جستجوی مقالات مرتبط با کلیدواژه « شاخص طعم » در نشریات گروه « باغبانی »

The production of misshapen fruits in 'Hayward' kiwifruit, due to genetic potential, or environmental conditions, is the main factor for reducing exportable and marketable fruits. To solve this problem and produce uniformity in the fruits, it is recommended to thin the malformed fruits immediately after setting. This study was conducted as a randomized complete block design with four replications. The experimental treatments included thinning all of the small, flat, fan-shape and misshapen fruits at four different times: 15, 30, 45 and 60 days after fruit set in the whole vine. Fruits were harvested when reached at maturity stage, and characteristics such as fruit yield per vine, fruit grading according to size, fruit firmness, dry matter percentage, soluble solids content, titratable acidity, TSS/TA, pH and ascorbic acid content were measured. The results showed that there was no significant difference between the thinned and control vines for fruit yield. Fruit thinning times caused a significant increase in the percentage of extra grade fruits, so that the highest extra fruit percentage was found when fruit thinning carried out 15 days after fruit set (49.01%), which showed an increase of about 25 percent compared to control (24.71%). Furthermore, fruits thinning reduced flesh firmness, titratable acid and ascorbic acid as compared to control, but increased fruits dry matter percentage, soluble solids, TSS/TA, pH and fruit volume. Overall, early fruit thinning; 15 days after fruit set, with increasing extra grade fruits and reducing grade 2 and out-of-grade fruits caused improve in proportion of marketable and exportable fruits.

Physalis (Physalis peruviana L.) is a popular fruit, which has received great attention due to its nutritional and medicinal properties. This valuable fruit has a short shelf life and so far, very little research has been done on postharvest physiology of shelf life. For this purpose, a factorial experiment was conducted based on a completely randomized design with three replications. The first factor was the different levels of γ- aminobutyric acid (GABA) concentrations (0, 5, 10 and 15 mM), the second factor was the storage time in three levels (7, 14 and 21 days) and the third factor was the harvesting stage (based on the appearance color of the fruit into two levels: yellowish green and orange). The obtained results showed that the weight loss in fruit treated with GABA at the end of the storage period was lower than untreated fruit, and the most weight loss (12.62%) was found in fruit harvested in the orange stage without any treatment. At the end of the storage period, the fruit firmness in fruit treated with GABA showed a lower decrease compared to the untreated fruit, so that the maximum decrease was observed in the orange stage after 21 days of storage in the untreated fruits. The application of GABA significantly reduced the fruit decay. The highest fruit decay (43.83%) was observed in the fruit harvested at the orange stage without GABA at the end of storage. The results showed that the application of GABA increased the activity of antioxidant enzymes during the storage period compared to untreated fruit. The highest activity of superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (GPX) and ascorbate peroxidase (APX) enzymes was observed in fruit treated with 15 mM GABA compared to untreated fruit. Overall, application of GABA after harvesting at a concentration of 15 mM is recommended to maintain the quality of physalis fruit.

This study was conducted to evaluate the morpho-physiological and pomological traits of 21 peach cultivars/genotypes under the Mashhad climatic conditions, during two years (2017-2019), based on a randomized complete block design with three replications. The results indicated significant differences between cultivars and genotypes in terms of morphological, pomological, and qualitative traits. The results showed that ‘Early-Red’ and ‘Vizivo’ were among the early flowering genotypes with a long flowering period (20 days). ‘Baby Gold-5’ and ‘PMsh-5’ were the earliest-ripening, and ‘PMsh-2’ and ‘PMsh-4’ were the latest-ripening genotypes. ‘Dixie Red’ and ‘PMsh-5’with 1.85 and 1.77 m3 respectively had the highest volume of the crown of the tree. ‘J.H.Hale’ had the highest fruit weight with an average of 148.92 g, while ‘Apago’, ‘Early-Red’, and ‘PMsh-5’ had the lowest fruit weight. ‘PMsh-1’, ‘Vizivo’, ‘PMsh-6’, and ‘Sorkho-Sefid Mashhad’ cultivars and genotypes had the highest fruit length, width, and shape index and placed statistically in the same group with ‘J.H.Hale’ cultivar. ‘Sorkho-Sefid Mashhad’ cultivar showed 59.1% more yield efficiency, compared to the control cultivar (‘J.H.Hale’). The highest yield efficiency belonged to ‘Baby Gold-5’, ‘PMsh-3’, ‘Suncrest’, and ‘PMsh-8’. The lowest acidity achieved in ‘Apago’, ‘Shasta’, and ‘PMsh-8’. ‘Sorkho-Sefid Mashhad’, had the highest TSS content, which was increased by 3.68% compared to the control cultivar (‘J.H.Hale’). ‘Apago’, ‘PMsh-1’, ‘Shasta’, and ‘Sorkho-Sefid Mashhad’, compared to ‘J.H.Hale’ cultivar, had higher flavor index, 16.17, 27.25, 26.29 and 26.67%, respectively. In general, based on the studied traits, ‘Sorkho-Sefid Mashhad’, ‘Vizivo’, ‘PMsh-1’, and ‘PMsh-6’ are recommended as promising cultivars and genotypes under Mashhad climatic conditions.

