scholarly journals Tolerance of Selected Orange and Mandarin Hybrid Fruit to Low-dose Irradiation for Quarantine Purposes

HortScience ◽  
2000 ◽  
Vol 35 (7) ◽  
pp. 1288-1291 ◽  
Author(s):  
W.R. Miller ◽  
R.E. McDonald ◽  
J. Chaparro
Keyword(s):  
Citrus Sinensis ◽  
Low Dose ◽  
Titratable Acidity ◽  
Soluble Solids ◽  
Citrus Reticulata ◽  
Citrus Fruits ◽  
Dose Irradiation ◽  
Irradiation Treatment ◽  
Dose Tolerance ◽  
Dose Dependent

Tolerance of many citrus cultivars to low-dose irradiation treatment is not known. Ten citrus cultivars grown in Florida, including the five orange [Citrus sinensis (L.) Osbeck] cultivars, Ambersweet, Hamlin, Navel, Pineapple, and Valencia, and the five mandarin hybrids (Citrus reticulata Blanco), `Fallglo', `Minneola', `Murcott', `Sunburst', and `Temple', were exposed to irradiation at 0, 0.15, 0.3, and 0.45 kGy, and stored for 14 days at 1 °C or 5 °C plus 3 days at 20 °C, to determine dose tolerance based on fruit injury. Softening of `Valencia', `Minneola', `Murcott', and `Temple' was dose-dependent, but that of other cultivars was unaffected. Only `Ambersweet', `Valencia', `Minneola', and `Murcott' did not develop peel pitting at 0.15 kGy or higher. Total soluble solids of `Ambersweet' and `Sunburst' declined slightly with increasing dose. Titratable acidity (TA) of oranges was not affected, but TA of `Sunburst' and `Temple' juice was slightly reduced by irradiation at 0.45 kGy. Juice flavor of `Hamlin', `Navel', `Valencia', and `Minneola', and pulp flavor of `Hamlin', `Valencia', `Fallglo', `Minneola', and `Murcott' was less acceptable after irradiation at 0.3 or 0.45 kGy. The appearance of all cultivars was negatively affected by the loss of glossiness with the 0.45 kGy dose. Less than 1.0% of fruit decayed and irradiation treatment had no effect on decay. Our study indicates that growers and shippers need to be aware that the effects of irradiation on citrus fruits are highly variable and both cultivar-dependent and dose-dependent.

Low dose irradiation of plum peel anthocyanins: Impact on stability and antioxidant activity

2021 ◽  
Author(s):  
Peerzada R. Hussain ◽  
Prashant P. Suradkar
Keyword(s):  
Antioxidant Activity ◽  
Low Dose ◽  
B Value ◽  
Natural Food ◽  
Thermal Methods ◽  
Dose Irradiation ◽  
Extraction And Purification ◽  
Irradiation Treatment ◽  
The Individual ◽  
Anthocyanin Degradation

Consumer demand for both natural food colorants and non-thermal methods of preservation has increased overwhelmingly during the last few decades. Preventing loss of appeal and color through non-thermal methods without compromising on quality will provide an alternative to conventional thermal methods. In the present study, irradiation of plum peel anthocyanins after extraction and purification was done in a range of 0.1-1.0 kGy. Results revealed that degradation was significantly (p ≤ 0.05) dependent on both time and dose of irradiation. The percentage degradation observed in the first 3 h of treatment was 9.0-21.0±1.2%. The maximum anthocyanin degradation recorded during 8 h of irradiation was 45.3%. Anthocyanin degradation was apparently less at 0.1-0.5 kGy compared to 0.6-1.0 kGy. The retention of anthocyanins was up to the extent of 88.8-62.3% in samples irradiated at 0.1-0.5 kGy. Comparison of the individual anthocyanin indicated that diglucoside anthocyanins were stable towards irradiation than monoglucoside anthocyanins. For monoglucoside anthocyanins, a 50% decrease was observed as the irradiation treatment exceeded 0.6 kGy. A close comparison of the data revealed that at irradiation dose of 1.0 kGy, the decrease in L* and a* values was almost four and three times higher than that observed in samples irradiated at 0.5 kGy and below; while an increase in b* value was almost double. In spite of marginal degradation in color, low dose irradiation (up to 0.5 kGy) significantly (p≤0.05) increased the antioxidant activity of the plum peel anthocyanins.

scholarly journals Postharvest Quality of Dragon Fruit (Hylocereus spp.) after X-ray Irradiation Quarantine Treatment

