Journal of the Japanese Society for Horticultural Science
Online ISSN : 1880-358X
Print ISSN : 0013-7626
ISSN-L : 0013-7626
Volume 45 , Issue 1
Showing 1-13 articles out of 13 articles from the selected issue
  • Hiroshi YAMAMURA, Ryuji NAITO, Keizo MOCHIDA
    1976 Volume 45 Issue 1 Pages 1-6
    Published: 1976
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    This experiment was carried out to obtain further information on the endogenous factors related to the thinning action of NAA in persimmon.
    Limbs of adult trees of‘Fuyu’were separately sprayed with NAA at 50ppm at various stages of fruit growth from 5 to 120 days after full bloom (F. B.). Each treatment was replicated five times. Fruit drop in the NAA-treated and non-treated (control) limbs was surveyed throughout the season. Further, fruits collected just prior to and 2 days after each NAA application were assayed for the activity of GA-, IAA-and ABA-like substances, peroxidase and IAA-oxidase in fruit tissue, and the activity of pectinase and cellulase in the abscission zone between the fruit and calyx tissues.
    Natural fruit drop occurred between 10 and 35 days after F. B. displaying two peaks about 20 and 30 days after F. B. NAA was effective for promoting fruit drop only when it was applied less than 30 days after F. B.
    The NAA applications between 10 and 20 days after F. B. were especially effective in stimulating fruit drop in company with rapid reduction in GA-and IAA-like substances and also with the increase in ABA-like substance, peroxidase and IAA-oxidase in the fruit tissue. Pectinase activity in the abscission zone did not exhibit any measurable changes associated with either natural or NAA-induced fruit drop. The level of cellulase in the zone, however, was extremely high during the time when natural fruit drop was observed, and it tended to be raised by the NAA applications effective for promoting fruit drop.
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  • Shuichiro MATSUI, Hirotaka TORIKATA
    1976 Volume 45 Issue 1 Pages 7-14
    Published: 1976
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    1. On a given shoot, young buds seemed to possess greater development potential than aged ones though all buds grew till mid-September. Therefore, the growth of each bud located on a shoot tip during the oviposition period of chestnut gall wasps progressed considerably by the time of the commencement of gall formation.
    2. With regard to the accumulation of catechol tannins, newly formed buds showed extremely high content though catechol tannins decreased with descent of bud position. However, they increased again in buds near the base of the shoot.
    3. Catechol tannins in the buds were small in amount in Chinese species (C. mollissima), which is susceptible to the parasite. In Japanese species (C. crenata), most varieties were proved to be more resistant than those of Chinese species though resistant varieties didn′t always contain more tannins than susceptible ones.
    4. In general, outer tissues in a bud contained more catechol tannins than inner ones. Scales contained total tannins which amounted to about 80% of the tannins of the whole bud. The total amount was higher in all tissues of susceptible varieties, Taishowase and Nakatetanba, than those of a resistant one, Ginyose.
    5. Catechol, pyrogallol and total tannins contained in gall tissues were reduced to 67, 34, and 38% of those of normal tissues, respectively. Callus tissues contained tannins similar in amount to those of galls. No difference was observed between susceptible and resistant varieties.
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  • Shigetoshi KAWAMATA
    1976 Volume 45 Issue 1 Pages 15-23
    Published: 1976
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    Recently, premature yellowing and abscission of pear leaves believed to be the typical symptoms of photochemical smog injury, have been observed in our orchard in the summer. This study was carried out by comparing the leaves injured in the field with those of trees kept in a controlled smog chamber.
    The results obtained are summarized as follows:
    1) The symptoms of chlorosis, browning and necrosis were found on the upper surfaces of mature leaves of growing shoots.
    2) Leaf lesions caused a notable decrease of the total chlorophyll and chlorophyll b contents in the leaf. When the leaf was slightly injured, starch accumulated remarkably in the leaf and then gradually disappeared as the injury worsened.
    3) The slightly injured leaf showed increased O2 uptake for respiration, but the respiratory quotient (RQ) remained at a lower level than that of the normal leaf on account of decreased CO2 production. Although the O2 uptake increased to some extent, the RQ of heavily injured leaf was low because of the decrease in CO2 production.
