جستجوی مقالات مرتبط با کلیدواژه « فعالیت پاداکسندگی » در نشریات گروه « باغبانی »

Lime fruit has significance important because of its economic value and beneficial nutritional composition. Fresh lime consumption compared to other processing methods is reduced for the lack of storage facilities and suitable packaging. This experiment was conducted to evaluate the effects of salicylic acid concentrations of 0, 1, 2 and 3 mM on the lime fruit shelf life (0, 20, 40 and 60 days) in a factorial arrangement based on a completely randomized design. According to the findings of this study, the index of chroma (5.5%), weight loss (9%) and vitamin C (66%) during storage were higher than harvest time, but pulp firmness (62%), total acidity (24%) and peel freshness (37%) decreased. Salicylic acid treatments were unable to maintain fruit weight, but salicylic acid 1 mM was effective in maintaining the antioxidant properties, and salicylic acid at 1 and 2 mM maintained peel firmness compared to control. At the end of the storage period, the highest pulp firmness and vitamin C related to application of salicylic acid at 2 mM. However, salicylic acid at 1 mM resulted in the highest soluble solids and acid contents. It seems that packaging lime with 1 and 2 mM salicylic acid was able to maintain the lime fruit quality up to 60 days.

Grape (Vitis vinifera L.) contains antioxidant compounds which are very useful for human. Unfortunately, most of the antioxidant compounds, such as flavenoides, are reduced during grape ripening stages. Therefore, the study of elicitors for increasing these compounds at the time of ripening, is necessary. In this study, the effect of salicylic acid (SA) spraying in three concentrations of 0 (control), 0.1 and 1mM on the leaves and fruits of two grape cultivars "Shahani" (with black berries) and "Fakhri" (with green berries) at two growth stages (unripe and ripe) were investigated. Detection indicators at unripe stage were acidity and berry size, and at ripe stage were juiciness and total soluble solid of berries . This study was conducted in 2013-2014 on the vineyards of the "Malayer Grape Research Center". The experimental vines were ten years old and their growing system was a row planting and drip irrigation method. This experiment was carried out based on completely randomized design (CRD) with seven treatments and three replications. The results showed that the maximum amount of carotenoids were at the unripe stage in the fruit skin of "Shahani" and "Fakhri" cultivars treated by SA at 0.1mM concentration to amount 73.65 and 69.94 mg/gFW, respectively. Results of comparing two growth stages showed that the maximum amount of anthocyanins were at ripe stages in the fruit skin and leaves of "Shahani" cultivar treated by SA at 0.1mM concentration to amount 3.21 and 2.343 mg/g FW respectively. In addition, Measurement of total flavonoids content as showed the increasing effect of SA at 0.1mM concentration on total flavonoids of leaves and all parts of fruits (exception of seeds) both "Shahani" and "Fakhri" cultivars at ripe stages were more effective. Also, SA treatment as significantly increased the antioxidant activity content of most parts both cultivars at unripe stages at 0.1mM concentration and ripe stages at 1mM concentration. These results showed that the use of common materials, such as SA, can greatly increase antioxidant properties of grapes during ripe stage.

Non-destructive methods are very important in agriculture because the tested product can return to the market process, and also they don’t have the problems of destructive methods such as time-consuming and cost. On the other hand, diversity and abundance of quality characteristics of agricultural products are considered as the other reasons for the development of non-destructive methods. Therefore, in this study the ability of the image processing method in order to predict the quality characteristics such as volume, weight, total soluble solids, titrable acid, total phenolic and antioxidant activity of three Zaghe Yazdi, Malase Yazdi and Malase Esfahan cultivars of pomegranate fruit during 2013 growth season, was investigated. Samples were collected at four stages of 50, 80, 110 and 140 days after full bloom and then the color and chemical characteristics were evaluated. Finally, the calibration models related to colorimetric data and chemical measurements were prepared.Results of validation of models showed that in Malase Esfahan cultivar, the standard deviation ratio was 2.3, 2.52, 1.8 and 2.95 for weight, volume, total soluble solids and antioxidant activity, respectively. Moreover, it was found that the changes of titratable acid and total phenolic had no significant correlation coefficient with the color of pomegranate fruit and there were not predictable by image processing technique. Overall, it can be concluded that the image processing technique is an efficient method and has a very strong potential for simultaneous and rapid detection of maturity stages and also to detect the status of qualitative characteristics in pomegranate fruit cv. Malase Esfahan.

Effects of different concentrations of salicylic acid on the storage of golden and red delicious apple fruits in Rafsanjan's Cantoie garden were studied at harvest time and 45, 90, 135 and 180 days after storage. Treatments were included no washing, distilled water, salicylic acid 1, 2, and 3 mM for 1 and 2 hours in cold storage room at 1 ± 2 ° C. A factorial experiment based on a completely randomized design was designed. In both cultivars, harvest index coincided with 170 days after full bloom. Results showed that weight loss, electrolyte leakage and decay reduced by salicylic acid and maintained total soluble solids, general acceptance and antioxidant activity. However, salicylic acid treatment had no effect on the color parameters, total acidity and pH of apple fruit. During storage, weight loos, total acidity, pH and decay in golden delicious apples were higher than the red delicious apple, also shelf life of red delicious apples was higher than that of golden delicious apples. Application of 3 mM salicylic acid resulted in increasing superficial scald, off-flavour, and reduced general acceptance, but fruits treated with 2 mM salicylic acid had better quality and more storage life compared to the other treatments.

In this research, the effect of chitosan, nano-chitosan, methylcellulose, and pectin on maintenance of bioactive compounds and storability of pomegranate aril cv. Rabbab-e-Neyriz were studied during storage time. Arils were treated with 1.5% chitosan, 3% methylcellulose, 3% pectin and pure nano-chitosan (100%) solutions and then stored at 5 °C for 16 days and sampling of stored arils was done at 4 days intervals. After 16 days of storage at 5 °C, fungal contamination was observed in all samples except for those treated with 1.5% chitosan. The most and the least weight loss in arils obtained in the control and those treated with 1.5% chitosan, respectively. The edible coatings especially chitosan significantly prevented from degradation of anthocyanin and ascorbic acid. Total phenoland antioxidant activity of juice decreased during storage; however chitosan coating significantly led tomaintain these bioactive compounds. Edible coating treatments and especially chitosan maintained the TSS, TA, flavor index in comparison with control. Overall, chitosan effectively reduced water loss, aril losses and maintained bioactive compounds during storage.

In order to improve yield and quality of sweet pepper cv. ‘California Wonder’ in Ilam province, effects of gibberellins (GA3 50 mg/l) or calcium (CaCl2 0.5 percent) spray at beginning or the end of harvesting season (70 and 120 days after transplanting, respectively) were evaluated. Either of the chemicals were sprayed two or three times per growth stage through a factorial assay on the basis of a randomized complete block design (RCBD). Results showed that gibberellic acid and calcium spray increased average yield in plant, weight, length, diameter, volume, texture stiffness, flesh thickness, dry weight, ascorbic acid content, antioxidant activity, chlorophyll a, b and total chlorophyll, as well as calcium content of fruits in both growth stages. Gibberellins with three sprays per growth stages performed the highest positive role in improvement of physical properties of fruits. Effect of gibberellins and calcium on all evaluated traits, except fruit density, were significantly higher at the late harvesting stage than early stages. Therefore, gibberellic acid and calcium spray especially at the end of harvesting season may be advised to improve yield and quality of sweet pepper.