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1.
Crit Rev Food Sci Nutr ; 63(32): 11310-11326, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35699651

RESUMO

n-3 Polyunsaturated fatty acids (n-3 PUFA) has been widely used in foods, and pharmaceutical products due to its beneficial effects. The content of n-3 PUFA in natural oils is usually low, which decreases its added value. Thus, there is an increasing demand on the market for n-3 PUFA concentrates. This review firstly introduces the differences in bioavailability and oxidative stability between different types of PUFA concentrate (free fatty acid, ethyl ester and acylglycerol), and then provides a comprehensive discussion of different methods for enrichment of lipids with n-3 PUFA including physical-chemical methods and enzymatic methods. Lipases used for catalyzing esterification, transesterification and hydrolysis reactions play an important role in the production of highly enriched various types of n-3 PUFA concentrates. Lipase-catalyzed alcoholysis or hydrolysis reactions are the mostly employed method to prepare high-quality n-3 PUFA of structural acylglycerols. Although many important advantages offered by lipases in enrichment of n-3 PUFA, the high cost of enzyme limits its industrial-scale production. Further research should focus on looking for biological enzymes with extraordinary catalytic ability and clear selectivity. Other novel technologies such as protein engineering and immobilization may be needed to modify lipases to improve its selectivity, catalytic ability and reuse.


Assuntos
Ácidos Graxos Ômega-3 , Ácidos Graxos Ômega-3/metabolismo , Ácidos Graxos Insaturados/metabolismo , Lipase/metabolismo , Hidrólise , Glicerídeos/química
2.
Compr Rev Food Sci Food Saf ; 18(2): 514-534, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33336946

RESUMO

Antarctic krill (Euphausia superba) oil has been receiving increasing attention due to its nutritional and functional potentials. However, its application as a novel food ingredient has not yet been fully explored. This review summarizes the chemical composition, extraction technologies, potential health benefits, and current applications of krill oil, with the aim of providing suggestions for its exploitation. Krill oil is a unique lipid consisting of diverse lipid classes and is characterized by a high concentration (39.29% to 80.69%) of phospholipids (PLs) associated with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). It also contains considerable amounts of bioactive minor components such as astaxanthin, sterols, tocopherols, vitamin A, flavonoids, and minerals. The current technologies used in krill oil production are solvent extraction, nonsolvent extraction, super/subcritical fluid extraction, and enzyme-assisted pretreatment extraction, which all greatly influence the yield and quality of the end-product. In addition, krill oil has been documented to have various health benefits, including anti-inflammatory effects, cardiovascular disease (CVD) prevention, women's health, neuroprotection, and anticancer activities. Although krill oil products used for dietary supplements have been commercially available, few studies have attempted to explore the underlying molecular mechanisms to elucidate how exactly the krill oil exerts different biological activities. Further studies should focus on this to improve the development of krill oil products for human consumption.

3.
Eur J Nutr ; 55(4): 1545-53, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26141258

RESUMO

PURPOSE: Fat randomization and interesterification change triacylglycerol (TAG) structure and its solid fat content profile. It has not been thoroughly investigated whether these changes affect lipid metabolism. METHODS: Two experiments were conducted to investigate the effects of TAG structure and solid fat content on feed intake, body weight change, and serum metabolite concentrations in mice. An experiment used two fats rich in 1,2-dipalmitoyl-3-oleoylglycerol (PPO) and 1,3-dipalmitoyl-2-oleoylglycerol (POP) as comparative pair of fats to assess the effect of TAG structure since PPO and POP have the same fatty acid composition and solid fat content at 37 °C. Another experiment used a fat rich in 1-palmitoyl-2,3-dioleoylglycerol (POO) with solid fat content of zero at 37 °C and a mixture of fats that had the same general fatty acid composition and palmitic acid positional distribution, but with solid fat content of 22 % at 37 °C. This pair of fats was used to examine the effect of solid fat content on blood lipid profile. RESULTS: After 6-week feeding, the pair of fats with different solid fat contents did not significantly affect the concentrations of total serum cholesterol, HDL cholesterol, TAG, non-esterified fatty acid (NEFA), or blood glucose. However, the PPO fat significantly reduced feed intake, body weight, and serum glucose concentration as compared to POP. CONCLUSION: These results suggest that the presence of solid fat at the level examined does not affect lipid metabolism and lipemia, but PPO diet significantly affects NEFA and glucose concentrations. Palmitic acid at the sn-2 position of the TAG may have significant effect on appetite, which may be mediated via the gut receptors.