    4) Nutrient contents in the injured leaves decreased on the whole. In particular, N and Mg contents notably decreased even in the slightly injured leaves. Though N and Ca contents declined in proportion to the degree of injury, further reduction in P, K, and Mg contents did not occur in the heavily injured leaves.
    5) High correlation coefficients were found between RQ and amounts of total chlorophyll, and chlorophyll a and b respectively. Correlation coefficients between N and total chlorophyll, between Ca and total chlorophyll, between N and RQ, and between Ca and RQ indicated significance at 0.1% level.
    6) The symptoms observed on Japanese pear leaves appeared to be caused by ozone or peroxyacetyl nitrate (PAN). However, since the photochemical smog of Tokyo contains a large percentage of SO2 and dust, it is possible that the injury observed was due to synchronistic actions between two or more of the pollutant factors.
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  • Yasuhiro MASUDA
    1976 Volume 45 Issue 1 Pages 24-32
    Published: 1976
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    Although it has been known that additions of organic amendments to nematode infested soils are effective for nematode control and growth promotion of crops, these effects may or may not appear in case of seedling stages of vegetable crops. In this experiment, accordingly, the effects of application of farmyard manure, without fertilization by synthetic fertilizer, were investigated in soils infested with the Cotton root-knot nematode, Meloidogyne incognita. The experiments were conducted under various environmental conditions, and all of the crops tested were directly seeded in the nematode infested and manured or unmanured test soils.
    The results obtained were summarized as follows:
    1. In late February, soy bean‘Hokkai Ichigo’and kidney bean‘Top Crop’were sown in the testing soils under an electric-heated hotbed, with a mean soil temperature of about 28°C. In the former crop, neither nematode injury nor the growth difference of plants between treatments were recognizable. However, in the latter crop, which is highly susceptible to nematode damage, significant plant growth acceleration excepting the plant height factor, was observed for the case of manured soil.
    2. The effect of the manure application on the growth acceleration in summer-sown cucumber and fig-leaf gourd (Cucurbita ficifolia), differed according to the initial nematode population level in the soils. In nematode-susceptible cucumber seedlings, a growth difference appeared when the initial population of the nematode was about 55 larvae per 50 grams of soil, but the difference disappeared when the population was more than 100 larvae per 50 grams. In case of fig-leaf gourd seedlings, which are more tolerant to the nematode, a growth acceleration in manured soil was observed when the population was about 100 larvae, but the effect was not observed for the case of population exeeding 300 larvae nematodes per 50 grams soil.
    3. Cucumber or Chinese cabbage sprouts were sown in nematode infested soils to which were applied washed manure. (Washed manure is the fibrous residue of the manure after soluble portions are washed out.) Beneficial effects on plant growth like those observed for the addition of ordinary manure were not observed, except in root growth of cucumber. Root systems of both crops suffered heavily from nematode infestation.
    4. Tolerance of the plant to nematode attack was recognized in lettuce sown at early in October, and marked growth promotion of plants in the manured soil was observed.
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  • Wen-Shaw CHEN, Shumpei UEMOTO
    1976 Volume 45 Issue 1 Pages 33-42
    Published: 1976
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    The most important purpose of the study was to clarify the effects of flowering and fruiting on calcium absorption in both the vegetative and reproductive phases of some vegetable crops. Two groups of vegetables, fruit vegetables of tropical origin and leaf vegetables of temperate origin, were tested. In the tropical category, tomato and eggplant, and in the temperate category, Chinese head in cabbage and head head lettuce were included, respectively.
    The results are summarized as follows:
    1. In comparison with the vegetative phase, the reproductive phase displayed a higher percentage of calcium content in the leaves of vegetable crops. In tomato and eggplant, the content of calcium in leaves increased in proportion to the number of fruit set, and decreased after the fruit was harvested. Thus it was found that a cyclic change in calcium content occurred in parallel with growth cycle of the plants. As both Chinese head cabbage and head lettuce have only one cyclic growth, the increase in the calcium content of the leaves for these crops was due to the process of flowering.
