• Journal of Korean Society of Forest Science
• /
• v.95 no.2
• /
• pp.174-176
• /
• 2006

The experiments were conducted by supplying hosts with natural food(chestnut, peach, Quince). The developmental difference of peach pyralid moth, Dichocrocis punctiferalis was examined in the laboratory under three different natural food regime. The periods of egg, larva and pupa were $6.01{\pm}0.07$, $12.23{\pm}0.03$ and $13.32{\pm}0.01$ days on the chestnut fruit, $6.21{\pm}0.01$, $18.69{\pm}0.02$ and $13.38{\pm}0.03$ days on the peach fruit and $7.02{\pm}0.04$, $22.62{\pm}0.04$ and $13.44{\pm}0.14$ days on the quince fruit, respectively. The growth of D. punctiferalis larva was better chestnut fruit than other tested fruits. The rates(%) of hatching, pupation and emergence were 94.0, 57.0 and 63.3 on the chestnut fruit, 89.2, 77.8 and 85.7 on the peach fruit and 79.6, 52.6 and 70.7 on the quince fruit, respectively. The survival rate(%) of D. punctiferalis from hatching to emergence were 31.0 on the chestnut fruit, 4.8 on the peach fruit and 14.3 on the quince fruit, respectively. The sex ratio (female: male) of all pupae obtained on the tested natural food fruits were 52.7 : 47.3. The sex ratio of D. punctiferalis reared on three difference food fruits were no significantly. It can be used a as the basic research for the study of D. punctiferalis.

• Food Science and Biotechnology
• /
• v.18 no.3
• /
• pp.808-812
• /
• 2009

The ${\alpha}-glucosidase$ inhibitory and antioxidant effects of water chestnut (Trapa japonica Flerov.) were assessed to explore its possible use as an anti-diabetic agent. Methanol extracts of the fruit shell and meat of water chestnut were assayed for inhibitory activity against yeast ${\alpha}-glucosidase$ and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. Effect of fruit shell extract on postprandial glucose response was assessed. Compared with fruit meat, shell extract showed stronger inhibition against ${\alpha}-glucosidase$ with an $IC_{50}$ of 273 ${\mu}g/mL$. Oral administration of fruit shell extract (500 mg/kg) significantly lowered the postprandial area under the glucose response curve to starch (1 g/kg) in streptozotocin (STZ)-induced diabetic rats (p<0.01). Compared with fruit meat, shell extract showed stronger scavenging activity against DPPH, with an $IC_{50}$ of 27.1 ${\mu}g/mL$. The results indicate that the fruit shell of water chestnut was effective in controlling postprandial hyperglycemia and exerted an antioxidant effect. Therefore, water chestnut may be useful in treating diabetes.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 2003.10a
• /
• pp.69.2-70
• /
• 2003

For the selection and breeding of chestnut varieties resistant to the chestnut blight fungus Cryphonectria parasitica, disease resistance and susceptibility of 28 varieties widely planted and growing in Korea were evaluated by artificial inoculation of a pathogenic fungus. For this experiment, a typical virulent strain (KCPC-19) was selected. Artificial inoculation was conducted into all varieties by using two different materials and methods, i.e., bark and wood tissue sections in the laboratory and living trees in the field. In the bark and wood tissue section method, the size of necrotic area and canker development on chestnut varieties were examined and compared 4 days after inoculation. There were wide variations of chestnut varieties in disease resistance and susceptibility against chestnut blight fungus, but 3 varieties, Daebo！, Ishizuchi, and Sandae, were shown to be relatively resistant to the disease with the necrotic area of 0.95-1.03 cm2, while Arima was the most susceptible with the size of 2.0 cm2. In the living tree inoculation examined 5 weeks after inoculation, 3 varieties, Daebo, Ishizuchi, and Riheiguri, showed the higher resistance, but Tono 2 did the highest susceptibility among tested varieties.

• Korean Journal of Food Science and Technology
• /
• v.30 no.3
• /
• pp.717-720
• /
• 1998

Some physico-chemical components of Chinese water chestnut were analysed to provide fundamental data for water chestnut processing and products development. The contents of moisture, crude protein, crude lipid, crude ash, crude fiber and carbohydrate of Chinese water chestnut were 79.40%, 1.74%, 0.06%, 1.10%, 0.60% and 17.71% respectively. Free sugars identified in Chinese water chestnut juice were sucrose 8.58%, glucose 1.64% and fructose 1.58% as major component and maltose as trace component. The proportion of major free sugars to total soluble solid content of juice was about 66.0%. Potassium content in Chinese water chestnut was 408.57 mg% as major mineral, iron and manganese content were 0.21 mg% and 0.08 mg% as minor mineral. $Vitamin\;B_1$ and C content were $31.2\;{\mu}g/100\;g$ and trace respectively. Organoleptic properties of Chinese water chestnut were fresh fruit odor and sweet taste as main flavor. Though water chestnut was boiled for 20 min, crunchy texture of flesh was almost maintained.

