Application Of Citric Acid Research Articles

Properties and applications of citric acid crosslinked banana fibre-wheat gluten films

Utilization of agricultural residues for sustainable development and creating products for a better future is gaining importance. Considerable efforts have been done to utilize agricultural residues to develop composites, fibres, films and other commodity products. Similarly, proteins such as wheat gluten, soy protein and casein are obtained as coproducts and considered for food and non-food applications. Fibres extracted from banana stems have been used as reinforcement and wheat gluten as matrix to develop composites. However, banana fibres and gluten are hydrophilic and composites developed do not have adequate mechanical properties. In this study, we have developed films from banana fibres and wheat gluten by solution casting and later compression molding. Further, crosslinking of fibre and gluten with citric acid was done to improve the mechanical properties and decrease water sorption of the bioproducts in comparison to glutaraldehyde (Gtld) as the crosslinker. Films developed were characterized for their water absorption, mechanical properties, effect of ratio of fibre and gluten, effect of the crosslinker type and concentration and changes in morphology. Films without any crosslinker showed maximum water absorption values up to 500% whereas crosslinking reduced water sorption drastically to about 200%. Crosslinking also led to substantial increase in strength of the films from 3.5 MPa to 13 MPa. It was found that citric acid crosslinked films had marginally higher strength compared to Gltd crosslinked films. Thermal studies confirmed that crosslinking increased resistance to thermal degradation. All the films passed the UL-94 V-1 classification requirements for flame retardancy. The films formed could be moulded into various products and used to replace the commercially available plastic based materials. Utilizing banana fibres and wheat gluten to develop bioproducts will assist towards developing a greener and better environment and also add considerable value to agricultural residues and coproducts.

Phytoremediation of Mn-contaminated paddy soil by two hyperaccumulators (Phytolacca americana and Polygonum hydropiper) aided with citric acid.

The purpose of this study was to investigate the phytoremediation potential of two hyperaccumulator plants, Phytolacca americana L. and Polygonum hydropiper L., on manganese-contaminated paddy soils. The biomass growth, Mn concentrations in plant tissues, and potential Mn removal efficiency from soils of these two plants were studied with citric acid, and the mechanisms of citric acid on these two plants were analyzed by examining the root activity, the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in leaves, as well as the concentrations of O2·- and H2O2 in leaves. The results showed that the biomass of these two plants were both promoted under low level of citric acid (3mmolkg-1). The concentration of Mn in the plants and the amount of Mn removed from the soil by the plants through harvesting were enhanced at low and intermediate (10mmolkg-1) citric acid application levels. The results also showed that root activity was enhanced at the low citric acid level and significantly inhibited under the intermediate and high levels (15mmolkg-1), which indicates the facilitative function of the low level of citric acid and the inhibitive function of the high level of citric acid application on plant biomass growth. Under the low and intermediate levels of citric acid application, O2·- in the plant leaves increased sharply, and the SOD, POD, and CAT activities also increased sharply, which made the level of H2O2 very similar to that of the control, ensuring the health of the plants. At the high level of citric acid application, however, the O2·- continued to rise sharply, while the activity of the three antioxidant enzymes declined sharply, causing the concentration of hydrogen peroxide to be much higher than that in the control, thus endangering the plants. The present study shows the potential of P. hydropiper for use in the phytoremediation of soil contaminated with a relatively low level of manganese.

Foliar application of citric and malic acid to stock plants of rose alters the rooting of stem cuttings

BackgroundAs the world’s best-selling cut flower, there is a high demand for propagated rose plants. Auxins are the dominant growth regulator used to improve the rooting of cutting; however, their application remains a labor-intensive process, and on the other hand, side effects like poor shoot growth exist. Organic acid sprays have enhanced many physiological traits of plants which justified surveying their possible effect on the rooting process in the current study.MethodsDifferent concentrations of citric or malic acid were sprayed to stock plants of rose (Rosa x hybrida cv. ‘Sherbet’) prior to taking cuttings. Malic or citric acid (3, 6, or 9 mM) was applied five times on a 14-day interval in a commercial cut flower production greenhouse. Single-node cuttings were prepared and were rooted under mist. Data collected included rooting percentage, root count, root and shoot length and dry weight, and root-to-shoot ratio (R:S).Results and discussionThe rooting percentage was enhanced by all treatments. Citric acid enhanced root number at 6 mM level followed by 3 mM citric acid. Average root length was increased by all treatments except 3 and 6 mM malic acid. All CA treatments increased shoot length, while it remained unaffected by MA treatments. CA at 3 and 6 mM level and 6 mM MA increased shoot dry weight, but only 9 mM CA increased the root dry weight.ConclusionBoth organic acids had positive effects on rooting response of ‘Sherbet’ roses. However, the mechanism of observed responses to organic acids remains to be studied. While they enhance the physiological performance of stock plants, they can also simultaneously both enhance the rooting as well as the shoot growth of the new plantlets.

