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1.
Food Chem X ; 24: 101790, 2024 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-39296481

RESUMEN

Plums (Prunus salicina and Prunus domestica) are prevalent in southwestern China, and have attracted interest owing to their delectable taste and exceptional nutritional properties. Therefore, this study aimed to investigate the nutritional and flavor properties of plum to improve its nutritional utilization. Specifically, we determined the soluble sugars, organic acids, and phenolic components in 86 accessions using high-performance liquid chromatography. Notably, glucose, fructose, malic, and quinic acids were the predominant sweetness and acidity in plums, with sucrose contributing more to the sweetness of the flesh than the peel. Moreover, The peel contains 5.5 fold more phenolics than flesh, epicatechin, gallic acid, and proanthocyanidins C1 and B2 were the primary sources of astringency. Correlation and principal component analyses showed eight core factors for plum flavor rating, and a specific rating criterion was established. Conclusively, these findings provide information on the integrated flavor evaluation criteria and for enhancing optimal breeding of plums.

2.
Food Chem X ; 23: 101722, 2024 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-39229615

RESUMEN

This study examined the impact of varying salt concentrations on microbiota, physicochemical properties, and metabolites in a secondary fortified fermentation process using multi-omics techniques. It aimed to determine the influence of salt stress on microbiota shifts and metabolic activities. The findings demonstrated that moderate salt reduction (MS) was found to enhance moromi's flavor and quality, while mitigating the negative effects of excessive low salt (LS). MS samples had 1.22, 1.13, and 2.92 times more amino acid nitrogen (AAN), non-volatiles, and volatiles, respectively, than high salt (HS) samples. In contrast, lactic acid and biogenic amines in LS samples were 1.56 g/100 g and 4115.11 mg/kg, respectively, decreasing to 0.15 g/100 g and 176.76 mg/kg in MS samples. Additionally, the contents of ethanol and small peptides increased in MS due to the growth of specific functional microorganisms such as Staphylococcus gallinarum, Weissella confusa, and Zygosaccharomyces rouxii, while food-borne pathogens were inhibited. Network analysis revealed that the core microbial interactions were enhanced in MS samples, promoting a balanced fermentation environment. Redundancy analysis (RDA) and correlation analyses underscored that the physicochemical properties significantly impacted bacterial community structure and the correlations between key microbes and flavor compounds. These findings provided a theoretical foundation for developing innovative reduced-salt fermentation techniques, contributing to the sustainable production of high-quality soy sauce.

3.
Int J Biol Macromol ; 271(Pt 1): 132627, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38797290

RESUMEN

Melanins are dark-brown to black-colored biomacromolecules which have been thoroughly studied in animals and microorganisms. However, the biochemical and molecular basis of plant melanins are poorly understood. We first characterized melanin from the black radish (Raphanus sativus var. niger) 'HLB' through spectroscopic techniques. p-Coumaric acid was identified as the main precursor of radish melanin. Moreover, a joint analysis of transcriptome and coexpression network was performed for the two radish accessions with black and white cortexes, 'HLB' and '55'. A set of R2R3-type RsMYBs and enzyme-coding genes exhibited a coexpression pattern, and were strongly correlated with melanin formation in radish. Transient overexpression of two phenol oxidases RsLAC7 (laccase 7) or RsPOD22-1 (peroxidase 22-1) resulted in a deeper brown color around the infiltration sites and a significant increase in the total phenol content. Furthermore, co-injection of the transcriptional activator RsMYB48/RsMYB97 with RsLAC7 and/or RsPOD22-1, markedly increased the yield of black extracts. Spectroscopic analyses revealed that these extracts are similar to the melanin found in 'HLB'. Our findings advance the understanding of structural information and the transcriptional regulatory mechanism underlying melanin formation in radish.


