- TREATMENTS TO INCREASE STORABILITY AND MARKETABILITY OF GUAVA (Psidium guajava L.) FRUITS
Mansoura Journal of Plant Production, الصفحات 857 - 876
Lo’ay, A.
أ.د/لطيف جرجس سمعان
أ.د/محمد عبدالرحيم عراقى
تيسير عبدالحميد عبدالغفار سراج
- EXOGENOUS SPRAY OF MANGO (Mangifera indica L.) TREES WITH ANTIOXIDANT SOLUTIONS IN RELATION TO CHANGES IN FRUIT QUALITY AND STORABILITY AT HARVEST AND DURING COLD STORAGE
مجلة العلوم الزراعية , الصفحات 617 - 639, ابريل
L. G. Samaan
E.F.A.El-Dengawy
Lo’ay, A.
هبه مصطفى مصطفى الفيومى - قسم الفاكهة- كلية الزراعة- فرع دمياط- جامعة المنصورة
الملخص الملخص EXOGENOUS SPRAY OF MANGO (Mangifera indica L.) TREES WITH ANTIOXIDANT SOLUTIONS IN RELATION TO CHANGES IN FRUIT QUALITY AND STORABILITY AT HARVEST AND DURING COLD STORAGE The present investigation was carried out in two successive seasons of 2008 and 2009 on “Hindi” and “Zibda” fruiting trees to study the effect of pre-harvest spray, ten days prior to harvest time, with each of vitamin C solution at 1.0gL-1 ”T1” and vitamin B12 solution at 1.0mgL-1 “T2”along with tap water to serve as control ”Tс” on three fruit physical characteristics including changes on fruit firmness, weight loss% and chilling injury incidence. Moreover, six chemical characteristics in fruit juice including changes on vitamin C content, total acidity %, total soluble solids %, total soluble solids/acid ratio and along with β-carotene and total chlorophyll pigments in fresh peels were examined at harvest time and throughout cold storage period(30 day) at 5±1°C and 80-85% RH. The tested trees were 20-years-old, almost uniform, apparently diseases free and grown in a commercial orchard located in Kafer Saker province, EL-Sharkia governorate, Egypt. The concerned results of physical and chemical characteristics (except for weight loss %) at harvest time and during cold storage period almost indicated significant differences among the tested treatments. The rate of changes differed among the tested treatments either at harvest time or throughout cold storage period. In general, pre-harvest sprayed trees of both mango cultivars with antioxidant solutions could be succeeded to improve the tested qualities of the treated fruit trees at harvest time and during cold storage period with different rates based on certain critical factors include the tested treatment, cultivar genotype and fruit characteristic under study. Antioxidant treatments also had an effect on shelf life of stored mango fruits with different rates due to the critical factors indicated above. Cold stored fruits of “Hindi” cultivar continued under provided storage conditions till 15th day determination without observing the incidence of chilling injury symptoms and could be extended to 20 day storage with mild symptoms. In case of “Zibda” stored fruits, they showed a similar behavior as “Hindi” fruits till 15 day storage, afterward both antioxidant treatments succeeded to store fruits till the 30th day determination (end of storage period) with mild chilling injury symptoms. Fruits of both cultivars during these cold storage periods were of firmness and qualities acceptable to consumers.
المرفقات
- EFFECT OF SOME CHEMICAL TREATMENTS AND HAND DEFOLIATION ON WINTER PRODUCTION AS YIELD, FRUIT QUALITY AND STORAGE LIFE OF GUAVA
مجلة العلوم الزراعية , الصفحات 467 - 478, مارس
أ.د. السيد البدوى طه الباز
Lo’ay, A.