Aplicación de ácido cítrico incrementa la calidad y capacidad antioxidante de germinados de lenteja

El contenido de compuestos antioxidantes en germinados de lenteja se relaciona con la prevención y el tratamiento de enfermedades degenerativas. Este tipo de compuestos podrían incrementarse por la aplicación de elicitores como el ácido cítrico, el cual promueve la sintésis de compuestos derivados de los fenilpropanoides y activa cascada de señalización que incrementan la actividad antioxidante. El objetivo de la presente investigación fue evaluar el efecto de la aplicación por aspersión de ácido cítrico (0, 10-2, 10-3, 10-4 y 10-5 M) en el contenido de compuestos fenólicos totales, flavonoides totales, capacidad antioxidante total de germinados de lenteja. Se utilizó un diseño completamente al azar con seis repeticiones de tratamiento. Los resultados mostraron que el ácido cítrico incremento significativamente los compuestos fenólicos y flavonoides totales. El valor más alto de compuestos fenólicos y flavonoides se obtuvo con el tratamiento 10-2 M de ácido cítrico con 185.5, 150 mg 100 g-1 peso fresco respectivamente. Igualmente, la capacidad antioxidante fue mayor con el mismo tratamiento (10-2 M), lo cual concuerda con los resultados de correlación obtenidos que indican que la capacidad antioxidante se debe en 86 y 78% a los compuestos fenólicos y flavonoides, respectivamente. Se concluye que la aplicación de concentraciones molares de moléculas inductoras del metabolismo secundario durante la etapa de desarrollo de germinados es un método útil y efectivo para estimular la biosíntesis de fitoquímicos bioactivos y mejorar la capacidad antioxidante de este tipo de alimento.

Foliar application of ascorbic and citric acids enhanced 'Red Spur' apple fruit quality, bioactive compounds and antioxidant activity.

This study aimed to assess the effect of the foliar application of ascorbic acid (AA) and citric acid (CA) on total antioxidant activity (TAA), total phenolics, total flavonoids, total anthocyanin content, antioxidant enzymes, phenylalanine ammonialyase (PAL), and polyphenol oxidase (PPO) activities in apple 'Red Spur'. The experiment was conducted on 12-years-old trees 'Red Spur' grafted on MM106 rootstock. The trees were sprayed with AA (0, 200 and 400mgL-1) and/or CA (0, 200 and 400mgL-1) at three different times during summer. Foliar application with AA and CA significantly (p<0.01) enhanced all measured quality attributes and decreased the activity of PPO. Fruit from trees treated with AA at 400mgL-1 and CA at 200mgL-1 showed the highest TAA and catalase (CAT) enzyme activity. Total phenolics increased in fruits when trees were sprayed with AA and CA. Contrasting, AA treatment, CA had no significant effect on guaiacol peroxidase (G-POD). A significant decrease in PPO activity was detected in fruits when treated with both AA and CA. Both treatments significantly decreased the activity of PAL at 400mgL-1. Considering the results, foliar application of AA and CA, either alone or in combination improved the quality and nutraceutical properties of 'Red Spur' apple.

Zinc and silica are active components to efficiently treat in vitro simulated eroded dentin.

