scholarly journals Hot-water Dips Extend the Shelf Life of Fresh Broccoli

HortScience ◽  
1995 ◽  
Vol 30 (5) ◽  
pp. 1054-1057 ◽  
Author(s):  
Charles F. Forney
Keyword(s):  
Weight Loss ◽  
Relative Humidity ◽  
Effective Treatment ◽  
Water Loss ◽  
Hot Water ◽  
Odor Control ◽  
Delayed Senescence ◽  
Heat Treated ◽  
Water Treatments ◽  
Decay Development

Freshly harvested heads of `Cruiser' or `Paragon' broccoli (Brassica oleracea L. Italica group) were heated by immersing in water at 42, 45, 48, 50, or 52C. Immersion times were decreased as treatment temperatures were increased and ranged from 20 to 40 minutes at 42C to 1 to 3 minutes at 52C. Control heads, dipped in 25C water for 0, 10, or 40 minutes, began to turn yellow after ≈3 days storage at 20C and 80% to 90% relative humidity. Immersion in 42C water delayed yellowing by 1 or 2 days; immersion in 45, 48, 50, or 52C prevented yellowing for ≤7 days. Water loss of broccoli during storage at 20C increased by ≤1% per day by some hot-water treatments. Immersion in hot water decreased the incidence of decay during storage at 20C. Immersion in 50 or 52C water for 2 minutes was most effective in controlling decay development. Broccoli immersed in 52C water for 3 minutes had a distinct off-odor. Control and treated broccoli held at 0C for 8 days following hot-water dips were similar in quality. Yellowing of heat-treated broccoli was inhibited when broccoli was warmed to 20C following storage at 0C. Hot-water treatments also delayed senescence at 20C when broccoli was treated following 3 weeks of storage at 0C. Immersion of broccoli in 50C water for 2 minutes was the most effective treatment for reducing yellowing and decay while not inducing off-odors or accelerating weight loss.

scholarly journals 934 PB 524 HEAT TREATMENTS EXTEND THE SHELF-LIFE OF FRESH BROCCOLI

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 568b-568
Author(s):  
Charles F. Forney
Keyword(s):  
Shelf Life ◽  
Brassica Oleracea ◽  
Water Loss ◽  
Free Water ◽  
Heat Treatments ◽  
Hot Water ◽  
Delayed Senescence ◽  
Heat Treated ◽  
Water Treatments

Freshly harvested heads of `Cruiser' or `Paragon' broccoli (Brassica oleracea L. Italica group) were heat treated by holding in water for 1 to 40 min at 42, 45, 48, 50, or 52C. Control heads were held in air at 20C or in 25C water for 40 min. Controls turned yellow in about 3 days at 20C. Treatments at 42C delayed yellowing by 1 or 2 days, while treatments of 45, 48, 50, and 52C prevented yellowing up to 7 days at 20C. Hot water treatments had no effect on water loss of broccoli during storage. Incidence of decay was greater in treated broccoli stored wet compared to the dry control. However, when free water was removed by spinning following treatment, no difference in decay was observed. Treatment of broccoli at 52C for 3 or more min sometimes induced a distinct off-odor. When broccoli was held at 0C for 3 weeks following treatment no differences were observed between control and treated broccoli. However, when broccoli was warmed to 20C following storage at 0C, yellowing of treated broccoli was inhibited. Hot water treatments also delayed senescence at 20C when broccoli was treated following 3 weeks of storage at 0C.

EFFECT OF PRE-FREEZING HAMS ON QUALITY ATTRIBUTES OF DRY-CURED PRODUCT

1972 ◽  
Vol 35 (2) ◽  
pp. 98-101 ◽  
Author(s):  
P. P. Graham ◽  
T. N. Blumer
Keyword(s):  
Weight Loss ◽  
Relative Humidity ◽  
Environmental Conditions ◽  
Water Loss ◽  
Moisture Loss ◽  
Internal Tissue ◽  
Surface Ph ◽  
Aging Period ◽  
Acceptable Quality ◽  
Fresh State

Hams were frozen, stored, and thawed before dry-curing to study the profiles of quality as related to environmental conditions. Quality appraisals and sampling were done after thawing, after curing, and after 30 days aging in an atmosphere where temperature and relative humidity were controlled at about 34.5 C and 62.5%, respectively. The pH, water, NaCl, and fat contents were determined. Surface pH of hams increased from the thawed fresh state to the unstored cured state, but decreased generally after the aging period (stored cured ham). The pH was higher on the surface than that of corresponding internal areas. The pH of the internal tissue was lower for thawed product than cured or aged product. The average percent water decreased during curing and aging periods. Water loss after curing and after aging in the prefrozen hams was greater than that reported for unfrozen hams. The quantity of water, NaCl, and fat varied among the several muscle areas and reasons for variation are discussed. All hams were of acceptable quality at each appraisal period. Decreasing moisture levels of hams were reflected by decreases in conformation scores throughout the processing periods. Increased firmness was accompanied by weight loss, moisture loss, and increased NaCl percentage.

