Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.844
Filtrar
1.
Bioresour Technol ; 321: 124471, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33296773

RESUMO

A promising pretreatment mediated by biomass-derived deep eutectic solvent (DES) with choline chloride to lactic acid was implemented to overcome the recalcitrant structure of poplar sawdust for effective enzymatic hydrolysis and valorized lignin. Results showed the DES applied was strongly selective towards removal of lignin and xylan while preserving cellulose. Under the optimal pretreatment condition (DES ratio: 1:2, temperature: 130 °C, time:1.5 h), the glucose yield from enzymatic hydrolysis was 75.8%. Chemical and structure changes of recovered lignin were evaluated to gauge its valorization potential. It indicated that the recovered lignin possessed molecular weight (4000-6000 g/mol), low polydispersity (PDI < 2.0), low quantity of ß-aryl-ethers with no recondensation, and an abundance of phenolic OH groups. The excellent antioxidant capacity of lignin demonstrated its great value as a polyphenolic antioxidant. Overall, this work demonstrated an emerging biorefinery technology method for effective fractionation and valorization of lignocellulosic biomass.


Assuntos
Antioxidantes , Lignina , Biomassa , Hidrólise , Solventes , Açúcares
2.
Bioresour Technol ; 321: 124424, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33298346

RESUMO

Pretreatment of lignocellulosic biomass at high temperatures or with oxidizing chemicals generate various inhibitors that restrict the efficient bioconversion of sugars in subsequent steps. The present study systematically investigates individual and combinatorial effects of pretreatment parameters on the generation of inhibitors. A plot between pretreatment temperature and inhibitor revealed optimum pretreatment temperature for energycane bagasse i.e., 170 °C beyond which total inhibitor production increased exponentially. No inhibitor production was observed on mechanical processing i.e., disk milling/cryogenic grinding of biomass. Evaluation of response surface regression exhibited that biomass solids loading has a significant effect on inhibitor generation at higher temperatures. The concentrations of certain inhibitors such as acetic acid, furfurals, and HMF increased more than 3-folds on doubling the solids loading. Furthermore, a novel low-severity approach of low-temperature hydrothermal pretreatment coupled with cryogenic grinding for lignocellulosic biomasses has been introduced which improved sugar yields while maintaining a low inhibitor concentration.


Assuntos
Carboidratos , Açúcares , Biomassa , Características da Família , Hidrólise , Temperatura
3.
Food Chem ; 340: 128183, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33032151

RESUMO

Non-centrifugal cane sugar (NCS) samples obtained by traditional moulding and granulation, and also via a novel spray-drying powdering process without additives, were assessed to characterise their sugar and phenolic profiles, flavonoid content, as well as colour parameters. As expected, sucrose was the predominant sugar (91.9-95.5%), followed by glucose (2.9-4.6%), and fructose (1.6-3.7%). Total phenolic content was between 0.4 and 0.6% and total flavonoid content into the range of 0.2-0.4%. Six phenolic acids were found in all NCS samples: protocatechuic acid (0.36-0.94 µg/100 g), vanillic acid (0.70-1.45 µg/100 g), chlorogenic acid (2.08-3.82 µg/100 g), syringic acid (1.08-2.80 µg/100 g), p-coumaric acid (0.69-1.35 µg/100 g), and ferulic acid (0.50-0.95 µg/100 g). The thermal treatment under high temperatures required in the production of granulated products was related with darker colours and changes in phenol and flavonoid contents. In contrast, spray drying generates clearer products, but with slightly less phenol and flavonoid contents.


Assuntos
Colorimetria , Manipulação de Alimentos , Açúcares/química , Antioxidantes/análise , Ácidos Cumáricos/análise , Flavonoides/análise , Hidroxibenzoatos/análise , Fenóis/análise
4.
Crit Rev Food Sci Nutr ; 61(2): 283-311, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32090597