Biomaterials for treating dentin hypersensitivity and dentin wear were evaluated to efficiently occlude the dentinal tubules and to increase dentin resistance to abrasion. Twenty-four dentin surfaces were treated with EDTA to expose dentinal tubules and were (1) non-brushed, (2) brushed with distilled water, or with pastes containing (3) monetite, (4) brushite, (5) Zn-monetite, (6) Zn-brushite, (7) Silica-brushite, and (8) NovaMin®. Topographical, nanomechanical, and chemical analysis were assessed on dentin surfaces (n = 3) after artificial saliva immersion for 24h, and after citric acid challenge. Twenty-one further dentin specimens were created to evaluate dentin permeability after brushing, saliva storage, and acid application (n = 3). ANOVA, Student-Newman-Keuls (p < 0.05), and Student t test (p < 0.001) were used. Particles containing major proportion of silica attained intratubular occlusion by carbonate crystals (Raman carbonate peak heights 15.17 and 19.24au; complex modulus 110 and 140GPa, at intratubular dentin). When brushing with pastes containing higher proportion of silica or zinc, phosphate calcium compounds were encountered into tubules and over dentin surfaces (Raman intratubular phosphate peak heights 49 to 70au, and at the intertubular dentin 78 to 92). The formed carbonated apatite and calcium phosphate layer were resistant to citric acid application. Zinc compounds drastically increased tubule occlusion, decreased dentin permeability (up to 30%), and augmented mechanical properties at the intertubular dentin (90-130GPa); it was maintained after acid challenging. Zinc-containing pastes occluded dentinal tubules and improved dentin mechanical properties. Using zinc as an active component to treat eroded dentin is encouraged.

Management of tannery wastewater for improving growth attributes and reducing chromium uptake in spinach through citric acid application.

The use of chromium (Cr)-contaminated tannery wastewater for irrigation is a common practice, especially in developing countries like Pakistan. This practice is due to the shortage of good quality irrigation water for crop growth as well as the issue of tannery wastewater disposal. The current study was done to evaluate the effect of citric acid (CA) (0, 1.0, and 2.0mM) on the growth and Cr uptake by spinach irrigated with different mixtures of tap water and tannery wastewater (100:0, 50:50, and 0:100 tap water to wastewater ratio). Plants were grown for 8weeks under ambient conditions. Results showed that 50:50% tap water and wastewater increased plant height, dry weights of shoots and roots, total chlorophyll contents, and gas exchange attributes than the plants treated with only tap water or only wastewater. Increasing wastewater ratio increased electrolyte leakage (EL) in plants and enhanced the leaf key antioxidant enzyme activities as well as increased Cr contents. Foliar application of CA increased the plant dry weights, photosynthesis, and enzyme activities, whereas reduced the EL and Cr concentrations in plants than respective treatments without CA application. It can be concluded that 50:50 tap water and wastewater irrigation along with foliar CA application might be an effective strategy for increasing vegetable growth with reduced metal concentrations.

Alleviation of copper toxicity in germinating pea seeds by IAA, GA3, Ca and citric acid

ABSTRACTThe ameliorating effects of four exogenous effectors were investigated in germinating pea seeds exposed to copper excess. The results showed that the application of IAA, GA3, Ca or citric acid alleviated Cu-induced inhibition of growth and simultaneously reduced the oxidative stress injury, particularly contents of hydrogen peroxide, malondialdehyde and carbonyl groups. The improving effects can probably be mediated by the decreases in lipoperoxidation and protein oxidation as evidenced by changes in antioxidant enzyme activities. In addition, the efficiency of this recovery was compared within two types of treatments. Obtained results demonstrated that the stress abruption by the addition of effectors after three days of Cu application (treatment of type II) seems to be more effective than the simultaneous application of ‘Cu + effectors’ at the beginning of germination (treatment of type I). Data could provide some clues to physiological and biochemical mechanisms of the response of germinating seeds to the addition of chemicals under heavy metal stress.

Effects of addition of malic or citric acids on fermentation quality and chemical characteristics of alfalfa silage

