جستجوی مقالات مرتبط با کلیدواژه "نشاسته" در نشریات گروه "باغبانی"

Grape is a non-climacteric fruit. Its ripening is associated with increased sugars, decreased acidity and development of color and flavor. Edible films and coatings could be used as a selective protection method to extend storage life of fruits. Edible coatings reduce the absorption amount of brine, osmotic solution and frying oil into foods, improve mechanical properties, facilitate displacement and storage strengthen food structure, reduce spoilage and increase its shelf-life. The coatings provide a protective layer for fresh fruits and act as like as modified atmosphere packaging, change the composition of internal gases, and increase the storage-life of fruits by reducing respiration rate. Zein, is an important protein in corn seed and consists about 45 - 50% of the corn proteins. This protein contains a group of Prolamines found in the corn endosperm. Zein has unique properties for preparing edible films and coatings in comparison to other plant proteins due to its high percentage of nonpolar amino acids.  Gluten is an insoluble in water protein of wheat that its disulfide bonds play an important role in the establishment of gluten films. Prepared films from wheat gluten are pure and transparent, but commercial gluten produces an opaque film due to gelatinization of its existing starch. Wheat gluten-based films have satisfactory mechanical resistance and very low oxygen permeability. Gluten can encapsulate flavors, colors, or medicines, providing slow-release materials. Bacteria, fungi, or other pest- or weed-control agents can be encapsulated in gluten granules that are then coated with oil to slow drying and maintain vitality.

This study was carried out to investigate the effects of gluten and zein coatings on postharvest quality of grape cultivars in a factorial arrangement based on randomized completely design with application of corn’s Zein coating treatments at four levels (control, 2, 4 and 6% w/w) and also wheat gluten at four levels (control, 2, 4 and 6% w/w) were performed in the grape cultivars (Meshkin cultivar). Grape fruits were harvested from the gardens of Meshkin city and moved to the laboratory in the University of Mohaghegh Ardabili. Then, after applying the treatments, fruits were kept at 0° C and humidity of 90-95% in cold storage. In this study, pH, total soluble solids, total acidity, starch, anthocyanin, firmness, taste, fruit storage-life, TSS/TA, weight loss, appearance and vitamin C content of fruits were measured in 30 days after applying the treatments.

The results of analysis of variance showed that using of zein as grape coating had significant effect on total soluble solids, vitamin C, taste and weight loss (p < 0.01) and on the TSS /TA attribute (p < 0.05).The use ofgluten also had a significant effect on total soluble solids, anthocyanin, weight loss and vitamin C (p < 0.01) and also on the fruit starch (p < 0.05). Interaction effect of gluten and zein treatments were significant on total soluble solids, vitamin C (p < 0.01) and fruit weight loss (p < 0.05). Based on the obtained results, the highest starch content, anthocyanin, maturity index and taste were achieved by using of gluten at 4 and 6% and the lowest amount of these substances was related to control treatment. A higher amount of anthocyanin (2.45 mg / 100 g) was retained in 6% gluten treatment, Moreover, in the fruit ripening index, the best result (41) was obtained from 6% zein treatment. The taste of the fruit was also more attractive in the 6% zein treatment without gluten consumption with a score of 8.5. Also, the best results in preservation of vitamin C (17.9), soluble solids (24 brix), fruit appearance (9.5 points) and the least weight loss of fruit (6.5%) were obtained from the combination of gluten and 6% zein treatment. Comparison of the means showed that vitamin C and soluble solids were better preserved by combined using of 4 and 6% gluten with 6 and 4% zein in storage period. These results showed that vitamin C and soluble solids had the lowest stability under control conditions. Also, the control treatment had the highest weight loss and the lowest score in the fruit preservation index. In overall, the best results in most of the studied parameters were obtained from the treatment combination of 6% gluten and zein.

Based on the obtained results, gluten and zein coatings in comparison to control treatment at levels of 6%, had significant positive effects on post-harvest quality and storage of grapes.