محمد على عوض الله صالح - بحوث البساتين – مركز البحوث الزراعية – الجيزة
محمد عاطف الشوبكى - بحوث البساتين – مركز البحوث الزراعية – الجيزة
الملخص الملخص EFFECT OF SOME CHEMICAL TREATMENTS AND HAND DEFOLIATION ON WINTER PRODUCTION AS YIELD, FRUIT QUALITY AND STORAGE LIFE OF GUAVA The present investigation was conducted during 2008 and 2009 seasons on common seedy guava trees grown in a private orchard at EL kefah village, Badr center Behera governorate to study the effects of different treatments of defoliation on tree yield and fruit quality at harvest time as well as loss in weight, decay and total loss during storage at room temperature as represent of marketing conditions of guava trees. All tested treatments gave significant increase in fruit quality(fruit weight, firmness, total sugars contents, vitamin c, acidity, SSC and SSC/ acid ratio), in both seasons of the study as compared with control. Both control fruits at the normal harvest period in the summer were held at 20-22 oC and RH 75% and fruits of other treatments were held at 12-14 oC and RH 82% at the winter season of harvest period in the winter. The obtained data indicated that urea 10% gave significant increase in yield of winter crop as compared with other treatments. In addition ZnSO4 2% + NH4NO3 4% gave significant improvement in fruit quality as compared with other treatments. Concerning fruits held at room temperature, ZnSO4 2% + NH4NO3 4% showed significant increase in in fruit quality (fruit weight, firmness, total sugars, vitamin c, acidity, SSC and SSC/ acid ratio) and gave the lowest weight loss after 9 days of room storage. Concerning control fruits (summer yield) the data indicated significant increase in yield, but a decrease in their quality and an increase in fruit weight loss and decay, due to fruits harvested in early dates in summer. The decay reached 100% after 3 days due to increased summer temperature. The winter crop of guava fruit trees from these treatments were good quality and its high price covered greatly the reduction in yield.
المرفقات
- VITAMINS APPLICATION AND PERSIMMON (Diospyros kaki L. CV ’COSTATA’), FRUIT QUALITY
مجلة العلوم الزراعية , الصفحات 367 - 375, مارس
أ.د. السيد البدوى طه الباز
أ.د. محمد عبدالرحيم عراقى
Lo’ay, A.
محمد رزق إبراهيم
الملخص الملخص VITAMINS APPLICATION AND PERSIMMON (Diospyros kaki L. CV ’COSTATA’), FRUIT QUALITY The present investigation was conducted during two seasons (2007 and 2008) on Japanese persimmon trees located at commercial orchard, cv Costata, which considered the main and early ripening cultivar. Spraying trees with ascorbic acid (AA) and cyanocobalamine (B12) in single or combined treatments were applied at different stages of development. Generally, fruit firmness values were gradually reduced from zero time of storage till the end of storage period in all treatments of AA and vitamin B12 alone or in combination. The influence of both AA and B12 in maintaining fruit firmness at harvest time and during the storage studied or shelf-life’ resulted in increasing fruits firmness than the control. Total Soluble Sugars increased by applying AA and B12 sprays alone or in combination at different concentrations. Total tannins content of fruits decreased significantly during shelf-life period. Generally all treatments of AA and B12 alone or in combinations decreased total tannins content. Total phenolic contents significantly increased in the persimmon fruit as affected by different treatments during per-harvest, period, whereas AA alone at 0.5 and 1% have achieved the highest contents of total phenolic substances followed by AA combined with B12 sprays at two season of the study at harvest time. Ion leakage percentage increased with advancing the shelf-life period till the end of storage to 15 days, as affected by different treatments applied of AA and B12 alone or in combination. It is apparent that tree sprayed with AA and B12 has less ion leakage than control fruits during shelf-life period.
المرفقات
- BIOLOGICAL INDICATORS TO MINIMIZE BERRY SHATTER DURING HANDLING OF ‘THOMPSON SEEDLESS’ GRAPEVINES
World Applied Sciences Journal , الصفحات 1107-1113, March 2011
Lo’ay, A.