Assuntos
Gorduras na Dieta/análise , Jejum , Triglicerídeos/sangue , Triglicerídeos/química , Animais , Glicemia/metabolismo , Peso Corporal , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Gorduras na Dieta/administração & dosagem , Ácidos Graxos/administração & dosagem , Ácidos Graxos/análise , Ácidos Graxos não Esterificados/sangue , Metabolismo dos Lipídeos/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ácido Palmítico/administração & dosagem , Ácido Palmítico/análise
4.
Biotechnol Lett ; 37(3): 691-6, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25367802

RESUMO

We report the synthesis of 1,3-dioleoyl-2-palmitoylglycerol (OPO) by a three-step method. Vinyl oleate was first synthesized by transvinylation between vinyl acetate and oleic acid. This was further reacted with glycerol at 35 °C for 8 h using 10% (w/v) Novozym 435 to synthesize 1,3-diolein. The 1,3-diolein content in the crude reaction mixture was 90.8% and was obtained at 82.3% (w/w) yield with 98.6% purity after purification. Finally, OPO was chemically synthesized by reacting purified 1,3-diolein with palmitic acid. 94.8% OPO was produced in the crude reaction mixture and the regiopurity of OPO after purification was 98.7% at 90.5% yield based on positional distribution analysis. This is an innovative approach for the synthesis of 1,3-diolein in a solvent-free system as an alternative to previously presented studies that applied solvent system.


Assuntos
Lipase/metabolismo , Triglicerídeos/síntese química , Triglicerídeos/metabolismo , Diglicerídeos/metabolismo , Enzimas Imobilizadas , Proteínas Fúngicas , Glicerol/metabolismo , Ácido Oleico/metabolismo , Ácido Palmítico/metabolismo , Temperatura , Fatores de Tempo , Compostos de Vinila/metabolismo
5.
Food Chem ; 448: 139100, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38552457

RESUMO

Phytosterol esters (PEs) and diacylglycerols (DAGs) have various health benefits in humans. In this study, PEs and DAGs were synthesized by lipase-catalyzed transesterification between a natural oil and phytosterols. First, commercial lipases were screened for transesterification and were further verified using multiple-ligand molecular docking. AYS "Amano" (a lipase from Candida rugosa) was found to be the optimum lipase. Subsequently, the enzymatic transesterification conditions were optimized. The optimized conditions were determined to be a 1:2 M ratio of phytosterols to oil, 100 mmol/L phytosterols, and 9 % AYS "Amano", and 50 °C for 24 h in 20 mL n-hexane. Under these conditions, over 70 % of phytosterols were converted to PEs. In this study, an efficient enzymatic process was developed to produce value-added functional oils rich in PEs and DAGs, with PEs content ≥ 31.6 %, DAGs content ≥ 11.2 %, acid value ≤ 0.91 mg KOH/g, and peroxide value ≤ 2.38 mmol/kg.

6.
Food Chem X ; 22: 101434, 2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-38779499

RESUMO

In this study, lipase from Candida rugosa was immobilized on hydrophobic hierarchical porous hollow silica microsphere (HPHSM-C3) via adsorption. The prepared biocatalyst HPHSM-C3@CRL exhibited higher activity, thermal and pH stability. HPHSM-C3@CRL remained 70.2% of initial activity after 30 days of storage at 24 °C and 50.4% of initial activity after 10 cycles. Moreover, HPHSM-C3@CRL was utilized in enzymatic enrichment of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) in glycerides, achieving ω-3 PUFAs content of 53.42% with the hydrolysis rate of 48.78% under optimal condition. The Km and Vmax value of HPHSM-C3@CRL was 42.2% lower and 63.5% higher than those of CRL, respectively. The 3D structure analysis of CRL, substrates and pore structure of HPHSM-C3 suggested that the hierarchical pore improved activity and selectivity of immobilized lipase. This result demonstrated that HPHSM-C3@CRL may be an effective biocatalyst for the enzymatic enrichment of ω-3 PUFAs in food industries.

