.66{\times}10^7\;dyne/cm^2$) in KK fermented for 14 days was higher than that of control ($2.67{\times}10^7\;dyne/cm^2$). The content of alcohol-insoluble substances in KK juice (1.281.08 g/100 g) was lower than that of control (1.45 g/100 g). In sensory evaluation, the appearance and texture of KK were better than those of control. Although some fishy flavor was noted in KK, this did not affect acceptability. Sourness was less, whereas ripened taste and overall acceptability were higher in KK (especially 12% KK) compared to control.

• Horticultural Science & Technology
• /
• v.30 no.4
• /
• pp.345-356
• /
• 2012

We investigated the changes of fruit quality parameters, polysaccharide contents and cell wall components during maturation and ripening of two Korean pear cultivar 'Hanareum' and 'Manpungbae' compared with 'Niitaka' pear (Pyrus pyrifolia Nakai) which showed different physiological maturity based on days after full bloom (DAFB). Flesh firmness decreased continuously with fruit development and maturation, reaching a final level of 29.4, 33.5, and 27.4N at maturity in 'Hanareum' (127 DAFB), 'Manpungbae' (163 DAFB), and 'Niitaka' (170 DAFB), respectively. The level of ethylene production was very low in early season 'Hanareum' pear which showed at most 0.39 ${\mu}L{\cdot}L^{-1}$ at maturity and no ethylene was detected in 'Manpungbae' and 'Niitaka' at maturity. Fructose was the most abundant soluble sugar during fruit maturation in the pears tested and an increase of sucrose was observed during fruit ripening in the Asian pears commonly. Ethanol insoluble solids (EIS) content decreased gradually with different levels among the pear cultivars as fruit ripens consisted of 10.79, 12.72, and 12.75 $mg{\cdot}g^{-1}$ FW. The amount of total soluble polyuronides was higher in early season cultivars 'Hanareum' than those of mid-season cultivar 'Manpungbae' and 'Niitaka'. In 'Niitaka' which harvested most late season, the level of 4% KOH soluble hemicelluloses was lower than 'Hanareum' and 'Manpungbae' and maintained constantly during fruit ripening period. Cellulosic residues were determined high level in 'Niitaka' which showed 612.33 ${\mu}g{\cdot}mg^{-1}$ EIS at maturity when compared with 'Hanareum' (408.0 ${\mu}g{\cdot}mg^{-1}$ EIS) and 'Manpungbae' (538.67 ${\mu}g{\cdot}mg^{-1}$ EIS). The main constituents of cell wall neutral sugars which consisted of arabinose, xylose, galactose, and glucose were decreased gradually with onset of fruit ripening regardless of cultivar. Arabinose which was predominant in 'Hanareum' pear decreased at the last stage of ripening, but the changes of cell wall neutral sugar during ripening were not occurred in 'Niitaka' pear. The change of molecular mass distribution in water soluble pectin observed dominantly at the early stage of fruit development. Depolymerization of 4% KOH-soluble hemicelluloses and degradation of xyloglucan showed in early-season cultivar 'Hanareum' during fruit maturation, and degradation of those fractions were detected only at the early stage fruit development in mid-season cultivar 'Manpungbae' and 'Niitaka'. The molecular mass profile of CDTA soluble pectin, $Na_2CO_3$-SP and 24% KOH soluble hemicelluloses showed no significant change during fruit maturation regardless of cultivar.

• Journal of Bio-Environment Control
• /
• v.26 no.4
• /
• pp.378-385
• /
• 2017

In this study, we evaluated the changes of fruit quality indices during fruit development and ripening in Korean new pear cultivar 'Changjo', developed from a cross between 'Tama' and '81-1-27' ('Danbae' ${\times}$ 'Okusankichi') in 1995 and named in 2009, to determine appropriate harvest time and to enhance the market quality and broaden the cultivation area. The fruits of 'Changjo' pears harvested from 132 days after full bloom (DAFB) to 160 DAFB. Fruit growth and quality indices were monitored at 1 week interval by measuring fruit weight, length, diameter, firmness, and taste related quality indices. The calculated fruit fresh weight increased continuously with fruit development and reached to an average of 594g on Sep. 20 (160 DAFB). The ratio of length to diameter declines as fruit maturation progress, resulting in 0.898 for ripe fruit stage as a round oblate shape. Flesh firmness of 'Changjo' pears showed over 30N until 153 DAFB and then decreased abruptly with fruit ripening, reaching a final level of about 26.44N on 160 DAFB. Starch content of fruit sap was also decreased abruptly after 146 DAFB which decreased almost half of the fruits harvested at 139 DAFB. In parallel with the decrease of flesh firmness, ethanol insoluble solids (EIS) content decreased sharply with fruit ripens, only 50% of EIS was detected on the fruits harvested on 160 DAFB when compared to that of the fruits harvested on 139 DAFB (Aug. 30). The maximum value of soluble solids contents was observed in the fruits harvested on 153 DAFB, resulting in $14.2^{\circ}Brix$. The changes of skin color difference $a^*$ which means loss of green color occurred only after 139 DAFB, coincide with the decrease of SPAD value of the fruit skin. The sugars of the 80% ethanol soluble fraction consisted mainly of fructose, sorbitol, glucose and sucrose, also increased during maturation and ripening. Fructose and sucrose contents were larger than those of glucose and sorbitol in flesh tissues. These results were explained that stored starch is converted to soluble sugars during fruit maturation, mainly in fructose and sucrose increasing the sweetness of this cultivar. Total polyphenols were increased up to middle of fruit maturation (146 DAFB) and then decreased continuously until the end of fruit maturation. Consequently, our results suggested that the commercial harvest time of 'Changjo' pears should not be passed 153 DAFB and late harvest of this cultivar would not good for quality maintenance during shelf-life. As a result of the post-harvest low-temperature acclimation experiment during the short-term transportation period, fruits harvested at 146 DAFB tended to maintain higher firmness after 14 days of simulated marketing at $25^{\circ}C$ compared to fruits harvested at 153 DAFB regardless of temperature set. And, the slower the rate of decrease to the final transport temperature of $5^{\circ}C$, the higher the incidence of internal browning and ethylene production. Therefore, in order to suppress the physiological disorder and to maintain the fruit quality when exporting to Southeast Asia in the 'Chanjo' pears, it is desirable to lower the temperature of the fruits within a short time after harvest and to set the harvest time before 146 days after full bloom.