The Experts below are selected from a list of 21417 Experts worldwide ranked by ideXlab platform
Eric A Decker - One of the best experts on this subject based on the ideXlab platform.
-
chemical and physical stability of citral and Limonene in sodium dodecyl sulfate chitosan and gum arabic stabilized oil in water emulsions
Journal of Agricultural and Food Chemistry, 2007Co-Authors: D Djordjevic, Jean Alamed, Luisito Cercaci, Julian D Mcclements, Eric A DeckerAbstract:Citral and Limonene are the major flavor components of citrus oils. Both of these compounds can undergo chemical degradation leading to loss of flavor and the formation of undesirable off-flavors. Engineering the interface of emulsion droplets with emulsifiers that inhibit chemical reactions could provide a novel technique to stabilize citral and Limonene. At present, emulsified flavor oils are usually stabilized by gum arabic (GA), which is a naturally occurring polysaccharide−protein complex. The objective of this study was to examine if citral and Limonene were more stable in emulsions stabilized with a sodium dodecyl sulfate (SDS)−chitosan complex than GA. Citral degraded less in GA-stabilized than in SDS−chitosan-stabilized emulsions at pH 3.0. However, SDS−chitosan-stabilized emulsions were more effective at retarding the formation of the citral oxidation product, p-cymene, than GA-stabilized emulsions. Limonene degradation and the formation of Limonene oxidation products, Limonene oxide and carvone...
-
chemical and physical stability of citral and Limonene in sodium dodecyl sulfate chitosan and gum arabic stabilized oil in water emulsions
Journal of Agricultural and Food Chemistry, 2007Co-Authors: D Djordjevic, Jean Alamed, Luisito Cercaci, Julian D Mcclements, Eric A DeckerAbstract:Citral and Limonene are the major flavor components of citrus oils. Both of these compounds can undergo chemical degradation leading to loss of flavor and the formation of undesirable off-flavors. Engineering the interface of emulsion droplets with emulsifiers that inhibit chemical reactions could provide a novel technique to stabilize citral and Limonene. At present, emulsified flavor oils are usually stabilized by gum arabic (GA), which is a naturally occurring polysaccharide-protein complex. The objective of this study was to examine if citral and Limonene were more stable in emulsions stabilized with a sodium dodecyl sulfate (SDS)-chitosan complex than GA. Citral degraded less in GA-stabilized than in SDS-chitosan-stabilized emulsions at pH 3.0. However, SDS-chitosan-stabilized emulsions were more effective at retarding the formation of the citral oxidation product, p-cymene, than GA-stabilized emulsions. Limonene degradation and the formation of Limonene oxidation products, Limonene oxide and carvone, were lower in the SDS-chitosan- than GA-stabilized emulsions at pH 3.0. The ability of an SDS-chitosan multilayer emulsifier system to inhibit the oxidative deterioration of citral and Limonene could be due to the formation of a cationic and thick emulsion droplet interface that could repel prooxidative metals, thus decreasing prooxidant-lipid interactions.
D Djordjevic - One of the best experts on this subject based on the ideXlab platform.
-
chemical and physical stability of citral and Limonene in sodium dodecyl sulfate chitosan and gum arabic stabilized oil in water emulsions
Journal of Agricultural and Food Chemistry, 2007Co-Authors: D Djordjevic, Jean Alamed, Luisito Cercaci, Julian D Mcclements, Eric A DeckerAbstract:Citral and Limonene are the major flavor components of citrus oils. Both of these compounds can undergo chemical degradation leading to loss of flavor and the formation of undesirable off-flavors. Engineering the interface of emulsion droplets with emulsifiers that inhibit chemical reactions could provide a novel technique to stabilize citral and Limonene. At present, emulsified flavor oils are usually stabilized by gum arabic (GA), which is a naturally occurring polysaccharide−protein complex. The objective of this study was to examine if citral and Limonene were more stable in emulsions stabilized with a sodium dodecyl sulfate (SDS)−chitosan complex than GA. Citral degraded less in GA-stabilized than in SDS−chitosan-stabilized emulsions at pH 3.0. However, SDS−chitosan-stabilized emulsions were more effective at retarding the formation of the citral oxidation product, p-cymene, than GA-stabilized emulsions. Limonene degradation and the formation of Limonene oxidation products, Limonene oxide and carvone...
