Postharvest physiology
M. Rahemi; M.H. Nazaran; S. Abolghasemi; S. Sedaghat; M. Zare
Abstract
Introduction
Low temperature storage is the most important method used to preserve harvested products. Keeping products at low temperatures, above the freezing point up to 10 degrees Celsius, can cause frost damage in fruits and vegetables, especially tropical and subtropical products. The use of heat ...
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Introduction
Low temperature storage is the most important method used to preserve harvested products. Keeping products at low temperatures, above the freezing point up to 10 degrees Celsius, can cause frost damage in fruits and vegetables, especially tropical and subtropical products. The use of heat treatments as safe, organic and alternative physical methods is increasing, these treatments are used to maintain the quality after harvesting and also to prevent frostbite of garden products. Also, one of the recommended methods to reduce fruit waste is to increase the calcium concentration of the fruit by using calcium solutions. Calcium is one of the most important mineral elements that is involved in determining the quality of the fruit and its shelf life. Studies conducted on the use of nano fertilizers in some species of fruit trees has shown their potential role in improving the yield of the product and the physical and chemical properties of the fruitThis study was conducted to investigate the effect of postharvest treatments of calcium chloride and nano chelated calcium fertilizers on chilling injury and physiological characteristics of local orange fruits stored at 2 ±0.5° C and 85% relative humidity for 60 to 120 days.
Materials and Methods
In this research, orange fruits of the local cultivar Citrus sinensis at the stage of commercial maturity based on the taste index (10TSS/TA⋍) were prepared from Darab city of Fars province and transferred to the Physiology Laboratory of Horticultural Sciences Department of Shiraz University. Then the fruits were disinfected with 2% sodium hypochlorite and washed with distilled water. Treatments included calcium chloride and nano chelated calcium fertilizers at different concentrations of zero, 3 and 6 dissolved in cold water (20°C) and hot water at 45 °C for 25 and 15 min, respectively. Sampling was done on days 60 and 120. To simulate shelf life conditions, before measuring the parameters, the fruits were kept at laboratory temperature for two days. In this research, the changes in fruit tissue firmness, freezing index, weight loss percentage, soluble solids, total acidity, ascorbic acid, ion leakage, potassium ion leakage, malondialdehyde, calcium content of fruit skin and flesh, fruit color, catalase enzymes and peroxidase were measured. Data analysis was done using SAS software version 4.9 and comparison of averages was done by LSD test at 5% probability level.
Results and Discussion
There was a significant difference between nano chelated calcium and calcium chloride in calcium enrichment in pulp and fruit skin Calcium chloride and nano chelated calcium treatments dissolved in hot water reduced weight loss, soluble solids content, acidity, ascorbic acid, ion leakage and malondialdehyde and the activity of the antioxidant enzymes catalase and peroxidase. Nano chelated calcium increased calcium content by 44% in fruit skin and up to 41% in fruit pulp compared to calcium chloride. Nano chelated calcium 3 and 6 % showed more stability in fruit weight (159 and 400%, respectively) compared to calcium chloride after two months of storage. After 60 and 120 days of storage, the content of ascorbic acid in fruits treated with 6 nano chelated calcium was 73% higher than calcium chloride. Nano chelated calcium 3 % compared to calcium chloride prevented 39.6 of potassium ion leakage during 60 days of storage. The amount of ascorbic acid in the 3% and 6% nano calcium treatment and the tissue hardness in the 3% nano calcium chelate treatment after two months of storage were estimated to be higher than the control and calcium chloride. Calcium nano chelate 6% improved the calcium content of fruit flesh and skin due to increased permeability. Warm water pretreatment with calcium compounds is an efficient and recommendable treatment for the preservation of orange fruits in cold storage conditions due to the improvement and reduction of the severity of the increase in indicators related to the occurrence of frost damage in the skin of fruits.
Conclusion
One of the primary concerns during storage is the loss of fruit weight. Calcium nano chelate, in comparison to the control and calcium chloride treatments, exhibited the least weight loss over the two months of storage. This is attributed to the critical role of calcium in influencing the shelf life of fruits. It was observed that immersing fruits in calcium compounds dissolved in hot water and utilizing 6% nano chelated calcium had a significant positive impact on enhancing and preserving the quality of orange fruits during cold storage.
