共查询到20条相似文献，搜索用时 390 毫秒
1.
I. Kadzere C. B. Watkins I. A. Merwin F. K. Akinnifesi J. D. K. Saka J. Mhango 《Agroforestry Systems》2006,68(2):133-142
Uapaca kirkiana (Muell. Arg.), a highly valued indigenous fruit species, is being domesticated to increase its utilization in southern Africa. Vendors, who were also the fruit gatherers, that were selling U. kirkiana fruits at roadside markets in Dedza, Malawi, were interviewed on four occasions during the marketing season (October 2003–January 2004) and fruit samples were concurrently sampled from each vendor. Information was obtained on when and how the fruits had been harvested and handled. Timing of fruit harvest was based on experience, aided by indicators such as occurrence of first heavy rains, natural abscission, size and color changes. Harvesting by knocking down unripe fruits from trees was practiced throughout the␣season, but naturally abscised fruits were also gathered in December and January. Fruits harvested when mature but unripe required incubation in soil, plain and woven plastic bags or clay-pots. The incubation method changed and the duration of incubation decreased between October (3–4 days) and January (≤2 days). Fruit samples were evaluated for damage, color and soluble solids concentration (SSC). Fruit SSC and color lightness/brightness (L*) increased from 10.1 to 16.4% (P<0.01) and from 45.7 to 50.5 units, (P<0.01), respectively. Higher SSC values were generally associated (R
2=0.68, P<0.001) with increasing pulp color intensity. Cracking, at 48%, constituted the most common form of damage in sampled fruits. On average, fruits were saleable for only 3–4 days, this being attributed to inherent fruit characteristics combined with immaturity at harvest, and damage during harvesting and storage in hot dry conditions. Lack of appropriate harvesting and handling techniques were associated with fruit darkening, drying, rotting and other postharvest problems. 相似文献
2.
《Scandinavian Journal of Forest Research》2012,27(2):179-191
The effects of felling season, log storage and kiln drying on stemwood discoloration of sixty mature silver birches ( Betula pendula ) were studied and provided with CIEL*a*b* colour coordinates. The colour differences were expressed as j E* including split up of j L*, j a* and j b*. The results showed that fresh wood colour depends on the felling season: light and pale colours were recorded for samples taken from autumn- and winter-felled trees, whereas the colour of fresh wood was considerably darker if the felling took place in the spring or summer. After storage, notable changes in colour were observed. After drying, all samples showed low lightness, moderate redness and relatively high yellowness under the drying conditions used in the study regardless of the felling season or duration of storage. The main colour component responsible for the discoloration was lightness, while chroma values redness and yellowness played a minor role. 相似文献
3.
桃的采收成熟度与果实的耐藏性有较密切的关系。在７～８成熟时的绿熟期采收,经贮藏后果面新鲜,果实硬而脆,褐变和腐烂少;采收过晚则果实易软化,容易褐变和腐烂。采前１个月用１００ｍｇ／ｋｇＧＡ３处理有利于提高桃果实的耐藏性,贮藏后处理果的硬度比对照高１倍;采前１～２ｄ用５００ｍｇ／ｋｇ朴海因处理大久保、京玉和燕红桃,贮藏好果率分别增加２２．８％,２２．９％和１８．３％;采前用混合液（ＧＡ３５０ｍｇ／ｋｇ,２,４－Ｄ５０ｍｇ／ｋｇ,多菌灵２０００倍）处理可减慢桃果实在贮藏期间的生理代谢,并能较好地保持品质,腐烂和褐变指数分别比对照降低７．７％和４．０％。 相似文献
4.
