• Korean Journal of Agricultural Science
• /
• v.27 no.2
• /
• pp.81-85
• /
• 2000

In order to find a proper storage temperature and times for vegetable waxy corn, several waxy hybrids used in the study. Among waxy hybrids, stem height and ear length of Daehakchal and Eulrukchal hybrides were higher than Chalok#1 and #2 used as a check, but flowering daus were later about 7 days than check. Sugar content of Daehakchal was not almost changed at $-4^{\circ}C$ and below, whereas it was rapidly decreased at $4^{\circ}C$. Most hybrids with high sugar content were fast converted into starch than lower content hybrid. While moisture contents of waxy hybrids used were almost constant regardless of storage temperature in vegetable com packaged with poly ethylene vinyl. From these results, storage temperature of vegetable waxy corn was recommended at least $-4^{\circ}C$ below. Under the $-10^{\circ}C$ and below, storage period of vegetable waxy corn could prolong 60 days and above because sugar and moisture content of vegetable corn measure at $-10^{\circ}C$ and $-20^{\circ}C$ were almost no changed compared with those of fresh corn measured at harvest.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.64 no.2
• /
• pp.102-108
• /
• 2019

Pericarp thickness of vegetable corns such as sweet and waxy corn is one of the crucial traits, contributing to their edible quality. This study was carried out to compare the pericarp thickness of super sweet and waxy corn hybrids measured with kernel samples prepared using different methods at different grain filling periods. The samples comprised excised pericarp from dried, frozen (at $-4^{\circ}C$), and fresh kernels. Analysis of variance performed separately on super sweet and waxy corn hybrids indicated a significant three-way interaction among cultivars, kernel sample preparation methods, and days after pollination (DAP). Dried samples of super sweet corn hybrids presented reasonably stable pericarp thickness measurements during grain filling, while all the sample preparation methods fluctuated less as grains of waxy corn hybrids matured. Waxy corn is best consumed at around 24 days after pollination. Pericarp thickness of waxy kernel samples regardless of preparation methods investigated was the same at 24 DAP with a few exceptions. Overall, the common method of drying kernel samples before pericarp excision can provide reliable data for estimating the tenderness of vegetable corn hybrids.

• Food Science and Preservation
• /
• v.3 no.1
• /
• pp.55-60
• /
• 1996

To obtain the basic data on precooling effects for establishment the suitable postharvest handling technique or method of keeping high quality of vegetalble corn, the sweet, supersweet and waxy corn, (Danok #2, Cocktail #86 and Chalok #1), being mainly consumed as vegetables in Korea, were precooled with ice or vacuum cooling method immediately after harvest. The vacuum cooling was the most effective for the field heat removal of vegetable corn. It took only 30 min. at 4 to 5 torr of cold chamber pressure of vacuum precooler to lower the corn temperature from 30 to 2$^{\circ}C$. The ice cooling was also thought to be a useful precooling method with relatively short cooling time of 6 hrs. The vegetable corn treated with vacuum or ice cooling showed low and stable respiration rates of 25.5 to 43.5 CO2 mg/kg/hr. when stored at 0∼2$^{\circ}C$ while the samples stored at room temperature (20∼25$^{\circ}C$) without precooling were as high as 64.1 to 245 CO, mg/kg/hr.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.44 no.3
• /
• pp.267-272
• /
• 1999

In order to determine the optimum harvest time of vegetable corns, the changes in sugars, soluble solids, and flavor of kernels of sweet (cv. ‘Golden Cross Bantam 70’), super sweet (cv. ‘Cocktail E-51’), and waxy corns (cv. ‘Chalok 2’) were observed at different ripening stages. Sucrose was a major sugar in the sweet and super sweet corns and the content increased from 15 to 21 and 27 days after silking (DAS), respectively and then decreased. Glucose and fructose contents of sweet and super sweet corns tended to decrease with kernel maturity. Total sugar content of the sweet corn analyzed by the anthrone method increased rapidly from 15 to 21 DAS, while that of the super sweet and the waxy corns increased slowly up to 24 and 26 DAS, respectively and decreased thereafter. The content of soluble solids in sweet corn was much higher than that of super sweet corn. Starch content of the sweet corn increased slowly from 15 to 33 DAS, while that of the super sweet corn increased a little rapidly from 15 to 21 DAS and then leveled off to 33 DAS. Starch content of the waxy corn increased continuously from 21 to 38 DAS. There was a positive correlation between the sum of individual sugars (sucrose, glucose, and fructose) and soluble solids in both sweet and super sweet corns, while the content of soluble solids was not related to the sum of individual sugars or total sugars. The flavor rate of sweet and super sweet corns maintained high between 21 and 27 DAS and that of waxy corn decreased from 24 to 33 DAS. The optimum harvest time for sweet, super sweet, and waxy corns was thought to be 21 to 24 DAS considering sugar and starch contents, flavor, and marketing.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.39 no.1
• /
• pp.73-78
• /
• 1994

