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Storage of durians on a semi-commercial scale
1997
Teeranud Romphophak | Jaroen Kunprom | Jingtair Siriphanich (Kasetsart Univ. Kamphaengsaen Campus, Nakhon Pathom (Thailand). Central Laboratory and Greenhouse Complex)
Large scale storage of durians was tested on fruits aged 118 and 125 days after anthesis, by short cooling them at 24 and 48 hours after harvest and keeping them at 13.5 deg and 16.5 deg C. At these storage temperature, the internal temperature of durians was found to be 15 deg and 18 deg C respectively. The younger durians developed chilling injury symptom at 13.5 deg C but could be stored for 15 days at 16.5 deg C. The older durians could also be stored for 15 days at 13.5 deg C but sustained only 10 days at 16.5 deg C. Precooling times had no effect on the storage life. The results indicated that an effective separation durians at different maturity would longthen their storage life. A semi-commercial scale storage of durian at 15 deg C was also conducted to compare the beginning of cooling times for upto 72 hours. Methods and time for fungicidal application, and hole size at the top and bottom of the durian cartons were also studied. It was found that durian could be stored at the most for only 2 weeks. For effective control of fruit rot, Forsetyl-aluminum at 4,000 ppm in combination with Carbendazim at 1,000 ppm must be used by 3 mins. submerging or dipping in solution containing surfactant within 24 hours after harvest. Forsetyl-aluminum alone could not control the disease. Cooling should begin 48 hours after harvest. The durian carton should have a hole size about 5 percent of the top and bottom surface area. This hole facilitated fast cooling and better ventilation resulting in low internal humidity and hence lower disease incidence and longer storage life.
Показать больше [+] Меньше [-]Quality of 'Kensington' mango (Mangifera indica Linn.) fruit following combined vapour heat disinfestation and hot water disease control treatments Полный текст
1997
Jacobi, Keryl K. | Giles, Janet E.
Changes in the quality of `Kensington' mangoes from the two major production regions in Queensland were measured after either a vapour heat treatment (VHT) in which seed surface temperature was held at 47°C for 15 min, or a hot water (HW) disease control treatment of 53°C for 5 min prior to VHT, combined with either storage at 10°C for 5 days followed by 22°C for 5 days or storage at 22°C for 10 days. Heat-treated mangoes had higher skin colour ratings, reflectance and chroma values, and lower hue angles than untreated fruit, indicating an enhancement of ripening. The severity of lenticel spotting and skin browning was increased in VHT fruit. Eating quality of the fruit was not altered by any of the heat treatments. The HW+VHT treatment combined with continuous storage at 22°C produced the highest quality fruit, and is recommended for air freight marketing.
Показать больше [+] Меньше [-]Powder formulations of Pseudomonas fluorescens to control pigeonpea wilt
1997
Vidhyasekaran, P. | Sethuraman, K. | Rajappan, K. | Vasumathi, K.
Pseudomonas fluorescens strains which effectively inhibited mycelial growth of Fusarium udum, the pigeonpea (Cajanus cajan) pathogen, were isolated from the rhizoplane of different crops. Various powder formulations of two efficient P. fluorescens strains were developed. All freshly prepared powder formulations were effective in controlling the disease, but their efficacies varied depending upon the length of storage. Talc formulations were effective even after 6 months of storage, while peat formulations were effective up to 60 days of storage. The shelf life of vermiculite, lignite, and kaolinite formulations was short. Unformulated bacterial suspensions could not be stored even for 10 days, at which time their efficacy was completely lost. The bacterial strains survived in pigeonpea rhizosphere throughout the crop-growth period. The talc-based powder formulations effectively controlled pigeonpea wilt and increased yield in two field trials. Development of powder formulations of P. fluorescens will aid large-scale application of biological control in farmers' fields.
Показать больше [+] Меньше [-]The impact of disease states as a modifying factor for nutrition toxicity
1997
Russell, R.M.