-
chemical and physical stability of citral and Limonene in sodium dodecyl sulfate chitosan and gum arabic stabilized oil in water emulsions
Journal of Agricultural and Food Chemistry, 2007Co-Authors: D Djordjevic, Jean Alamed, Luisito Cercaci, Julian D Mcclements, Eric A DeckerAbstract:Citral and Limonene are the major flavor components of citrus oils. Both of these compounds can undergo chemical degradation leading to loss of flavor and the formation of undesirable off-flavors. Engineering the interface of emulsion droplets with emulsifiers that inhibit chemical reactions could provide a novel technique to stabilize citral and Limonene. At present, emulsified flavor oils are usually stabilized by gum arabic (GA), which is a naturally occurring polysaccharide-protein complex. The objective of this study was to examine if citral and Limonene were more stable in emulsions stabilized with a sodium dodecyl sulfate (SDS)-chitosan complex than GA. Citral degraded less in GA-stabilized than in SDS-chitosan-stabilized emulsions at pH 3.0. However, SDS-chitosan-stabilized emulsions were more effective at retarding the formation of the citral oxidation product, p-cymene, than GA-stabilized emulsions. Limonene degradation and the formation of Limonene oxidation products, Limonene oxide and carvone, were lower in the SDS-chitosan- than GA-stabilized emulsions at pH 3.0. The ability of an SDS-chitosan multilayer emulsifier system to inhibit the oxidative deterioration of citral and Limonene could be due to the formation of a cationic and thick emulsion droplet interface that could repel prooxidative metals, thus decreasing prooxidant-lipid interactions.
Mihaly Matura - One of the best experts on this subject based on the ideXlab platform.
-
air oxidation increases skin irritation from fragrance terpenes
Contact Dermatitis, 2009Co-Authors: Mihaly Matura, Johanna Bråred Christensson, Ann-therese Karlberg, Pia Forsstrom, Annmarie WennbergAbstract:Background: Linalool and Limonene are common fragrance terpenes that autoxidize on air exposure. The pure compounds are not allergenic but their oxidation products can cause contact allergy. Little has been investigated regarding the irritancy of oxidized terpenes. Aim: The aim of this study was to investigate the irritating effect of pure and oxidized R-Limonene and linalool in concentration series and to study the MNIC (Maximum Non Irritant Concentration) of autoxidized linalool and Limonene. Patients/methods: Patch testing was performed in dermatitis patients and controls with sequentially diluted concentrations of oxidized and non-oxidized linalool, and oxidized and non-oxidized R-Limonene. Readings were made with visual assessment and using laser Doppler imaging. Results: The non-oxidized terpenes were non-irritating in all tested concentrations. Both linalool and especially R-Limonene were more irritating after oxidation compared with the pure compounds. No difference in response was seen between dermatitis patients and controls. Conclusion: Autoxidation of the fragrance terpenes linalool and R-Limonene increases irritation. Oxidized linalool is less irritating than oxidized R-Limonene. In this study, we found no advantages in using laser Doppler technique compared with visual assessment.
-
not only oxidized r but also s Limonene is a common cause of contact allergy in dermatitis patients in europe
Contact Dermatitis, 2006Co-Authors: Mihaly Matura, Maria Skold, Anna Borje, Klaus Ejner Andersen, M Bruze, Peter J Frosch, An Goossens, Jeanne D Johansen, Cecilia SvedmanAbstract:Limonene, one of the most often used fragrance terpenes in any kind of scented products, is prone to air-oxidation. The oxidation products formed have a considerable sensitizing potential. In previous patch test studies on consecutively tested dermatitis patients, oxidized R-Limonene has been proven to be a good and frequent indicator of fragrance-related contact allergy. The current study extends these investigations to 6 European clinics of dermatology, where the oxidation mixture of both enantiomers of Limonene (R and S) have been tested in 2411 dermatitis patients. Altogether, 63 out of 2411 patients tested (2.6%) reacted to 1 or both the oxidized Limonene preparations. Only 2.3% reacted to the oxidized R-Limonene and 2.0% to the oxidized S-Limonene. In 57% of the cases, simultaneous reactions were observed to both oxidation mixtures. Concomitant reactions to the fragrance mix, colophonium, Myroxylon pereirae, and fragrance-related contact allergy were common in patients reacting to 1 or both the oxidized Limonene enantiomers. Our study provides clinical evidence for the importance of oxidation products of Limonene in contact allergy. It seems advisable to screen consecutive dermatitis patients with oxidized Limonene 3% petrolatum, although this patch test material is not yet commercially available.
