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1.
Bai B Chen F Wang Z Liao X Zhao G Hu X 《Journal of agricultural and food chemistry》2005,53(18):7103-7107
While green discoloration during garlic processing is of a major concern, this greening is desirable and required for the traditional homemade Chinese "Laba" garlic. To obtain insights into the mechanism of color formation, simulation of the greening of "Laba" garlic was carried out in the laboratory by soaking aged garlic in 5% (v/v, pH 2.33) acetic acid solution. After 2 days, the garlic cloves turned green. Up to 4 days, pigment(s) diffused from garlic cloves to the pickling solution. The solution exhibits two maximal absorbances at approximately 440 and approximately 590 nm, corresponding to yellow and blue species, respectively, the combination of which creates the green coloration. With increasing time from 4 to 25 days, the concentration of both yellow and blue species increases at nearly the same rate, while after 25 days, the concentration of the yellow species increases faster than that of the blue species. Interestingly, most thiosulfinates ( approximately 85%) in garlic cloves were converted within 4 days, suggesting that thiosulfinate conversion is proportional to the formation of the pigments. Consistent with this conclusion, alliinase and acetic acid were required for the color formation. UV-vis spectral measurements and pH results suggest that the color formation occurs by two kinds of processes: one enzymatic and the other nonenzymatic. Low pH (2.0-3.0) favors nonenzymatic reactions, while high pH (6.0 or above) is conducive to enzymatic reactions. Thus, the ideal pH for the entire process of garlic greening is between 4.0 and 5.0, which is a compromise of the optimal pH of both the enzymatic and nonenzymatic reactions. 相似文献
2.
低分子量有机酸对可变电荷土壤铝活化动力学的影响 总被引：1，自引：0，他引：1
从动力学角度研究了几种低分子量有机酸对2种酸性土壤中铝的活化和活化铝在土壤固/液相之间分配的影响。结果表明:对于络合能力弱的醋酸和乳酸,主要通过质子作用活化铝,且活化作用明显小于盐酸。而络合能力较强的苹果酸、草酸和柠檬酸,主要通过络合作用促进铝的释放,且这种作用随有机酸根阴离子络合能力的增强而增加。在氧化铁含量较高的砖红壤中,苹果酸、草酸和柠檬酸通过专性吸附增加土壤表面负电荷,从而增加土壤交换态铝;但在氧化铁含量较低的红壤中,草酸和柠檬酸主要通过形成可溶性铝络合物降低交换态铝。活化铝在土壤固/液相间的分配主要决定于溶液中有机阴离子与土壤固相表面对铝离子的竞争。醋酸和乳酸活化的铝主要以交换态铝存在;而草酸和柠檬酸活化的铝主要以有机酸-铝络合物存在于溶液中,特别是在氧化铁低的红壤中,这将促进铝在土壤-水体中的迁移。 相似文献
3.
低分子量有机酸对不同合成磷源的释磷效应 总被引：9，自引：1，他引：9
采用化学浸提方法,研究了5种低分子量有机酸(草酸、柠檬酸、酒石酸、苹果酸、乙酸)对不同合成磷源的释磷效应。结果表明:供试有机酸(低浓度乙酸除外)均能促进不同合成磷源(DCP、OCP、FA、Fe-P、A l-P)中磷素的释放;其释磷效果与有机酸的种类和浓度有关,强弱顺序依次为柠檬酸、草酸、酒石酸、苹果酸、乙酸,有机酸浓度越高其释磷效果越好;有机酸与氟磷灰石(FA)反应后,溶液pH值升高。低浓度条件下pH值变化较大,而高浓度条件下pH值变化较小。 相似文献
4.
为比较蜡样芽孢杆菌及其生物被膜对环境压力的抗性,该文主要研究了4种有机酸（乙酸、柠檬酸、乳酸和苹果酸）和乙醇对蜡样芽孢杆菌及其生物被膜存活率的影响。结果表明：生物被膜态蜡样芽孢杆菌对乙酸的抗性高于浮游态菌。扫描电镜结果显示,经乙酸处理后,浮游态蜡样芽孢杆菌的细胞表面严重受损,而生物被膜态菌的表面形态未发生明显变化。在柠檬酸、乳酸、苹果酸和乙醇存在的条件下,生物被膜态蜡样芽孢杆菌比浮游态菌表现出更强的压力抗性,特别是在高浓度（有机酸16%～20%,乙醇50%～60%）的情况下,该现象尤为显著。因此,在食品工业中控制被膜态蜡样芽孢杆菌对预防和阻止食品腐败非常重要。该研究结果为实际生产中有效控制蜡样芽孢杆菌及其生物被膜的形成提供参考。 相似文献
5.