We studied the effects on alfalfa preservation and chemical composition of the addition of different levels of malic acid and citric acid at ensiling as well as the utilization efficiency of these 2 organic acids after fermentation. Alfalfa was harvested at early bloom stage. After wilting to a dry matter content of approximately 40%, the alfalfa was chopped into 1- to 2-cm pieces for ensiling. Four levels (0, 0.1, 0.5, and 1% of fresh weight) of malic acid or citric acid were applied to chopped alfalfa at ensiling with 4 replicates for each treatment, and the treated alfalfa forages were ensiled for 60 d in vacuum-sealed polyethylene bags (dimensions: 200 mm × 300 mm) packed with 200 to 230 g of fresh alfalfa per mini silo and an initial density of 0.534 g/cm3. The application of malic or citric acids at ensiling for 60 d led to lower silage pH than was observed in the control silage (0% of malic or citric acids). Application of the 2 organic acids led to higher lactic acid concentration in alfalfa silage than in the control silage except with the application rate of 1% of fresh weight. Silages treated with both organic acids had lower nonprotein nitrogen concentrations than the control silages, and the nonprotein nitrogen concentrations in ensiled forages decreased with the increase in malic or citric acid application rates. The application of the 2 organic acid additives led to lower saturated fatty acid proportions and higher polyunsaturated fatty acid proportions in ensiled alfalfa than in the control silage. The amount of malic and citric acids degraded during ensiling of alfalfa was 1.45 and 0.63 g, respectively. At the application rate of 0.5% of fresh weight, residues of malic acid and citric acid in alfalfa silage were 11.1 and 13.6 g/kg of dry matter. These results indicate that including malic or citric acids at the ensiling of alfalfa effectively improved silage fermentation quality, limited proteolysis, improved fatty acid composition of the ensiled forage, and could provide animals with additional feed additives proven to promote animal performance. However, when the application rate of both organic acids reached 1%, the concentration of lactic acid in silages decreased notably. Additionally, 0.5 and 1% application rates also increased the yeast count in ensiled alfalfa.

低分子有機態炭素施用によるキャベツ苗の乾燥ストレス耐性向上 : II. クエン酸施用効果の検証

低分子有機態炭素施用によるキャベツ苗の乾燥ストレス耐性向上 : II. クエン酸施用効果の検証

Postharvest life of different cultivars of Narcissus (daffodil) as influ-enced by various preservative solutions

Post harvest life has always being of critical importance in high value flower crops. Our investigation was concerned in evaluating the varietal response of different preservative soloutions on post harvest life of Narcissus (daffodil). The effects of the application of citric acid, aluminium sulphate, silver thiosulphate and calcium chloride at three different levels 0, 100 ppm, 200 ppm along with carbohydrate source sucrose 4% on different floral attributes of Narcissus (daffodil) cultivars California, Pheasants eye and Acetea were stud-ied. The recorded traits included water loss/water uptake ratio, scape length, cup depth, cup diameter, relative water content and membrane stability index. Results of this study showed that within all treatments aluminium sulphate + sucrose 4% showed the best effect. Among the cultivars evaluated California proves best in term of parameters studied (overall post harvest life). The minimum values for these traits were recorded in the untreated control.

Citric acid as waterproofing additive in butt joints linear wood welding

Citric acid was used to improve resistance to water of the welded joint of spruce along the end-grain-to-end-grain faces. The use of 10–20% citric acid as treatment during a very short time has been shown to markedly improve both the mechanical performance and the water resistance of welded spruce. Based on the results of the water resistance tests it appears that the application of citric acid as a natural waterproofing additive in wood welding is possible. The use of citric acid thus allows the preparation of welded wood joints satisfying the requirement of frequent short-term and long-term exposure to water. 13C NMR analysis indicated that lignin modification of the welded material is related to the improvement of water resistance and shear properties of the welded joints.

Phytoextraction of contaminated urban soils by Panicum virgatum L. enhanced with application of a plant growth regulator (BAP) and citric acid

Lead (Pb) contamination in soil represents a threat to human health. Phytoextraction has gained attention as a potential alternative to traditional remediation methods because of lower cost and minimal soil disruption. The North American native switchgrass (Panicum virgatum L.) was targeted due to its ability to produce high biomass and grow across a variety of ecozones. In this study switchgrass was chemically enhanced with applications of the soil-fungicide benomyl, chelates (EDTA and citric acid), and PGR to optimize phytoextraction of Pb and zinc (Zn) from contaminated urban soils in Atlanta, GA.Exogenous application of two plant hormones was compared in multiple concentrations to determine effects on switchgrass growth: indole-3-acetic acid (IAA), and Gibberellic Acid (GA3), and one PGR benzylaminopurine (BAP), The PGR BAP (1.0 μM) was found to generate a 48% increase in biomass compared to Control plants.Chemical application of citric acid, EDTA, benomyl, and BAP were tested separately and in combination in a pot experiment in an environmentally controlled greenhouse to determine the efficacy of phtyoextraction by switchgrass. Soil acidification by citric acid application resulted in highest level of aluminum (Al) and iron (Fe) in plants foliage resulting in severe phytotoxic effects. Total Pb phytoextraction was significantly highest in plants treated with combined chemical application of B + C and B + C + H.Suppression of AMF activities by benomyl application significantly increased concentrations of Al and Fe in roots. Application of benomyl reduced AMF colonization but was also shown to dramatically increase levels of septa fungi infection as compared to Control plants.