Postharvest physiology
M.J. Karami; M. Rahemi; M. Yassaie; A. Karami
Abstract
Introduction
Raisins are dried grapes and are prepared from some varieties of grapes (Vitis vinifera) in different ways, such as exposing grapes to direct sunlight and mechanical methods. There is a possibility of contamination of various types of raisins with different microorganisms during the ...
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Introduction
Raisins are dried grapes and are prepared from some varieties of grapes (Vitis vinifera) in different ways, such as exposing grapes to direct sunlight and mechanical methods. There is a possibility of contamination of various types of raisins with different microorganisms during the stages of harvesting and drying grapes, transportation and marketing of raisins, especially when they are presented in open boxes. The traditional process of preparing and packing raisins in Bovanat region (the main raisin production area of Fars province) makes this product prone to microbial contamination dangerous for human health. The history of consumption of raisin is very old. The Bible provides the first written mention of raisin around 1000 B.C., drying is one of the oldest methods of food preservations; the main purpose of this experiment is reducing the moisture content to level which allows safe storage without spoilage. It has been reported that the use of hydrogen peroxide (H2O2) treatments reduces the microbial contamination loads in dried raisins. Moreover, washing with hydrogen peroxide solution can markedly reduce the loads of human pathogens including Escherichia coli. Primitive methods of making and packaging of raisins in Bavanat region contribute to make them vulnerable to microbial contamination and may be harmful for health. This research was conducted in order to determine the initial microbial contamination on the surface of three types of raisins prepared from the Keshmeshi grape cultivar and using hydrogen peroxide to reduce these microbial contaminations.
Materials and Methods
The use of hydrogen peroxide as a potential antimicrobial treatment was investigated for three types of raisins in Bovanat region. For this purpose, three samples of raisins (Sun-dried, Shade-dried and Sultana raisins) have investigated. Raisins samples randomly were purchased from a local retailer in Shiraz (Iran). For this experiment, raisin samples with uniform size were selected and damaged or diseased berries were discarded. Two concentrations of hydrogen peroxide applied to microbial disinfection were 0% and 0.9%. The raisins that were prepared underwent a treatment process where they were dipped for 5 minutes in solutions containing either 0% or 0.9% hydrogen peroxide. Afterward, the raisins were washed with distilled water for 1 minute to remove any residue. A control group was also included, consisting of raisin samples treated with water (0% hydrogen peroxide). For each sample, measurements were taken for microbial count, population of yeasts and other molds, Aspergillus, Coliform bacteria, and Escherichia coli. The experiment was designed as a factorial (2x3) based on a completely randomized block design with 3 replications. The data were analyzed using SPSS 22.0, and mean data were compared using Duncan's multiple range tests at a 1% probability level.
Results and Discussion
The results showed that there was a significant difference (P≤1%) between hydrogen peroxide concentration treatments regarding to microbial contamination. There was also a significant difference (P≤1%) between the raisin samples in terms of microbial contamination. The results also revealed the presence of high amount of microbial infection on surface of all raisin samples. The microbial contamination load of Sultana raisins was higher than other raisins. The results also indicate that Escherichia coli was not detected in both sun-dried and shade-dried samples, but it was observed in Sultana raisins. Surface disinfection of Sultana raisin samples with 9% of hydrogen peroxide removed Escherichia coli infection. Hydrogen peroxide was effective in reducing the microbial contamination of all three raisin samples. It seems hydrogen peroxide to be more effective in reducing microbial contamination in sun-dried and shade-dried samples. Sultana raisin had highest contamination of mold and yeast while sun-dried and shade-dried raisins were lowest. The effect of hydrogen peroxide on reducing mold and yeast contamination was not the same in all raisin samples, so that the highest effect on reducing mold and yeast contamination was found in sun-dried and shade-dried raisins. The least effect on this contamination was observed in sultana raisins. Aspergillus was not detected in sun-dried and shade-dried samples but it was observed in sultana raisins. Hydrogen peroxide was not effective against Aspergillus. The microbial contamination of all raisin samples which affected by 0.9% hydrogen peroxide was decreased significantly (P≤1%). Effect of hydrogen peroxide at 0.9% on removing of microbial infection in sun-dried and shade- dried raisins was similar and it was more than Sultana raisins.
