Quality response of table grapes (Vitis viniferaL.) during cold storage to postharvest cap stem excision and hot water treatments

‘Keitt’ mango is one of the most important cultivars, and it is usually stored at a low temperature during its commercialization to extend shelf life and reach distant markets. However, it is susceptible to chilling injury (CI) and some prestorage treatments are required to reduce the incidence of this disorder. This research shows for the first time the protective effect of a combination hot water-calcium lactate (Ca) against CI in mango fruit cv. Keitt. Fruit were subjected to hot water treatment (HWT) (46.1 °C, 75–90 minutes) or treated with 0.5% Ca or with the combination HWT + Ca, stored at 5 °C for 20 days, and ripened at 21 °C for 7 days. CI index (CII), electrolyte leakage (EL), malondialdehyde (MDA) production, bioactive compounds, antioxidant capacity [2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) and 2,2-diphenyl-1-picrylhydrazil (DPPH)], and activity of antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX)] were analyzed in mango samples after 0, 10, and 20 days of cold storage and after ripening. Hot water treatments (HWT and HWT + Ca) were more effective than Ca in providing protection against CI as evidenced by lower incidence of symptoms and lower EL and MDA. HWT + Ca increased the content of phenolics, flavonoids, and carotenoids during the cold storage, which correlated with the antioxidant capacity by ABTS. SOD and APX showed higher activity in HWT + Ca–treated fruit, whereas CAT activity was higher in fruit with HWT and Ca. These results suggest that HWT + Ca provided CI tolerance of ‘Keitt’ mango by activation of the enzymatic and nonenzymatic antioxidant systems.

Download Full-text

Shelf-Life and Acceptability of Hot Water-Treated Mangos

The Journal of Agriculture of the University of Puerto Rico ◽

10.46429/jaupr.v72i3.6875 ◽

1969 ◽

Vol 72 (3) ◽

pp. 469-474

Author(s):

Noemí Díaz ◽

Teresita Rodríguez ◽

Isabel B. De Caloni

Keyword(s):

Water Treatment ◽

Shelf Life ◽

Cold Storage ◽

Hot Water ◽

Hot Water Treatment ◽

Physical Chemical ◽

Organoleptic Characteristics ◽

Fruit Decay ◽

Water Treatments

Mangos given hot water treatments for 0 , 90, 120, 150 and 180 minutes, followed by cold storage for seven and 14 days, were sensory-evaluated for overall quality, shelf life, and percentage fruit decay. Hot water treatment did not affect the physical, chemical and organoleptic characteristics studied. The decay observations indicate that fruits held for seven days in cold storage (50-55° F and 85-90% RH) should be of good marketing quality for up to 12 days. If kept for 14 days in cold storage, they should be marketed within four to five days after removal from the cold.

Download Full-text

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.

Download Full-text