Witches’ broom disease of lime (WBDL), caused by ‘Candidatus Phytoplasma aurantifolia’, is major limiting factor for Mexican lime (Citrus aurantifolia Swingle) production in southern Iran. In this investigation, biochemical composition profiling of the healthy and infected rooted Mexican lime wasmonitored during WBDL progression (90-330 days) as well as to distinguish infected from healthy Mexican limes under greenhouse conditions. For this aim, stem cuttings is taken from healthy Mexican lime. After three months, half of Mexican lime cutting were inoculated by bark-grafting from WBDL-affected Mexican. Six healthy and infected plants were sampled 90, 150, 210, 270 and 330 days after inoculation with Phytoplasma. Pigments, total phenol, antioxidant capacity, soluble carbohydrate and starch content in leaves were measured. Results showed Phytoplasmal infection caused growth inhibition and reduced stem and root dry mater. Moreover, infection mostly caused to a marked decrease in pigments and significantly increased soluble carbohydrates and starch. In Mexican lime leaves, phenol contents and antioxidant capacity were increased after inoculation with Phytoplasma. In addition, the principal components analysis (PCA) revealed a clear distinction between the leaf biochemical profiles of healthy and infected plants during the progression of WBDL. In conclusion, this study provides new insights into the lime response to phytoplasma infection during the progression of WBDL. Finally, we showed that healthy plants can be isolated from infected plants using biochemical profiles.

Nitrogen plays an important role in managing the nutrition of citrus. In this study effects of three concentrations of urea (0, 0.75%, and 1.5%) and three times of urea foliar application (Dec 22, Jan 5, and Jan 20) on biochemical characteristics of the kinnow mandarin trees were evaluated. the experiment was conducted as factorial based on a randomized complete block design with three replications. Sampling was done from leaves and nodes at 1, 3 and 5 weeks after spraying. The yield and biochemical characteristics such as carbohydrate, starch, protein, total chlorophyll, proline were measured. The results of this study showed that in the five weeks after foliar application, the highest leaf carbohydrate, starch, protein and node starch obtained from plants sprayed with urea on Jan 5 in off year. The three weeks after foliar application, the highest amount of leaf and node proline (respectively 348.5 and 383.3 µmol g-1 FW) were related plants sprayed with urea on Jan 22 in on year. The highest amounts of carbohydrate and total chlorophyll of nodes (respectively 85.88 and 1.6 mg g-1 FW) were reported in off year with 1.5% urea concentration on the 30th January. According to the results of this study, urea foliar application in January 15th, can be advised in order to increase yield and control of alternate bearing in the Kinnow Mandarin trees.

Soil salinization, resulting from the accumulation of water- soluble salts in the soil, adversely impacts on agricultural production including figs. To investigate the effects of different salinity levels (0.6, 4, 6 and 8 mmhos.cm-1 NaCl) on four fig hybrids, an experiment was performed as factorial based on completely randomized design. The investigated seedlings were offsprings of ‘Sabz’ as maternal parent and four caprifigs namely ‘Pouz Donbali’(P), ‘Khormaei’(K), ‘Shahanjiri’(Sh) and ‘Daneh sephid’(D); (S×P, S×K, S×Sh and S×D). Salinity at level 8 mmhos.cm-1 increased proline (9.18-fold), carotenoids (8.04%) and stomata density (54.13%), and also decreased relative water content (15.24%), starch (39/42%), length (23.68%) and width (24.60%) of stomata and stomata conductance (73.59%) compared with the control treatment. With increasing salinity level to 6 mmhos.cm-1 increased total soluble sugars, Chlb and total Chl in comparison with the control treatment. The most proline, Chla, Chlb, total Chl, carotenoids, total soluble sugars, starch was measured in S×K hybrid, whereas the lowest relative water content was measured in S×D hybrid and the lowest Chlb and total Chl was measured in S × Sh hybrid. Moreover, S × Sh hybrid had the most decrease in stomata length and width and most increase in stomata density under the salinity condition, while the lowest stomata density was found in S×K hybrid. Moreover, the most and lowest changes in the percentage of stomata conductance under treatment 8 mmhos.cm-1 in comparison with the control treatment were found in S×P and S×K hybrids, respectively. Among the studied hybrids, S×K was shown salinity tolerance more than other hybrids and it is possible to use of this hybrid in the salinity soils up to 8 mmhos.cm-1.