RESUMO

This review paper describes our exploratory experimental studies on the functionality of sucrose and other sugars in cake-baking, and effects on cake quality. We have used the American Association of Cereal Chemists Method 10-90.01 as a base cake-baking method, and have applied Differential Scanning Calorimetry, Rapid Visco-Analyzer, and time-lapse photography analyses in experimental design studies of the effects of the following ingredient and formulation variables on cake quality (e.g. texture, color, moisture content) and other finished-product properties (e.g. shape, dimensions): (a) cake formula levels of sucrose and water, in terms of %Sucrose and Total Solvent; (b) concentration of sucrose or other sugars (e.g. xylose, ribose, fructose, glucose, maltose, polydextrose) vs. wheat flour starch gelatinization temperature and starch pasting during baking and gluten development during mixing; (c) unchlorinated flour vs. chlorinated flours (of varying pH); (d) cake formula %Sucrose and TS vs. cake color, shape, and dimensions; (e) cakes formulated with sucrose or other sugars (i.e. xylose, fructose, glucose), and variable %S and TS, and unchlorinated or chlorinated flour (pH 4.6), vs. cake color, shape, and dimensions.


Assuntos
Farinha , Açúcares , Glutens , Amido , Triticum
5.
Food Chem ; 339: 128064, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32950902

RESUMO

Ultrasonic degradation has become a fascinating strategy for preparing modified pectin, contributing to the improvement of pectin's functional characteristics. In this study, the impacts of structural and conformational characteristics of original and ultrasound-treated citrus pectins on their functional properties were examined. The results showed that compared with ultrasound-treated pectins, untreated pectin presented higher rheological and gelling properties primarily attributed to its larger weight-average molecular weight (Mw), degree of methoxylation, amount of neutral sugar side chains, and z-average radius of gyration, as well as the more extended flexible-chain conformation. However, the ultrasound-treated pectins had better emulsifying properties than untreated pectin in an oil-in-water emulsion system. These properties, visually suggested by morphology analysis, including enhanced emulsifying capacity, emulsifying stability, reduced mean droplet size and negatively charged zeta potential. Moreover, the Mw and chain conformation of untreated and ultrasound-treated pectins played more decisive roles in their functional properties than the others.


Assuntos
Emulsificantes/química , Pectinas/química , Configuração de Carboidratos , Conformação Molecular , Peso Molecular , Monossacarídeos/análise , Reologia , Açúcares , Ultrassom
6.
Food Chem ; 338: 128005, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32977138

RESUMO

Peach (Prunus persica L.) fruit are highly susceptible to chilling injury during cold storage, resulting in internal flesh browning and a failure to soften normally. We have examined the effect of a postharvest treatment consisting of a brief (30 s) dip in the natural plant hormone jasmonic acid, prior to storage at 4 °C. Jasmonic acid treatment reduced the severity of internal flesh browning and did not inhibit fruit softening over a 35 d storage period. Two major physiological effects of jasmonic acid on the fruit were observed, an increase in ethylene production and a prevention of the decline in soluble sugar content seen in controls. An increased soluble sugar content may have multiple benefits in resisting chilling stress, scavenging reactive oxygen species and acting to stabilize membranes. Our results show that a treatment with jasmonic acid can enhance chilling tolerance of peach fruit by regulating ethylene and sugar metabolism.


Assuntos
Ciclopentanos/farmacologia , Etilenos/metabolismo , Frutas/efeitos dos fármacos , Oxilipinas/farmacologia , Prunus persica/efeitos dos fármacos , Prunus persica/metabolismo , Açúcares/metabolismo , Temperatura Baixa , Armazenamento de Alimentos/métodos , Frutas/genética , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Reguladores de Crescimento de Planta/farmacologia , Proteínas de Plantas/genética , Prunus persica/genética
7.
Food Chem ; 339: 128096, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32979713

RESUMO

The changes of texture and cell wall characteristics of apricot were investigated in ten clones at two maturity stages. Fruit firmness, cell wall composition and enzyme activity of three apricot flesh zones were analysed. The AIS (alcohol-insoluble solids) were characterised by high amounts of uronic acid (179-300 mg g-1 AIS) and relatively high amounts of cellulosic glucose (118-214 mg g-1 AIS). The methylesterification degree varied significantly among the different clones ranging from 58 to 97 in Ab 5 and Mans 15 respectively. Conversely to zones firmness, enzymatic activity was higher in pistil followed by equatorial and peduncle zones. The ripening effect has been observed in firmness evolution according to enzymatic activity. This correlation allowed a classification of clones depending on softening. Among studied clones, Ab 5, Marouch 16, Mans 15 and Cg 2 were less influenced by softening and have the advantage of a technological valorisation for the processing industry.