研究了 5种低分子量有机酸 ,即醋酸、柠檬酸、马来酸、苹果酸和草酸 ,对昆明和徐闻两种砖红壤动电性质的影响。结果表明 ,在试验条件下 ,两种砖红壤的 ζ电位随醋酸浓度的递增逐渐正移 ,而后 ζ电位正移速率显著增大 ,再后 ζ电位渐趋稳定 ;两者的 ζ电位随柠檬酸浓度的增加向更负的方向移动 ,在试验浓度范围 (0～ 0 .1 5mmolL-1 )内 ,负移的速率没有明显差别。在pH 3.2至 6 .0之间 ,含有不同有机酸的两种砖红壤悬液的ζ电位均具有如下顺序 :醋酸 >马来酸 >苹果酸 >柠檬酸 >草酸 ;含同一有机酸的悬液在相同pH下的 ζ电位 ,昆明砖红壤总是高于徐闻砖红壤。在不同有机酸存在下 ,两种砖红壤悬液等电点的顺序与上述的 ζ电位顺序相同 ;对于相同处理来说 ,昆明砖红壤的等电点高于徐闻砖红壤者 0 .5～ 1 .0pH单位。 相似文献
6.
E. A. Elkhatib 《植物养料与土壤学杂志》1990,153(3):201-205
A simple and precise ion chromatographic (IC) method for determination of citric, malonic, succinic, formic, acetic and propionic acids in soil solution was developed. It requires a prior cleanup to the soil solution samples by anion exchange resin (AG1-X8) and determination of organic acids using a Dionex Model 2010i IC. Separation of organic acids by IC permitted their quantitation by conductivity measurements, following suppression of background conductivity by a fiber suppressor. A high degree of precision was achieved in the quantitation of organic acids studied. With the IC method, citric, malonic, succinic, formic, acetic and propionic acids can be determined simultaneously in 16 min. A single operator can analyze about 30 samples in a single working day. 相似文献
7.
绿肥腐解液中有机酸组成对铝磷和铁磷活化能力的影响 总被引：1，自引：0，他引：1
8.
Adem Oral 《Journal of plant nutrition》2018,41(11):1482-1490
One of the strategies of the plants growing in phosphorus (P)-deficient environments is to exudate low-molecular-weight organic acids (LMWOA). Thus, we aimed to investigate the effect of LMWOA on phosphorus uptake of barley from either fertilizer or inherited soil phosphorus. The experiment was set up in full factorial arrangement in completely randomised design with two phosphorus (0 and 50 mg P kg?1), five organic acids, LMWOA (malic acid, oxalic acid, citric acid, acetic acid, ascorbic acid), and four organic acid rates (0, 10, 20, and 30 mmol kg?1). The effects of LMWOA on yield in descending order were: oxalic acid > ascorbic acid > malic acid > acetic acid > citric acid. The maximum P concentration in grain was obtained at 30 mmol kg?1 LMWOA treatments. As a result, it was found that oxalic acid was the most effective LMWOA in increasing nutrient uptake induced grain yield with and without phosphorous fertilizer application. 相似文献
9.