الملخص الملخص BIOLOGICAL INDICATORS TO MINIMIZE BERRY SHATTER DURING HANDLING OF ‘THOMPSON SEEDLESS’ GRAPEVINES ’Thompson seedless’ (Vitis vinifera L.) is widely cultivar in many countries and Egypt. Moreover, it is considered a highly perishable fruits, thereafter, bunches are rapidly lose their quality after harvesting because precooling is absent. Therefore, bunches water loss, berry shatter and stem browning are main postharvest problem during handling and marketing by increasing water loss after harvesting until bunches arrived to market. Some factors are effected in bunches quality such as water stress and biological differences are effected on berry losses during handling. A series of experiments was carried out during 2007-2008 seasons in commercial farm to study these effects. The first experiment was conducted on stressed vines for one month to study berry shatter and stem browning during 30 days (stressed treatment). The second experiment was carried out in order to study the effect of different bunch locations (sunny and shadow side of vine) and shape (compactness and looseness) presented a significant effect in berry shatter percentage and stem browning. The third experiment was applied to minimize water loss, berry shatter and stem browning by using ascorbic acid (AA) and Cyanocobalamin (B12) before 14 days of bunches harvesting time. Both chemicals application were used. The concentrations applied were 2.8 and 5.6 mM of AA and 0.37 and 0.74 mM B12. Ascorbic acid at (5.6 mM) decrease berry shatter% and stem browning index compared with B12 treatment during 4 days shelf-life without promising bunches quality. Overall, the results indicate that the effect of AA treatment on berry shatter and stem browning are commercially significant given that they are two common and important quality defects of table grapes particularly at retail level
- CYANOCOBALAMIN CONTROL FRUIT RIPENING OF PERSIMMON FRUITS
مجلة العلوم الزراعية, الصفحات 1653 - 1663, ديسمبر
Lo’ay, A.
الملخص الملخص CYANOCOBALAMIN CONTROL FRUIT RIPENING OF PERSIMMON FRUITS Cyanocobalamin (B12) may generate many different physiological processes in plant tissue such as: protein metabolism, soluble lipids, carbohydrates and ethylene. Changes in tannins and total sugars in astringent persimmons cultivar ‘Costata’ were investigated during shelf-life postharvest period. Soluble tannins exhibited significant decreases up to the experiment end. Total sugars increased 4 fold with fruit immersed in B12 0.444 µM compared with other treatments. Fruit firmness decreases with increasing B12 concentration during the entire period monitored. Moreover, it also significantly retarded the increase in -carotene content and ion leakage % while decreased the fruit firmness and increased h◦ up to day 10 then decreased and be constant during shelf-life. Generally, B12 treatments can greatly extend the postharvest life and increased fruit quality of ‘Costata’ persimmon fruit during shelf-life.
المرفقات
- INCREASING THE STORAGE ABILITY OF ZIBDA MANGOES
مجلة العلوم الزراعية, الصفحات 1637 - 1652, ديسمبر
Lo’ay, A.
الملخص الملخص INCREASING THE STORAGE ABILITY OF ZIBDA MANGOES Mango (Mangifera indica L.), Zibda cultivar is considered as a sensitive cultivar to low storage temperature. Fruits were from Zibda CV harvested at three different maturity stages and stored at 4oC (85–90% RH) for 35 days after treatment with ascorbic acid (AA) as antioxidants. Chilling injury (CI) was observed initially as a black spot and loss of peel color by end of the storage time pulp color changed into the seed area. In the case of mango, CI begins at 4oC. The storage, handling and transport potential of fruits is limited by susceptibility to diseases, and sensitivity to low storage temperatures. To increasing the tolerant of Zibda fruits under cold storage may be achieve by minimizing the oxidative reactions during storage using addition antioxidants such as ascorbic acid (AA) to fruits at different immersing time. Normally, at storage temperature of 4oC, CI appeared after 10 days, thereafter developed more rapidly with passing storage period. Using addition antioxidant delays CI up to 25 days. Delaying CI appearance of sensitivity cultivar may be useful for marketing Zibda fruits to long distance
المرفقات
- Antioxidant enzymes and oxidative stress in
mangoes
Wageninegn University, The Netherlands, الصفحات 119-162, 2005
Lo’ay, A.