Conclusion
All three raisin samples were infected with Coliform bacteria, mold and yeast. In the case of Escherichia coli infection, it was detected only in sultana samples. Hydrogen peroxide was effective in reducing the microbial infection of all raisin samples. It was more effective in reducing the total number of microbes in sun-dried and shade-dried raisins. Hydrogen peroxide with a concentration of 0.9% is effective for eliminating the microbial infection of raisins, and the use of hydrogen peroxide with a concentration of 0.9% can be used to disinfect raisins.
allah karam rostaami; majid rahemi; Mahmood Eizadi
Abstract
Introduction: As one of the oldest fruit trees, palm, from almost 5,000 years ago till now, has been growing in North Africa and the Middle East. Phenological ripening process of fruit trees are determined through factors such as genetic, environmental and controlled practices. Among these factors, radiation ...
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Introduction: As one of the oldest fruit trees, palm, from almost 5,000 years ago till now, has been growing in North Africa and the Middle East. Phenological ripening process of fruit trees are determined through factors such as genetic, environmental and controlled practices. Among these factors, radiation as a natural factor affects other processes such as photosynthesis, flowering, performance and color of a fruit. Considering the importance of producing organic fruits, it is highly effective to use different coatings to improve the gardening products .Results of this study showed the effect of light on strawberry fruit coating which has the capacity to pass higher levels of UV light. As a result of applying coating the average fruit weight, fruit number, phenols, pigments, anthocyanins and flavonoids were significantly increased, but no significant difference was observed for the total yield. Use of coverage on apple trees reduced physical damage and improved the color of the fruit. The blue covering improved the physical and chemical factors in banana. Date palm bunch covers offer several advantages to protect fruits from high humidity and rain, from bird attacks and also from damage caused by insects and diseases. A sturdy light-brown craft-paper is used in the USA to cover and provide good protection of the bunch during the ripening season. Bunch covering is, however, not only practiced against rain damage but traditionally is also used in the form of coarsely woven well-ventilated baskets (sund) to protect the maturing fruits from birds and prevent early ripening fruit from falling to the ground. Bagging treatment has been widely used as a physical protection technique in other fruit-tree species for not only protecting fruits from diseases and pests, but also changing the microenvironment of fruit development growth, which subsequently affects internal and external qualities, such as skin color, acidity, sweetness and aroma. A large number of experimental data obtained in peach, pear, apple etc, showed that bagging treatment might lead fruits to increase or decrease of ascorbic acid (Vc), TSS, anthocyanin, organic acids contents etc.
This study also aimed to show how the quality, quantity and speed of the ripening process of fruit date palm Kabkab can be improved using covering method.
Material and Methods: This research was carried out at the Tropical Fruits and Dates Research Station in Bushehr Province. Considering the above purpose, a complete randomized block design was employed. Accordingly, 6 treatments including bags with dimensions of 120 × 70 cm in 5 colors (green, yellow, white, gray, and blue) and with a four-time repeating pattern were applied to 20 years old Kabkab palm trees. All trees were pollinated by a controlled pollinator. Factors measured included the ripening speed of fruit per unit of time, the weight of the entire cluster, cluster weight, fruit weight, TSS, TA and pH.
Data collection and Analysis: factorial complete randomized block design was carried out and data were analyzed statistically by analysis of variance and least significant differences (LSD 5%).