低分子量有机酸对高岭石中铝释放的影响 总被引：22，自引：3，他引：22
选择了几种土壤中可能存在的低分子量脂肪羧酸 ,研究了它们对高岭石中铝释放的影响。结果表明 ,有机酸可以通过络合作用促进高岭石中铝的释放。几种有机酸对体系中可溶性铝影响的大小顺序为 :草酸 >柠檬酸 >丙二酸 >苹果酸 >乳酸。草酸、柠檬酸和乳酸对可溶性铝释放的促进作用随体系pH的升高而减小 ,其中草酸体系中可溶性铝随pH的变化幅度最大。在苹果酸体系中 ,可溶性铝随pH的升高而稍有增加。体系中的可溶性铝随有机酸浓度的增加而增加 ,而交换性铝随柠檬酸浓度的增加而减少 ,先随苹果酸浓度增加而增加 ,然后又逐渐减少。与对照相比 ,柠檬酸和草酸使交换性铝的量减小 ,苹果酸和乳酸在低pH下使交换性铝明显增加 ,而苹果酸在较高pH下使交换性铝减少。有机酸影响释放出的铝在固液相间的分配比 ,苹果酸在低pH下使体系中释放出的大部分铝以交换性形态存在 ,而在较高pH下 ,大部分铝以可溶形态存在。在草酸体系中 ,释放出铝的大部分都以可溶形态存在。不同有机酸的不同表现与体系中铝的溶解平衡、铝的吸附 -解吸平衡、有机酸的吸附 -解吸平衡、有机酸的离解平衡和铝与有机酸的络合 -离解平衡有关。 相似文献
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11.
腌制剂对脉动压腌制咸鸡蛋的影响 总被引：1，自引：0，他引：1
为丰富咸蛋品种,改善咸蛋风味,提高咸蛋的腌制速率,应用脉动压技术,以鸡蛋为原料,选取白酒、香辛料、柠檬酸为影响因素,通过单因素及正交试验,考察咸蛋腌制中蛋质量增加率、蛋清含盐率和蛋黄含盐率的变化,对腌制禽蛋工艺进行优化。结果表明：白酒和柠檬酸对盐分渗入有促进作用,而香辛料则阻碍了盐分的渗入,影响咸蛋综合评分的因素从高到低依次为香辛料、白酒、柠檬酸,且香辛料对咸蛋综合评分的影响显著,柠檬酸对蛋清含盐率的影响显著。在高压幅值140 kPa、脉动比2.5 min/5min饱和食盐溶液中腌制96 h,风味咸蛋腌制 相似文献
12.
为研究有机酸添加后煤矸石碎屑组成及其速效养分变化,以淮南潘集矿区为研究区域,选取矿区内多处煤矸石山上大块煤矸石人工破碎后作为供试材料,向其中添加10 mmol/L低分子量有机酸和腐殖酸水溶液,恒温培养120 d,在不同培养阶段取出部分样品测定煤矸石碎屑颗粒组成、EC、pH和速效养分等指标。结果表明,有机酸的添加总体上促进了煤矸石碎屑颗粒的细化。其中,黏粒平均增幅达81.90%,极细砂增幅在42%以上,粉粒和极粗砂粒含量平均下降幅度分别为21.05%、62.34%。有机酸添加有助于煤矸石碎屑颗粒基质结构向好的方向发展,并且以柠檬酸和腐殖酸效果最好。培养后的各处理pH值、电导率、速效养分对有机酸种类和培养时间的响应存在显著差异。有机酸添加后,酒石酸、草酸和腐殖酸处理pH均上升较大,平均pH值分别为7.69、7.75和7.71,显著大于对照处理(P<0.05),达到微碱性水平。除苹果酸处理外,其他处理的pH随培养时间的变化表现“N”型特征。电导率的变化与pH值变化正好相反,以苹果酸处理上升最大,比培养前增幅达146.78%;有机酸添加极大促进了煤矸石碎屑碱解氮(AN)和速效磷(AP)的释放,前者以苹果酸效果较好(释放量最大为CK的1.56倍和培养前的13.03倍),后者以柠檬酸效果较好(释放量最大为培养前的2.56倍和CK的3.39倍)。随着培养时间延长,碱解氮和速效磷释放量均逐渐增加;水分浸润和有机酸溶液添加均在前期表现一定抑制煤矸石碎屑颗粒速效钾(AK)释放的作用,后期逐渐表现一定促进释放的作用,但各有机酸处理之间差异不显著。有机酸对煤矸石山生态修复肯有一定积极作用。 相似文献
13.