Thierry Koumbi-Mounanga Daniela Tudor Brigitte Leblon Kevin Groves Paul A. Cooper Tony Ung 《Wood material science & engineering》2018,13(4):204-221
A combination of statistical techniques of analyses were used to evaluate the potential of International Commission on Illumination (CIE) lightness (L*), redness (a*) and yellowness (b*) colour space system and near-infrared spectroscopy (NIRS) to assess surface changes in relation with progressive decay of beech (Fagus grandifolia Ehrh.) by wood-inhabiting lignicolous fungi Inonotus hispidus, Trametes versicolor and Xylaria polymorpha. pH effects based modelling predictions of beech earlywood and latewood tissues were also included. Multivariate analysis techniques included response surface optimization, sample-specific standard error of prediction (SEP) method and projection to latent structures partial least squares (PLS) regression. Strong statistical relationships were derived for pH predictions with R2 values ranged: from 0.77 to 0.84 for I. hispidus; from 0.77 to 0.84 for T. versicolor and from 0.83 to 0.91 for X. polymorpha. R2 values for CIE-based L*a*b* colour space measurements ranged: from 0.43 to 0.69 (L*), 0.66 to 0.76 (a*), 0.42 to 0.53 (b*) for I. hispidus; from 0.59 to 0.69 (L*), 0.69 to 0.79 (a*), 0.64 to 0.79 (b*) for T. versicolor; and from 0.51 to 0.75 (L*), 0.89 to 0.94 (a*), 0.85 to 0.89 (b*) for X. polymorpha. Multivariate technical analysis (response surface analysis, sample-specific SEP, PLS regression) of CIE L*a*b* system and NIRS results should be able to characterize pH effects and surface changes of wood spalted by lignicolous fungi as a quick and reliable non-destructive method relevant to wood-spalting concerns and the forest products industry. 相似文献
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6.
Sugi green logs with red or black heartwood were smoke-heated, and the changes in the color of the heartwood after ultraviolet
(UV) (λ = 365 nm) radiation exposure were then observed. After UV radiation exposure, the redness and yellowness increased in both
the red and black heartwoods, whereas the brightness decreased. In the black heartwood, the resulting color turned from yellowish
white to reddish brown. Reddening in black heartwood after exposure to a combination of smoke heating and UV radiation is
thought to be due to a decrease in brightness and an increase in both redness and yellowness. However, the degree of change
in heartwood color by UV radiation exposure was not greatly affected by smoke-heating treatments of various lengths. When
methanol extracts were fractionated and exposed to UV radiation, the yellowness increased in the n-hexane-soluble portion and the redness increased in the acetone-soluble fractions from the n-hexane-insoluble portion. These results suggest that the n-hexane-soluble fraction contains the substances that allow heartwood color to change to yellow after UV radiation exposure,
and the acetone-soluble-fraction from the n-hexane-insoluble portion contains the substances that allow it to change to red.
Received: November 14, 2001 / Accepted: June 3, 2002
Acknowledgment This research was supported in part by a Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of
Science.
This study was presented in part at the 51st Annual Meeting of the Japan Wood Research Society, Tokyo, April 2001
Correspondence to:N. Yoshizawa 相似文献
7.
Hermann Pleschberger Alfred Teischinger Ulrich Müller Christian Hansmann 《Wood material science & engineering》2014,9(2):92-101
Effects of different thermal treatments (maximum treatment temperatures of 200, 210 and 220°C for 2.5 hours) on solid spruce (Picea abies L. Karst.) and ash (Fraxinus excelsior L.) were investigated in this study. The fracture behaviour in radial/longitudinal as well as in tangential/longitudinal and the change of the wood colour (CIEL*a*b* colour space) on all principal anatomical surfaces (cross sectional, radial and tangential) were analysed. The specific fracture energy and the maximum breaking load decreased almost significantly after all thermally treated samples in comparison to the untreated (standard dried) sample. The wood colour changed also significantly, in particular the lightness decreased with increasing intensity of thermal treatment on all investigated surfaces. A comparison of the percentage loss of the different fracture and colour values has shown a strong correlation between the maximum breaking load and the lightness after several thermal treatments, in both investigated crack propagation systems, on all measured surfaces and for both analysed species. 相似文献
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Myrica esculenta, Buch-Ham. Ex. D.Don is a common under-canopy associate of chir pine and banj oak forests in the Kumaun and Garhwal Himalayas.
The species commonly known as Kaiphal is a small moderate sized evergreen dioecious tree. The species is well known for its
edible fruit and other by products and has emerged as a potential income generating species in the Kumaun and Garhwal region.
The regeneration of Myrica esculenta is poor in natural habitats mainly due to intense anthropogenic pressure on it. To synchronize artificial regeneration of
such species exact knowledge of maturity time is essential to avoid the collection of immature and non-viable seeds. Fruits
of Myrica esculenta were collected from nine sites varying from lower, mid and high range of species distribution (900–2,100 masl) for assessing
seed maturation indicators. Across all the sites the colour change from green to dark red/blackish red appears as one of the
indicator of maturity. In addition to the colour change seed maturity and maximum germination was found in seeds when the
weight of 100 fruits was between 41 and 60 g, fruit moisture content between 62 and 69% and seed moisture content between
30 and 32%. 相似文献
10.
