• Horticultural Science & Technology
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• v.17 no.1
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• pp.11-14
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• 1999

This experiment was conducted to estimate seasonal changes in the properties and chemical components of xylem sap from 'Hayward' (Actinidia chinensis Planch) and wild kiwifruit species (Actinidia aguta Sieb. et Zucc. Planch) in 1996 and 1997. Amount of bleeding sap from kiwifruit vines considerably decreased with collection time in both species. There was no difference in water content, soluble solid content, viscosity, and pH of the sap between 'Hayward' and wild species, while turbidity and organic acid contents were much higher in 'Hayward'. Fructose content was highest among free sugars, followed by glucose, sucrose, galactose and manitol in 'Hayward', but only low concentration of fructose and glucose was detected in wild species. The major inorganic components in the sap were calcium, potassium, and magnesium, and calcium was dominant among them. The saps of 'Hayward' and wild species were composed of 17 kinds of amino acids respectively, and major amino acids were glutamic acid, lysine, and isoleucine. Glutamic acid content was highest in both species and except histidine, contents of methionine and tyrosine were much higher in 'Hayward' than wild species. Concentrations of inorganic elements and amino acids were slightly increased with delaying collection time, but sugar contents decreased.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.6
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• pp.429-436
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• 2003

The relationship between seeding depth and apical hook opening was investigated in the hypocotyl hook of soybean (Glycine max Merr., cv. Hwanggeum). Seeds were sawn in different depths (2.5, 5.0, 7.5, and 10.0 cm). The hook opening was slowly progressed with seeding depth. Hook angle opening velocity was negatively correlated with hypocotyl growth at the significant level of P<0.01. It was also clearly observed that seeding depth was positively correlated with hypocotyl growth, suggesting the induction of hypocotyl growth by deep sawing. Futhermore, the contents of fructose and glucose in hypocotyls were about higher than in cotyledons. Both sugars in hypocotyls were highest at the emergence stage. After emergence, their levels were obviously reduced. Total soluble sugar contents continuously retained in cotyledons which were grown at 2.5 and 5.0 cm seeding depths whereas the contents in cotyledons of deep sawn soybean were extremely lowered. It seemed that sugars were actively used to cell construction during the hypocotyl elongation. The results demonstrated that apical hook opening is closely related with light signal after emergence. It implied that the delay of hook opening in deep sawn seeds was resulted from hypocotyl growth in darkness. We suggest that apical hook opening is progressed in sucrose catabolism by light.

• Korean Journal of Food Science and Technology
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• v.5 no.3
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• pp.183-187
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• 1973

Soong-Neung is a Korean traditional beverage served after meals and is made from Soong-Neung producing rice (Noo-Roon-Bap) which is cooked and toasted rice produced on the bottom of the container during the rice cooking process. In order to study the chemical changes occurring in Soong-Neung producing rice with temperature$(20{\sim}220^{\circ}C)$ during the cooking process, thermal analysis, total sugars, total nitrogen, reducing sugars, water soluble nitrogen, total acid, carbonyl content, phenolic compounds were determined. Thermal analysis showed that decrease of weight and endothermic reaction caused by evaporation of water in the sample appeared at $95{\sim}130^{\circ}C.$ The production of volatile compounds increased gradually beginning at $130^{\circ}C$, however, those compounds increased markedly at $160^{\circ}C$ and above. Maximum absorption of ultraviolet spectra of an aqueous distillate occurred at about $273m{\mu}$. Organoleptic analysis showed that an acceptable flavor was produced in the temperature range of $125{\sim}155^{\circ}C.$

• Food Science and Preservation
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• v.9 no.1
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• pp.61-66
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• 2002

