Hot Water Treatments of Fruits and Vegetables for Postharvest Storage

2011 ◽  
pp. 191-212 ◽  
Author(s):  
Elazar Fallik
2020 ◽  
pp. 1081-1087
Author(s):  
M.M. Abubakar ◽  
M. Norida ◽  
M.Y. Rafii ◽  
J.J. Nakasha

During the postharvest management of fruits and vegetables, the losses range from 10 to 30% of the entire production. This is due to numerous causes, but the most important reason is infestation by fungi. Many synthetic fungicides are employed for postharvest treatment of fruit and vegetables throughout the world. However, fungicidal residues often represent a significant threat to human health. The current study examined the use of hot water treatments on rock melon fruit. Hot water treatments at 55℃ was arranged into four treatments of different dipping periods of 0 minutes (control), 1 minute, 2 minutes, and 3 minutes. The postharvest hot water treatments on rock melon fruit were found to increase the shelf life up to 21 days by minimizing the weight loss, maintaining firmness, preventing the damage of sucrose, retaining the rind size, maintaining the fruit appearance, and reducing fungal infection. The one-minute dip was more effective than other treatments. The treatment successfully extends the shelf life of rock melon fruit quality for the market until three weeks of storage at 21 ± 1 ℃ compared with the control, which was only stored for one week. The results showed the importance of hot water treatments as an alternative to fungicides or chemical treatments, which have a high risk to the health of consumers. Hot water treatment is economical and easier to access than the chemical treatments.


2021 ◽  
pp. 096739112110060
Author(s):  
Mouna Werchefani ◽  
Catherine Lacoste ◽  
Hafedh Belguith ◽  
Chedly Bradai

The present work is a comparative study of the impact of Alfa fiber modifications on the Cereplast composites mechanical behavior. Various treatments have been employed, including mechanical, soda, saltwater-retting, hot-water treatments and enzymatic treatment using xylanase. Chemical and morphological analyses were carried out in order to determine the changes of the biochemical composition and the dimensions of fibers. Cereplast composites reinforced with Alfa fibers were fabricated using a twin-screw extrusion followed by an injection molding technique with a fiber load of 20 wt. %. Resulting materials were assessed by means of tensile, flexural and Charpy impact testing. Scanning Electron Microscopy analysis was carried out to investigate the interfacial properties of the composites. The results have shown a significant enhancement of mechanical strengths and rigidities for the xylanase-treated fiber composites, owing to the increase of cellulose content, the enhancement of defibrillation level and the improvement of matrix-fiber adhesion. The data proved that the technology of enzymes can be used as a powerful and eco-friendly approach to modify fiber surfaces and to increase their potential of reinforcement.


2003 ◽  
Vol 66 (7) ◽  
pp. 1241-1246 ◽  
Author(s):  
BALASUBRAHMANYAM KOTTAPALLI ◽  
CHARLENE E. WOLF-HALL ◽  
PAUL SCHWARZ ◽  
JURGEN SCHWARZ ◽  
JAMES GILLESPIE

The use of Fusarium-infected barley for malting may lead to mycotoxin production and decreased product quality. Physical methods for the treatment of Fusarium-infected barley may prevent these safety and quality defects and allow the use of otherwise good quality barley. Hot water and electron beam irradiation were evaluated for their effectiveness in reducing Fusarium infection while maintaining germinative energy in barley samples. Hot-water treatments involved temperatures of 45, 50, 55, and 60°C and treatment times of 0, 1, 5, 10, and 15 min. Electron beam irradiation involved doses ranging from 0 to 11.4 kGy. Treatment with water at 45°C for 15 min resulted in a reduction in Fusarium infection from 32 to 1% after 15 min, with only a very slight reduction in germination. Treatment with water at 50°C for 1 min resulted in a reduction in Fusarium infection from 32 to 2%, and no effect on germination was observed for up to 5 min of treatment. At higher water temperatures, Fusarium infection was essentially eliminated, but germination was also severely reduced. Electron beam irradiation of Fusarium-infected barley reduced Fusarium infection at doses of >4 kGy, and a slight increase in germination for dry samples was observed with doses of 6 to 8 kGy. Doses of >10 kGy significantly decreased germination. Physical methods may have potential for the treatment of Fusarium-infected malting barley.


Nutrients ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 4495
Author(s):  
Filipa Campos ◽  
Andreia F. Peixoto ◽  
Pedro A. R. Fernandes ◽  
Manuel A. Coimbra ◽  
Nuno Mateus ◽  
...  

Type 2 diabetes mellitus (T2DM) is one of the most prevalent chronic metabolic diseases of the 21st century. Nevertheless, its prevalence might be attenuated by taking advantage of bioactive compounds commonly found in fruits and vegetables. This work is focused on the recovery of polyphenols and polysaccharide–polyphenol conjugates from grape pomace for T2DM management and prevention. Bioactives were extracted by solid–liquid extraction and by pressurized hot water extraction (PHWE). Polyphenolic fraction recovered by PHWE showed the highest value for total phenolic content (427 mg GAE.mg−1), mainly anthocyanins and proanthocyanidins, and higher antioxidant activity compared to the fraction recovered by solid–liquid extraction. Polysaccharide–polyphenol conjugates comprehended pectic polysaccharides to which approximately 108 mg GAE of phenolic compounds (per mg fraction) were estimated to be bound. Polyphenols and polysaccharide–polyphenol conjugates exhibited distinct antidiabetic effects, depending on the extraction methodologies employed. Extracts were particularly relevant in the inhibition of a-glucosidase activity, with free polyphenols showing an IC50 of 0.47 mg.mL−1 while conjugates showed an IC50 of 2.7, 4.0 and 5.2 mg.mL−1 (solid–liquid extraction, PHWE at 95 and 120°C, respectively). Antiglycation effect was more pronounced for free polyphenols recovered by PHWE, while the attenuation of glucose uptake by Caco-2 monolayers was more efficient for conjugates obtained by PHWE. The antidiabetic effect of grape pomace bioactives opens new opportunities for the exploitation of these agri-food wastes in food nutrition, the next step towards reaching a circular economy in grape products.


2006 ◽  
Vol 131 (2) ◽  
pp. 209-213 ◽  
Author(s):  
Pauliina Palonen ◽  
Leena Lindén

`Maurin Makea', `Muskoka', ` Ottawa', and `Preussen' red raspberry (Rubus idaeus L.) canes were collected from the field and subjected to different hot water treatments (20, 35, 40, 45, and 50 °C) to determine if endodormancy could be removed by a near lethal stress. Estimation of days for 50% budbreak (DD50) was found useful for describing the state of bud dormancy in the samples. Bud dormancy was broken in `Ottawa' by immersing the canes in 45 °C water for 2 hours, in `Maurin Makea' by treating the canes in 40 °C water, and in `Preussen' by both 40 and 45 °C treatments. The influence of this treatment on dormancy and cold hardiness at different times of the winter was further examined using `Ottawa' raspberry. The treatment removed bud dormancy most effectively in October, when the samples were in deepest dormancy. A slight effect was observed in November, but no effect in January. During ecodormancy in February the treatment delayed budbreak. Hot water treatment reduced cold hardiness of `Ottawa' canes by 8 to 15 °C, and that of buds by 9 to 13 °C during both endo- and ecodormancy. Based on the capacity of buds and canes to reacclimate, recovery from the stress treatment was possible at temperatures ≥4 °C. Loss of cold hardiness was caused by high treatment temperature itself and was not related to breaking of dormancy in samples. This finding suggests that dormancy and cold hardiness are physiologically unconnected in raspberry.


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