Jeremy Harbinson
Olaf Van Kooten
Linssen JPH
الملخص الملخص Antioxidant enzymes and oxidative stress in
mangoes The activities of the antioxidant enzymes superoxide dismutase (SOD), catalase
(CAT), glutathione reductase (GR) and ascorbate peroxidase (APX) were
measured in the peel and pulp of two mango varieties (Mangifera indica L. ‘
Zibdia’ and ‘ Hindi Be-Sennara’) during storage at 4 and 10oC for periods of up to
35 days. Low initial activities of antioxidant enzymes (AE) at harvest time were
observed, though this varied according to the maturity stage of the fruits at harvest.
During the storage period fully mature fruits displayed the highest activities of AE
compared to immature and half-mature fruits. In both varieties AE activities also
increased during the first 15 days of storage, even at the lowest storage
temperatures, although Zibdia showed higher activities of AE activity in this period.
Thereafter, the AE activity decreased during the rest of the storage time. In
conclusion, the AE activity increases up to ?15 days of storage time after which
they decreased in both the pulp and peel of both varieties and at all maturity
stages. This decrease of AE leads to auto-formation of free radicals. The degree of
oxidative stress pronounced by the cell is a function of the activity of free radical
generation reaction on the one hand, and the activity of the free radicals
scavenging system on the other hand. The imbalance between generation and
scavenging free radicals are attributed to an increased lipid peroxidation, thereafter,
leading to a breakdown of the thylakoid membranes. Chilling injury symptoms are
clearly visible on mango fruits. The storage time and temperature are shown to be
important factors in determining decreases in AE activity, which influence chilling
injury presenting in mango fruits. Decreases in AE activity is varied between the
selected varieties and maturity stages.
- Chilling injury and the balance between active oxygen species and the scavenging capacity: a review
Wageningen University, الصفحات 23-52, 2005
Lo’ay, A.
Jeremy Harbinson - Wageningen University
Olaf van Kooten - Wageningen University
الملخص الملخص Chilling injury and the balance between active oxygen species and the scavenging capacity: a review Chilling injury occurs when certain plants, or organs thereafter, are exposed to
temperatures below 15oC, but above the freezing point of the tissue. After a certain
period of storage at these temperatures, and especially after a subsequent rise in
temperatures, certain injuries in the plant tissue can be seen, such as water
soaking, pitting, or browning. The possible causes of this type of injury will be
reviewed and the consequences for cell components summarized. A distinction is
made between the primary processes of chilling injury and subsequent secondary
injuries. The membrane phase change and oxidative stress models of primary
chilling injury are introduced. How cell components are affected by chilling injury is
then discussed, as is the relationship between pre-harvest conditions, post-harvest
handling, and injury. Lastly, the roles of different anti-oxidants and anti-oxidant
enzymes are discussed and some techniques used for the measurement of chilling
injury are introduced.
- Chlorophyll fluorescence assessment of chilling injury in ‘Zibdia’ and ‘Hindi Be-
Sennara’ mango varieties
Wageningen University, The Netherlands, الصفحات 53-82, 2005
Lo’ay, A.