In this research, effect of different levels of salinity and application of different concentration of putrescine were investigated for decreasing harmful effects of salt on morphological and physiological characteristics of wild ‘Konar’. A factorial experiment was arranged in a Compelet Randomized Design (CRD) with 4 replications. Treatments were 4 levels of 0, 3.2, 6.4 and 12.8 g/l sodium chloride and 3 levels of 0, 0.01 and 0.1 mM putrescine. The results showed that with increasing salinity, all growth indices such as leaf number, stem length leaf and root fresh and dry weight reduced and spraying application of putrescine especially with 0.1 mM concentration ameliorated seedlings growth in salt condition. Salt stress increased Na and Cl- uptake and declined K uptake. Foliar Putrescine application reduced and increased Na and K uptake, respectively. Salinity also reduced the amount of chlorophyll and starch, but the amount of proline and soluble sugars were increased. Applied putrescine reduced the damaging effect of salt on chlorophyll degradation and also increased the amount of proline, sugar and starch.

This research was carried out to determine the chilling and heat requirements of grapevine cultivars(Rotabi, Siah Shiraz and Yaguti) and carbohydrate and hormones changes in chilled cuttings. Uniform cuttings of above mentioned cultivars were harvested when leaves were abscised in autumn, and then transferred to refrigerator (2˚C). Cuttingswere subjected to 0 (unchilled control), 100, 200, 300, 400, 500 chilling hours, then cuttings were put in distilled water at room temperature and continues light conditions. Results indicated that the highest bud break percent of ‘Siah Shiraz’, ‘Rotaby’ and ‘Yaguti’ were obtained from 500, 400 and 400 h respectively. The shortest time (29d) to 50% bud break of ‘Siah Shiraz’ was in 500 h(29 d), in ‘Rotabi’ and ‘Yaguti’ were in 400 h (20 and 16d) chilling. Rate of starch content in all cultivars were decreased when chilling exposed hours increased, while soluble carbohydrate content in cuttings increased with increasing chilling hours. Also, with increasing chilling exposed hours, GA, Cytokinin and Auxin contents increased whereas ABA decreased. In conclusion, chilling requirement of ‘Yaguti’, ‘Rotabi’ and‘Siah Shiraz’cultivars were 400, 400, 500 hours and heat requirements were 4320, 5472 and 8064 GDH, respectively.

In this investigation, the effect of zinc excess and its interaction with ascorbic acid on some growth parameters (root and shoot, fresh and dry weight, leaf blade area and length of root and stem), proline content, soluble sugars and starch plant were studied on canola. Experimental plants were treated with different concentrations of zinc sulfate ie. 0.7 (control), 50, 100, 250, 500 and 700 mM) and one set with the same zinc concentrations (except control) mixed with 1M of ascorbic acid in Hougland nutrient solution for two weeks. Results indicated that any increase in zinc content leads to considerable decrease in starch level, leaf blade area, stem and root length, but proline and soluble sugars increased significantly in shoot and roots of rape seed. In higher concentrations of zinc sulfate in the presence of 1M ascorbic acid, the above-mentioned effects of zinc sulfate excess on growth parameters were considerably blocked. In the presence of 700 mM of zinc sulfate, chlorosis and necrosis were occurred on the leaves of rape seed, but at the copresence of 1 mM of ascorbic acid, mentioned symptoms was disappeared. It means that at the presence of ascorbic acid the plant could tolerate the toxicity of zinc sulfate excess. In the other word, ascorbic acid could considerably reduce the toxicity of high concentrations of zinc and induce poison durability.