Packaging to reduce water loss can delay ripening of mango (Mangifera indica L. cv. ‘Kensington Pride’) fruit

1997 ◽  
Vol 37 (4) ◽  
pp. 463 ◽  
Author(s):  
A. J. Macnish ◽  
D. C. Joyce ◽  
S. E. Hetherington
Keyword(s):  
Weight Loss ◽  
Relative Humidity ◽  
Water Loss ◽  
Mangifera Indica ◽  
Free Water ◽  
Fruit Weight ◽  
Mango Fruit ◽  
Diameter Hole ◽  
Postharvest Handling ◽  
Plastic Containers

Summary. Water loss and premature ripening during postharvest handling reduce the market quality of mango fruit. Towards investigating the use of moisture barrier liners for mango fruit trays, relationships between in-package relative humidity and weight loss and ripening of ‘Kensington Pride’ fruit were studied. Individual fruit were held at 20°C in sealed plastic containers (small 1.2 L buckets). The lid of each container had a single circular hole. Holes were of various sizes, ranging from 5 to 135 mm diameter. Ripening mature green fruit held at the lowest relative humidity of 57% (135 mm diameter hole) lost weight at a significantly (P£0.05) greater rate (10 mg/g initial FW. day) than fruit at higher relative humidities of 59 (open air), 60 (95 mm diameter hole), 61 (55 mm diameter hole), 71 (35 mm diameter hole), 74 (25 mm diameter hole) and 83% (25 mm diameter hole plus free water). These fruit at higher relative humidities lost weight at rates ranging between 9 and 4 mg/g initial FW. day. Fruit softening and skin colouring rates were similar across all relative humidities. In a second experiment, mango fruit were allowed to ripen in containers with smaller holes, ranging from 5 to 95 mm diameter, in their lids. Fruit at the lowest relative humidity (60%, 95 mm diameter hole) lost weight at a significantly (P≤0.05) greater rate (9 mg/g initial FW. day) than fruit from other treatments. Furthermore, these fruit ripened about 2 days sooner than fruit at higher relative humidities: 85 (25 mm diameter hole), 88 (15 mm diameter hole), 91 (10 mm diameter hole) and 93% (5 mm diameter hole). Fruit at the higher relative humidities lost weight at rates between 6 and 2 mg/g initial FW. day, and ripened in 6 to 12 days. Thus, hole size can be varied in order to control in-package relative humidity and regulate mango fruit weight loss and ripening. Australian Journal of Experimental Agriculture, 1997, 37, 463–7 463

scholarly journals Heat treatment effects on ACC oxidase activity of 'Keitt' mangoes

2003 ◽  
Vol 15 (3) ◽  
pp. 145-148 ◽  
Author(s):  
Renar João Bender ◽  
Eduardo Seibert ◽  
Jeffrey K. Brecht
Keyword(s):  
Ethylene Production ◽  
Oxidase Activity ◽  
Acc Oxidase ◽  
Hot Water ◽  
In Vitro Activity ◽  
Ethylene Dibromide ◽  
Heat Treated ◽  
Physical Treatments ◽  
Water Treatments

With the use of ethylene dibromide for mango disinfestation being ruled out, vapor heat or hot water treatments are the only alternatives for quarantine treatments of mangoes. Physical treatments such as heat treatments have been implicated in higher incidence of physiological disorders and enhancement of ripening processes. Therefore, the objective of the present work was to determine the effects of hot water treatments on ethylene production and on the in vitro activity of ACC oxidase. Cv. Keitt mangoes were immersed for 3 min in hot water at 53 °C or 90 min in water at 46 °C. Immediately after the treatments, some of the mangoes were analyzed for ACC oxidase activity and others were stored to be analyzed after 4 days at 12 °C. There was a significant increase in the ACC oxidase activity just after the hot water treatments. After 4 days, only the mangoes treated for 90 min maintained high ethylene production and ACC oxidase activity. Tissue from the outer layers of the mesocarp had higher enzyme activity compared to tissues from the innermost layers of the mesocarp of heat-treated mangoes.

scholarly journals Reduction of Chilling Injury in Stored `Hass' Avocado Fruit by 38 °C Water Treatments

HortScience ◽  
1997 ◽  
Vol 32 (7) ◽  
pp. 1247-1251 ◽  
Author(s):  
Allan B. Woolf
Keyword(s):  
Electrolyte Leakage ◽  
Chilling Injury ◽  
Persea Americana ◽  
Hot Water ◽  
Skin Tissue ◽  
Heat Treated ◽  
Avocado Fruit ◽  
Temperature Damage ◽  
Hass Avocado ◽  
Water Treatments