Tong Bao Tie-Heng Sun 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(4):305-312
Abstract The influence of Fe-deficiency on the root exudation of low molecular weight organic acids (LMWOAs), pH alteration and cadmium (Cd) accumulation and translocation were investigated in morel (Solanum nigrum L.) in hydroponic culture experiments. Tartaric, citric, malic and acetic acids were monitored because these acids were abundant and often detected as root exudates. Results showed that Fe-deficient plants excreted large amounts of LMWOAs in comparison with Fe-sufficient plants across all Cd treatments (p <0.05). In both cases the concentrations of the four organic acids were tartaric > citric > malic > acetic. The results showed that the Fe-deficient plants with higher concentrations of LMWOAs accumulated more Cd (p <0.05) and induced a decrease in solution pH compared with the Fe-sufficient plants. Cadmium accumulation in the Fe-deficient and Fe-sufficient plants had significant positive correlations with the exudation of malic and acetic acids (p <0.05 and p<0.01). Cadmium accumulation in the Fe-sufficient plants had a significant (p<0.01) positive correlation with the exudation of tartaric acid, whereas there was a negative correlation (p<0.01) between Cd accumulation and the exudation of tartaric acid in the Fe-deficient plants. No significant correlation between the exudation of citric acid and Cd accumulation was obtained. Our results indicate that Fe-deficiency could induce Cd accumulation and translocation through an increase of LMWOAs exudation and pH alteration, both of which enhance Cd bioavailability. 相似文献
14.
添加有机酸对土壤镉形态转化及苋菜镉积累的影响 总被引：6，自引：0，他引：6
植物根系分泌的低分子量有机酸能够与土壤中的镉形成镉–有机酸复合体,从而影响根际镉的移动性。本文通过添加有机酸对土壤镉形态转化的研究,阐明有机酸与镉生物积累的关系。采用盆栽试验及土壤培养等方法,研究了添加苹果酸、柠檬酸对赤红壤和黄棕壤中镉的形态转化以及超积累型苋菜天星米镉生物积累的影响。结果表明,与Cd 25 mg/kg处理比较,Cd 25 mg/kg＋苹果酸、Cd 25mg/kg＋柠檬酸处理对苋菜生物量未产生影响,但显著增加苋菜根系及地上部镉含量;添加苹果酸、柠檬酸处理显著降低土壤专性吸附态Cd含量,却显著增加了交换态Cd、碳酸盐结合态Cd和有机结合态Cd含量。说明添加苹果酸、柠檬酸还能够通过影响土壤镉形态转化而促进苋菜对镉的积累。 相似文献
15.
The influence of organic matter and its cycling on soil pH change is still unclear. This study investigated the effect of organic compounds on carbon and nitrogen dynamics and their relationship with pH changes in two soils differing in initial soil pH (Podosol of pH 4.5 and Tenosol of pH 6.2). Seven organic compounds representing common compounds in decomposing plant residues or root exudates were added to the soils and incubated for 60 d. The largest cumulative soil respiration occurred when glucose, malic acid and citric acid were added. In addition, the Tenosol had the greater respiration compared to the Podosol. The addition of organic acids (acetic, malic, citric, ferulic and benzoic acid) instantly decreased soil pH due to the dissociation of H+ from the acids. The pH of both soils was then restored over time, which was positively correlated with decomposition % of these compounds. The pH of the Tenosol amended with all the organic acids and of the Podosol with malic acid exceeded that of the control, and net alkalization occurred, with the degree of alkalization being greater with malic and citric acid. Adding organic acids to the Tenosol generally increased NH4 concentrations but decreased NO3 concentrations. The addition of glucose decreased pH in Podosol but slightly increased it in the Tenosol. The addition of glucosamine hydrochloride decreased pH due to significant nitrification. The results suggest that the addition of organic acids stimulates microbial NO3 uptake, and ammonification and decomposition of indigenous soil organic matter, resulting in a priming effect on alkalinity release, and that the degree of the priming effect is influenced by the type of organic acid and initial soil pH. 相似文献
16.