7.
Food Chem ; 412: 135501, 2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-36716621

RESUMO

Acyl migration of 2-monoacylglycerols (2-MAGs) rich in DHA is a universal reaction occurring during storage and structural lipid synthesis, and affects their nutritional value. In this study, their acyl migration was investigated under different systems and temperatures. The enhanced temperature promoted acyl migration, leading to a 5.6-fold increase from 20 °C to 50 °C. The kinetic study indicated rate constants followed the order: hexane > solvent-free > dichloromethane > ethanol ≈ acetone ≈ acetonitrile > t-butanol, and positively correlated with log P of solvent. During acyl migration in ethanol, acetone, acetonitrile and t-butanol at 40 °C, DHA content in 2-MAGs was higher than in 1-MAGs, indicating slow acyl migration of DHA; while at 50 °C, the difference of DHA distribution was small, due to increasing acyl migration rate. The results suggest that acyl migration of different fatty acids can be regulated by changing conditions to enrich DHA at sn-2 position.


Assuntos
Acetona , Monoglicerídeos , Solventes/química , Monoglicerídeos/química , Temperatura , terc-Butil Álcool , Etanol/química , Acetonitrilas
8.
Food Chem ; 400: 134115, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36087482

RESUMO

In this study, enzymatic two-step hydrolysis of tuna oil was performed to release saturated (SFAs) and monounsaturated fatty acids (MUFAs) from triacylglycerols (TAGs) to obtain acylglycerols rich in ω-3 polyunsaturated fatty acids (PUFAs). At the first step, AY "Amano" 400SD was chosen to mainly hydrolyze MUFAs from tuna oil under the conditions as described previously. At the second step, second hydrolysis by Candida antarctica lipase A (CAL-A) was conducted to mainly remove SFAs in acylglycerols isolated from the hydrolysate obtained at the first step. The second hydrolysis conditions were optimized. Under the optimum conditions, the content of ω-3 PUFAs in acylglycerols increased from initial 34.3% in tuna oil to 57.65% after initial hydrolysis and further to 68.94% after second hydrolysis. The most important finding in this study is that AY "Amano" 400SD and CAL-A selectively hydrolyze MUFAs and SFAs, respectively, which may have the potential application for PUFAs concentration.


Assuntos
Ácidos Graxos Ômega-3 , Lipase , Animais , Catálise , Ácidos Graxos Monoinsaturados , Ácidos Graxos Insaturados , Glicerídeos , Hidrólise , Triglicerídeos , Atum
9.
Food Chem ; 429: 136943, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37517224

RESUMO

While branched-chain fatty acids (BCFA)-enriched triacylglycerols (TAG) has various health benefits, its preparation has not been reported. This study aimed to synthesize high-purity BCFA-enriched structured TAG. First, BCFA was enriched from lanolin through saponification, calcification, and urea complexation. Next, BCFA-enriched TAG was synthesized by enzymatic esterification of BCFA and glycerol. Then, lipases were screened by molecular docking and practical experiments, which suggested that Lipozyme 435 was the best lipase for esterification since it had the lowest binding energy. Structured TAG containing 92.23% BCFA was synthesized under conditions optimized by single-factor experiments. Furthermore, molecular distillation was adapted to remove excess fatty acids and small molecule impurities. Finally, high-purity BCFA-enriched structured lipid containing 70.26% TAG was obtained. Overall, this study successfully developed a method for synthesizing BCFA-enriched structured TAG, which holds great promise for applications in value-added foods.