HortScience ◽  
2008 ◽  
Vol 43 (7) ◽  
pp. 2115-2119 ◽  
Author(s):  
Marisa M. Wall ◽  
Shakil A. Khan
Keyword(s):  
Titratable Acidity ◽  
Soluble Solids ◽  
Postharvest Quality ◽  
X Ray ◽  
Irradiation Treatment ◽  
Dragon Fruit ◽  
Fruit Decay ◽  
Irradiation Stress ◽  
Solids Content

The quality of three dragon fruit clones (Hylocereus spp.) was determined after x-ray irradiation for disinfestation of quarantine pests. Fruit were treated with irradiation doses of 0, 200, 400, 600, or 800 Gy and stored for 12 days at 10 °C. Irradiation did not affect soluble solids content, titratable acidity, or fructose concentrations. Glucose, sucrose, and total sugar concentrations decreased linearly as dose increased. Minimal softening occurred in the outer flesh layers for fruit treated with 400 or 600 Gy irradiation. Surface color, peel injury, and bract appearance differed among the three clones with irradiation stress, but in all cases, visible changes were minor. Fruit decay was absent or minimal, and disease ratings were not affected by irradiation. Irradiation treatment of dragon fruit at doses 800 Gy or less would ensure visual and compositional quality while providing quarantine security.

scholarly journals Population dynamics of aphids (Aphididae) on orange (Citrus sinensis ‘Thomson Navel’) and mandarin (Citrus reticulata ‘Blanco’)

2016 ◽  
Vol 107 (1) ◽  
pp. 137 ◽  
Author(s):  
Salim LEBBAL ◽  
Malik LAAMARI
Keyword(s):  
Citrus Sinensis ◽  
Common Species ◽  
Aphid Species ◽  
Climatic Conditions ◽  
Citrus Reticulata ◽  
Citrus Fruits ◽  
June July August ◽  
Aphis Spiraecola ◽  
June July ◽  
Orange Trees

Citrus fruits represent one of the most important fruit productions worldwide. However, they suffer from a numerous constraints. Aphids are among the causes of the decline in the production of citrus. In this study, the diversity of citrus aphids and their seasonal occurrence were explored on orange and mandarin, during 2012 and 2013, in an orchard located in Skikda province (Algeria). In total, six different aphid species were found during two years. The most common species was <em>Aphis spiraecola </em>Patch, 1914.  Climatic conditions had an important role in the infestation level by aphids. There were changes of aphid dynamics between the two years of the investigation. No aphids was recorded in six months in 2012 (January, June, July, August, September and December) and in three months in 2013 (January, February and August).  Besides, the number of identified aphid species increased from two to five. On the other hand, the orange trees seemed to be the most infested host species.

Effect of Sugar and Low-Dose Irradiation on Toxin Production by Clostridium botulinum in Comminuted Bacon

1986 ◽  
Vol 49 (2) ◽  
pp. 112-116 ◽  
Author(s):  
C. N. HUHTANEN ◽  
J. SHIEH ◽  
E. WIERBICKI ◽  
L. ZAIKA ◽  
R. K. JENKINS ◽  
...  
Keyword(s):  
Incubation Period ◽  
Clostridium Botulinum ◽  
Low Dose ◽  
Titratable Acidity ◽  
Toxin Production ◽  
Dose Irradiation ◽  
Toxin Formation

Comminuted bacon, processed to contain target levels of 40 μg NaNO2/g and 0, 0.25 or 0.75% sucrose or 0.75% glucose, was inoculated with a mixture of spores of 20 strains of Clostridium botulinum (400 spores per g) and was canned under vacuum. Portions were irradiated using 137Cs at doses of 0, 0.19, 0.38, 0.75, 1.12 and 1.5 Mrad. Cans were incubated for 1, 2, 4 or 8 wk at 30°C. Some cans of nonirradiated bacon without or with 0.25% sucrose became toxic in 2 wk; with 0.75% sucrose, toxin production was delayed to 8 wk. Bacon irradiated at 0.75 Mrad, made with or without sucrose, became toxic in 2 to 4 wk, whereas most cans of bacon irradiated at 1.5 Mrad remained toxin-free for the 8-wk incubation period. A comparison of bacon made with 0.75% sucrose or glucose showed no difference between the sugars in the rates of toxin production by C. botulinum in irradiated cans of bacon. Irradiation at 0.19 Mrad increased the rate of toxin formation over nonirradiated bacon in sugar-containing (0.75%) bacon, but had no effect in sugar-free bacon. The pH of nonirradiated bacon containing 0.75% glucose or sucrose decreased from pH 6.12 and 6.11, respectively, to pH 5.63 and 5.67 after 8 wk of incubation at 30°C. The titratable acidity showed a concurrent increase. The pH and titratable acidity of bacon irradiated at 0.19 Mrad or higher showed no changes.