Jeremy Harbinson
Olaf Van Kooten
الملخص الملخص Chlorophyll fluorescence assessment of chilling injury in ‘Zibdia’ and ‘Hindi Be-
Sennara’ mango varieties Chlorophyll fluorescence (Fv/Fm ratio) of mango (Mangifera indica L.) fruits was
evaluated as an indicator of chilling injury development during storage. The Fv/Fm
ratio of two mango varieties ‘Zibdia’ and ‘Hindi’ was determined during a 36 day
storage period at temperatures of 2, 4, 7, 10 and 20oC and at different harvest
maturity stages, i.e. immature (M1), half-mature (M2) and fully mature (M3). In
general, ’Zibdia’ mango had a higher incidence of chilling injury at low temperatures
than ’Hindi’, and the M3 fruits revealed more injury than M1 and M2 fruits in both
mango varieties. However, the initial occurrence of injury after 10 days of storage
was similar for both varieties and it was only after 20 days of storage that it was
possible to identify differences between the cultivars. The Fv/Fm ratio of darkadapted
fruits decreased rapidly after 12 days of storage in ‘Zibdia’. In ’Hindi’ it
decreased gradually until the end of the experiment. However, harvest maturity
stages did not present any differences in Fv/Fm ratio between both varieties. The
correlation of the Fv/Fm ratio with chilling injury was observed for both varieties
during storage. The results of this study suggest that Fv/Fm ratio during storage may
be a good tool to assess chilling injury development before visible symptoms
appear. Zibdia is more sensitive to low storage temperatures than the Hindi cultivar
and the sensitivity varied according to the harvest maturity stages.
- On the Ethylene production, respiration rate
firmness and ion leakage in mango fruits
Wageningen University, The Netherlands, الصفحات 163-190, 2005
Lo’ay, A.
Jeremy Harbinson
Olaf Van Kooten
الملخص الملخص On the Ethylene production, respiration rate
firmness and ion leakage in mango fruits Physiological changes such as: ethylene production, respiration rate, firmness, and
ion leakage were studied on two mango varieties (Mangifera indica L. ‘Zibdia’ and
‘Hindi Be-Sennara’). These changes were monitored at 3 different harvest maturity
stages for fruits stored for up to 35 days at different temperatures (2, 4, 7, 10, and
20oC). C2H4 production increased to a maximum production rate after the 5th day of
storage. The climacteric respiration showed a peak after day 10. Fully mature (M3)
fruits produced more ethylene and respiration compared to immature (M1) and half
mature fruits (M2). Thereafter they decreased until day 35. Hindi fruits show higher
firmness than Zibdia fruits. Both mango varieties show higher firmness at low
storage temperature (2 or 4oC) compared with fruits stored at 7 or 10oC. Ion
leakage in Zibdia fruits was higher than Hindi fruits when the fruits were stored at 2
or 4oC compared with fruits stored at 7 or 10oC. Fruit pulps showed higher ion
leakage than peel. Decreased firmness and increased ion leakage due to ripening
processes when fruits were stored at 20oC which are related to changes in cell lipid
membrane. Physiological changes are induced by the severity effects of low
storage temperatures at different storage times. At lower temperature, storage
induced CI in both varieties as an effect of generation active oxygen species
(AOS). These AOS react with cell lipid membranes and initiate lipid peroxidation.
Because of these processes, chilling injury will result which affects the quality
elements of mango fruits.
- Influence of mango maturity and location on its behavior during cold storage
Journal of Plant Production, الصفحات 1409 - 1418
Lo’ay, A.
الملخص الملخص Influence of mango maturity and location on its behavior during cold storage Abstract:
This investigation was carried out during 2006 and 2007 on two mango cultivars ‘Ewais’ and ‘Hindi Be-Sennara’ to study the effect of two stage maturity, half mature (M2) and full mature fruit (M3) which were harvested from three different locations (sunny, shadow and inside tree) on fruit behavior during prolong cold storage at 4oC. Both CVs present different responses during storage period. Since, Ewais CV presents more injuries than Hindi Be-Sennara especially with M3 compared to M2 for both CVs at chilled temperature. Increased, chilling injury symptoms of M3 fruits which were harvested from sunny side of tree than the same fruit that harvested form shadow and inside tree. The profits of these differences by which can be classified fruits into three classes according to fruit position on tree. The Full mature fruits which were harvested from sunny side of tree were more sensitive to low storage temperature compared other fruits harvested from shadow and inside of trees.