Asunto(s)
Regulación de la Expresión Génica de las Plantas , Melaninas , Monofenol Monooxigenasa , Raphanus , Raphanus/genética , Raphanus/metabolismo , Melaninas/metabolismo , Monofenol Monooxigenasa/genética , Monofenol Monooxigenasa/metabolismo , Transcriptoma , Perfilación de la Expresión Génica , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/química , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Factores de Transcripción/química , Ácidos Cumáricos/metabolismo
4.
Food Chem X ; 21: 101214, 2024 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-38379805

RESUMEN

The study explores diverse strains of Lachancea thermotolerans in single-inoculum wine fermentation conditions using synthetic grape must. It aims to analyze the role of the species without external influences like other microorganisms or natural grape must variability. Commercial strains and selected vineyard isolates, untested together previously, are assessed. The research evaluates volatile and non-volatile chemical compounds in final wine, revealing significant strain-based variations. L. thermotolerans notably produces lactic acid and consumes malic acid, exhibiting moderate ethanol levels. The volatile profile displays strain-specific impacts, affecting higher alcohol and ester concentrations compared to S. cerevisiae. These effects vary based on the specific compounds. Using a uniform synthetic must enables direct strain comparisons, eliminating grape-related, environmental, or timing variables in the experiment, facilitating clearer insights into the behavior of L. thermotolerans in wine fermentation. The study compares for the first time all available commercial strains of L. thermotolerans.

5.
Food Chem X ; 20: 100953, 2023 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-37929267

RESUMEN

Chinese cherry is an economically important fruit crop native to China. Flavor quality is greatly influenced by compositions of soluble sugars and organic acids. To better understand the flavor quality of Chinese cherry, we determined sugar and acid components in thirty-eight landrace and cultivar collections, and two wild resources using the HPLC method. Glucose and fructose were the main components, accounting for 85.91% of soluble sugars. Malic acid was the predominant organic acid, with an average proportion of 65.73% of total acids. Correlation and PCA analysis revealed seven key indicators for evaluating fruit flavor. Compared with wild Chinese cherry, the cultivated collections exhibited higher levels of soluble sugars, especially fructose, and lower levels of organic acid, particularly malic acid in fruits. Finally, we have established grading criteria for seven flavor indicators in Chinese cherry. Our study provides valuable references for identifying flavor compounds and improving flavor quality of Chinese cherry.

6.
Food Chem X ; 19: 100835, 2023 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-37636899

RESUMEN

Wampee is a tropical fruit having high medicinal value. To fully realize the fruit's potential, it is essential to reveal the flavor characteristics. In this study, a comprehensive analysis of the aroma and taste profiles of different parts from the wampee fruit was conducted. The aroma profile was analyzed by E-nose, and 67 volatile components were identified through HS-SPME-GC-MS. Among them, 11 were considered as crucial compounds. Additionally, 42 volatile components were identified by HS-GC-IMS, with 22 compounds showing a variable importance in projection scores greater than 1.0. Moreover, the taste profile and representative compounds were analyzed by E-tongue and HPLC, and 12 compounds were considered as important taste contributors based on taste activity value. These findings shed light on the various compounds responsible for the unique aroma and taste of the wampee fruit, providing theoretical foundation for exploring ways for its comprehensive utilization and development.

7.
Food Chem ; 343: 128409, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33218856

RESUMEN

We investigated the effect of temporary rearing in brackish water on the taste quality in meat of crab cooked. The main salinity-responsive factors included 5'-nucleotides and free amino acids (FAAs) in crab meat that were identified using tri-step infrared spectroscopy. Compared to the fresh water group, the contents of 5'-adenosine monophosphate and 5'-inosine monophosphate in the brackish water group significantly increased in the 2nd week and decreased in the 6th week, respectively. The contribution ratio of umami FAAs increased from 8.1 to 13.5% in the 4th week in the brackish water group, showing maximum value of equivalent umami concentration. Moreover, Ca2+ and Cl- contents significantly increased in the 4th and 6th weeks, respectively (P < 0.05). Infrared spectroscopy was an effective method to identify the taste components. With respect to the taste quality, four weeks were determined as the best period for temporary rearing of the crab in brackish water.


Asunto(s)
Acuicultura/métodos , Braquiuros , Aguas Salinas/química , Mariscos , Gusto , Adenosina Monofosfato/análisis , Aminoácidos/análisis , Animales , Culinaria/métodos , Inosina Monofosfato/análisis , Masculino , Nucleótidos/análisis , Espectrofotometría Infrarroja
8.
Carbohydr Polym ; 229: 115476, 2020 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-31826488

RESUMEN

The objective of present study is to explore whether polysaccharide could be a crystal growth inhibitor in poorly soluble antitumor drug Ibrutinib (IBR) formulation. In this work, small molecular ligands (amino or organic acids) in co-amorphous system (CAS) were preliminarily screened. A polysaccharide, microcrystalline cellulose (MCC) was selected to stabilize amorphous drug and enhance pharmacokinetic properties. Fourier-transform infrared, Raman, and X-ray photoelectron spectroscopy confirmed the ionic interaction of the ternary IBR formulation. Moreover, the biosafety of the ternary formulation was the same as that of IBR while the in vitro performance advantage of the ternary formulation was converted into higher bioavailability in vivo experiments. Overall, MCC as an effective crystal growth inhibitor in the novel ternary IBR formulation is a promising approach to improve the dissolution rate of crystalline drugs and the stability of amorphous drugs, as well as providing a theoretical basis for clinical applications.