Assuntos
Ácidos Graxos , Glicerol , Triglicerídeos/química , Esterificação , Simulação de Acoplamento Molecular , Ácidos Graxos/metabolismo
10.
J Food Sci ; 88(7): 2858-2869, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37219384

RESUMO

n - 3 Polyunsaturated fatty acids (n - 3 PUFA) have special physiological effect, but their contents in natural oils may not meet the growing demand. Lipase-catalyzed selective methanolysis could be used to produce acylglycerols rich in n - 3 PUFA. To explore the kinetics of enzymatic methanolysis, factors affecting the reaction, including reaction system, water content, substrate molar ratio, temperature, lipase loading, and reaction time, were first investigated in the view of optimizing the reaction. Then the effects of triacylglycerol concentrations and methanol concentrations on initial reaction rate were studied. Finally, the key kinetic parameters of methanolysis were determined subsequently. The results showed that under optimal conditions, the n - 3 PUFA content in acylglycerols increased from 39.88% to 71.41%, and the n - 3 PUFA yield was 73.67%. The reaction followed a Ping-Pong Bi Bi mechanism with inhibition by methanol. The kinetic analysis indicated the lipase could selectively remove saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) in acylglycerols. The inhibition constant of methanol to the n - 3 PUFA (KiM , 0.30 mmol/L) was lower than that to the SFA and MUFA (219.64 and 79.71 mmol/L). The combined effects of the fatty acid selectivity of Candida antarctica lipase A and methanol inhibition resulted in an enrichment of n - 3 PUFA in acylglycerols. Overall, the methanolysis reaction catalyzed by the lipase A is a prospective enrichment method. PRACTICAL APPLICATION: This study demonstrated that enzymatic selective methanolysis is a prospective enrichment method to produce acylglycerols rich in n - 3 PUFA. This method is highly efficient, environment-friendly, and simple. n - 3 PUFA concentrates have been widely applied in the food, health-care food, and pharmaceutical industries.


Assuntos
Ácidos Graxos Ômega-3 , Ácidos Graxos Ômega-3/química , Glicerídeos/química , Cinética , Metanol , Estudos Prospectivos , Ácidos Graxos Insaturados , Ácidos Graxos , Lipase/metabolismo , Ácidos Graxos Monoinsaturados
11.
Environ Pollut ; 318: 120863, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36526056

RESUMO

Pearl millet (Pennisetum glaucum L.) is a highly nutritive-value summer-annual forage crop used for hay, silage, grazing, and green chop. However, abiotic stresses including salinity negatively affect its growth and productivity. Furthermore, the nanotechnology is attaining greater consideration to reduce the impact of environmental stresses in plants. In the present study, transcriptome responses of silver nanoparticles (AgNPs) in pearl millet under salinity were investigated. The treatments were given as Control, NaCl (250 mM), AgNPs (20 mg/L), and NaCl + AgNPs to pearl millet seedlings after thirteen days of seed sowing. After 1 h of given treatments, leaf samples were collected and subjected to physio-chemical examination and transcriptome analyses. Salt stress increased the hydrogen peroxide (H2O2), malondialdehyde (MDA) content, and proline as compared to other treatments. In addition, the combined applications of NaCl + AgNPs ameliorated the oxidative damage by increasing antioxidant enzymes activities including superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD). Furthermore, RNA sequencing data showed 6016 commonly annotated Differentially Expressed Transcripts (DETs) among various treated combinations. Among them, 427 transcripts were upregulated, and 136 transcripts were downregulated at nanoparticles vs control, 1469 upregulated and 1182 downregulated at salt vs control, 494 upregulated and 231 downregulated at salt + nanoparticles vs control, 783 upregulated and 523 downregulated at nanoparticles vs salt. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that Mitogen-activated protein kinase (MAPK) signaling pathway, biosynthesis of secondary metabolites, and plant hormonal signal transduction pathway were the enriched among all identified pathways. In addition, Reverse transcription quantitative real-time polymerase chain reaction (qRT-PCR) showed that salinity up regulated the relative expression of DETs in pearl millet while, AgNPs optimized their expression that are associated with various molecular and metabolic functions. Overall, AgNPs treatments effectively improved the morphology, physiology, biochemistry, and gene expression pattern under salinity which could be attributed to positive impacts of AgNPs on pearl millet.


