Postharvest application of hydrogen peroxide affects physicochemical characteristics of tomato fruits during storage

Author(s):  
Huseyin Torun ◽  
Selman Uluisik
Author(s):  
María Lorena Luna-Guevara ◽  
Teresita González-Sánchez ◽  
Adriana Delgado-Alvarado ◽  
María Elena Ramos-Cassellis ◽  
José Guillermo Pérez-Luna ◽  
...  

Objective: To study the effect of storage temperatures and dehydration conditions (solar and convective drying; SD, CD), on the quality, physicochemical parameters and antioxidant properties of tomato fruits. Methodology: The physicochemical characteristics pH, titratable acidity, soluble solids (°Bx) and color parameters (L*, a* and b*), were evaluated. The lycopene, carotenoids and antioxidant activity percentages retention of tomatoes fruits stored at 7 and 22 ° C for 5 days and subjected to SD (Temperature (T) of 67 °C and luminescence of 685 lum/sqf) and CD (T 70 °C, flow rates 0.5, 1.0 and 1.5 m/s), were analyzed. Results: The fruits reached humidities of 17 and 15% for SD and CD. The parameters pH, °Bx, L*, a*, b* were highest with 22°C and CD (1.5 m/s). The value of the carotenoids was higher in fruits stored at 7 ° C and subjected to CD (1.0 and 1.5 m/s) and SD with values of 83.85, 85.98 and 99.43%, respectively. The CD (0.5 m/s) and SD improved lycopene (94.37 and 95.14%) and the antioxidant activity with values of 73.06 and 97.21%. Implications: The application of solar dehydration depends on luminescence condition; however, it is inexpensive and environmentally friendly alternative. Conclusions: The results derived in a viable alternative for the conservation and commercialization of tomato fruits in rural communities


Author(s):  
Alfaro-Sifuentes ◽  
Juan ◽  
Meca ◽  
Elorrieta ◽  
Valenzuela

Tomatoes are among the most important horticultural crops; however, it is estimated that 30% of tomato yield is lost due to postharvest rot due to Rhizopus stolonifer, a fungus which requires lesions to initiate the infectious process. Tomato fruit cracking is a physiopathy which causes significant economic losses, since cracking is the door used by the fungus. In this experiment, 14 cultivars of tomato of different types were used. Fruit sampling was carried out in the middle of the crop cycle, coinciding with the peak of yield; then, the fruits were divided into two groups: one group was inoculated with Rhizopus in order to assess the effectiveness of washing, whilst the other was treated with sterile water. The fruits of each group were divided into lots to be treated with six washing treatments: dipping in hot water at 20, 40 and 60 °C for 20 s; the fruits were then sprayed with the following solutions: 0.6% of Hydrogen Peroxide 23% + Peracetic acid 15%; commercial bleach at 0.5% and 2% of Hydrogen Peroxide 50%. The control sample was not washed. The results show that there was an influence of cultivar on fruit cracking, which was strongly related with Rhizopus infection. Three cultivars were not susceptible to cracking, and therefore, were not sensitive to Rhizopus infection. The effectiveness of different washing treatments of tomato fruits depends on several factors; nonetheless, hot water treatment has been shown to be more effective than the use of chemical products such as commercial bleach or hydrogen peroxide. Another factor, the susceptibility of cultivars to cracking, determines the effectiveness of the washing treatment. The results provide an important basis for making decisions about the washing management of tomato fruits in packaging houses.


Author(s):  
Mohamed S. AL-Saikhan ◽  
Tarek A. Shalaby

Tomato is a perishable vegetable crop and it faces several problems during marketing and storage. Postharvest losses during storage of tomato fruits are mainly due to decay. In this study, the effect of postharvest application of hydrogen peroxide on quality and decay of tomato fruits during storage under two storage temperatures (10 ºC and 20 ºC) was studied. Tomato fruits (Red rose cv.) at light red maturity stage were dipped in a solution of hydrogen peroxide (0, 5 and 15 mM) for 30 min, then air-dried at room temperature and stored at room temperature (20ºC) for three weeks in fridge (10ºC) for 4 weeks. A factorial (3 x 2) complete randomized design with three replications was used. The results showed that Hydrogen peroxide treatments reduced weight loss and disease incidence percentage of fruits compared with control treatment (0 mM hydrogen peroxide). Moreover, hydrogen peroxide treatments had slight effect on fruit firmness. Regarding TSS% and ascorbic acid content, there were no significant differences among treatments. In addition, storage temperature affected tomato fruit quality during storage time. Therefore, the use of hydrogen peroxide in postharvest treatments is useful to keep quality of tomato fruits under storage conditions.