    2. In the reproductive phase of tomato and Chinese head cabbage, increases of water soluble calcium (water soluble organic acid salt and inorganic compound) and hydrochloric acid soluble calcium (oxalate calcium) were found in leaves, and these phenomena were more evident in the leaves of tomato which were nearest to the first fruit cluster. Moreover, oxalic acid and citric acid in leaves accumulated at a higher rate in flowered or fruited plants than in deflorated or head formed plants. Thus it was clearly recognized that an increase in the content of calcium influenced by organic acid in leaves was shown in flowered or fruited plants.
    3. In tomato, the content of potassium and magnesium in leaves indicated a noticeable decrease in fruiting plants, and phosphorus showed a slight increase in leaves due to fruiting.
    4. In Chinese head cabbage, the content of nitrogen, phosphorus and potassium in leaves was not effected by the flowering and head forming of the plants.
    5. In tomato and Chinese head cabbage, a quantitative balance between total cation (K, Ca, Mg and Na) and total anion (inorganic acid and organic acid) was found in leaves.
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  • Shoji TACHIBANA, Tokutaro INDEN
    1976 Volume 45 Issue 1 Pages 43-49
    Published: 1976
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    The authors have previously reported the influence of external solution concentrations on the growth, mineral nutrition and water relations of fruit vegetables. This report describes the micronutrient nutrition of vegetable crops as affected by the concentration of nutrient solutions.
    1. Seedlings of tomato and cucumber were grown fifteen days in solutions of different concentrations raised by multiplying a Hoagland and Snyder solution. The concentration of micronutrient elements was held constant. The pH of solutions was adjusted initially to 6.0.
    2. Higher salt concentration caused growth depression of tomato and cucumber, in that the growth of the latter was repressed to a lesser extent at relatively lower ranges of the multiples.
    3. Absorption of Mn was markedly suppressed by increasing solution concentrations. This trend was a little more pronounced in cucumber.
    4. Contents of B in the leaves also decreased at higher solution concentrations. This decrease was more remarkable in the tomato leaves.
    5. Higher external concentrations brought about an increase in Fe contents of leaves, and exerted only a slight influence upon Zn contents. Cu contents were affected differentially according to crops, that of cucumber leaves being decreased, while that of tomato leaves showed no consistent trend.
    6. Sulphur contents of leaves increased in accordance with solution concentrations, especially in the lower leaves of tomato.
    7. pH of nutrient solutions had a tendency to rise following culture, and the lower the concentration was, the greater was the degree of rise.
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  • Takaya OSAWA, Hideo IKEDA
    1976 Volume 45 Issue 1 Pages 50-58
    Published: 1976
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    Nine species of vegetable crops were grown in solution culture in order to investigate the effect of iron concentration in the nutrient solution on manganese toxicities in the vegetable crops. Hoagland′s No. 1 solution was used as the basic nutrient solution. Manganese was supplied at levels of 0.5, 10, 30, and 100ppm. At each manganese level iron was supplied at rates of 1, 3, 10, and 30ppm. Thus, the iron/manganese ratio ranged from 0.01 to 60. The pH of the nutrient solution was adjusted to about 6.
    1. Manganese-induced chlorosis could be classified into two types, interveinal chlorosis on upper leaves apparently identical with the iron deficiency symptom, and marginal chlorosis on lower leaves often accompanied with brown necrotic spots; the former occurred in spinach, tomato, pepper, and bean, and the latter in lettuce, celery, and cabbage. Eggplant and Welsh onion developed no chlorosis.
    2. In general, increasing the iron supply was effective in preventing the development of interveinal chlorosis or reducing its severity, while such an effect was scarcely observed in the case of marginal chlorosis with the exception of lettuce.
    3. From the analytical result of leaves the interveinal chlorosis was considered to be iron deficiency symptom. On the other hand, the marginal chlorosis appeared to be due to excessive accumulation of manganese.
    4. The effect of the increasing iron supply to alleviate the growth reduction due to manganese excess varied greatly with the vegetable species. The effect was remarkable in spinach. Also in tomato, bean, pepper, lettuce, and eggplant the effect was observed to some extent. In celery, cabbage, and Welsh onion, however, there was almost no effect. Besides in pepper, lettuce, and eggplant the iron 30 ppm treatments caused growth inhibition due to iron excess. Factors in the alleviation effect of manganese toxicities by the increasing iron supply were considered to be as follows: (a) Reduction or prevention of manganese-induced chlorosis. (b) Suppression of excessive accumulation of manganese in plants. (c) Tolerance of vegetable crops to excessive iron.