Assuntos
Nanopartículas Metálicas , Pennisetum , Pennisetum/genética , Pennisetum/metabolismo , Prata/toxicidade , Prata/metabolismo , Nanopartículas Metálicas/toxicidade , Peróxido de Hidrogênio/metabolismo , Cloreto de Sódio/toxicidade , Cloreto de Sódio/metabolismo , Estresse Salino , Perfilação da Expressão Gênica , Estresse Fisiológico/genética , Antioxidantes/metabolismo
12.
J Food Sci ; 87(11): 4945-4955, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36200532

RESUMO

The natural source of human milk fat substitute (HMFS) is a field worth exploring. In this study, tilapia oil was extracted and analyzed. In the triacylglycerol fraction, the contents of sn-2 palmitic acid and total sn-1,3 oleic acid and linoleic acid were 48.01% and 66.62%, respectively. The optimal solvent fractionation conditions were determined to be a tilapia oil-to-acetone ratio of 1:8 (w/v), crystallization temperature of -30°C, and crystallization duration of 16 h, giving a solid fraction yield of 64.20%. In fractionated tilapia oil, the total content of 1-oleoyl-2-palmitoyl-3-linoleoylglycerol (OPL) and 1,3-dioleoyl-2-palmitoylglycerol (OPO) increased by 20.38%, as determined by reversed-phase liquid chromatography. Ultra-high-performance combined-phase chromatography combined with quadrupole time-of-flight mass spectrometry analysis showed that OPL (17.45%) was the most abundant triacylglycerol in fractionated tilapia oil, followed by OPO (13.90%). Fractionated tilapia oil is thus an excellent source of OPL and has great potential for incorporation in HMFS. PRACTICAL APPLICATION: Human milk fat substitutes are an important component of infant formulas. This work provides an excellent natural source of oil rich in OPL, which has great potential in the field of preparing human milk fat substitutes highly similar to human milk fat.


Assuntos
Substitutos da Gordura , Tilápia , Lactente , Animais , Humanos , Substitutos da Gordura/análise , Leite Humano/química , Solventes , Triglicerídeos/química
13.
Foods ; 11(20)2022 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-37430962

RESUMO

Enzymatic alcoholysis was performed in an organic medium to synthesize 2-monoacylglycerol (2-MAG) rich in arachidonic acid. The results showed that solvent type and water activity (aw) significantly affected the 2-MAG yield. Under the optimum conditions, 33.58% 2-MAG was produced in the crude product in t-butanol system. Highly pure 2-MAG was obtained after two-stage extraction using 85% ethanol aqueous solution and hexane at first stage and dichloromethane and water at second stage. Isolated 2-MAG was used as substrate to investigate the effect of solvent type and aw on 2-MAG acyl migration in a lipase-inactivated system. The results indicated that non-polar solvents accelerated the acyl migration of 2-MAG, whereas isomerization was inhibited in polar solvent systems. The aw exhibited the strongest inhibition effect on 2-MAG isomerization at 0.97, but also affected the hydrolysis of glycerides and lipase selectivity.

14.
J Oleo Sci ; 70(5): 599-606, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33952786

RESUMO

Palmitoleic acid shows a variety of beneficial properties to human health. In this study, enrichment of palmitoleic acid from sea buckthorn pulp oil by two-step solvent crystallization and molecular distillation was investigated. Sea buckthorn pulp oil was first converted to its corresponding mixed fatty acids (SPOMFs) containing 27.17% palmitoleic acid. Subsequently, the effects of various factors on crystallization (i.e., crystallization temperature, type of solvent, ratio of SPOMFs to solvent (w/v), crystallization time) and molecular distillation (distillation temperature) were assessed on a 5-g scale. It was found that optimal primary crystallization conditions were a 1:15 ratio of SPOMFs to methanol (w/v), -20°C and 12 h. Secondary crystallization conditions were set to a 1:4 ratio of methanol to palmitoleic acid product obtained from the first step crystallization to methanol (w/v), -40°C and 6 h. For further purification of palmitoleic acid by molecular distillation, the optimal distillation temperature was determined to be 100°C. After purification by crystallization and molecular distillation under the optimal conditions, the final product consisted of 54.18% palmitoleic acid with an overall yield of 56.31%. This method has great potential for adoption by the food and medical industries for the preparation of palmitoleic acid concentrate for nutritional studies.