Author(s):  
George E. Childs ◽  
Joseph H. Miller

Biochemical and differential centrifugation studies have demonstrated that the oxidative enzymes of Acanthamoeba sp. are localized in mitochondria and peroxisomes (microbodies). Although hartmanellid amoebae have been the subject of several electron microscopic studies, peroxisomes have not been described from these organisms or other protozoa. Cytochemical tests employing diaminobenzidine-tetra HCl (DAB) and hydrogen peroxide were used for the ultrastructural localization of peroxidases of trophozoites of Hartmanella sp. (A-l, Culbertson), a pathogenic strain grown in axenic cultures of trypticase soy broth.


Author(s):  
Arezki Tagnit-Hamou ◽  
Shondeep L. Sarkar

All the desired properties of cement primarily depend on the physicochemical characteristics of clinker from which the cement is produced. The mineralogical composition of the clinker forms the most important parameter influencing these properties.Optical microscopy provides reasonably accurate information pertaining to the thermal history of the clinker, while XRDA still remains the proven method of phase identification, and bulk chemical composition of the clinker can be readily obtained from XRFA. Nevertheless, all these microanalytical techniques are somewhat limited in their applications, and SEM/EDXA combination fills this gap uniquely by virtue of its high resolution imaging capability and possibility of instantaneous chemical analysis of individual phases.Inhomogeneities and impurities in the raw meal, influence of kiln conditions such as sintering and cooling rate being directly related to the microstructure can be effectively determined by SEM/EDXA. In addition, several physical characteristics of cement, such as rhcology, grindability and hydraulicity also depend on the clinker microstructure.


2020 ◽  
Vol 48 (6) ◽  
pp. 2657-2667
Author(s):  
Felipe Montecinos-Franjola ◽  
John Y. Lin ◽  
Erik A. Rodriguez

Noninvasive fluorescent imaging requires far-red and near-infrared fluorescent proteins for deeper imaging. Near-infrared light penetrates biological tissue with blood vessels due to low absorbance, scattering, and reflection of light and has a greater signal-to-noise due to less autofluorescence. Far-red and near-infrared fluorescent proteins absorb light >600 nm to expand the color palette for imaging multiple biosensors and noninvasive in vivo imaging. The ideal fluorescent proteins are bright, photobleach minimally, express well in the desired cells, do not oligomerize, and generate or incorporate exogenous fluorophores efficiently. Coral-derived red fluorescent proteins require oxygen for fluorophore formation and release two hydrogen peroxide molecules. New fluorescent proteins based on phytochrome and phycobiliproteins use biliverdin IXα as fluorophores, do not require oxygen for maturation to image anaerobic organisms and tumor core, and do not generate hydrogen peroxide. The small Ultra-Red Fluorescent Protein (smURFP) was evolved from a cyanobacterial phycobiliprotein to covalently attach biliverdin as an exogenous fluorophore. The small Ultra-Red Fluorescent Protein is biophysically as bright as the enhanced green fluorescent protein, is exceptionally photostable, used for biosensor development, and visible in living mice. Novel applications of smURFP include in vitro protein diagnostics with attomolar (10−18 M) sensitivity, encapsulation in viral particles, and fluorescent protein nanoparticles. However, the availability of biliverdin limits the fluorescence of biliverdin-attaching fluorescent proteins; hence, extra biliverdin is needed to enhance brightness. New methods for improved biliverdin bioavailability are necessary to develop improved bright far-red and near-infrared fluorescent proteins for noninvasive imaging in vivo.


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