Chemical composition of fresh and dried leaves and stems and fresh and cured tubers of bacon (Polymnia sonchifolia) was investigated. The moisture content of fresh leaves, stems, and tubers was 83.38, 92.30 and 89.52%, and there of dried leaves and stems were 18.08 and 27.97% and that of cured tubers was 27.97%. The content of lipid, protein, soluble solid, ascorbic acids chlorophyll and tannin was higher in leaves of yacon than in stems of that. In fresh and cured yacon, the content of protein were 0.04% both of them, of lipid was 0.31 and 0.54%; of ash, 0.40 and 0.42%; of ascorbic acids 2.77 and 2.87 mg/100 g. The major minerals of leaves, stem, and tubers of bacon were P, K, and Mg. The major free sugars of leaves, stems and tubers of bacon were glucose and fructose and after curing all free sugars of tubers of bacon were increased. The most abundant free amino acid was isoleucine in the leaves, stem, and tubers of bacon. The content of beta-carotene was 9.01 $\mu\textrm{g}$/100g in fresh leaves and 107.87 $\mu\textrm{g}$/100 g in dried leaves, and 0.40 $\mu\textrm{g}$/100 g in fresh tubers of bacon and 055 $\mu\textrm{g}$/100 g in cured tubers.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.869-875
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• 1997

The chemical components of Korean pollens and pollen extracts were analysed to provide fundamental data for pollen processing and products development. The contents of crude protein, crude lipid, crude ash, crude fiber and carbohydrate of pollens were $14.0{\sim}22.3%,\;3.0{\sim}8.8%,\;2.2{\sim}3.3%,\;0{\sim}37.5%,\;and\;31.9{\sim}64.4%$ respectively, showing the specially high crude fiber content (37.5%) in Pine pollen. Almost all the carbohydrate, lipid, protein and ash components except fiber were extracted by water and n-hexane. Free sugars identified in water extracts $(10\;^{\circ}Bx)$ of pollens were fructose and glucose as major component and maltose as minor component. The proportions of three free sugars to total soluble solid content of Mixed, Acorn, and Pine water extracts were 73.6%, 85.4% and 47.7% respectively. Potassium and phosphorus content in pollens and pollen water extracts were high, but Ca, Na, Mg, Fe and Zn were not major mineral components. The essential amino acids such as leucine, phenylalanine, methionine, lysine, valine, isoleucine and threonine were contained richly in pollens and those were almost completely extracted by water. Vitamin $B_1$ and C were not detected, but only small amount of vitamin $B_2$ was detected in the pollens and pollen extracts tested. The essential fatty acids such as linoleic acid and linolenic acid were contained richly in pollens. The proportion of unsaturated fatty acids to total fatty acid content in Mixed, Acorn and Darae pollen except Pine was higher than 50%.

• Food Science and Preservation
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• v.13 no.5
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• pp.589-595
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• 2006

Vitamin U (5-methylmethionine) levels of Chinese cabbages at $4^{\circ}C$ were investigated to establish its physiological characteristics and also amino acids and sugars levels to find out their relationship with vitamin U were determined The levels of vitamin U showed different from parts of Chinese cabbages. The highest value was shown in outward leaf in Wineter Pride (12.70 mg/100 g fresh wt.) and core leaf in 55 Days cultivars (18.60 mg/100 g fresh wt.). leaf pare were 1.7-9.0 times higher in vitamin U levels than those in midribs in both cultivars. levels of vitamin U in stored Chinese cabbages increased with storage time. Moreover, two cultivars used far this experiment showed different pattern during storage. In Winter Pride, vitamin U levels sharply increased in leaf and midrib of cote part during storage. This value reached about 2.5 times for leaf and 4 times for midrib compared to the levels of initial storage time in core part In 55 Days cultivars, outward leaf showed an increased level of vitamin U of 1.8 times compared to that of 1 month storage time. Methionine known as a precursor of vitamin U synthesis did not showed clear relationship with vitamin U levels. Methionine was either not detected or at negligibly low levels in Chinese cabbages during storage. Methionine may not play a role in an increase of vitamin U during storage of Chinese cabbages at $4^{\circ}C$. No clear relationship of free amino acids and soluble sugars for vitamin U accumulation during storage of Chinese cabbages was shown in this study.