Asunto(s)
Celulosa/química , Pirazoles/química , Pirimidinas/química , Adenina/análogos & derivados , Animales , Disponibilidad Biológica , Línea Celular Tumoral , Fenómenos Químicos , Cristalización , Composición de Medicamentos , Humanos , Masculino , Piperidinas , Pirazoles/farmacocinética , Pirazoles/farmacología , Pirimidinas/farmacocinética , Pirimidinas/farmacología , Ratas
9.
Food Chem ; 310: 125980, 2020 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-31838371

RESUMEN

Cyanidin-3-O-glucoside (C3G) is principal anthocyanin in Chinese bayberry wine and its degradation is main problem with respect to wine color. Effect of five organic acids existing in bayberry wine on C3G oxidation mediated by iron was investigated in model wine. Fe(II) oxidation was found to follow a decreasing order in oxalate > citrate > tartrate > malate model wine whereas it hardly occurred in succinate model wine. The C3G oxidation mediated by iron followed an increasing order in citrate > oxalate > succinate > malate > tartrate model wine. More degradation products were observed in succinate, malate and tartrate model wine than in citrate and oxalate model wine. C3G degradation mediated by Fe(III) was faster than that mediated by Fe(II) in oxalate, succinate, malate, and tartrate model wine, but not in citrate model wine. C3G oxidation mediated by iron is probably not main mechanism of anthocyanin degradation in bayberry wine.


Asunto(s)
Antocianinas/metabolismo , Ácidos Dicarboxílicos/química , Glucósidos/metabolismo , Hierro/metabolismo , Myrica , Vino , Antocianinas/química , Color , Ácidos Dicarboxílicos/metabolismo , Glucósidos/química , Hierro/química , Malatos/química , Myrica/química , Myrica/metabolismo , Oxidación-Reducción , Ácido Succínico/química , Ácido Succínico/metabolismo , Tartratos/química , Vino/análisis
10.
Food Chem ; 283: 239-247, 2019 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-30722867

RESUMEN

Power ultrasound as an emerging processing technology has been investigated for stimulating seeds to enhance germination and accumulation of health-promoting metabolites, such as γ-aminobutyric acid (GABA) and phenolic compounds. This work was undertaken to evaluate the effects of power ultrasound (25 kHz) on the nutritional properties of germinated oats, and the microstructure of oat groats after treatment. The changes in the external and internal microstructures of the ultrasound-treated oats kernel were investigated using Environmental Scanning Electron Microscopy (ESEM) and 3D X-ray Micro Computed Tomography (Micro-CT). Physicochemical properties of oats including GABA, free sugars, avenanthramides, total phenolic content, and antioxidant capacities were enhanced after germination. Furthermore, the power ultrasound treatment for 5 min after soaking significantly enhanced the GABA (48-96 h), alanine (24-96 h), succinic acid (48-72 h), total phenolic content (24 h), and total avenanthramides (24 h) in the germinated oats.


Asunto(s)
Avena/metabolismo , ortoaminobenzoatos/metabolismo , Antioxidantes/química , Avena/química , Cromatografía Líquida de Alta Presión , Germinación , Espectrometría de Masas , Fenoles/análisis , Fenoles/química , Fenoles/metabolismo , Semillas/química , Semillas/metabolismo , Sonicación , Factores de Tiempo , Microtomografía por Rayos X , Ácido gamma-Aminobutírico/análisis , Ácido gamma-Aminobutírico/metabolismo , ortoaminobenzoatos/análisis
11.
Food Chem ; 284: 296-302, 2019 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-30744861

RESUMEN

Bio-electronic tongue was linked to artificial intelligence processing unit and used for classification of wines based on carboxylic acids levels, which were indirectly related to malolactic fermentation. The system employed amperometric biosensors with lactate oxidase, sarcosine oxidase, and fumarase/sarcosine oxidase in the three sensing channels. The results were processed using two statistical methods - principal component analysis (PCA) and self-organized maps (SOM) in order to classify 31 wine samples from the South Moravia region in the Czech Republic. Reference assays were carried out using the capillary electrophoresis (CE). The PCA patterns for both CE and biosensor data provided good correspondence in the clusters of samples. The SOM treatment provided a better resolution of the generated patterns of samples compared to PCA, the SOM derived clusters corresponded with the PCA classification only partially. The biosensor/SOM combination offers a novel procedure of wine classification.