Citric acid application for denitrification process support in biofilm reactor

The study demonstrated that citric acid, as an organic carbon source, can improve denitrification in Anaerobic Sequencing Batch Biofilm Reactor (AnSBBR). The consumption rate of the organic substrate and the denitrification rate were lower during the period of the reactor's acclimatization (cycles 1–60; 71.5 mgCOD L−1 h−1 and 17.81 mgN L−1 h−1, respectively) than under the steady state conditions (cycles 61–180; 143.8 mgCOD L−1 h−1 and 24.38 mgN L−1 h−1). The biomass yield coefficient reached 0.04 ± 0.02 mgTSS· mgCODre−1 (0.22 ± 0.09 mgTSS mgNre−1). Observations revealed the diversified microbiological ecology of the denitrifying bacteria. Citric acid was used mainly by bacteria representing the Trichoccocus genus, which represented above 40% of the sample during the first phase of the process (cycles 1–60). In the second phase (cycles 61–180) the microorganisms the genera that consumed the acetate and formate, as the result of citric acid decomposition were Propionibacterium (5.74%), Agrobacterium (5.23%), Flavobacterium (1.32%), Sphaerotilus (1.35%), Erysipelothrix (1.08%).

Thallium Uptake and Translocation in Barley and Sunflower Grown in Hydroponic Conditions

Thallium (Tl) is highly toxic to humans compared with other heavy metals and metalloids, but the risk of its bioaccumulation has not been adequately considered. Thus, Tl uptake and translocation in barley and sunflower under hydroponics with the applications of diethylene triamine pentaacetic acid (DTPA) and citric acid were investigated. Thallium concentrations in roots of both the plants were higher than those in the shoots. Translocation index (TLI) of Tl in barley decreased from 14.9 to 10.0% with increasing Tl treatments in barley, but it increased from 5.9 to 7.5% in sunflower. The concentration of Tl in the barley tissues increased with DTPA applications, but it decreased with citric acid treatments. In contrast, Tl in the sunflower tissues decreased with DTPA treatments, while it increased with the applications of citric acid. However, Tl concentrations in the tissues of both plants were not significantly different between the two concentrations (5.0 and 30 mg/kg) of DTPA and citric acid applications.

Effects of Tetracycline, EDTA and Citric Acid Application on Nonfluorosed and Fluorosed Dentin: An In Vitro Study.

Fluorosis is one of the factors that may bring about mineralization changes in teeth. Routine treatment of root biomodification is commonly followed during Periodontal therapy.Background:The Purpose of the present study was to compare and evaluate the morphological changes in fluorosed and nonfluorosed root dentin subsequent to the application of Tetracycline, EDTA and Citric acid. Both fluorosed and nonfluorosed teeth comprising of periodontally healthy and diseased were included in this study.Method:Each of them was grouped into Tetracycline Hydrochloride, EDTA and Citric acid treatment groupes. Using scanning electron microscope (SEM), the photomicrographs of dentin specimens were obtained.Results:Showed that there was no significant difference in exposure of number of tubules in different groups, while significant increase in the tubular width and tubular surface area was seen in fluorosed healthy, followed by fluorosed diseased groups, nonfluorosed healthy and nonfluorosed diseased groups after root biomodification procedure using various root conditioning agents. The root biomodification procedure brings in definite difference between fluorosed and nonfluorosed dentin specimens.