    5. In spinach the iron/manganese ratio in the nutrient solution was closely related to normal plant growth; that is, the decrease of the ratio resulted in growth reduction and occurrence of manganese-induced chlorosis. In tomato, pepper, bean, lettuce, and eggplant, however, both the iron/manganese ratio and the manganese concentration in the nutrient solution affected the plant growth and/or the occurrence of manganese-induced chlorosis, while in the case of celery, cabbage, and Welsh onion, the absolute concentration of manganese in the nutrient solution appeared to be the dominant factor.
    6. There was a considerably close relationship between the iron/manganese ratio in leaves and the plant growth of each vegetable species, provided that the iron 30 ppm treatments were excepted; that is, the decrease of the ratio was associated with growth reduction. The growth inhibition due to iron excess could not be explained from the increase of the ratio.
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  • Yoshio NISHIUCHI, Hiroshi MYODO
    1976 Volume 45 Issue 1 Pages 59-64
    Published: 1976
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    The present investigation aimed at the development of a new technique for propagation of tulip bulb by means of tissue culture in vitro. Excised scales of the bulbs derived from eight commercial varieties; i. e., ‘Apeldoorn’, ‘César Frank’, ‘Cramoisi Brilliant’, ‘Defiance’, ‘Fuga’, ‘Monsieur S. Mottet’, ‘Red Emperor’, ‘William Pitt’and three botanical species, namely, Tulipa hageri, T. praestans and T. tubergeniana‘Emir’which were cultured on synthetic media for the purpose of determining the most favorable conditions for their organ formation.
    1) Callus formation of cultured scales obtained from‘Apeldoorn’, ‘Red Emperor’, ‘Defiance’and T. praestans was spontaneously induced on the modified Murashige and Skoog medium supplemented with α-naphthaleneacetic acid (NAA) or 2, 4-dichlorophenoxyacetic acid (2•4-D) at the appropriate concentration, whereas the scales of‘William Pitt’and‘Cramoisi Brilliant’failed to develop the callus in any case.
    2) With regard to the formation of shoot-like protuberances on the cultured scales, the scale tissue of‘Apeldoorn’cultured on the medium containing either NAA 5mg/l plus kinetin 1mg/l or 2•4-D 1mg/l plus kinetin 1mg/l was capable of producing the shoot like protuberances. In the case of T. hageri, the protuberances were formed on a medium with NAA 2, 10 and 25mg/l to each of which was added 1mg/l kinetin.
    3) The scales of‘Apeldoorn’, ‘William Pitt’and‘Fuga’formed adventitious roots 20 to 30 weeks after inoculation, when they were cultured on a medium supplemented with NAA or a suitable combination of NAA and kinetin.
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  • Koshiro KAWASE, Yotaro TSUKAMOTO
    1976 Volume 45 Issue 1 Pages 65-75
    Published: 1976
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    1. To understand the quantitative effect of major pigments on flower color variation in chrysanthemum cultivars (Chrysanthemum morifolium), carotenoid and anthocyanin pigments were extracted from the flowers and analyzed both qualitatively and quantitatively.
    The flower color was also measured with a color difference meter (Model; NDK- 5, Nihondenshoku kogyo) and recorded with L, a, and b values to indicate individual colors. In this study, 68 cultivars were classified into four groups according to the following petal colors: group (1), white; group (2), pink (pink to red-purple); group (3), yellow, and group (4), (i) orange and (ii) red.
    The relationship between flower color and kinds or content of pigments in these groups was discussed. Also, the results were compared with data obtained from absorption spectra of intact, fresh petals. The detailed results are described below.
    2. In qualitative analysis by thin layer chromatography, three major spots of anthocyanins were detected in 49 cultivars, all of which showed the same qualitative distribution pattern of anthocyanins, and ten major spots of carotenoids were noticed in 26 cultivars, which also showed the same qualitative pattern.
    3. Carotenoids were responsible for flower colors of the yellow, the orange and the red groups, and the number of cultivars with high carotenoid content were greater in the red group than in the yellow and the orange groups.