Asunto(s)
Ácidos/análisis , Técnicas Biosensibles/métodos , Vino/análisis , República Checa , Técnicas Electroquímicas , Electroforesis Capilar , Fumarato Hidratasa/metabolismo , Oxigenasas de Función Mixta/metabolismo , Compuestos Orgánicos/química , Análisis de Componente Principal , Sarcosina-Oxidasa/metabolismo
12.
Int J Pharm ; 554: 61-71, 2019 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-30347274

RESUMEN

Celecoxib (CEL) is a selective cyclooxygenase-2 (COX-2) inhibitor therapeutically indicated for the treatment of rheumatoid arthritis, osteoarthritis, acute pain, and inflammation. However, its poor solubility and dissolution rate significantly hinders its broader application. In this study, eutectic mixtures, as binary pharmaceutical compositions of CEL with adipic acid (ADI) and saccharin (SAC), were identified through a phase diagram and Tammann's triangle intended to improve the wettability and dissolution rate of poorly water-soluble CEL. The contact angles at 0s in the liquid-solid interface were approximately θs (theta) 79.7 ±â€¯0.50° and 86.65 ±â€¯0.45° for CEL-ADI and CEL-SAC, respectively, which were much lower than the value obtained for CEL (92.05 ±â€¯0.75° θ). Moreover, a comparison of the disk intrinsic dissolution rate and powder dissolution properties demonstrated that eutectic mixtures significantly increased the dissolution rate compared with CEL and physical mixtures. A general relationship was elucidated and indicated that the dissolution rate was increased as the contact angle decreased (correlation coefficient, r = 0.9966 ±â€¯0.0031). Therefore, CEL-ADI and CEL-SAC eutectics may offer a novel formulation strategy to enhance the solubility and oral bioavailability of CEL.


Asunto(s)
Adipatos/química , Celecoxib/administración & dosificación , Inhibidores de la Ciclooxigenasa 2/administración & dosificación , Sacarina/química , Administración Oral , Celecoxib/química , Química Farmacéutica/métodos , Inhibidores de la Ciclooxigenasa 2/química , Liberación de Fármacos , Excipientes/química , Solubilidad , Humectabilidad
13.
Food Chem ; 243: 239-248, 2018 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-29146334

RESUMEN

Model wine solutions containing organic acids, individually or combined, and iron(III), were exposed to light from fluorescent lamps or stored in darkness for four hours. (-)-Epicatechin was then added, and the solutions incubated in darkness for 10days. Browning was monitored by UV-visible absorption spectrophotometry and UHPLC-DAD. The pre-irradiated solutions containing tartaric acid exhibited increased yellow/brown coloration compared to the dark controls mainly due to reaction of the tartaric acid photodegradation product glyoxylic acid with (-)-epicatechin to form xanthylium cation pigments. In these solutions, browning decreased as the concentrations of organic acids other than tartaric acid increased. Xanthylium cations were also detected in the pre-irradiated malic acid solution. However, in the malic acid, succinic acid, citric acid and lactic acid solutions, any coloration was mainly due to the production of dehydrodiepicatechin A, which was largely independent of prior light exposure, but strongly affected by the organic acid present.