Effect of Pre-harvest Foliar Application of Citric Acid, Malic Acid and Tryptophan on The Growth, Flowering and Post-harvest Vase Life of tuberose Plants (B) Effect of Pre-harvest Treatments on Post-harvest Vase Life

Tuberose (Polianthes tuberosa L.), is one of the most famous cut flowers used due to its delicate fragrance and commercial demand, nevertheless, the vase life of the inflorescence declines rapidly at home. To overcome this problem an experiment was conducted to find a suitable pre-harvest foliar application which provides the longest vase life of tuberose. Three foliar applications were used in the form of malic acid, citric acid and tryptophan after planting the bulbs with concentrations of (0, 100, 200 and 300 mg/L) for each chemical. Cut inflorescences were then placed into a standard vase solution containing 4% sucrose and 200 mg/L of salicylic acid. Results showed that malic acid at the concentration of (300 mg/L), significantly affected all the vegetative parameters tested with the highest vase life 12.00 and 12.33 days compared with the control (8.33 and 7.66 days). Malic acid also gave the highest total chlorophyll and carbohydrates in the inflorescences of tuberose as compared with the control.

Drought stress alleviation of cabbage seedlings by citric acid application

Drought stress alleviation of cabbage seedlings by citric acid application

Exogenous Application of Citric Acid Ameliorates the Adverse Effect of Heat Stress in Tall Fescue (Lolium arundinaceum).

Citric acid may be involved in plant response to high temperature. The objective of this study was to investigate whether exogenous citric acid could improve heat tolerance in a cool-season turfgrass species, tall fescue (Lolium arundinaceum), and to determine the physiological mechanisms of citric acid effects on heat stress tolerance. The grasses were subjected to four citric acid levels (0, 0.2, 2, and 20 mM) and two temperature levels (25/20 and 35/30 ± 0.5°C, day/night) treatments in growth chambers. Heat stress increased an electrolyte leakage (EL) and malonaldehyde (MDA) content, while reduced plant growth, chlorophyll (Chl) content, photochemical efficiency (Fv/Fm), root activity and antioxidant enzyme activities (superoxide dismutase, SOD; catalase, CAT; peroxidase, POD). External citric acid alleviated the detrimental effects of heat stress on tall fescue, which was evidenced by decreased EL and MDA content, and improved plant growth under stress conditions. Additionally, the reduction in Chl content, Fv/Fm, SOD, POD, CAT and root activity were ameliorated in citric acid treated plants under heat stressed conditions. High temperature induced the expression of heat shock protein (HSP) genes, which exhibited greater expression levels after citric acid treatment under heat stress. These results suggest that exogenous citric acid application may alleviate growth and physiological damage caused by high temperature. In addition, the exogenously applied citric acid might be responsible for maintaining membrane stability, root activity, and activation of antioxidant response and HSP genes which could contribute to the protective roles of citric acid in tall fescue responses to heat stress.

Citric acid- and Tween(®) 80-assisted phytoremediation of a co-contaminated soil: alfalfa (Medicago sativa L.) performance and remediation potential.

A pot experiment was designed to assess the phytoremediation potential of alfalfa (Medicago sativa L.) in a co-contaminated (i.e., heavy metals and petroleum hydrocarbons) soil and the influence of citric acid and Tween(®) 80 (polyethylene glycol sorbitan monooleate), applied individually and combined together, for their possible use in chemically assisted phytoremediation. The results showed that alfalfa plants could tolerate and grow in a co-contaminated soil. Over a 90-day experimental time, shoot and root biomass increased and negligible plant mortality occurred. Heavy metals were uptaken by alfalfa to a limited extent, mostly by plant roots, and their concentration in plant tissues were in the following order: Zn > Cu > Pb. Microbial population (alkane-degrading microorganisms) and activity (lipase enzyme) were enhanced in the presence of alfalfa with rhizosphere effects of 9.1 and 1.5, respectively, after 90days. Soil amendments did not significantly enhance plant metal concentration or total uptake. In contrast, the combination of citric acid and Tween(®) 80 significantly improved alkane-degrading microorganisms (2.4-fold increase) and lipase activity (5.3-fold increase) in the rhizosphere of amended plants, after 30days of experiment. This evidence supports a favorable response of alfalfa in terms of tolerance to a co-contaminated soil and improvement of rhizosphere microbial number and activity, additionally enhanced by the joint application of citric acid and Tween(®) 80, which could be promising for future phytoremediation applications.