Seyed Yousef Pourmir; Alireza Sadeghi Mahoonak; Javad Fattahi Moghadam; Yahya Maghsoudlou; Mohammad Ghorbani
Abstract
Introduction: Citrus fruits, which belong to the family of rutaceae are one of the main fruit tree crops grown throughout the world. Although sweet orange (Citrus sinensis) is the major fruit in this group accounting for about 70% of citrus output.Citrus fruits are well – appreciated fortheir refreshing ...
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Introduction: Citrus fruits, which belong to the family of rutaceae are one of the main fruit tree crops grown throughout the world. Although sweet orange (Citrus sinensis) is the major fruit in this group accounting for about 70% of citrus output.Citrus fruits are well – appreciated fortheir refreshing juice and health benefits.The health benefits of citrus fruits are linked to the high amounts of photochemical and bioactive compoundssuch as flavonoids, carotenoids, vitamins and minerals available in their juice.These phytonutrientsmay act as antioxidants, stimulate the immune systems; induce protective enzymes in theliver or blockthe damage of the genetic materials. The phytonutrients and vitamins may be responsible for theantioxidant, anticancer and anti-inflammatory properties of the citrus species.Citrus fruits processing accounts for approximately one third of total citrus fruitproduction, more than 80% of it is orange processing, mostly for orange juice production.The most important processed citrus fruits product isorange juice. Orange juice can be presented in different forms. The major types of orangejuice are the freshly squeezed orange juice and concentrated orange juice.Siavaraz local orange is an orange cultivar grown in north of Iran which is used mainly in orange juice production. There is no systematic study about the relation between physical characteristic of fruit at harvest time and its juice quality and quantity. Materials and methods:In this study, the physical characteristics, quantitative-qualitive properties of siavaraz local orange at harvesting times and changes in anti-oxidant components of its juice during processing and storage were investigated.The fruit were collected in eleven different harvest time (start of fruit harvesting and every two week intervals) and different parameters including fruit length, diameter, spherical coefficient, density, peel thickness, juice percentage, total soluble solid (TSS),titrable acidity(TA) were evaluated. In next stage ascorbic acid, total phenolics and anti-oxidant capacity of different fruit juice include fresh squeezed juice by hand and extractor, juice reconstituted from orange concentrate with 60° brix, juice reconstituted from orange concentrate with 65° brixwere evaluated and compared. Finally, changes in vitamin C content during refrigerated storage infresh squeezed juice by hand andjuice reconstituted from orange concentrate were measured. Results & Discussion:Results showed that siavaraz local orange was in four size with different physical characteristics. The highest amount of density was belonged to small fruits with 0.977 at the first harvest stage. Small oranges with lowest peel thickness had the highest juice percentage but the large oranges with the higher TSS showedhigher production efficiency (327.24%). The TA and pH in first stage of harvest were the highest and the lowest, respectively compared to other stage. The highest concentrate efficiency (6.42%) and juice quality (9.88° brix) were obtained at the harvest stagenumber six and seven, respectively. The lowest amount of juice percentage for concentrate production was observed at the stagenumber six (15.6 kg). By investigating the anti-oxidant compounds, results reveals that ascorbic acid and anti-oxidant capacity of juice taken by juicer extractor, were higher (p
Zahra Shabanian; Javad Fattahi Moghadam; Seyed Abolhasan Alavi
Abstract
Introduction: Thomson orange is an important citrus verity which cultivated and produced widely in the north and south of Iran. The extra part of this production is stored in the common storage for several monthsespecially in the north area. The role of storage and fruit coating are important due to ...
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Introduction: Thomson orange is an important citrus verity which cultivated and produced widely in the north and south of Iran. The extra part of this production is stored in the common storage for several monthsespecially in the north area. The role of storage and fruit coating are important due to maintain the nutritional value and enhancing the ‘Thomson’ orange storage life. The aim of this study was to investigate the possibility of maintainingthe fruit quality using coatingtreatmentsin common storage.Materials and methods: In this experiment the harvested fruits were divided in to seven groups randomly, then thefruits of each group were treated using different coating (Polyethylene wax, Shine wax, Storage-wax, Britex Ti wax, Freezer bag, Fungicide ‘Tecto 60’) and Control group without any coating. All the groups were stored in the common storage (5-12 oC and 75-85% RH) for tree month. Some physicochemical and sensory characteristics were investigated including percentage of juice, weightless, losses rate, total soluble solid (TSS), titratable acidity (TA), TSS/TA, peel and pulp total phenolics, ascorbic acid, antioxidant activity in peel and pulp, color indices (L*, chroma and hue angle), peel and pulpAppearance, aroma, flavor, sweetness, sourness, off-flavor, bitterness, acceptance of the fruit each 30 days intervals during storageResults and discussion: Results showed that, the juice percentage declined with decreasing of weight loss in all treatments, but the fruits which treated by freezer bag had the highest juice percentage (38.4%) and the lowest weight loss (1.04 g). Weight loss in Citrus fruit depended on the length and storagetemperature during storage and usually increased on low moisture conditions.Therefore, fruits which packed by polyethylene bags were resistance to water loss through surface peel as well as during storage. The losses increased during the early month of storage especially in freezer bags and shine wax treatments by 4.67 and 3.33% respectively. It seems that bags inner spaceis suitableatmosphere for growing of peniciilium fungi. Color indices (L*, c, h) were in optimum range in all treatments during storage. The length of storage had no significant effect on total soluble solid but affected significantly using coating treatments than control. Moreover, the titratable acidity gradually declined during storage but wax coating maintained TA value higher than other treatments significantly. Overall, the TSS/TA level was increased during storage and the highest ratio (16.14) was observed in control. The increase in TSS/TA was due todecreasing of acidityandincreasing of polysaccharidesduring storage. The total phenolics content decreased in all treatment in peel and pulp as the highest phenolics content with 0.71 mg.g-1 occurred in freezer bag treatment. The amount of ascorbic acid were increased with 42.33 mg.100gr-1 in fruits which treated by Britex Ti wax than control at the end of storage. It seems that lower observation ofascorbic acid in coating treatment due to reduction of the oxygen molecules in fruit tissue by coating. Antioxidant capacity was increased in both peel and pulp of fruits, except in the freezer bag and control treatments. The freezer bag treatment had highest sweetness 7.22 and lowest sourness 1.79 compared to the other treatments and the control. The Britex Ti treatment had the highest level of off-flavor (2.15) and bitterness (1.56) compared to the other treatments and the control. The freezer bag treatment had the highest score (8.09) in the acceptance of the fruit, compared to the other treatments.Conclusion: According to physiochemical and sensory evaluation, Britex Ti, storage-waxes and freezer bag treatments had positive influences on fruit quality in common storage.Thereforethe Storage-wax which produced by the internal companies,it is preferable to be use by citrus growers to maintaining the fruits quality in the common storage.