Germination of Acer pseudoplatanus L. and Acer platanoides L. seeds was increased by moist storage of the intact fruits (seed + pericarp) at 5 degrees C, but not at 17 degrees C. In both species, germinative capacity of isolated embryos (seeds with testa removed) was increased by moist storage of fruits at either 5 or 17 degrees C. Thus dormancy loss by intact seeds and excised embryos was not necessarily correlated. Loss of dormancy in isolated embryos was associated with a reduction in free abscisic acid (ABA) content. Embryos from freshly harvested fruits of A. pseudoplatanus had a higher germinative capacity and a lower free ABA content than embryos from freshly harvested fruits of A. platanoides. Morever, germinative capacity increased, and free ABA content decreased, more rapidly with length of fruit storage in A. platanoides embryos than in A. pseudoplatanus embryos. 相似文献
11.
2005年,在天津市大港区大安村矮化密植园内,研究了采前喷施己酸二乙氨基乙醇酯(DA-6)和2-(3,4-二氯苯氧基)-乙基-二乙胺(DCPTA)处理对冬枣果实品质发育的影响.在盛花期、盛花期后20、40 d.用15 mg·kg-1的DA-6 0.67 mL·L-1的DCPTA和清水(对照)喷施树冠,并在冬枣果实发育过程中定期取样进行品质指标的测定.试验结果表明:2种药剂采前处理增大了冬枣果实的单果质量,但对果形指数没有影响;处理增加了果实硬度.提高了Vc含量,DA-6处理优于DCPTA处理;2个处理对SSC及TA均没有显著影响;处理提高了冬枣果实在发育初期的GSH含量(与对照相比,DA-6处理提高了23.77%,DCPTA处理提高了15.09%),但在后期差异不显著.总体看来,DA-6和DCPTA处理对冬枣果实的品质发育有一定促进作用,DA-6处理优于DCPTA处理. 相似文献
12.
为了探究油茶种仁油脂与淀粉之间转化的可能性,提高油茶果实采后可溶性淀粉和油脂的含量,从而为油茶果实的科学采摘及晾晒提供参考依据,以国家审定品种‘华硕’不同发育时期的果实为试材,研究了近成熟期种仁油脂与淀粉含量的变化规律,以及采后自然晾晒和不同光质条件下晾晒对其油脂与淀粉含量的影响情况。结果表明:油茶近成熟期果实发育及采后自然晾晒过程中油脂与可溶性淀粉的含量变化均呈极显著正相关;采后自然晾晒能促进近成熟期果实对油脂和可溶性淀粉的积累,但对成熟果实却没有促进作用;不同光质条件下晾晒过程中油脂和可溶性淀粉的含量变化间虽然存在负相关性,但其相关性不显著;覆蓝色膜晾晒最有利于近成熟期果实采后可溶性淀粉转化为油脂。 相似文献
13.
Methods were developed to quantify variation in the fruit, nut and kernel traits using the fruits from four trees of Irvingia gabonensis, an indigenous fruit tree of west and central Africa. The measurement of 18 characteristics of 16–32 fruits per tree identified significant variation in fruit, nut and kernel size and weight, and flesh depth. Differences were also identified in shell weight and brittleness, fruit taste, fibrosity and flesh colour. Relationships between fruit size and weight with nut and kernel size and weight were found to be very weak, indicating that it is not possible to accurately predict the traits of the commercially-important kernel from fruit traits. Seven key qualitative traits are recommended for future assessments of the levels of genetic variation in fruits and kernels. These traits describe ideotypes for fresh fruit and kernel production.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
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15.
Eveliina Hiltunen Kirsi Mononen Leila Alvila Tuula T. Pakkanen 《Wood Science and Technology》2008,42(2):103-115
A discolouration that appeared on the surfaces of a European white birch (Betula pubescens) board during vacuum drying was studied by means of colour measurements (CIEL*a*b*), elemental analysis and the analysis of extractives. The discoloured surface layer of the dried board contained substantially
more methanol-soluble extractives than did the light-coloured part (50.7 mg g−1 vs. 26.7 mg g−1 dry wood), and the colour difference (ΔE*
ab
20.0) between the two extracts was notable. Characterization by means of GC and 13C NMR spectroscopy showed that the extracts contain sugars (mainly glucose and fructose), low-molecular-weight phenolic compounds,
proanthocyanidins, Brauns’ lignin and fatty acid esters. Concentrations of sugars, low-molecular-weight phenols, proanthocyanidins
and Brauns’ lignin were higher in the discoloured surface layer than in the light-coloured part. The yellowness of the surface
layer was associated with the accumulation of low-molecular-weight phenolic extractives, and the redness with Brauns’ lignin
and possibly proanthocyanidins. 相似文献
16.
