scholarly journals Effect of Autoclave and Hot Water Treatments on Surface Structure and In Vitro Apatite-Forming Ability of NaOH- and Heat-Treated Bioactive Titanium Metal

2013 ◽  
Vol 54 (5) ◽  
pp. 811-816 ◽  
Author(s):  
Masakazu Kawashita ◽  
Naoko Matsui ◽  
Toshiki Miyazaki ◽  
Hiroyasu Kanetaka
2003 ◽  
Vol 15 (3) ◽  
pp. 145-148 ◽  
Author(s):  
Renar João Bender ◽  
Eduardo Seibert ◽  
Jeffrey K. Brecht

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.


2003 ◽  
Vol 13 (2) ◽  
pp. 333-338 ◽  
Author(s):  
Joseph L. Smilanick ◽  
David Sorenson ◽  
Monir Mansour ◽  
Jonah Aieyabei ◽  
Pilar Plaza

A brief (15 or 30 seconds) high-volume, low-pressure, hot-water drench at 68, 120, 130, 140, or 145 °F (20.0, 48.9, 54.4, 60.0, or 62.8 °C) was applied over rotating brushes to `Eureka' lemons (Citrus limon) and `Valencia' oranges (Citrus sinensis). The impact of this treatment on populations of surface microbes, injury to the fruit, the incidence of green mold (Penicillium digitatum)or sour rot (Geotrichum citri-aurantii), when inoculated into wounds one day prior to treatment, and temperatures required to kill the spores of these fungi and P. italicum suspended in hot water were determined. Fruit microbial populations were determined immediately after treatment. Decay and injuries were assessed after storage for 3 weeks at 55 °F (12.8 °C). The efficacy of the hot water treatments was compared to immersion of fruit in 3% wt/vol sodium carbonate at 95 °F (35.0 °C) for 30 seconds, a common commercial practice in California. Initial yeast and mold populations, initially log10 6.0 per fruit, were reduced to log10 3.3 on lemons and log10 4.2 on oranges by a 15-second treatment at 145 °F. Green mold control improved with increasing temperature and treatment duration. Green mold incidence was reduced from 97.9% and 98.0% on untreated lemons and oranges, respectively, to 14.5% and 9.4% by 30 seconds treatment with 145 °F water. However, immersion of lemons or oranges in 3% wt/vol sodium carbonate was superior and reduced green mold to 8.0% and 8.9%, respectively. Sour rot incidence on lemons averaged 84.3% after all water treatments, and was not significantly reduced, although arthrospores of G. citriaurantii died at lower water temperatures than spores of P. digitatum and P. italicum in in vitro tests. Sodium carbonate treatment for 30 seconds at 95 °F reduced sour rot to 36.7%. None of the treatments caused visible injuries to the fruit.


HortScience ◽  
1997 ◽  
Vol 32 (7) ◽  
pp. 1247-1251 ◽  
Author(s):  
Allan B. Woolf

`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.


HortScience ◽  
1995 ◽  
Vol 30 (5) ◽  
pp. 1054-1057 ◽  
Author(s):  
Charles F. Forney

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.


HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 568b-568
Author(s):  
Charles F. Forney

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.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 824A-824
Author(s):  
Charles F. Forney ◽  
Michael A. Jordan

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.


Plant Disease ◽  
1998 ◽  
Vol 82 (5) ◽  
pp. 491-495 ◽  
Author(s):  
John M. Wells ◽  
Ching-Hsing Liao ◽  
Arland T. Hotchkiss

EDTA and the antibiotic nisin, in combination with heat, were tested for inhibition of growth of six pectolytic, soft-rotting bacteria in 80% trypticase soy broth (TSB). Fifty percent reduction of growth by EDTA at 25°C in TSB occurred at 3.24 mM for Erwinia chrysanthemi, 2.57 mM for Pseudomonas fluorescens, 0.96 mM for E. carotovora (subsp. carotovora), 0.48 mM for P. viridiflava, 0.17 mM for Xanthomonas campestris (pv. campestris), and 0.16 mM for Cytophaga johnsonae. Nisin at 50 ug/ml was effective against X. campestris and C. johnsonae (over 90% inhibition of growth) but not against the other four bacteria (less than 20% inhibition), which are the more economically important soft-rotters. Combinations of EDTA and nisin were synergistic. A combination of 0.3 mM EDTA + nisin at 50 μg/ml inhibited growth of E. carotovora, E. chrysanthemi, and P. viridiflava by over 70%, and growth of P. fluorescens by 37%. Hot water treatments for 0.3 min at 37 or 49°C reduced survival of bacteria in the presence of EDTA + nisin, but not of EDTA, nisin, or water alone. EDTA + nisin at 37°C reduced CFU/ml of E. carotovora, E. chrysanthemi, P. fluorescens, and P. viridiflava by 2 log units, and at 49°C by 3 log units, compared with the 25°C treatment. Decay of carrot disks inoculated at two inoculum levels (103 and 104 CFU per disk) with E. carotovora, P. fluorescens, or P. viridiflava was reduced by a 1.5-min immersion in 45°C water, with or without EDTA and nisin additives. Immersion in 0.3 mM EDTA + nisin at 15 to 50 μg/ml at 45°C reduced decay due to E. carotovora and to P. fluorescens at the lower inoculum level by an average of about 50% compared with water alone at 45°C, but differences were statistically significant only at the 90% level of confidence and no different than a standard chlorine dip, current commercial practice for cut carrot slices.


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