Asunto(s)
Hierro/química , Iluminación/métodos , Vino , Catequina/química , Ácido Cítrico/química , Color , Fluorescencia , Glioxilatos/química , Malatos/química , Fotólisis , Espectrofotometría Ultravioleta , Ácido Succínico/química , Tartratos/química , Vino/análisis
14.
Carbohydr Polym ; 181: 292-299, 2018 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-29253975

RESUMEN

1,2,3,4-Butanetetracarboxylic acid (BTCA) can efficiently esterify cellulose with pyrophosphoric acid (PPA) as a catalyst to remove protons of reaction intermediates. However, valence and relative concentration ratio (RCR) of catalyst anions correlating to pH of finishing bath played a critical role in the reactions. Results here indicated that wrinkle recovery angle, tensile strength retention and ester absorbance of fabrics treated at pH of 2.8 showed higher values. It was a competing reaction for BTCA molecules to esterify or depolymerize cellulose. Importantly, divalent PPA anions were more efficient than monovalent ones in catalyzing the esterification between anhydrides and cellulose, which was confirmed by FTIR results and two-dimensional correlation spectroscopy analyses and by the RCRs of PPA anions and their changing rates versus pH. Furthermore, the higher catalytic efficiency of divalent anions was proved by the selected model catalysts. Meaningfully, the fabrics treated at pH≤3.2 presented good durability.

15.
Int J Food Microbiol ; 265: 1-8, 2018 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-29107841

RESUMEN

This study investigated the effects of sequential inoculation (Seq-I) of Bifidobacterium animalis subsp. lactis or Lactobacillus casei with yeast Williopsis saturnus on durian pulp fermentation. Seq-I of W. saturnus following B. animalis subsp. lactis did not bring about any significant differences compared to the B. animalis subsp. lactis monoculture due to the sharp early death of W. saturnus soon after inoculation. However, Seq-I of W. saturnus significantly enhanced the survival of L. casei and improved the utilization of fructose and glucose compared to L. casei monoculture. In addition, there were significant differences in the metabolism of organic acids especially for lactic acid and succinic acid. Furthermore, Seq-I produced significantly higher levels of volatile compounds including alcohols (ethanol and 2-phenylethyl alcohol) and acetate esters (2-phenylethyl acetate, isoamyl acetate and ethyl acetate), which would positively contribute to the flavour notes. Although the initial volatile sulphur compounds were reduced to trace levels after fermentation, but the durian odour still remained. This study suggests that the use of probiotics and W. saturnus to ferment durian pulp could act as a potential avenue to develop a novel non-dairy durian-based functional beverage to deliver probiotics.


Asunto(s)
Bebidas/análisis , Bifidobacterium animalis/metabolismo , Bombacaceae/metabolismo , Lacticaseibacillus casei/metabolismo , Probióticos/metabolismo , Williopsis/metabolismo , Acetatos/metabolismo , Ácido Acético/metabolismo , Bebidas/microbiología , Reactores Biológicos , Bombacaceae/microbiología , Etanol/metabolismo , Fermentación , Fructosa/metabolismo , Glucosa/metabolismo , Ácido Láctico/metabolismo , Pentanoles/metabolismo , Alcohol Feniletílico/análogos & derivados , Alcohol Feniletílico/metabolismo , Ácido Succínico/metabolismo
16.
Food Chem ; 221: 473-481, 2017 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-27979230

RESUMEN

In the present work, we studied the chemical composition of Chinese artichoke (S. affinis tubers) by analyzing its polar constituents and its macro- and micro- nutrients. A total of nine compounds were isolated from the tuber ethanolic extract and structurally elucidated by Nuclear Magnetic Resonance (NMR) spectroscopy and mass spectrometry (MS). The marker compounds identified were oligosaccharide stachyose and the organic acid, succinic acid, as well as phenylethanoid and iridoid glycosides. The macronutrient profile was dominated by carbohydrates (36.9% dw), whereas potassium (2.36%) was the most abundant micro-nutrient. The tuber ethanolic extract was able to efficiently protect human cells (Caco-2, SHSY-5Y and K562) against t-BHP-induced oxidative damage.


Asunto(s)
Glicósidos Iridoides/análisis , Extractos Vegetales/química , Especies Reactivas de Oxígeno/análisis , Stachys/química , Ácido Succínico/análisis , Células CACO-2 , Humanos , Espectroscopía de Resonancia Magnética , Valor Nutritivo
17.
Carbohydr Polym ; 144: 282-8, 2016 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-27083819

RESUMEN

1,2,3,4-Butanetetracarboxylic acid (BTCA) imparts good anti-wrinkle property to cotton fabrics and results in significant strength loss due to cross-linking and acid degradation of cellulose simultaneously. However, benzophenone-3,3',4,4'- tetracarboxylic acid (BPTCA), an aromatic acid, crosslinks cellulose effectively but causes less strength loss to the products under similar conditions. The difference in damages to cellulose fibers was analyzed by using diffusibility and corresponding affinity of the acids to cellulose fibers, which were estimated by their molecular sizes and Hansen solubility parameters (HSP). Both experimental results and theoretical speculations revealed consistent agreement, indicating that smaller acid molecules could diffuse into cellulose fiber more rapidly and deeply, resulting in more acid degradation. Besides, the aliphatic acid such as BTCA has higher molecular affinity than BPTCA to cellulose, causing additional more degradation of cellulose. Both factors are potential reasons of the observed more severe tensile strength loss of the BTCA treated cotton fabrics.


