EFFECTS OF HOT WATER TREATMENTS ON POSTHARVEST QUALITY AND ETHYLENE SYNTHESIS OF BANANAS

Breadfruit from Samoa potentially host the Pacific fruit fly (Bactrocera xanthodes) and so their export to New Zealand requires a disinfestation treatment. Heat treatments by air (HAT) or water (HWT) are common fruit-fly disinfestation treatments for tropical crops. Two breadfruit cultivars – Puou and Ma’afala – were subjected to three heat treatments, HAT-1 (minimum 47.2oC for 20 min at core), HAT-2 (49.0oC for 100 min at core) and HWT (47.2oC for 20 min at core), and an untreated control was also included. Fruit were stored for one week at 15oC followed by three days at 25oC. Disorders observed were heat damage to the skin (blackening) and increased decay on the body and stem-end. Heat damage was at an acceptably low level following HAT-1 but was unacceptable following HAT-2 or HWT. Initial results suggest that a HAT can be tolerated, but the effect of ramp rate and the potential of using a two-step HWT system should be examined.

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Hot Water Combined with Calcium Treatment Improves Physical and Physicochemical Attributes of Kiwifruit (Actinidia deliciosa cv. Hayward) during Storage

HortScience ◽

10.21273/hortsci.50.3.412 ◽

2015 ◽

Vol 50 (3) ◽

pp. 412-415 ◽

Cited By ~ 2

Author(s):

Shirin Shahkoomahally ◽

Asghar Ramezanian

Keyword(s):

Hot Water ◽

Actinidia Deliciosa ◽

Postharvest Quality ◽

Total Phenolic ◽

Long Term Storage ◽

Water Treatments ◽

Term Storage

Kiwifruit has a short storage life and encounters severe disorders during maintenance mainly as a result of its climacteric behavior. The role of calcium and heat treatment in delaying degenerative processes during storage has been revealed. This study investigated the effects of hot water combined with calcium (Ca) dips on the quality of kiwifruit (Actinidia deliciosa cv. Hayward). Whole fruits were treated with hot water for 5, 10, and 15 minutes at 47 °C, therefore dipped in CaCl2 solution (2% w/v) and stored at 0 °C for up to 120 days. During storage, fruit were sampled at 0, 30, 60, 90, and 120 days for postharvest quality evaluation. Postharvest evaluations included chromatic parameters (L*, a*, b*, hue, and chroma), firmness, and physiological parameters [phenolic content and polyphenol oxidase (PPO)]. Heating combined with Ca dips significantly reduced PPO activity. The results showed that mild heat treatments in combination with CaCl2 maintained chromatic parameters for kiwifruits compared with control and hot water or CaCl2 treatments solely. In addition, the levels of total phenolic compounds remained significantly higher for hot water combined with CaCl2-treated fruit as compared with control or untreated fruits. According to the results, hot water treatments had a significant firming effect, whereas CaCl2 dips solely had less effect on chromatic parameters. However, the influence of hot water treatments was dependent on application time with (treatment that showed significant results) showing significant improved kiwifruit postharvest qualities. Overall, with this simple and non-contaminant technology, after long-term storage, quality of kiwifruit could be even greater than in recently harvested fruits.

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Alfa fibers for Cereplast bio-composites reinforcement: Effects of chemical and biological treatments on the mechanical properties

Polymers and Polymer Composites ◽

10.1177/09673911211006067 ◽

2021 ◽

pp. 096739112110060

Author(s):

Mouna Werchefani ◽

Catherine Lacoste ◽

Hafedh Belguith ◽

Chedly Bradai

Keyword(s):

Charpy Impact ◽

Impact Testing ◽

Hot Water ◽

Cellulose Content ◽

Twin Screw ◽

Electron Microscopy Analysis ◽

Alfa Fibers ◽

Charpy Impact Testing ◽

Water Treatments ◽

The Impact

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.

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