Manju V. Sharma Catherine M. Collins Simon R. Leather 《Journal of Sustainable Forestry》2013,32(6):563-575
Myristica dactyloides is characteristic of the mid- and high-elevation evergreen forests of the Western Ghats of India. Aril and seeds of the species are valuable nontimber forest products and are harvested extensively. We made visual estimates of fruit crop size in nine populations. We assessed disturbance using five variables: distance from road, method of harvesting fruits, nonforest matrix around the population, seedling regeneration, and protected area status. Unsustainable harvest and proximity to road impacted fruit crop, as did the nonforest matrix (F = 38.17 df = 5,102, p < .001). While high protection and measures against harvesting keep some populations safe, the harvest method plays a crucial role in determining total fruit production and seedling recruitment in the species. 相似文献
17.
采收成熟度对次郎甜柿产量和品质的影响 总被引：1，自引：0，他引：1
对次郎甜柿不同成熟度采收试验结果:在果面橙黄和橙红期采收的产量分别比在緑黄、淡橙黄期采收的增加68.8%、24.8%和92.5%、42.3%;果肉可溶性固形物含量分别提高4.1%、2.0%和5.7%、3.6%,果肉硬度分别降低1.7 kg/cm2、0.8 kg/cm2和2.4 kg/cm2、1.5 kg/cm2。橙黄、橙红期采收的果实品质好,无涩味,果肉脆嫩,品质评价中上和上等;緑黄、淡橙黄、橙黄期采收的果实货架期品质无显著变化,橙红期采收的果实货架期硬果率仅55%,其余的软熟,品质降低。因此认为,外销次郎甜柿应于橙黄期采收,本地上市的可迟至橙红期采收。 相似文献
18.
Data on the seasonal patterns of fruit growth and dark respiration of two peach (Prunus persica (L.) Batsch) cultivars were combined with temperature data to calculate the carbohydrate requirements of an "average" peach fruit from bloom to harvest. The two peach cultivars used were June Lady (an early maturing (mid-June) cultivar) and O'Henry (a late maturing (early-August) cultivar). At harvest, the mean dry weight of the June Lady fruit was 17.8 g (139.7 g fresh weight) and of O'Henry fruits was 30.9 g (213.9 g fresh weight), and the times from full bloom to harvest were 107 and 154 days, respectively. The total calculated fruit respiration requirements were 132 and 300 mmol CO(2) fruit(-1) season(-1) for June Lady and O'Henry fruits, respectively. Total calculated carbohydrate requirements for fruit growth and respiration are 23.9 and 43.8 g CH(2)O fruit(-1) season(-1) for June Lady and O'Henry fruits, respectively. Fruit respiration accounted for 16.3% of the total carbohydrate requirements of June Lady fruits and 0.5% of the total carbohydrate requirements of O'Henry fruits. 相似文献
19.
Terminalia bellerica Roxb.(Belleric myrobalan)is one of the important multipurpose trees in central India.The fruits of the tree are highly valued for medicinal uses,with the greatest demand coming from the pharmaceutical industry.This has resulted in overexploitation and present harvesting practices have led to a significant decline in natural regeneration for this tree species.Our study was conducted from 2006 to2009 in Chhattisgarh(India)to standardize suitable harvesting practices for sustainable management for this valuable species.Experiments were conducted at four different sites located in Dhamtari,Sarguja,and Raigarh forest divisions of the state,covering both protected and open forest in a complete randomized block design(RCBD).At each site,linear transects of 200 m別100 m(2 ha)were randomly selected to sample the initial population and study the effects of two harvesting methods(traditional and nondestructive)and four harvesting intensities(60%,70%,80%,and 90%)on the sustainability of T.bellerica.Fruits were collected and analyzed for their tannin and gallic acid content.Significant increase in tannin and gallic acid content was found with the maturity of fruits(September to December).This is the first study to experimentally assess the consequences of harvesting of T.bellerica fruits in central India.Our findings reveal that harvesting intensity,time,and method are key factors for maintaining the population.Nondestructive harvesting methods were found to be superior to traditional harvesting in terms of regeneration,recruitment,and concentration of active ingredients.When the fruits were harvested through non-destructive means at maturity,the population of species increased.The study concludes that 70%harvest of T.bellerica fruits through non-destructive means maintains the sustainability and provides quality raw material for the pharmaceutical industry. 相似文献