Acquired kidney and liver diseases are relatively common diseases that can raise the potential for nutrient intoxication. For example, high-protein diets increase glomerular blood flow and the blood pressure gradient across the glomerular capillary wall in the kidney, which can result in injury to membranes. Likewise, the liver can increase nutrient intoxication because it is involved in the intermediary metabolism of many nutrients, serves as the storage organ for many nutrients, and is important in the biotransformation and excretion of nutrients. In this paper, vitamin A serves as an example to illustrate how kidney disease and liver disease can increase a single nutrient's toxicity.
Показать больше [+] Меньше [-]Effect of modified atmosphere for control of black spot, caused by Alternaria alternata, on stored persimmon fruits Полный текст
1997
Prusky, D. | Perez, A. | Zutkhi, Y. | Ben-Arie, R.
Modified atmosphere packaging (MAP) of persimmon fruit resulted in the accumulation of acetaldehyde to a level of 80 micrograms/ml; ethanol to a level of 900 micrograms/ml; and CO2 up to 30%. When fruits were stored at -1 degrees C for 4 months in such atmospheres, the incidence of black spot disease, caused by Alternaria alternata, was reduced. The effects of each of these gases were examined to determine their individual involvement in the inhibition of Alternaria development during storage. When A. alternata, grown at 20 degrees C on potato dextrose agar or inoculated in persimmon fruit, was exposed for 24 h to different levels of each volatile, acetaldehyde was the most fungistatic but only at concentrations higher than those that accumulated under MAP; CO2 was moderately inhibitory at concentrations from 10 to 60%, whereas ethanol had no effect. Similar inhibitory effects were obtained with acetaldehyde at 620 micrograms/ml or 30% CO2 when in vitro cultures of A. alternata and infected fruits were exposed for up to 2 weeks at 20 degrees C, but 1,000 micrograms of ethanol per ml had only a transitory inhibitory effect under these conditions. Based on analysis of the effect of concentration versus time for each gas accumulating in MAP, we suggest that the increasing concentration of CO2 during storage is the principal factor in the inhibition of black spot disease development.
Показать больше [+] Меньше [-]Lipid oxidation products and their significance
1997
Bastic, Lj. (Institut za higijenu i tehnologiju mesa, Beograd (Yugoslavia)) | Kocovski, T. | Starcevic, G.
Lipid autooxidation is a phenomen which has important effects on quality deterioration in foods. Oxidation of lipids is also important in the production of compounds of significants physiological activity. Cholesterol oxidation products in recent years received considerable attention due to their biological activities associated with human disease. They have been detected in animal food stuffs which are commonly subjected to elevated processing temperatures, pro-oxidative conditions, for storage. The possible role of lipids and their oxidation products in the formation of heterocyclic aromatic amines are also discussed.
Показать больше [+] Меньше [-]Biotic and abiotic initiators for rishitin formation and accumulation in tomato Полный текст
1997
Ahmed, E. S. | El-Essaway, A. A. | Abou El-Hawa, M. E. | Ezzat, S. M. | Batta Metwaly, M.
γ-Ray irradiation of pre-sowing seeds of tomato did not trigger the formation of the phytoalexin “rishitin” in either leaves or fruits of tomato plants through different growth seasons. Application of copper sulfate initiated rishitin formation in both leaves and fruits. Increasing of γ-ray dose was accompanied by decreasing rishitin accumulation in the presence of copper sulfate. Rishitin of tomato leaves was found to be reduced significantly, concomitant with increasing the disease incidence for late and early blight, and Fusarium wilt disease, after applying γ-irradiation, in the case of biotic initiators Phytophthora infestans, Alternaria solani or Fusarium oxysporum alone or together with the abiotic inducer copper sulfate. Shelf-extending γ-ray doses of 1.0, 1.5 and 2.0 kGy decreased rishitin amounts in tomato fruits treated with copper sulfate alone or infected with Phytophthora infestans. Also, the amount of formed rishitin was reduced by extending the storage period.