Rajib Saha - One of the best experts on this subject based on the ideXlab platform.
-
metabolic engineering of the pentose phosphate pathway for enhanced Limonene production in the cyanobacterium synechocysti s sp pcc 6803
Scientific Reports, 2017Co-Authors: Fuzhong Zhang, Rajib Saha, Himadri B PakrasiAbstract:Isoprenoids are diverse natural compounds, which have various applications as pharmaceuticals, fragrances, and solvents. The low yield of isoprenoids in plants makes them difficult for cost-effective production, and chemical synthesis of complex isoprenoids is impractical. Microbial production of isoprenoids has been considered as a promising approach to increase the yield. In this study, we engineered the model cyanobacterium Synechocystis sp. PCC 6803 for sustainable production of a commercially valuable isoprenoid, Limonene. Limonene synthases from the plants Mentha spicata and Citrus limon were expressed in cyanobacteria for Limonene production. Production of Limonene was two-fold higher with Limonene synthase from M. spicata than that from C. limon. To enhance isoprenoid production, computational strain design was conducted by applying the OptForce strain design algorithm on Synechocystis 6803. Based on the metabolic interventions suggested by this algorithm, genes (ribose 5-phosphate isomerase and ribulose 5-phosphate 3-epimerase) in the pentose phosphate pathway were overexpressed, and a geranyl diphosphate synthase from the plant Abies grandis was expressed to optimize the Limonene biosynthetic pathway. The optimized strain produced 6.7 mg/L of Limonene, a 2.3-fold improvement in productivity. Thus, this study presents a feasible strategy to engineer cyanobacteria for photosynthetic production of isoprenoids.
Dongguang Xiao - One of the best experts on this subject based on the ideXlab platform.
-
simultaneous improvement of Limonene production and tolerance in yarrowia lipolytica through tolerance engineering and evolutionary engineering
ACS Synthetic Biology, 2021Co-Authors: Kun Zhu, Dongguang Xiao, Yu Zhao, Lin Miao, Lanxin Rong, Cuiying Zhang, Jee Loon FooAbstract:Limonene is an important plant natural product widely used in food and cosmetics production as well as in the pharmaceutical and chemical industries. However, low efficiency of plant extraction and high energy consumption in chemical synthesis limit the sustainability of industrial Limonene production. Recently, the advancement of metabolic engineering and synthetic biology has facilitated the engineering of microbes into microbial cell factories for producing Limonene. However, the deleterious effects on cellular activity by the toxicity of Limonene is the major obstacle in achieving high-titer production of Limonene in engineered microbes. In this study, by using transcriptomics, we identified 82 genes from the nonconventional yeast Yarrowia lipolytica that were up-regulated when exposed to Limonene. When overexpressed, 8 of the gene candidates improved tolerance of this yeast to exogenously added Limonene. To determine whether overexpression of these genes could also improve Limonene production, we individually coexpressed the tolerance-enhancing genes with a Limonene synthase gene. Indeed, expression of 5 of the 8 candidate genes enhanced Limonene production in Y. lipolytica. Particularly, overexpressing YALI0F19492p led to an 8-fold improvement in product titer. Furthermore, through short-term adaptive laboratory evolution strategy, in combination with morphological and cytoplasmic membrane integrity analysis, we shed light on the underlying mechanism of Limonene cytotoxicity to Y. lipolytica. This study demonstrated an effective strategy for improving Limonene tolerance of Y. lipolytica and Limonene titer in the host strain through the combinatorial use of tolerance engineering and evolutionary engineering.