    On the other hand, anthocyanins were considered to be responsible for the flower color expression of the pink, the orange and the red groups, and the number of cultivars containing large quantities of anthocyanins were greater in the pink, especially red-purple cultivars, and the red groups than in the orange group.
    4. The content of carotenoids was sufficient, even in low concentration, to reveal a yellowish tone in the yellow, the orange and the red groups, but in the case of anthocyanins, a high concentration was necessary to reveal a pinkish tone in the pink group and reddish tone in the orange and the red groups.
    5. A method of evaluating the flower color according to the UCS system (Uniform Chromaticity Scale system) made it possible to distinguish slight color differences among the 68 cultivars of chrysanthemum. The classification of flower color by this method coincided with that of the previous experiment, in which the same 68 cultivars were used and the flower colors were derived into four groups according to the absorption curves of intact, fresh petals. Although the difference between deep red and deep red-purple flower colors, in both of which lightness (L) was very low, could be distinguished readily by visual judgement, those flower colors evaluated by UCS system assumed nearly the same position on Hunter′s diagram of chromaticity.
    6. Carotenoids had no influence on the lightness of flower color determined according to the UCS system, while anthocyanins had an influence on the lightness, which decreased as the content of anthocyanins increased in the pink, the orange and the red groups.
    7. Correlation was recognized between the content of carotenoids and a, b, or √<a2+b2> (chroma) values obtained in each flower color group. A similar relationship was found also between the content of anthocyanins and color values. The anthocyanins contributed not only to the shift of hue, but also to the shift of chroma, especially in the pink group. The carotenoids exerted a large contribution on the variation of chroma in the yellow, the orange and the red groups.
    Thus, the methods of spectrophotometric and color difference metric analysis of flower color are very useful to clarify the relationship between flower color variation and the kinds or content of pigments in petals.
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  • Masatsugu KUSUMOTO, Fujio YOSHIMURA
    1976 Volume 45 Issue 1 Pages 76-80
    Published: 1976
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    Using four astringent cultivars of persimmon (Diospyros Kaki L.) fruits, changes in contents of soluble tannin and some volatile compounds were determined in relation to the process of removal of astringency. While various treatments have been known to be effective for removing astringency, the methods used in this study were as follows; drying at an ambient temperature after peeling, dipping in warm water of 40°C for 24 hours, freezing at -30°C for two months, and storing at room temperature for sufficient days to ripen to a soft consistency.
    When the fruits were softening and losing their astringency during the treatments, except for frozen ones, soluble tannin content decreased rapidly, and alcohols and acetaldehydes content showed an increase. About the time when the contents of these volatiles reached maximum the fruits became non-astringent. In the fruits which had their astringency been removed, contents of tannin cells were already coagulated and shrunk easily. The production of alcohols preceded that of acetaldehyde and was dominant in quantity among the volatiles. Ethanol was applied to pulpslice or squeezed-juice and the reaction was observed microscopically, but no coagulating effect was found even when there was a high concentration of alcohol. Therefore it is unlikely that the alcohols have a direct effect, and an accumulation of acetaldehyde even at a low level would play an important role in coagulation of tannin and thus removal of astringency as reported previously.
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  • Takashi TAJIRI, Kumaichi MATSUMOTO, Kazuko HARA
    1976 Volume 45 Issue 1 Pages 81-88
    Published: 1976
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    The effect of L-cysteine-hydrochloride addition upon the carotene retention in freeze-dried carrots stored at various temperatures of 0°C, 5°C and 10°C was studied. Aa s control, homogenized raw carrots treated with L-cysteine hydrochlorides and kept at the same temperature were used. The effect of L-cysteine hydrochlorides varied largely according to the amount added and the storage temperatures.
    The control raw material could not be kept more than 30 days at 0°C and 15 days at 10°C. On the other hand, when L-cys′-hyd′ was supplemental levels as high as 20% to the raw material and stored 0°C, the carrot was kept for 100-150 days.
    With freeze-dried materials, addition of 20% L-cys′-hyd′ and low storage temperature of 0°C showed marked effect, and carotene decreased only 22% during 300 days, in comparison with 54% in not added material.