This experiment was carried out to investigate the major characteristics associated with the flavor rate and their changes according to days after silking of super sweet corn(Cocktail 86) for vegetable and waxy corn(Chalok 1). Ear elongation finished around 22∼24 days after silking. In kernel development, elongation was much more prominant in super sweet corn than that in waxy corn but thickness was vice versa. Pericarp thickness and kernel hardness of super sweet corn were slightly increased but those of waxy corn were increased rapidly as the ears matured. Moisture and sucrose content of super sweet corn remained high but the waxy corn was not. The reducing sugars(glucose, fructose) were relatively high at the early maturity stage but they were decreased as the ears matured and negatively correlated with sucrose and flavor rate. Soluble solids (Brix %) were positively correlated with sucrose and total sugar(sucrose+ glucose+fructose) content in waxy corn but not in super sweet corn and was considered as inappropriate criate criterion to envaluate the sugar content and flavor rate. Pericarp thickness and sucrose content were positively correlated with the flavor rate in both hybrids but total sugar content, and kernel hardness were positively correlated with flavor rate in super sweet corn and waxy corn respectively.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.57 no.2
• /
• pp.195-201
• /
• 2012

It is important to determine the optimum harvesting time that impact decisively on the quality of vegetable waxy corns. In general, it takes 20~25 days from silking to harvest according to ecotype when waxy corn hybrids were sown in April. We identified the optimum harvesting time by the ecotypes and seeding dates for the establishment of corn double cropping system of waxy corn. It takes 23~25 days from silking to harvest regardless of ecotype, when waxy corns were sown at early in April or late in June. It takes 28~31 days when Chalok1, early maturing type, was sown between in July 10, and in July 30. It takes 29~31 days when Ilmichal, medium late maturing type, was sown between in July 10 and in July 20, but 39 days were required when sown at in July 30. The cumulative temperature for harvesting was about $1700^{\circ}C{\sim}2100^{\circ}C$. The minimum cumulative temperature from seeding to harvest was approximately $600^{\circ}C$. These results will be helpful to the farmers for determining the optimum harvest time of vegetable waxy corns.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.42 no.1
• /
• pp.95-103
• /
• 1997

This experiment was carried out to obtain the basic information necessary to establish suitable postharvest handling techniques and to keep high quality of the sweet(Danok 2), supersweet(Cooktail 86) and waxy(Chalok 1) corn which are mainly consumed as vegetable in Korea. Vegetable corns were cooled with ice fragments in the insulation box immediately after harvest and stored in low temperature warehouse at 0 to 2$^{\circ}C$. During the 15 days short-term storage, changes of chemical components were compared with those of uncooled corns. The losses of moisture in kernels were as high as 7.4 to 24.4％ in uncooled corns while those of ice cooled corns increased 0.4 to 0.5％ of their weight. The ratio of pericarp and alcohol insoluble solid(AIS) content increased as the storage days prolonged in all treatments but increasing rates were much higher in uncooled samples. On the other hand, the total sugar loss during storage was the least in supersweet corn when they were cooled with ice fragments in insulation box. After 5 days storage, the ice cooled samples showed the highest free amino acid contents compare to those of uncooled and stored at room temperature (25 to 3$0^{\circ}C$) or low temperature warehouse, and ${\gamma}$-aminobutylic acid (GABA) which was known as a fuctional amino acid was detected in all three kinds of vegetable corns.