Asunto(s)
Butanos/química , Ácidos Carboxílicos/química , Celulosa/química , Fibra de Algodón , Fenómenos Mecánicos , Difusión , Programas Informáticos , Solubilidad
18.
Meat Sci ; 117: 163-72, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26986230

RESUMEN

Meat colour is one of the cues available to the consumer to gauge overall meat quality and wholesomeness. Colour stability of meat is determined by several factors both inherent to the animal and post-slaughter conditions, including ageing, storage/packaging and display times. A hydrophilic interaction liquid chromatography-mass spectrometry (HILIC-MS) based metabolomics study was undertaken to identify and compare polar metabolites between ovine meat samples that were exposed to different durations of ageing, storage conditions, and display times. Primary metabolites comprising amino acids, sugars, nucleotides, nucleosides, organic acids and their breakdown products were mainly identified as discriminating factors. For the first time, boron complexes of sugar and malic acid were also tentatively identified. As expected, most compounds identified were related to myoglobin chemistry, and compounds with antioxidant properties were found in higher levels in colour stable samples. Supplementary studies identifying semi-polar, non-polar and volatile compounds will provide a holistic understanding of the chemical basis of colour stability in ovine meat.


Asunto(s)
Cromatografía Liquida/métodos , Análisis de los Alimentos/métodos , Espectrometría de Masas/métodos , Carne/análisis , Animales , Interacciones Hidrofóbicas e Hidrofílicas , Metabolómica , Ovinos/fisiología
19.
Food Chem ; 192: 1015-24, 2016 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-26304442

RESUMEN

Methodologies for chemometric classification of five authentic red wine varieties from Murfatlar wine center, Romania, young and aged are reported. The discriminant analysis based on several anthocyanins, organic acids, (13)C/(12)C, (18)O/(16)O and D/H isotopic ratios, (1)H and (13)C NMR fingerprints revealed a very satisfactory categorization of the wines, both in terms of variety and vintage, thus illustrating the validity of selected variables for wine authentication purposes. LDA applied to the combined data shows 85.7% classification of wines according to grape variety and 71.1% classification of wines according to vintage year, including a control wine set for each categorization, thus allowing an accurate interpretation of the data. Thereby, anthocyanins, certain anthocyanin ratios, oxalic, shikimic, lactic, citric and succinic acids, sugars like glucose, amino acids like histidine, leucine, isoleucine and alanine, and also 2,3-butanediol, methanol, glycerol and isotopic variables were significant for classification of wines.


Asunto(s)
Análisis Multivariante , Vino/análisis , Vino/clasificación , Aminoácidos/análisis , Antocianinas/análisis , Butileno Glicoles , Ácidos Carboxílicos/análisis , Análisis Discriminante , Humanos , Isótopos/análisis , Espectroscopía de Resonancia Magnética , Ácido Oxálico , Rumanía , Vitis/química
20.
Food Chem ; 185: 200-4, 2015 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-25952858

RESUMEN

The contributions of free hydrogen ions, undissociated hydrogen ions in protonated acid species, and anionic acid species to sour taste were studied through sensory experiments. According to tasting results, it can be inferred that the basic substance producing a sour taste is the hydrogen ion, including free hydrogen ions and undissociated hydrogen ions. The intensity of a sour taste is determined by the total concentration of free hydrogen ions and undissociated hydrogen ions. The anionic acid species (without hydrogen ions) does not produce a sour taste but can intensify or weaken the intensity of a sour taste. It seems that hydroxyl or conjugated groups in anionic acid species can intensify the sour taste produced by hydrogen ions. The following strategy to reduce the sensory sourness is advanced: not only reduce free hydrogen ions, namely elevate pH value, but also reduce the undissociated hydrogen ions contained in protonated acid species.


Asunto(s)
Cerveza/análisis , Ácido Acético/química , Protones , Percepción del Gusto
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