Assuntos
Cristalização/métodos , Destilação/métodos , Ácidos Graxos Monoinsaturados/química , Solventes/química , Ácidos Graxos , Hippophae/química , Metanol/química , Óleos de Plantas/química , Temperatura
15.
Foods ; 10(11)2021 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-34829168

RESUMO

Antarctic krill oil is an emerging marine lipid and expected to be a potential functional food due to its diverse nutrients, such as eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), phospholipids, astaxanthin and tocopherols. Although krill oil has been previously proved to have anti-inflammatory activity, there is little information about the relationship between its chemical compositions and anti-inflammatory activity. In this study, the RAW264.7 macrophages model was used to elucidate and compare the anti-inflammatory potential of different krill lipid fractions: KLF-A, KLF-H and KLF-E, which have increasing phospholipids, EPA and DHA contents but decreasing astaxanthin and tocopherols levels. Results showed that all the krill lipid fractions alleviated the inflammatory reaction by inhibition of production of nitric oxide (NO), release of tumor necrosis factor-α (TNF-α), interleukin (IL)-1ß and IL-6 and gene expression of proinflammatory mediators including TNF-α, IL-1ß, IL-6, cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). In addition, KLF-E with the highest phospholipids, EPA and DHA contents showed the strongest inhibition effect on the LPS-induced proinflammatory mediator release and their gene expressions. The results would be helpful to provide powerful insights into the underlying anti-inflammatory mechanism of krill lipid and guiding the production of krill oil products with tailor-made anti-inflammatory activity.

16.
Food Chem ; 346: 128743, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33419584

RESUMO

Most natural oils are low in n-3 polyunsaturated fatty acids (n-3 PUFAs) content, which limits their application in health products. In this study, n-3 PUFAs in glyceride form were selectively enriched by lipase-mediated hydrolysis of n-3 PUFA-containing oils. First, commercial lipases were screened, and the lipase AY "Amano" 400SD from Candida cylindracea was the best choice in producing n-3 PUFA glycerides from tuna oil. Subsequently, the hydrolysis conditions were optimized. Under the optimal conditions, the highest n-3 PUFA content in the glyceride fraction was found to be 57.7% after enzymatic hydrolysis. Addition of Ca2+ to the system significantly shortened the reaction time from 10 to 4 h. When algal oil was used as substrate, total PUFA contents in the glyceride fraction were 89.9%. This study provides an efficient enzymatic process to produce n-3 PUFA-enriched glyceride concentrates and demonstrates that AY "Amano" 400SD can effectively discriminate against n-3 PUFAs during hydrolysis.


Assuntos
Ácidos Graxos Ômega-3/metabolismo , Glicerídeos/metabolismo , Animais , Cálcio/metabolismo , Óleos de Peixe/metabolismo , Hidrólise
17.
J Agric Food Chem ; 68(44): 12358-12364, 2020 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-33084305

RESUMO

Acyl migration occurs in many reactions and is the main obstacle for structured lipid synthesis. In this study, 2-monoacylglycerol (2-MAG) was prepared by enzymatic ethanolysis in three different media to evaluate the effect of environment on product composition. The contents of 2-MAG obtained in ethanol, hexane + ethanol, and t-butanol + ethanol systems were 30.6, 15.7, and 32.4%, respectively, after 3 h reaction. Afterward, the acyl migration kinetics of 2-MAG were studied in solvent and solventless systems without the use of lipase. Results indicate that 2-MAG in the solventless system had the highest acyl migration rate. The isomerization was efficiently prevented by the use of polar solvents, especially t-butanol. The rate constants were shown to be the highest and activation energy values were the lowest in solventless systems. The novel finding in this study was that solvent had inhibitory effect on 2-MAG isomerization, but the nonpolar hexane had the lowest inhibition of acyl migration compared to other solvents.


