جستجوی مقالات مرتبط با کلیدواژه "پرتقال خونی" در نشریات گروه "کشاورزی"

Nowadays, citrus fruits, especially oranges, is very important in the human nutrition regime, and its quality characteristics assessment is very important. This study aimed to predict some biochemical characteristics of blood orange, using machine vision and artificial neural networks. In this experiment, the amount of vitamin C content, sugar content, and acidity (pH) were obtained using destructive laboratory methods. Images of blood orange samples were captured and 108 texture features and 57 color features were extracted on CIElab, RGB, HSV, and HIS color spaces and finally, the artificial neural networks method has been used to estimate the desired properties. To evaluate and select the most optimal artificial neural network, a feed-forward neural networks with Levenberg-Marquardt learning algorithm, the different number of neurons, and different transfer functions in the hidden and output layers was used. Finally, using the best neural network and 165 textural-color features, the amount of vitamin C content, sugar content, and pH were estimated with a correlation coefficient of 0.950, 0.968, and 0.884, respectively. Therefore, considering the appropriate correlation coefficient, machine vision and image processing technology can estimate some biochemical characteristics of blood oranges accurately.

The different factors such as harvest time, product handling, temperature and storage duration can be influenced on the different properties of citrus fruits and has considerable economic consequences. Therefore a factorial experiment based on completely randomized design with 3 replications was performed to evaluate the effects of harvest times (start of color change, 50% of color change and full color change of fruits), storage period (0, 25, 50 and 75 days) at 7ºC on total soluble solids, titrable acidity, ascorbic acid, total phenol content, flavonoid, antioxidant capacity, anthocyanin and activity of L-phenylalanin ammonia-lyase. The results showed that the harvest times and storage period had significant effect on the measured properties. So that the after 75 days of storage, peak phenylalanin ammonia-lyase activity and total flavonoid observed concomitantly with the accumulation of anthocyanin in ripe blood orange fruit but decreased antioxidant capacity and total phenol after 25 days of storage. Also, the highest vitamin C content and total soluble solids were measured in full ripening of fruits before storing and decreased after 75 days storage. So, according to changes in all of measured characteristics, the apropriate time of harvesting of Moro blood orange was the stage of commercial maturity of fruits.

Quality and flesh colour characteristics of blood oranges following harvest is related to and dependent upon temperature and storage conditions. To investigate the effects of different temperatures (8، 15 and 22ºC) and different storage period (0، 25، 50 and 75 days) on total soluble solids، titrable acidity، pH، ascorbic acid، total phenolic contents، antioxidant capacity، anthocyanin level، activity of L-phenylalanin ammonia-lyase، and as well on total protein content in ripe Moro blood orange، a factorial experiment، based upon a completely randomized design of 3 replications was performed. The results revealed that at 8ºC and after 75 days past، phenylalanin ammonia-lyase activity and total protein increased concomitantly with total anthocyanin، but antioxidant capacity and total phenols decreased. Besides، in other temperatures this process has been on the decrease. The highest vitamin C content، titrable acidity as well as total soluble solids were evaluated in control fruits before storage and were shown to decrease after 75 days of storage. As a final result، all the evaluated characteristics of Moro blood orange decreased considerably by increase in temperature and in storage period.

Blood orange has high nutritional value due to high concentrations of vitamin C، fiber، folate، minerals and phytochemical compounds، such as flavonoids، amino acids، triterpenes، phenolic acids and carotenoids. The blood oranges contain greater amounts of antioxidants than other oranges. Orange fruit continue to respire، after harvest so there are probability changes of bioactive compounds that present in this fruit. The aim of this study was to investigatethe changes of the bioactive compounds، antioxidant activity and their relationship with respiration rate of blood orange during storage. Blood oranges var. sangria was purchased from the Citrus Research Institute of Iran. The fruits were transported to the laboratory immediately after harvesting and were stored at 5-4°C and 85-90% relative humidity for 50 days. Changes of concentration of vitamin C، flavonoid compounds، total carotenoids، antioxidant activity and respiration rate were evaluated once a week during storage. The concentration of vitamin C decreased، but the concentration of flavonoid، total carotenoids، antioxidant activity and respiration rate of blood orange increased during storage. The concentration of vitamin C، flavonoid، total carotenoid، antioxidant activity and respiration rate of blood orange changed during storage. With attendance to nutritional value and the functional compounds of orange fruit، use of appropriate actions are recommended to better maintenance of the bioactive compounds and antioxidant activity. Also، considering effects of respiration rate on the bioactive compounds and antioxidant activity، decrease of respiration rate of blood orange during storage could lead to be better preservation of the functional compounds.

Postharvest losses are a limiting factor on storage life of many vegetables and fruits including citrus. Therefore a study was conducted to evaluate the effects of thermal treatments and herbal thyme oil spray on Sanguinello blood oranges in Golestan province in the northern part of Iran. The tests have been performed one day after harvesting، under four different treatments: hot water at 55˚C for 3 minutes، flushing of steam at 100˚C for 30 seconds، and spraying of fruits with two-percent thyme using surfactant. The fruits of each treatment were then kept in some boxes and placed in a cold storage at 8˚C and relative humidity of 85±5 percent، for two months. Results showed that the treatments had no significant effect on the quality parameters of fruits such as acidity، total soluble solid، maturity index and sensory evaluation. However، among all treatments، the steaming treatment had the greatest impact in preventing weight loss during storage.

Antioxidant capacity and quality of fruits usually changed during storage. In the current study, the changes of antioxidant capacity and postharvest quality of two blood (pigmented) orange cultivars (‘Tarocco’ and ‘Morro’) and ‘Thompson navel’ orange, after 60 days storage at 7ºC and 90 RH% was investigated. During fruit storage weight loss, TSS, TA, TSS/TA, vitamin C, total phenol, anthocyanins and also juice antioxidant capacity by DPPH scavenging activity test were determined. Fruit weight loss in blood oranges was more than ‘Thompson navel’ orange and increased gradually during cold storage. Fruit TSS declined in blood orange significantly but was constant in ‘Thompson navel’ orange. In contrast, TA decreased the most in ‘Thompson navel’ orange. Vitamin C slightly increased during storage time but total phenolics increased only in ‘Taracco’. The results showed that antioxidant capacity in oranges fruits decreased with storage time and ‘Morro’ fruits with the anthocyanin synthesis and accumulation during postharvest time had shown the highest antioxidant capacity. Finally, the results showed that quality of oranges decrease during long term storage except to blood orange that increase antocyanin and phenolic contents.