Results and Discussion: Based on the results obtained, the direction and color of the bag on the characteristics of fruit appearance has no significant effect. Awad (2007) achieved similar results with colored bags including black, white, blue and white coating on the date palm Helali obtained. Alcobendas (2012) found that the geographical location of peach fruit on the tree has no effect on the weight of meat, fruit weight, fruit diameter, fruit dry weight and pulp to stone ratio. The results showed that bunch weight and fruit weight significantly increased in the north. Tyas et al (1998) reported lychee trees in directions of northeastern and northwestern produces the highest and directions of southwest and the southeast had the least amount of fruit. Gray coverage significantly increased the rate of ripening of the fruit in the unit time in both years. Awad (2007) said it might be possible that bunch bagging, especially with black and blue polyethylene bags, accumulated higher heat units than other bags and the controls. Consequently, accumulated heat might induce higher respiration rates and the CO2 accumulation within bags might lead to more acetaldehyde production and removal of astringency.
Conclusions: According to data obtained from physiological factors it can be concluded that palm bunch covering accelerates the ripening of fruits. Also, the data obtained from the directions of bunch shows those bunches located on the north side of the palm tree weigh more.
somayeh rastegar; majid rahemi
Abstract
In this research different compounds such as moisture,protein,nutrition,fructose and glucose,cartenoid,organic acid,phenolic acid of piarom,shahani and deiry were studied.Suger was analyzed by (HPAEC-PAD). organic acids and phenoilc acids were studied by (HPLC). According to our result, shahani, piarom ...
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In this research different compounds such as moisture,protein,nutrition,fructose and glucose,cartenoid,organic acid,phenolic acid of piarom,shahani and deiry were studied.Suger was analyzed by (HPAEC-PAD). organic acids and phenoilc acids were studied by (HPLC). According to our result, shahani, piarom and deiry as soft, semi-dry and dry cultivars showed significant differences (p < 0.05) between most properties. Piarom has the highest organic acid compared other cultivar. Piarom has the highest organic acid, but in nutrition, total phenol and phenolic acids, deiry has first value. In three cultivars, among the minerals studied, potassium was most abundant with a concentration of 1170–2440 mg/100 g. Shahani has the highest reducing sugar (68.8%) and showed significant differences in compared to piarom and deiry. Deiry has the highest proteins (7.3%) as compared to other cultivars
Sh. Amini; M. Arab; majid rahemi; A.R. Rahimi
Abstract
This research was carried out in order to evaluate the influence of different concentrations of ethanol and methanol (0, 4, 6 and 12%) and two pulse treatments (12 and 24 hour) on longevity of cut standard-carnation (Sensi cultivar) in a factorial based on randomized completely design with three replications, ...
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This research was carried out in order to evaluate the influence of different concentrations of ethanol and methanol (0, 4, 6 and 12%) and two pulse treatments (12 and 24 hour) on longevity of cut standard-carnation (Sensi cultivar) in a factorial based on randomized completely design with three replications, at Tehran University, Aboreyhan Pardis, horticulture department, during 2010. The results showed that the effect of alcohol treatments and interaction effect of alcohols and pulse on vase life were significant (at what level?????), whereas solution uptake and relative fresh weight were not affected by mentioned treatments. The highest (17.33 day) and lowest (11 day) amount of carnation vase life were obtained by ethanol 12% at pulse of 12 hours and control treatments, respectively. Ethanol 6% at pulse of 24 hours, ethanol 12% and methanol 6% at pulse of 12 hours were more effective in increasing the longevity of carnation than other pulse, while in other treatments, no significant differences were observed between the pulse times. Moreover, the highest of ethylene production obtained by control, while ethanol 4% and 6% at pulse of 24 hours, ethanol and methanol 12% at pulse of 12 hours and methanol 6% at both time of pulse markedly decreased the production of ethylene and lead to significantly increase in vase life. The relative extension of flowers and relative fresh weight had a positive correlation with vase life, while solution uptake had non correlation or negative correlation with other treats.
F. Salmanizade; S.M. Nassiri; majid rahemi; A.A. Jafari
Abstract
In the present study application of X-ray computed tomography as a nondestructive technique for estimation of some qualitative parameters of pomegranate fruit was studied. For this purpose, three local cultivars of pomegranate fruit of Fars province, Iran that included; Rabab Malas, Rabab Torsh and Khani ...