scholarly journals Effect of Alcoholic Extracts of Cymbopogon citratus upon the Control of Colletotrichum gloeosporioides in vitro and upon the Post-harvest Quality of Guavas

2019 ◽  
pp. 1-8
Author(s):  
Ana P. F. A. Santos ◽  
Amanda P. Mattos ◽  
Adriana T. Itako ◽  
João B. Tolentino Júnior ◽  
Gabriela S. Moura ◽  
...  
Keyword(s):  
Colletotrichum Gloeosporioides ◽  
Titratable Acidity ◽  
Physicochemical Characteristics ◽  
Soluble Solids ◽  
Post Harvest ◽  
Methanolic Extracts ◽  
Dose Dependent

Aims: This work aimed at evaluating the effects of ethanolic and methanolic extracts of lemongrass upon the control in vitro of Colletotrichum gloeosporioides and upon the post-harvest quality of guavas “Paluma”. Methodology: We analyzed the inhibition of mycelial growth and sporulation of the pathogen at different concentrations of the extracts (8%; 5%; 3%; 1.5% and 0.5%). In the post-harvest assay, the guavas were treated by immersion in distilled water, ethanolic and methanolic extracts (1%; 0.5% and 0.25%) and stored at 25ºC ± 2ºC for eight days. We evaluated mass loss, total soluble solids, total titratable acidity, ratio, reducing and non-reducing sugars, ascorbic acid and pH and the incidence of anthracnose. Results: In the test in vitro, the pathogen growth inhibition was dose-dependent and the sporulation was completely inhibited upon higher concentrations of extract. At post-harvest, the fruits maintained their physicochemical characteristics, and the treatments were not efficient at retarding fruit ripening. Although the tested treatments inhibited the plant pathogen C. gloesporioides in vitro, they were not efficient at controlling the disease in vivo. Conclusion: The extracts showed control in vitro of C. gloeosporioides at 8%. However, the extracts were not effective at controlling the disease after harvest.

scholarly journals 121 Postharvest Rripening of Tomato Following Low-dose Gamma-irradiation and Water-based Chemical Treatment

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 410A-410
Author(s):  
G. Findley ◽  
F.M. Woods ◽  
D.E. Conner ◽  
C. Mosjidis ◽  
S.J. Weese ◽  
...  
Keyword(s):  
Gamma Irradiation ◽  
Foodborne Pathogens ◽  
Chemical Treatment ◽  
Fruits And Vegetables ◽  
Low Dose ◽  
Soluble Solids ◽  
Ethylene Concentration ◽  
Carbohydrate Concentration ◽  
Irradiation Treatment ◽  
Water Based

Low-dose gamma-irradiation is becoming increasingly an attractive viable technology for control of food-borne pathogens and extension of shelf life of fruits and vegetables. Typically, gamma-irradiation treatment appears to transiently stimulate ethylene synthesis in tomato, which appears to be stress associated, and dose dependent (Larrigaudie et al., 199l). We have investigated the effects of gamma-irradiation treatment at doses of 0, 0.5, 0.75, and 1.0 kGy, alone and in combination with water-based chemical treatment for improving the storage of tomato maintained at 20 °C and 95% RH for 20 days of storage. Changes in ethylene, ascorbic acid and total antioxidant content, color, total soluble solids and carbohydrate concentration were examined. Our preliminary results indicate that these treatments are effective in reducing ethylene concentration in storage while providing a means of eliminating foodborne pathogens without adversely affecting tomato quality.

scholarly journals Phytosanitary Irradiation Preserves the Quality of Fresh Blueberries and Grapes during Storage

HortScience ◽  
2015 ◽  
Vol 50 (11) ◽  
pp. 1666-1670 ◽  
Author(s):  
Jonathan Tong ◽  
Cyril Rakovski ◽  
Anuradha Prakash
Keyword(s):  
Titratable Acidity ◽  
Soluble Solids ◽  
Target Dose ◽  
Ambient Temperatures ◽  
Solids Concentration ◽  
Irradiation Treatment ◽  
Grape Varieties ◽  
Dose Levels ◽  
Soluble Solids Concentration