    In the carrot which lost more than half of the carotene, discoloration, off-flavro, and stickiness became clear, and these deterioration was found within 100 days at 5 °C and 80 days at 10°C.
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  • Mitsuaki AOYAGI, Hogara MAKINO, Jiro SATO
    1976 Volume 45 Issue 1 Pages 89-96
    Published: 1976
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    In our country white flesh peach fruits are mostly harvested at shipping maturity, i. e. initial stage of ripening, to protect from over-softening and bruising during distribution which is usually carried out at ambient room temperatures (25°C-30°C). 2-4 days are needed from producers to consummers. Recently there has been increased public interest in peaches harvested at the full ripe stage. The fruit is shipped at a low temperature in order to offer higher quality peaches to consummers.
    The present experiment was designed to simulate the conditions of transportation facilities for distribution. Peach fruit was held for 4 days after harvest at the room temperature of about 27°C or at 3°C. Their tastes were compared by 100 panel members and further quality changes were estimated by measuring total sugar, titratable acidity, ground color of peel and softening. Three cultivars belonging to fruits having white flesh, ‘Sunago’‘Hakuho’and‘Aichi Hakuto’were used in the experiment.
    1. When harvested at conventional shipping maturity and held at 3°C, there was no advantageous effect of low temperature on the taste of fruits.
    2. When harvested at full ripe stage and held at 3°C, sweetness was superior to the fruits harvested at shipping maturity and held at room temperature thereafter. At that time, the fruits at 3°C contained 8.8% total sugar and had 40ml of acid determined by titration with 0. 1N sodium hydroxide in 100ml juice, while the fruits held at room temperature displayed 8.3% and 55ml, respectively.
    3. The decreasing rates of sugar content during 4-day-holding in fruits held at room temperature and 3°C were 3.4% and 1.1%, respectively, and the decreasing rates of titratable acidity were 12.3% and 7.0%, respectively. The ground color of peel in the fruits at room temperature turned from light green to light yellow and fruit flesh softened to some extent during holding, while these changes in the fruits at 3°C were hardly detectable. It seemed therefore that the changes of ground color of peel and softening were strongly influenced by storage and shipping temperatures, but total sugar content and titratable acidity were hardly influenced at all.
    4. Total sugar content in peach fruits increased with the stage of ripening at harvest time, and then decreased at overripe or senescent stage. Titratable acidity decreased with the stage of ripening. The fruits softened characteristically, and the ground color of peel changed markedly from light yellow during ripening.
    In conclusion, the optimum time of harvest is the most important factor for distribution of peach fruit having good quality. This time is the full ripe stage of fruits for the case of short-haul transportation facilities as in our country when fruits are held at a low temperature.
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  • Masatoshi MANABE, Masatoshi KANAYA, Takayuki TARUTANI
    1976 Volume 45 Issue 1 Pages 97-102
    Published: 1976
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    This work was undertaken to clarify the relation between the pulp quality and properties of pectic substances during ripening after the harvest of peaches. The varieties studied were white-pulp peaches (Kurakata-wase and Okubo) and yellow-pulp peaches (Kanto No.2, No.5, and No.14).
    The firmness of the Okubo-type decreased markedly during ripening. It became noticeable after only three day′s ripening after harvest. In the case of the yellow varieties, the firmness decreased gradually during ten day′s ripening.
    In white varieties, water-soluble pectin increased remarkably with advancing ripeness, reaching about 50% or more after four day′s ripening. In the yellow varieties, the pectin level was considerably lower than in white varieties. The decrease in pulp firmness was found to be closely related to both the increase in the proportion of watersoluble pectin and to the decrease in the proportion of hydrochloric acid-soluble pectin with advancing ripeness.
    The properties of crude pectins isolated from alcohol insoluble solids were as follows. In the water-soluble pectin of the Okubo-type, a continuous decrease in the uronic acid and methyl ester content, and a continuous increase in the hexose (determined as glucose) in the pectic substance were found to occur as ripening progressed. However, pectins from the yellow varieties do not exhibit this behavior. The intrinsic viscosity of both water- and acid-soluble pectin from Okubo-type decreased rapidly with advancing ripeness. The pectic substances from yellow varieties do not exhibit such a decreasing pattern.
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