低分子量有机酸对石灰性土壤磷素形态转化及有效性的影响 总被引：11，自引：1，他引：11
采用室内培养和化学分析的方法研究了几种低分子量有机酸对石灰性土壤中磷的活化作用。结果表明:供试有机酸通过溶解、螯合等作用均能不同程度地促进合成磷酸盐的磷素释放。活化DCP、ODP、Fe-P、A l-P的能力依次为柠檬酸>草酸>苹果酸>酒石酸>乙酸;活化FA的能力是草酸>柠檬酸>苹果酸>酒石酸>乙酸。同种有机酸作浸提剂时,有机酸浓度越高磷酸盐中磷素释放量也越大。施加各种有机酸可以不同程度地降低土壤中Fe-P、A l-P和Ca10-P,增加Ca2-P、Ca8-P和O-P含量,总的趋势是促进土壤中植物难以利用的无机磷形态向有效性较高的形态转化。这种促进作用大小顺序为草酸>柠檬酸>酒石酸。 相似文献
17.
低分子量有机酸对石灰性土壤有机磷组成及有效性的影响 总被引：4，自引：2，他引：4
为探索提高土壤磷素有效性的途径,采用室内培养的方法,研究不同有机酸对土壤速效磷含量及有机磷组分的影响。结果表明,添加有机酸后土壤速效磷含量发生显著变化,其中草酸处理下土壤速效磷含量显著高于其他处理,而柠檬酸和苹果酸对土壤速效磷含量具有抑制作用,其活化量为负值;随着培养时间的延长,速效磷含量缓慢降低。速效磷含量随着草酸浓度的升高而升高,随着苹果酸、柠檬酸浓度的升高而降低;有机酸处理后,土壤活性、中活性、中稳性有机磷升高,高稳性有机磷降低,这说明有机酸能促进土壤有机磷由有效性低的形态逐步向有效性高的形态转化,其中草酸的作用效果总体上较柠檬酸和苹果酸强。 相似文献
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19.
G. Cieslinski K. C. J. Van Rees A. M. Szmigielska P. M. Huang 《Journal of plant nutrition》2013,36(6):753-764
Knowledge of the composition and quantity of organic substances released from roots of different plant species is necessary for understanding the chemical and biological processes in the rhizosphere. The present study was undertaken to quantify low molecular weight organic acids (LMWOAs) released from roots of five cultivars/lines of durum wheat (Triticum turgidum var. durum L.): Kyle, Sceptre, DT618, DT627, and DT637 and four cultivars/ lines of flax (Linum usitatissiumum L.): Somme, Flanders, AC Emerson, and YSED 2. Plants were grown in sterile nutrient solution cultures and amounts of organic acids exuded by roots were analyzed by gas chromatography. The LMWOAs varied significantly among both durum wheat and flax cultivars and oxalic, malonic, fumaric, succinic, acetic, malic, citric and tartaric acids were detected in root exudates of both species. Generally, oxalic and acetic acids were predominant in durum wheat exudates and oxalic, acetic and malic acids were predominant in flax root exudates. High oxalic acid concentrations occurred in root exudates of durum wheat cultivars DT627 and DT637, and flax cultivar YSED 2. Compared with the other durum wheat cultivars, Kyle released the lowest total amount of LMWOAs, whereas among the flax cultivars, YSED 2 had the highest total amount of acids secreted from roots. The data showed that the release of LMWOAs from roots was cultivar dependent. The results provide valuable background information for studying the role of root exudates in soil‐plant relationships. 相似文献
20.
红大烤烟主要非挥发性有机酸含量变化及其对感官评吸质量的影响 总被引：1，自引：0，他引：1
以云南大理C3F等级烟叶为材料,采用GC方法测定了烤烟样品中的草酸、苹果酸和柠檬酸含量,对不同品种、烟田类型、海拔高度、生态区域的烤烟非挥发性有机酸含量进行了比较分析。结果表明:①红大非挥发性有机酸总量平均为39.499mg/g,其中草酸、苹果酸和柠檬酸含量平均分别为12.012、25.175和2.313mg/g。②红大品种草酸、苹果酸、非挥发性有机酸总量显著高于其他品种,而柠檬酸含量显著低于其他品种。③旱地种植的红大烤烟的苹果酸含量显著高于水稻田。④在高海拔种植红大品种的苹果酸含量和非挥发性有机酸总量显著高于中、低海拔。⑤金沙江流域、澜沧江流域、滨湖流域的红大烤烟非挥发性有机酸总量显著高于红河源流域。⑥灰色关联分析表明烟叶非挥发性有机酸主要影响感官评吸质量评价指标中的刺激性、劲头和浓度。 相似文献