- Effect of potassium soil and foliar fertilization on leaf potassium content, yield and berry qualities of Thompson seedless grape
J. Agric. Sci. Mansoura Univ.,, الصفحات 1153-1162, 1996
أ.د. محمد عبد الرحيم عراقى
M.. El-Boray
M. F. M. Mostafa
Lo’ay, A.
- Ascorbic acid and tissue browning in mango CV Hindi Be-Sennara fruits (Mangifera indica L.) under cold storage
Journal of Plant Production Sciences, الصفحات 11301-11310, 2009
Lo’ay, A.
الملخص الملخص Ascorbic acid and tissue browning in mango CV Hindi Be-Sennara fruits (Mangifera indica L.) under cold storage This study was conducted to find out the relationship between ascorbic acid (AA), and internal browning (IB) incidence in Hindi Be-sennara mango fruits (Mangifera indica L.) during cold storage (4oC). Ascorbic acid content in two main parts (stem and calyx end of fruit) and three sub-main parts (peels, inner and outer pulps) of the fruits were measured. Internal browning in mango fruits found to be dependant on the fruit AA content. Exogenous application of AA (5.6 mM) decreased IB incidence when the fruits immersed for 24 hour compared to these immersed in water for the same time and stored at ambient conditions for 35 days. Mango fruits pre-storage immersing in diluted AA (5.6 mM), water is absorbed throughout the peel cells causing an increase on AA content and a decrease on its concentration. The decrease of IB incidence was appeared due to such increase on AA content in inner and outer parts of the fruit. This protection of the treated fruits may be related to the consumption of the externally added AA. Therefore, it could be said that the application of AA increases mango fruit quality, through protecting the from development of IB, also, the obtained results indicated that such treatment maintain the total phenols (TP) content in fruits during cold storage constant
- Changes in the concentration of water and
lipid-soluble antioxidants during cold storage
of Zibdia’ and ‘Hindi Be-Sennara’ mango fruits
Wageningen University, The Netherlands, الصفحات 83-118, 2005
Lo’ay, A.
Jeremy Harbinson
Olaf Van Kooten
الملخص الملخص Changes in the concentration of water and
lipid-soluble antioxidants during cold storage
of Zibdia’ and ‘Hindi Be-Sennara’ mango fruits The predominant water (ascorbic acid (ASC)) and lipid soluble (?-Tocopherol (?-
TOC) and ?-Carotene (?-CAR)) antioxidants (WSA and LSA, respectively) of two
mango varieties (Mangifera indica L. ‘Zibdia ‘and ‘Hindi Be-Sennara) were
measured in the peel and the pulp of fruits stored at temperatures of 2 - 20oC for 35
days. The initial amounts of WSA at the time of harvest were found to differ
according to the maturity stage of the fruit. The WSA content also decreased during
storage dependent on maturity stage at harvest. Zibdia had a higher initial ASC
content than Hindi and had a higher content in for M1 and M2 fruit relative to M3
fruits in both peel and pulp. For the LSA, the patterns of change were more
complex. In the peel of Hindi the initial level of ?-TOC increased with increasing
maturity stage, but decreased during cold storage, and the same pattern was found
in Zibdia except that the initial level of ?-TOC was lower than for Hindi. In the pulp
of Hindi the ?-TOC increased strongly with maturity stage and decreased during
storage, whereas with Zibdia the ?-TOC hardly changed with maturity stage. ?-CAR
contents that increased by increasing fruit maturity in both Zibdia and Hindi and
also increased during storage, even at 2°C. These results were pronounced even
before visible CI symptoms. Storage Zibdia fruits at 10oC can be considered as the
optimum storage temperature for however, 7oC is optimum for Hindi in terms of
preserving anti-oxidant levels
- Delaying guava ripening by exogenous salicylic acid
Journal of Plant Production
Lo’ay, A.
A. Y. El-Khateeb
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