• Korean Journal of Plant Resources
• /
• v.27 no.1
• /
• pp.72-79
• /
• 2014

This study was investigated the changes in quality of peeled chestnut according to peeling method, including abrasion and knife, and 3 kinds of storage temperatures. The weight loss rate of peeled chestnut during storage period was observed in all treatment groups, peeling methods showed no difference of the loss. However, the moisture content of peeled chestnut during storage in all treatments showed a tendency to decrease. Moisture content of the abrasion peeled chestnut in all treatments was higher than that of the knife peeled chestnut. In the case of a, b, and ${\Delta}E$ value of peeled chestnut chromaticity increased during storage in all treatments, whereas, L values decreased during storage. But, browning of abrasion peeled chestnut was higher than that of the knife peeled chestnut. The hardness of the abrasion and knife peeled chestnuts were the highest in $-1^{\circ}C$ storage, soluble solid content was decreased with storage time in all treatments, but showed a tendency to increase within 24 days. Palatability and texture of peeled chestnuts decreased in all treatments during storage period, 15 days after storage decreased rapidly. Thus, results showed that peeled chestnuts stored at $4^{\circ}C$ and $2^{\circ}C$ were rapidly decreased in the quality after 15 days, whereas, peeled chestnuts stored at $-1^{\circ}C$ slowly decrease in the fruit quality. It can be recommended that chestnut in vacuum film is good to maintain at $-1^{\circ}C$ storage for 15 days. Also, if we can reduce the browning of abrasion peeled chestnut, we will produce peeled chestnut of high quality.

• Korean journal of applied entomology
• /
• v.41 no.2
• /
• pp.107-112
• /
• 2002

Seasonal occurrence pattern of the peach pyramid moth (PPM), Dichocrosis punctfferahs, was studied by sex pheromone traps and mercury light traps in several Fuyu persimmon orchards under different control pressures in southern region of Korea in 2000 and 2001. Fruit damage by the larvae was also checked at harvesting time from 1999 to 2001. The pattern showed 3 distinct peaks; the 1st one in mid to late June, the 2nd one in mid to late August, and the 3rd one in late September. Number of PPM catches was higher in less controlled than in intensively controlled orchards. There were no persimmon fruits damaged by the larvae of PPM and persimmon fruit moth, Stathmopoda masinissa, in our samples from the testing orchards at harvesting time. Therefore, it is unlikely that these two quarantine pests are included in the exporting fruits. Considering flora adjacent to the tested orchards and zero levels of fruit damage by the larvae, there is a strong possibility that the moths flew from neighbouring chestnut trees or other host plants to be attracted to the traps in the persimmon orchards.

• Korean journal of applied entomology
• /
• v.53 no.4
• /
• pp.339-346
• /
• 2014

To control populations of the chestnut weevil, Curculio sikkimensis Heller, the effects of various immersion temperatures and times on the chestnut weevil were tested. The effects of immersion treatments on chestnut fruits were also analyzed. The mortality levels of C. sikkimensis larvae were evaluated at various temperatures ($30^{\circ}C$, $35^{\circ}C$, $40^{\circ}C$, $45^{\circ}C$, and $50^{\circ}C$) and time intervals (1, 2, 3, 5, 7, 10, 15, 22, and 24 h). Changes in the chestnut fruit due to the immersion treatment were measured in terms of color (lightness, redness, and yellowness), physiological effects (germination rate and decay rate), hardness, and change in constituent properties (moisture content, free sugar content, and tannin content). Mortality levels of C. sikkimensis larvae after immersion treatment at $30^{\circ}C$ were over 70% and 100% after 2 h and 7 h, respectively. Color (lightness, redness, and yellowness) of the chestnut fruits was not significantly different at $30^{\circ}C$ and $35^{\circ}C;$ however, the color was affected at temperatures over $40^{\circ}C$. The germination rate of the fruit was not affected by the immersion treatments, but the decay rate at $40^{\circ}C$ increased with an increase in immersion time. The hardness of the fruits decreased with an increase in immersion times and temperatures. These results can be used in the future for developing methods for the control of chestnut weevil populations.