• Food Science and Preservation
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• v.14 no.3
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• pp.227-232
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• 2007

The development of an effective long-term storage protocol for harvested fresh pepper is urgently required to increase the market for pepper products. The protocol must minimize quality loss, so that the product may be used either as a spice or as a raw material for processed pepper products, both in the home and in food processing plants. We investigated the optimum size of pepper fruits, freezing temperatures, storage periods, and thawing methods, to establish an optimum storage protocol. This study was conducted not only to develop freezing and thawing methods for long term storage of harvested red pepper, but also to develop processed pepper products utilizing the stored pepper. We aimed to expand the pepper products market and to increase the incomes of pepper growers. Whole red pepper, sliced red pepper, and crushed red pepper were frozen and stored at $-5^{\circ}C,\;-20^{\circ}C,\;or\;-40^{\circ}C$. The soluble solid content and the vitamin C level showed maximal stability at $-40^{\circ}C$, although total free sugars decreased on storage at all temperatures tested. Such Changes were more marked at $-5^{\circ}C$ than at the other(lower) temperature tested. The vitamin C content of whole red pepper was higher than that of sliced red pepper or crushed red pepper. Room-temperature thawing resulted in twice the drip loss seen on low temperature($5^{\circ}C$) thawing or microwave oven thawing. Brown discoloration was a serious problem with room temperature thawing. Total free sugars were higher in samples thawed at low temperature or in the microwave oven, compared to the level seen after room-temperature thawing. pepper samples thawed at low temperature scored higher in sensory tests than samples thawed at room temperature.

• The Korean Journal of Food And Nutrition
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• v.18 no.4
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• pp.316-324
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• 2005

The objectives of this study were to examine effect of ion chip and yellow soil on the growth and physicochemical characteristics of soybean sprouts. The weight and length increased rapidly in soybean sprouts cultivated for 4 days and then the increases slowed. Ascorbic acid increased rapidly after day 6 in soybean sprouts cultivated with ionized water (I.W), $1.0\%$ yellow soil in tap water (T.W+l.0) and $1.0\%$ yellow soil in ionized water (I.W+l.0). The detected content of minerals such as Mg, Ca, K and Fe in soybean sprouts was higher than other minerals. Iron content was the highest in soybean sprouts cultivated by I.W+1.0. The detected levels of glutamic acid in soybean sprouts cultivated for 4 days with ionized water was higher than in those grown with tap water. In all soybean sprouts, nucleotides such as UMP, CMP, AMP, Hx and soluble free sugars like sucrose, raffinose, stachylose were detected, and the levels of UMP were found to be the highest among nucleotides and sucrose among free sugars.

• Journal of Bio-Environment Control
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• v.33 no.3
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• pp.129-138
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• 2024

This study was conducted to determine the differences in bioactive compounds and antioxidant activity according to the ripening stage of tomato fruits with different skin colors. The tomato samples used three tomato cultivars distinguished by their skin colors as yellow, black, and red at the mature stage. Tomato samples were analyzed for soluble sugars, lycopene, ascorbic acid, polyphenols, and antioxidant activity after being harvested at green, breaker, turning, and mature. The major sugars in tomato fruits are fructose and glucose. The content of fructose and glucose in yellow tomatoes gradually increased during the ripening stages. However, red and black tomatoes, their levels exhibited an initial increase at the breaker points, followed by a period of relative constancy. The lycopene contents in fruits of all skin colors showed a significant increase during ripening stages. The highest content of lycopene was observed at the mature stage in red tomato fruits. Differential patterns in the accumulation of ascorbic acid between yellow and black or red tomato fruits were detected during the entire ripening stages. In yellow tomato fruit, the content of ascorbic acid remained consistently low throughout the ripening stages. Ascorbic acid content in black tomato fruits significantly increased to 2,249 mg·kg^-1 of tomato fruits at the mature stage, while in red tomato fruits, it gradually increased to 3,529 mg·kg^-1 of fruits at the mature stage. Quercitrin content in tomato fruits gradually decreased during the ripening stages. In yellow tomato fruits, the ABTS radical scavenging activity abruptly increased at the turning stages, while in black and red tomato fruits, it gradually increased according to the ripening stages. The DPPH radical scavenging activity in tomato fruits significantly increased at the turning stages.

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