`Hass' avocado (Persea americana Mill.) fruit were heat treated in water at 38 °C for 0 to 120 minutes, and stored at 0.5 °C for up to 28 days. After storage, fruit were ripened at 20 °C and their quality evaluated. External chilling injury (CI) developed during storage in nonheated fruit. Skin (exocarp) sectioning showed that browning developed from the base of the exocarp, and with longer storage, this browning moved outwards toward the epidermis. Longer durations of hot water treatment (HWT) progressively reduced CI; 60 minutes was the optimal duration that eliminated external CI, while best maintaining fruit quality. Concomitantly, electrolyte leakage of heated skin tissue increased ≈70% during storage, whereas electrolyte leakage of nonheated skin tissue increased ≈480% over the same period. Thus, significant protection was conferred by HWTs against low temperature damage to avocados and these effects are reflected in the morphology and physiology of the skin tissue.

scholarly journals Effect of pre-storage hot air and hot water treatments on post-harvest quality of mango (Mangifera indica Linn.) fruit

2020 ◽  
Vol 12 (4) ◽  
pp. 842-851
Author(s):  
Oluwole O. OLADELE ◽  
Olajide I. FATUKASI
Keyword(s):  
Weight Loss ◽  
Mangifera Indica ◽  
Colour Change ◽  
Titratable Acidity ◽  
Hot Water ◽  
Soluble Solids ◽  
Fruit Peel ◽  
Post Harvest ◽  
Hot Air ◽  
Heat Treated

Mature, green and fresh mango fruits were harvested from an orchard and sorted before they were subjected to hot air (HA) and hot water (HW) treatments. Before treatment, the fruits were washed with clean water, disinfected for 10 min in 0.385% m/v of sodium hypochlorite and allowed to air-dry at 26 °C before they were separately immersed in HA and HW at 52 and 55 ºC for 1, 3 and 5 min each before storage at 28 ± 2 ºC and 75 ± 5% relative humidity inside sterilized desiccators where the fruit peel colour change was evaluated at intervals of 5days for 20 days while fruits that were not heat treated served as control. Each treatment contained a replicate of five fruits. After 20 days in storage, the heat-treated fruits were then assessed for post-harvest quality characteristics including weight loss, firmness, titratable acidity (TA) and total soluble solids (TSS). Only fruits treated with HA at 52 °C-3 min and 55 °C-3 min retained the mango peel greenness for 20 days while those treated with HW at 55 ºC-1min and 55 ºC-3 min equally retained the peel greenness but for 15 days in storage. Thus, they were considered as effective and interestingly, the weight loss, firmness; TA and TSS of the treated fruits were not significantly affected by these effective treatments as compared with untreated fruits.

scholarly journals Heat-induced Volatiles in Fresh Broccoli

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 824A-824
Author(s):  
Charles F. Forney ◽  
Michael A. Jordan
Keyword(s):  
Dimethyl Sulfide ◽  
Dimethyl Disulfide ◽  
Heat Treatments ◽  
Hot Water ◽  
Physiological Changes ◽  
Induced Volatiles ◽  
Heat Treated ◽  
Relationship Of ◽  
Water Treatments ◽  
Methyl Thiocyanate

Heat can induce physiological changes in plant tissues, including the inhibition of broccoli senescence. Hot water treatments at 52C for 3 or more minutes may induce off-odors in fresh broccoli. The objective of this study was to identify heat-induced volatiles that may indicate physiological injury and/or be responsible for off-odors. Heads of fresh broccoli (Brassica oleracea L. Italica group cv. `Paragon') were immersed in water at 25C for 10 min (control); 45C for 10, 15, or 20 min; or 52C for 1, 2, or 3 min. Following treatment broccoli was held at 20C in the dark. Volatiles in the headspace above treated broccoli were trapped on Tenax-GR 2, 24, and 72 h after treatment and analyzed on a GC-MS. Heat treatments increased the production of ethanol, dimethyl disulfide (DMDS), dimethyl sulfide (DMS), dimethyl trisulfide (DMTS), hexenol, methyl thiocyanate, and several other unidentified compounds. Two hours after treatment, ethanol and hexenol concentrations in the headspace of all heat-treated broccoli were greater than those of the 25C/10 min controls. In the 52C/3 min-treated broccoli, headspace concentrations of ethanol, hexenol, DMDS, and methyl thiocyanate were 600-, 42-, 4-, and 4-fold greater than those of controls. After 72 h at 20C, concentrations of DMDS, DMS, and DMTS in broccoli from all six heat treatments were 10- to 200- fold, 8- to 35-fold, and 1.5- to 23- fold greater than those of controls, respectively. Concentrations of ethanol and methyl thiocyanate did not change relative to the controls during the additional 70 h at 20C. Concentrations of hexenol decreased in heat-treated broccoli during this time. The relationship of these volatiles to physiological changes and off-odor development in treated broccoli will be discussed.

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

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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