-
engineering the oleaginous yeast yarrowia lipolytica to produce Limonene from waste cooking oil
Biotechnology for Biofuels, 2019Co-Authors: Yaru Pang, Yu Zhao, Cuiying Zhang, Yakun Zhao, Dongguang XiaoAbstract:Limonene is an important biologically active natural product widely used in the food, cosmetic, nutraceutical and pharmaceutical industries. However, the low abundance of Limonene in plants renders their isolation from plant sources non-economically viable. Therefore, engineering microbes into microbial factories for producing Limonene is fast becoming an attractive alternative approach that can overcome the aforementioned bottleneck to meet the needs of industries and make Limonene production more sustainable and environmentally friendly. In this proof-of-principle study, the oleaginous yeast Yarrowia lipolytica was successfully engineered to produce both d-Limonene and l-Limonene by introducing the heterologous d-Limonene synthase from Citrus limon and l-Limonene synthase from Mentha spicata, respectively. However, only 0.124 mg/L d-Limonene and 0.126 mg/L l-Limonene were produced. To improve the Limonene production by the engineered yeast Y. lipolytica strain, ten genes involved in the mevalonate-dependent isoprenoid pathway were overexpressed individually to investigate their effects on Limonene titer. Hydroxymethylglutaryl-CoA reductase (HMGR) was found to be the key rate-limiting enzyme in the mevalonate (MVA) pathway for the improving Limonene synthesis in Y. lipolytica. Through the overexpression of HMGR gene, the titers of d-Limonene and l-Limonene were increased to 0.256 mg/L and 0.316 mg/L, respectively. Subsequently, the fermentation conditions were optimized to maximize Limonene production by the engineered Y. lipolytica strains from glucose, and the final titers of d-Limonene and l-Limonene were improved to 2.369 mg/L and 2.471 mg/L, respectively. Furthermore, fed-batch fermentation of the engineered strains Po1g KdHR and Po1g KlHR was used to enhance Limonene production in shake flasks and the titers achieved for d-Limonene and l-Limonene were 11.705 mg/L (0.443 mg/g) and 11.088 mg/L (0.385 mg/g), respectively. Finally, the potential of using waste cooking oil as a carbon source for Limonene biosynthesis from the engineered Y. lipolytica strains was investigated. We showed that d-Limonene and l-Limonene were successfully produced at the respective titers of 2.514 mg/L and 2.723 mg/L under the optimal cultivation condition, where 70% of waste cooking oil was added as the carbon source, representing a 20-fold increase in Limonene titer compared to that before strain and fermentation optimization. This study represents the first report on the development of a new and efficient process to convert waste cooking oil into d-Limonene and l-Limonene by exploiting metabolically engineered Y. lipolytica strains for fermentation. The results obtained in this study lay the foundation for more future applications of Y. lipolytica in converting waste cooking oil into various industrially valuable products.
-
advances in metabolic engineering for the microbial production of naturally occurring terpenes Limonene and bisabolene a mini review
Chinese Journal of Biotechnology, 2018Co-Authors: Yaru Pang, Dongguang XiaoAbstract:Limonene (C₁₀H₁₆) and bisabolene (C₁₅H₂₄) are both naturally occurring terpenes in plants. Depending on the number of C₅ units, Limonene and bisabolene are recognized as representative monoterpenes and sesquiterpenes, respectively. Limonene and bisabolene are important pharmaceutical and nutraceutical products used in the prevention and treatment of cancer and many other diseases. In addition, they can be used as starting materials to produce a range of commercially valuable products, such as pharmaceuticals, nutraceuticals, cosmetics, and biofuels. The low abundance or yield of Limonene and bisabolene in plants renders their isolation from plant sources non-economically viable. Isolation of Limonene and bisabolene from plants also suffers from low efficiency and often requires harsh reaction conditions, prolonged reaction times, and expensive equipment cost. Recently, the rapid developments in metabolic engineering of microbes provide a promising alternative route for producing these plant natural products. Therefore, producing Limonene and bisabolene by engineering microbial cells into microbial factories is becoming an attractive alternative approach that can overcome the bottlenecks, making it more sustainable, environmentally friendly and economically competitive. Here, we reviewed the status of metabolic engineering of microbes that produce Limonene and bisabolene including microbial hosts, key enzymes, metabolic pathways and engineering of Limonene/bisabolene biosynthesis. Furthermore, key challenges and future perspectives were discussed.