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81.
82.
Effects of ascorbic acid addition on the contents of retinyl palmitate isomers in skim milk treated with or without 3 mg/mL added riboflavin were studied during storage for 30 h under fluorescent light. Light illumination induced the reduction of all-trans-retinyl palmitate and 13-cis isomer, but promoted the production of 9-cis isomer in the skim milk. Riboflavin increased the reduction of all-trans-retinyl palmitate, but decreased the formation of 9-cis isomer in lightstored skim milk. The addition of ascorbic acid greatly inhibited the light-induced reduction of all-trans-retinyl palmitate and 13-cis isomer in skim milks. Ascorbic acid also greatly increased the formation of 9-cis-retinyl palmitate in skim milks during light storage. 相似文献
83.
Stored-product Coleoptera were monitored continuously over 22 months using pitfall traps at an operating food mill and adjacent warehouse in Kansas. Mill management practiced conventional pest management, including monthly crack and crevice applications of a residual insecticide and semi-annual fumigation with methyl bromide in the mill, and application of dichlorvos+pyrethrin (commonly called fogging) in the warehouse. The dynamic temporal changes in insect captures and effect of the global interventions on insect captures were analyzed. Data show that more Trogoderma variabile individuals were captured in the warehouse than any other species, but Tribolium castaneum was captured with greater frequency. Trogoderma variabile captures inside the warehouse tended to mirror outside captures suggesting immigration from the outside. The food mill was infested year round with T. castaneum but developed substantial populations of Typhaea stercorea during the warm months from May through October. Stored-product insects were nearly always captured during the first trapping interval following methyl bromide or dichlorvos+pyrethrin applications, but it was not clear if the insects were surviving inside the structure or if they were rapidly recolonizing after treatment. Population increases immediately following fumigation or fogging occurred only in fungus-feeding species in late spring or summer. The most successful fumigation was conducted late in the autumn when environmental conditions prevented insect activity outside. Information contained in this study provides data that could be used to improve insect management programs for milling and processing facilities. 相似文献
84.
85.
Foliage of coriander crop is a rich source of pro-vitamin-A carotenoids and phenolics of relevance to human health. Foliar-application of plant growth regulators – methyl jasmonate and salicylic acid, differentially elicited total carotenoids, β-carotene, lutein, chlorophylls, total phenolics and chlorogenic acid in coriander, GS4 Multicut and Mahak, the cultivars with high and low carotenoids respectively. Carotenoids and total phenolics increased 6.8 and 3 folds respectively when treated with methyl jasmonate (10 μmol/L), whereas salicylic acid (500 μmol/L) showed 5.4 and 3.5 folds of respective compounds. These treatments also enhanced levels of β-carotene, lutein, chlorophylls and chlorogenic acid, as observed by HPLC/MS analyses. Carotenoid and phenolic extracts of the best treatments showed significant increase in hydroxyl and superoxide radical scavenging antioxidant activities compared with controls. The observations made here indicate that the precise use of plant growth regulators is a simple method for naturally augmenting the nutritionally important compounds in coriander crop. 相似文献
86.
J.?Fernando?Ayala-Zavala Shiow?Y.?Wang Chien?Y.?WangEmail author Gustavo?A.?González-Aguilar 《European Food Research and Technology》2005,221(6):731-738
The antioxidant capacity, total anthocyanins, total phenolics, volatile compounds, and postharvest quality of strawberry fruit
were evaluated after treatment with natural antimicrobial compounds and during storage at 7.5 °C. Strawberries treated with
methyl jasmonate (MJ) in conjunction with ethanol (MJ-ETOH) showed higher antioxidant capacity, total phenolics, and anthocyanins
than those treated with ethanol or control (non-treated). MJ-ETOH and ethanol treatments also increased volatile compounds
during storage period. However, individual volatile compounds were affected differently. Methyl acetate, isoamyl acetate,
ethyl hexanoate, butyl acetate, and hexyl acetate increased, while ethyl butanoate, 3-hexenyl acetate, and methyl hexanoate
decreased during storage. The postharvest life was longer for those berries treated with MJ-ETOH and MJ than for those treated
with ethanol or control fruit. In conclusion, strawberries treated with MJ-ETOH maintained an acceptable overall quality for
the longest storage duration and retained higher levels of volatile compounds; also, berries treated with MJ showed the highest
antioxidant capacity compared with other treatments during the postharvest period. 相似文献
87.
The comparative performance of photogalvanic cells has been studied for solar energy conversion and storage by using Methyl Orange, Rose Bengal, Toluidine Blue and Brilliant Cresyl Blue as different photosensitizers with d-Xylose as reductant and Sodium Lauryl Sulphate (NaLS) as surfactant in the different systems. The photogeneration of photopotential are 890.0, 885.0, 945.0 and 940.0 mV whereas the maximum photocurrent is 625.0, 575.0, 510.0 and 480.0 μA, respectively. The short circuit current or photocurrent at equilibrium is 480.0, 460.0, 430.0 and 440.0 μA, respectively. The observed conversion efficiencies for Methyl Orange, Rose Bengal, Toluidine Blue and Brilliant Cresyl Blue with d-Xylose and Sodium Lauryl Sulphate systems are 1.6245, 1.5261, 1.4323 and 1.1057%, respectively. The fill factors 0.3244, 0.3151, 0.3120, and 0.2408 are experimentally determined at the power point of the cell where the absolute value is 1.0. The photogalvanic cells so developed can work for 160.0, 145.0, 130.0 and 140.0 min in dark if it is irradiated for 180.0, 165.0, 135.0 and 150.0 min, respectively where the percentage of storage capacity of photogalvanic cells are found 87.87%-96.29%. All observed results are the higher among the reported results so far in the literature. 相似文献
88.
89.
The essential oils of Foeniculum vulgare subsp. piperitum were subjected to detailed GC-MS analysis in order to determine possible similarities and differences in their chemical compositions, depending on growth years (2001 and 2002). In both oils, methyl chavicol (40.29 and 21.69%), limonene (17.66 and 22.24%), fenchone (16.90 and 12.98%), α-pinene (1.86 and 34%) and α-phellandrene (2.30 and 2.74%) were the main components, respectively. A total of 32 components were identified accounting for 85.01 and 67.14% of the oils of F. vulgare, respectively. The main characteristic of the oils is the high content of the limonene, fenchone and estragol. Our findings indicated that the oil of Turkish bitter fennel belonged to methyl chavicol rich type. 相似文献
90.
L-抗坏血酸棕榈酸酯的合成研究进展 总被引:10,自引:0,他引:10
L-抗坏血酸棕榈酸酯是优良的天然抗氧化剂。综述了L-抗坏血酸棕榈酸酯合成研究进展,归纳了L-抗坏血酸棕榈酸酯的几种合成方法,如化学合成法和酶催化法,为其合成研究提供一些线索。 相似文献