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In the present study application of X-ray computed tomography as a nondestructive technique for estimation of some qualitative parameters of pomegranate fruit was studied. For this purpose, three local cultivars of pomegranate fruit of Fars province, Iran that included; Rabab Malas, Rabab Torsh and Khani Kazeroon were used. The X-ray CT images of pomegranate fruits were prepared using CT-Scan device. Corresponding CT numbers that indicate X-ray absorption value of objective were extracted using K-PACS software. The qualitative parameters such as anthocyanin, titratable acidity, soluble solids, taste index and pH of different pomegranate fruits were measured. Relationships between qualitative parameters and the obtained CT numbers were evaluated using linear regression models. The results indicated that R2 for estimation of qualitative parameters for all models was more than 0.900. The CT number had positive correlation with titratable acidity and negative correlation with anthocyanin, soluble solids and pH for all pomegranate varieties. The relations for estimating the qualitative parameters of Rabab Malas variety showed the highest precision (0.971, 0.947, 0.963 and 0.946 for anthocyanin, soluble solids, titratable acidity and pH, respectively). The highest correlation was observed between the amount of anthocyanin and CT number for all pomegranate fruit cultivars (with coefficient of determination of 0.971, 0.943 and 0.960 for Rabab Malas, Rabab Torsh, Khani Kazeroon, respectively). Overall results revealed that CT number can be applied as a useful index for estimation of qualitative parameters of pomegranate fruit especially for real-time sensing situations.
L. Taghipour; majid rahemi
Abstract
Abstract
To evaluate the effects of some chemical agents on fruit thinning percent and fruit quality of apricot cv ‘Khiary’ an experiment were carried out in the commercial orchard at Neyriz, Fars province, Iran. Naphthaleneacetic acid (NAA)( 10, 20 and 40 mg l-1 ), naphthaleneacetamide (NAD) ( ...
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Abstract
To evaluate the effects of some chemical agents on fruit thinning percent and fruit quality of apricot cv ‘Khiary’ an experiment were carried out in the commercial orchard at Neyriz, Fars province, Iran. Naphthaleneacetic acid (NAA)( 10, 20 and 40 mg l-1 ), naphthaleneacetamide (NAD) ( 20, 40 and 80 mg l-1 ), ethephon ( 50, 100 and 200 mg l-1 ) and urea( 0.2, 0.4 and 0.6%) were sprayed on selected branch units 2 weeks after full bloom (AFB) in 2006. Results showed that all treatments except urea at 0.6% significantly increased fruit drop in comparison with control (P=0.05). Chemical agents increased fruit volume, length, diameter, total soluble solids (TSS), Tss/total acid ratio, nut weight and flesh/nut ratio. Between control and other treatments had no significant effect on total acidity (TA) of fruits.
Key words: Ethephon, Naphthaleneacetic acid (NAA), Naphthaleneacetamide (NAD), Urea
M. Siahkoohi; majid rahemi; .Amanollah Javanshah
Abstract
Abstract
The present research was conducted in a commercial orchard of pistachio during 2006-2007 in Rafsanjan, Iran. Gibberellic acid (GA3) were applied at 0, 25, 50 and 75 mgL-1 and at three time of spray (the first of June, July and August) on “Ahmad-aghai” pistachio cultivar. Two branches of ...
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Abstract
The present research was conducted in a commercial orchard of pistachio during 2006-2007 in Rafsanjan, Iran. Gibberellic acid (GA3) were applied at 0, 25, 50 and 75 mgL-1 and at three time of spray (the first of June, July and August) on “Ahmad-aghai” pistachio cultivar. Two branches of each tree was sprayed during two years of study. Spraying at June had least of early splitting. GA3 at 50 and 75 mgL-1 significantly reduced early splitting and cracking. Time of application had no significant effect on in dehiscent of pistachio nut. Percentage of indehiscent pistachio nut was increased by increasing the concentration of GA3. Spraying in August increased fat and protein content of kernel of pistachio nut. Treatments of GA3 had no significant effect on fat and protein content of kernel. GA3 was increased chlorophyll content of kernel of pistachio nut at 75 mgL-1.
Key words: “Ahmad-aghai”, Indehiscent pistachio, Protein content of kernel, Chlorophyll content of kernel