• Korean journal of applied entomology
• /
• v.50 no.4
• /
• pp.379-382
• /
• 2011

The damage rates of peach pyralid moth(Dichocrocis punctiferalis), which damages the chestnut fruits, were investigated annually from 1995 to 2010 according to year, region, and maturity. The damage rate by D. punctiferalis was the highest (34.5%) in 1998 and was the lowest (17.9%) in 2000. The pattern of the damage rate showed a repeating three-year cycle. There was a negative correlation ($-0.6261^*$) between rainfall and damage rate. There was a positive correlation ($0.5826^*$) between temperature and damage rate. The average damage rate of all surveyed regions was 22.2%. Of the surveyed areas, Hapcheon had the highest at 27% and Hamyang had the lowest at 15.0%. The damage rate of chestnut fruit depending on the maturity was 26.1% in an early maturing cultivar (Dantaek), and 19.3% and 21.1% in a late maturing cultivar (Eungi) and a medium maturing cultivar (Chukpa), respectively.

• Journal of Korean Society of Forest Science
• /
• v.101 no.4
• /
• pp.567-573
• /
• 2012

This study was carried out to examine the effect of soil amendment treatments [(organic fertilizer: 20 kg $tree^{-1}$; compound fertilizer+wood-char fertilizer: compound fertilizer 4 kg $tree^{-1}$+wood-char 2 kg $tree^{-1}$; lime fertilizer: 3 kg $tree^{-1}$; mixed fertilizer: compound fertilizer 1 kg $tree^{-1}$+organic fertilizer 10 kg $tree^{-1}$+wood-char 1 kg $tree^{-1}$; control (no fertilizer)] on flowering and fruit characteristics in chestnut (Castanea crenata S. et Z.) orchards in Jinju and Sancheong, Gyeongsangnam-do. Diameter of fruiting shoot increased generally after soil amendment treatments compared with the control, while number of leaf, female and male flowers were not affected by the treatments. Nut weight increased after soil amendment treatments in Jinju, but was not affected by the treatments in Sancheong. There was a positive correlation between soil pH (r=0.91) or exchangeable $Ca^{2+}$ (r=0.99) and nut weight in Jinju and a positive correlation (r=0.97) between organic carbon content and soluble solid concentration, while a negative correlation (r=-0.92) between exchangeable $Mg^{2+}$ and soluble solid concentration of nuts in Jinju. However, the nut weight and soluble solid concentration in Sancheong were not correlated with soil properties. The results indicate that the characteristics of flowering and nuts in chestnut orchards depend on soil properties after soil amendment treatments between regions which show better responses on poor sites than on good sites.

• Journal of Korean Society of Forest Science
• /
• v.105 no.1
• /
• pp.93-102
• /
• 2016

This research was conducted for major cultivated chestnut (Castanea spp.) in Korea to compare chestnut quality characteristics according to storage temperatures ($4^{\circ}C$ vs. $-1^{\circ}C$) and cultivars. Color, hardness, soluble solids content (SSC), rate of decay and sensory evaluation were investigated during 16 weeks storage. Cultivars 'Tsukuba' and 'Ishizuchi' showed the least pericarp color change while cultivars 'Riheiguri' and 'Daebo' showed the most pericarp color change during storage. Chestnut fruits stored at $-1^{\circ}C$ showed less pericarp color change than those stored at $4^{\circ}C$. Cultivars 'Arima' and 'Tanzawa' exhibited the decrease tendency of hardness with lowest hardness during storage at $-1^{\circ}C$. Chestnut fruits stored at $4^{\circ}C$ showed high hardness than those stored at $-1^{\circ}C$. Cultivars 'Riheiguri' showed the highest increase of SSC, while cultivar 'Arima' showed the lowest increase of SSC after 16 weeks of storage. The SSC increased in nuts from all cultivars at both temperatures, but nuts stored at $-1^{\circ}C$ showed higher increases in SSC than nuts stored at $4^{\circ}C$. Cultivars 'Ishizuchi' and 'Riheiguri' showed high rates of decayed nuts in contrast to cultivars 'Daebo', 'Okkwang' and 'Tanzawa' that showed low rates of decayed nuts during storage. The chestnut fruit stored at $-1^{\circ}C$ showed less decay than fruit stored at $4^{\circ}C$. Texture and sweetness were tested for sensory evaluation. Among the tested cultivars, 'Riheiguri', 'Daebo' and 'Tsukuba' showed hard texture and very sweetness, while 'Tanzawa' showed relatively soft texture. 'Arima' and 'Okkwang' showed weak sweetness during storage. Nuts stored at $4^{\circ}C$ exhibited harder texture than nuts stored at $-1^{\circ}C$ while $-1^{\circ}C$ exhibited more sweetness than nuts stored at $4^{\circ}C$. Chestnuts for hard texture and short-term storage (less than one month), $4^{\circ}C$ will be a proper storage temperature, while in order to store long-term (more than 4 month), $-1^{\circ}C$ will be a proper storage temperature. Result from this study provide base-line data of postharvest management for Korean cultivated chestnut as well as contributing increased product value and income for chestnut producers.