The effects of postharvest dip treatment in hot water and carbendazim fungicide on sensory, physicochemical, and antioxidant characteristics determining the internal and external quality of sweet lime (Citrus limettioides Tan.) fruit were studied. Treatments included a 4 min dip in 45 °C hot water, 0.5 g L-1 carbendazim solution and distilled water (control). Fruits were stored at 10 °C and 85% relative humidity for 90 days, with characteristics being measured at 30-day intervals. Compared to control fruits, treated fruits by hot water had lower weight loss and decay, better taste index, and higher content of total phenol in peel and ascorbic acid in the juice. After one month of the storage, they showed higher levels of enzymatic antioxidant activity (superoxide dismutase, catalase, ascorbate peroxidase, and guaiacol peroxidase) and more non-enzymatic antioxidants such as total phenol in peel and ascorbic acid in juice when compared to control. Afterwards, peel enzymatic antioxidant activity increased in control fruits while decreasing in hot water-treated fruits. Based on non-enzymatic antioxidants content and sensory evaluation after 3-months storage, hot water-treated fruits possessed the best internal and external quality, while fungicide-treated fruits with a pale appearance had the lowest quality in peel color and firmness. At this time, investigations on the peel content of hydrogen peroxide and enzymatic antioxidant activity revealed that fungicide-treated fruits experienced more stress and oxidative injury than control fruits. As a result, hot water dip treatment was recognized as a safe treatment for improving and extending the storability of sweet lime, as well as a suitable substitute for chemical fungicides.

Strawberry fruit has very short postharvest life because of its soft texture. To evaluate application effects of amino acids on Post-harvest life of Strawberry fruits, a factorial experiment was carried out based on completely randomized design in Research Greenhouse of Ferdowsi University of Mashhad. Experimental treatments were three amino acids (Arginine, Glutamine and Alanine) at three levels (0, 500 and 1000 µM) and two cultivars of strawberry (Camarosa and Gaviota). Strawberry fruits were harvested at commercial maturity stage and transported to the laboratory. Then fruits were kept in plastic containers and stored at 4 ºC. After 15 days, total soluble solids (TSS), titrable acidity (TA), flavor index (TSS/TA), total anthocyanin, total phenol, phelavonoid, total antioxidant capacity and percentage of fruit weight loss were determined. Results showed that the highest flavor index (18.41) was observed in Alanine1000- cultivar Gaviota. Also, the lowest fruit weight loss was related to Alanine 500- cultivar Gaviota (18%) and Arginine 500- cultivar Gaviota (14.5%) treatments. These two treatments were not statistically different. The highest fruit-weight loss (65.5%) was observed in Glutamine 500- cultivar Gaviota. Also, Glutamine 500- cultivar Gaviota had the highest Antocyanine. It can be concluded from this experiment that application of Arginine and Alanine amino acids prior to harvest of strawberry fruits can increase their postharvest life and quality.

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.

Production of high quality with high shelf life of apple fruits, is of great importance. Present study investigates the effects of ammonium nitrate and iron on quality and antioxidant properties of apple fruit cultivar Gala in a randomized complete block design. Foliar application of iron chelate in three levels (0, 5 and 10 mg/l) and soil nutrition of ammonium nitrate in three levels as strip (0, 40 and 60 mg/kg per tree), were applied. Results showed that using iron and ammonium nitrate had a significant effect (P≤0.01) on fruit quality. According to these results, using ammonium nitrate increased total antioxidant activity and total phenolic compounds. With increasing iron concentrations, total antioxidant activity increased, but it reduced the amount of total phenolic compounds. Application of iron decreased total acidity and increased fruit flavor index. According to results, treatments had no significant effect on TSS and color indices. This study showed that balanced nitrogen and iron fertilization could increase the quality and antioxidant contents of apple cv. Gala.