The objective of this study was to monitor the effects of irradiation on the quality of blueberries and grapes treated at phytosanitary dose levels. Blueberry varieties ‘Star’, ‘Jewel’, and ‘Snowchaser’ and grape varieties ‘Sugraone’ and ‘Crimson Seedless’ were irradiated at a target dose of 400 Gy (range of 400–590 Gy for blueberries and 400–500 Gy for grapes) and stored for 3 and 18 days under refrigeration, plus 3 days at ambient temperatures and evaluated for quality. Storage affected quality of both fruit more than irradiation treatment and there were significant differences among varieties. Irradiated ‘Star’ blueberries maintained their firmness and sensory scores and resisted decay. Alternatively, irradiated ‘Jewel’ blueberries decreased in firmness but sensory scores for overall liking were higher than the control following 3 weeks of storage. ‘Snowchaser’ blueberries were harvested late in the blueberry season and were not as affected by treatment or time due to their initial compromised nature. Firmness was the primary attribute affected by irradiation for both varieties of grapes, but sensory testing showed that consumers did not have a preference for control or irradiated fruit. With respect to other attributes such as color, weight loss, and soluble solids concentration (SSC)/titratable acidity (TA), there were differences among fruit varieties but treatment effects were not significant. Our results show that both, blueberries and grapes, have a high tolerance for phytosanitary irradiation and that storage affects their quality more than irradiation treatment.

scholarly journals Effects of Gamma Radiation (Co 60) in Cachaça containing grapes (Crimson)

2015 ◽  
Vol 6 (1) ◽  
pp. 51
Author(s):  
Juliana Angelo Pires ◽  
Aline Da Silva Delabio ◽  
Rafaela Prezotto Vicente ◽  
Marcia Nalesso Costa Harder ◽  
Lucia Cristina Aparecida Santos Silva ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Statistical Difference ◽  
Titratable Acidity ◽  
Soluble Solids ◽  
Chemical Characteristics ◽  
Physical And Chemical Characteristics ◽  
Irradiation Treatment ◽  
And Control ◽  
Physical And Chemical

<p>The current study deals with <em>cacha&ccedil;a</em> irradiation in the presences of grapes, with the use of gamma radiation (Co 60) to evaluate its effects on the physical and chemical characteristics of this beverage. The research had as objective to assess the effects of irradiation in <em>cacha&ccedil;as</em>, in the extraction of compounds present in the pickled grapes in the <em>cacha&ccedil;a</em>. Samples were prepared with grapes type Crimson, in polypropylene bottles, with and without grapes. Both types of samples were irradiated with doses of 0 (control) and 300Gy. Later were performed physical and chemical analyzes (pH, titratable acidity, soluble solids) during a 5-day span after irradiation treatment. Significative statistical difference was noticed in titratable acidity of the samples that contained grapes, larger values when compared with pure samples. However, there was no statistical difference when comparing the pure beverage with control or the beverage containing grapes and control. For pH the values for the samples with grapes is statistically lower than the others. The results for soluble solids (&ordm;Brix) displayed an increase on both types of samples comparing with their respective controls. In conclusion, the 300Gy dose was effective for increasing soluble solids quantity both in pure <em>cacha&ccedil;as</em> as in presences of grapes. Relating to pH and acidity, this dose shows interference when grapes are presents.</p><p>&nbsp;</p><p>DOI: 10.14685/rebrapa.v6i1.199</p>

scholarly journals Chitosan and fungicides on postharvest control of Guignardia citricarpa and on quality of 'Pêra Rio' oranges

2011 ◽  
Vol 37 (3) ◽  
pp. 142-144 ◽  
Author(s):  
Maria Cristina Canale Rappussi ◽  
Eliane Aparecida Benato ◽  
Patrícia Cia ◽  
Sérgio Florentino Pascholati
Keyword(s):  
Black Spot ◽  
Storage Period ◽  
Ascorbic Acid Content ◽  
Titratable Acidity ◽  
Soluble Solids ◽  
Citrus Fruits ◽  
Ripening Process ◽  
Guignardia Citricarpa ◽  
Postharvest Control

Citrus fruits are affected by the black spot disease caused by the fungus Guignardia citricarpa. Chitosan can be used as covering for fruits and may delay the ripening process and inhibit the growth of some fungi. Thus, the control of citrus black spot using chitosan and the fungicides thiabendazole and imazalil was assessed in addition to the physicochemical quality of 'Pêra Rio' oranges. The oranges were immersed into chitosan, thiabendazole or imazalil, and in chitosan mixed with both fungicides. The fruits were then stored at 25 °C, 80% RH, for 7 days and, after this storage period, subjected to physicochemical analyses. Chitosan in association with the fungicides reduced black spot in 'Pêra Rio' oranges and delayed the change in the orange skin colour from green to yellow during the postharvest storage. Total soluble solids, titratable acidity, pH, ascorbic acid content and ratio were not influenced by the treatments. Thus, chitosan applied with the fungicides thiabendazole and imazalil showed potential to control the development of black spot lesions on 'Pêra Rio' oranges during the postharvest period.

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