Assuntos
Etanol/química , Monoglicerídeos/química , Enzimas Imobilizadas/química , Hexanos/química , Isomerismo , Lipase/química
18.
Food Chem ; 283: 331-337, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30722880

RESUMO

Structured TAGs with palmitic acid and polyunsaturated fatty acid (PUFA) at the sn-2 position have various health benefits for infants. In this study, we first compared two enzymatic routes for preparation of the structured TAGs. Results showed that the one-pot and two-step syntheses led to 37.6% and 55.4% oleic acid incorporation, respectively, after 10 h and reaction route had little effect on the sn-2 fatty acid composition. Subsequently, reaction variables of the two-step synthesis were optimized. Under the optimal conditions, 53.5% oleic acid was incorporated into the structured TAGs after 6-h acidolysis. Major fatty acids at the sn-2 position were palmitic acid (68.7%), ARA (9.8%) and oleic acid (7.9%). This is the first study reporting a two-step enzymatic method for structured TAGs preparation. Compared to the one-pot synthesis, current method significantly improves the efficiency of the acidolysis by product inhibition elimination. The synthetic TAGs have potential use in infant formulas.


Assuntos
Ácido Araquidônico/metabolismo , Fórmulas Infantis/análise , Ácidos Palmíticos/metabolismo , Triglicerídeos/química , Ácido Araquidônico/química , Ácidos Graxos Insaturados/química , Ácidos Graxos Insaturados/metabolismo , Humanos , Lactente , Lipase/metabolismo , Ácido Oleico/química , Ácido Oleico/metabolismo , Ácidos Palmíticos/química , Triglicerídeos/metabolismo
19.
J Oleo Sci ; 68(6): 559-566, 2019 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-31092793

RESUMO

The effects of four different frying oils and three emulsifiers on oil absorption by steam-and-fried instant noodles were evaluated. The blended oil (high oleic sunflower oil/soybean oil/palm oil = 24:25:1 (v/v/v)) containing approximately 50% oleic acid was chosen as the proper frying oil due to lower oil absorption by instant noodle compared to palm, soybean, and high oleic sunflower oils. Among the four oils, the interfacial tension between high oleic sunflower oil and instant noodle was the lowest (0.073 mN/m), resulting in the highest oil uptake (15.47%), while the lowest interfacial tension (0.30 mN/m) between blended oil and instant noodle resulted in the lowest oil uptake by the fried product (12.63%). Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) were used to observe surface properties and oil distribution. The instant noodle fried in blended oil was found to have uniform oil distribution and smooth surface. After selecting the proper frying oil, three emulsifiers (soybean lecithin, Tween-80, Span-80, at 0.2% (v/v)) were added to the blended frying oil. Adding emulsifier into frying oil significantly decreased the interfacial tension between frying oil and instant noodle. Among the three emulsifiers, addition of soybean lecithin resulted in the lowest interfacial tension (0.010 mN/m) and the highest oil uptake (18.36%). Therefore, from this study, we do not recommend adding emulsifier into frying oil.


Assuntos
Adsorção , Gorduras Insaturadas na Dieta , Emulsificantes , Fast Foods , Manipulação de Alimentos/métodos , Óleo de Palmeira , Óleo de Soja , Óleo de Girassol , Emulsificantes/efeitos adversos , Hexoses/efeitos adversos , Lecitinas/efeitos adversos , Óleo de Palmeira/química , Polissorbatos/efeitos adversos , Óleo de Soja/química , Óleo de Girassol/química , Propriedades de Superfície , Tensão Superficial
20.
Bioresour Technol ; 262: 278-283, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29723787

RESUMO

Utilization of algae oil and glycerol for preparation of value-added products is vital for sustainable development of related industries. In this study, we aimed to prepare highly pure diacylglycerols (DAG) rich in docosapentaenoic acid (DPA). First, content of DPA in form of triacylglycerols (TAG) increased from 16.4% to 28.1% after low-temperature crystallization of Schizochytrium sp. oil at -80 °C for 6 h. Subsequently, DPA-enriched DAG was prepared by the enzymatic glycerolysis of the enriched oil. Under the optimum conditions, there was 48.4% DAG produced in the crude mixture. To remove polar impurities from the crude product, a novel two-step purification was developed and the final product consisted of 75.1% DAG and 24.9% TAG with a low peroxide value. The current method for the synthesis of DAG rich DPA is effective and relatively mild and the successful preparation of value-added product will reduce production costs for algae and biodiesel industries.


Assuntos
Diglicerídeos/química , Ácidos Graxos Insaturados/química , Lipase , Triglicerídeos
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