Показать больше [+] Меньше [-]Integration of ultraviolet (UV-C) light with yeast treatment for control of postharvest storage rots of fruits and vegetables
1997
Stevens, C. | Khan, V.A. | Lu, J.Y. | Wilson, C.L. | Pusey, P.L. | Igwegbe, E.C.K. | Kabwe, K. | Mafolo, Y. | Liu, J. | Chalutz, E. | Droby, S.
Applications of low doses of ultraviolet light-C (254 nm, UV-C), UV-C in combination with a biocontrol agent, Debaryomyces hansenii, or postharvest fungicides were compared for their ability to reduce the incidences of brown rot caused by Monilinia fructicola of peach, green mold (Penicillium digitatum) of tangerine, and Rhizopus soft rot (Rhizopus stolonifer) of tomato and sweetpotato that resulted from both field infections and artificial inoculations. UV-C light alone reduced the incidence of storage rots of all produce. However, in general, application of the postharvest fungicide benomyl (Benlate 50 DF; methyl-1-(butylcarbomoyl)-2-benzimidazole carbamate) or dichloran (Botran 75WP; 2,6-dichloro-4-nitroaniline) was more effective than UV-C treatment alone. When the produce were treated with D. hansenii 2 to 3 days after UV-C treatment, the reduction of storage rots was better than when UV-C was used alone. The percentage of brown rot infection of "Elberta" peaches 36 h after artificial inoculation were untreated control, 100%; UV-C alone, 55%; D. hansenii alone, 67%; UV-C + D. hansenii, 12%; and benomyl alone (12%). Because the efficacy of UV-C + D. hansenii was comparable to that of the postharvest fungicide used alone, it is indicated that an integration of UV-C with the yeast treatment can be as effective as commercial postharvest fungicide treatment in reducing storage rots. Thus, integrated treatment with UV-C and the biocontrol agent (yeast) has potential as an alternative means of postharvest disease control.
Показать больше [+] Меньше [-]High-frequency in vitro multiplication of disease-free Zingiber officinale Rosc Полный текст
1997
Sharma, T.R. | Singh, B.M.
High-frequency in vitro multiplication of disease-free clones of ginger (Zingiber officinale Rosc.) was obtained by culturing small and active buds of ginger on MS medium supplemented with 2 mg/l Kin and 20 g/l sucrose. An average of 7.7 shoots per bud was obtained on this medium after 4 weeks of culture. A high multiplication rate of well-developed plantlets (7.0 shoots per bud) with a 6.8-cm shoot length and a 7.0-cm root length was also obtained on MS medium containing 2.0 mg Kin. 2.0 mg NAA and 20 g sucrose per liter. The multiplication rate did not decrease even up to 28 months of subculture on the same medium. A simple method of successfully transferring more than 95% of tissue-cultured plants into pots was also standardized. In vitro-derived plants performed well under field conditions, were morphologically identical to the mother plants and were free from ginger yellows (Fusarium oxysporum f. sp. zingiberi). Well-developed rhizomes obtained from the tissue-cultured plants did not rot during storage of up to 6 months, thus indicating that the method is also effective in checking storage rot caused by F. oxysporum f. sp. zingiberi.
Показать больше [+] Меньше [-]Differences in tuber rot development for North American clones ofPhytophthora infestans Полный текст
1997
Lambert, D. H. | Currier, A. I.
The relative aggressiveness ofPhytophthora infestons clones in potato tubers was compared in three trials using 7 to 24 isolates of 2 to 4 clones. Visible rot developed slowly at 13C with isolates of the US-1 genotype, the only significant clone found in North America prior to 1979, but substantially faster with most isolates of the newer clonal genotypes US-6, US-7 and US-8. Certain US-7 isolates were similar to US-1, and US-6 isolates also had a broad range of aggressiveness. Secondary infection byFusarium sp. increased rot development in many instances, but this effect was not clone-related. Differences in rot development may affect potato storage or late blight disease transmission.
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