Assuntos
Parede Celular/química , Frutas/citologia , Prunus armeniaca/química , Prunus armeniaca/citologia , Açúcares/análise , Hidrolases de Éster Carboxílico/metabolismo , Frutas/química , Humanos , Pectinas/metabolismo , Proteínas de Plantas/metabolismo , Prunus armeniaca/crescimento & desenvolvimento , Açúcares/química , beta-Galactosidase/metabolismo
8.
Bioresour Technol ; 319: 124242, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33254465

RESUMO

Cellulosomes are scaffold proteins displaying enzymes on the cell wall to efficiently obtain nutrient sources. CcGlcNAcase is a novel cellulosomal component. Based on sequence analysis, CcGlcNAcase was predicted to be a chitinolytic enzyme based on high homology with the discoidin domain-containing protein and chitobiase/ ß-hexosaminidase C terminal domain. CcGlcNAcase expression was notably increased when chitin was present. CcGlcNAcase produced N-acetyl-d-glucosamine from various lengths of N-acetyl-d-glucosamine. CcGlcNAcase bound to chitin (89%) and fungi (54.10%), whereas CcGlcNAcase exhibited a low binding ability to cellulose and xylan. CcGlcNAcase hydrolyzed fungi, yielding maximum 3.90 g/L N-acetyl-d-glucosamine. CcGlcNAcase enhanced cellulase toward fungi-infected lignocellulosic biomass, yielding 18 mg/L glucose (1.32-fold) and 1.72-fold increased total reducing sugar levels, whereas cellulase alone produced 13 mg/L glucose. Taken together, CcGlcNAcase can be utilized to enhance the degradation of fungi-infected lignocellulosic biomass and exhibits potential applications in the wood and sugar industry.


Assuntos
Acetilglucosaminidase , Açúcares , Biomassa , Fungos , Lignina
9.
Food Chem ; 338: 128117, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33091985

RESUMO

Sugars are critical components of fruit juice. The binding of sugars and aroma compounds may affect the release of flavor in juices. In this study, the effects of sucrose, glucose, and fructose on the release of active aroma compounds in fresh and high hydrostatic pressure-processed (HPP) Tainong mango juice were evaluated. Using gas chromatography-mass spectrometry/olfactometry and odor activity values, four volatiles were identified as active aroma compounds in fresh and HPP mango juice. Furthermore, Fourier transform infrared spectroscopy and isothermal titration calorimetry illustrated that the sugar-volatile interaction was hydrophobically-driven, with hydrogen bonding to some extent. As the concentrations of sugar were increased in the fresh juice, a significant change in the release of active volatiles occurred, while HPP juice showed stronger retention of the active volatiles. The results suggest that high hydrostatic pressure processing maintained the freshness of mango juice flavor by strengthening aroma retention within the juice matrix.


Assuntos
Manipulação de Alimentos , Sucos de Frutas e Vegetais/análise , Mangifera/química , Odorantes/análise , Açúcares/química , Cromatografia Gasosa-Espectrometria de Massas , Pressão Hidrostática , Paladar
10.
Food Chem ; 338: 127800, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32798815

RESUMO

For the first time, a method is proposed for colorimetric determination of reducing sugars in cachaça employing digital image and a smartphone as detector. The method was based on the reduction of Cu(II) to Cu(I) by sugars and followed by the formation of a colored Cu(I)-Neocuproine complex. A calibration curve was linear from 0.1 to 15 g L-1 for glucose and fructose with limits of detection of 0.012 g L-1 and 0.010 g L-1, respectively. It was observed that the non-aged cachaças, known for having inferior flavors and aromas, had a reducing sugar content three times higher than the aged cachaças, once a common practice among producers is to add sugar to adjust sensory deficits in the final product. Furthermore, the method is simple, does not require complex technical knowledge and it could be used as a tool to check possible fraud, adulteration or non-compliance to the law.


Assuntos
Bebidas Alcoólicas/análise , Análise de Alimentos/instrumentação , Análise de Alimentos/métodos , Smartphone , Açúcares/análise , Colorimetria/instrumentação , Colorimetria/métodos , Cobre/química , Desenho de Equipamento , Contaminação de Alimentos/análise , Frutose/análise , Glucose/análise , Fenantrolinas/química , Saccharum
11.
Food Chem ; 340: 127919, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32889210

RESUMO

Non-enzymatic electrochemical sensors for the monitoring of reducing sugars in foods has great potential as a rapid in-situ detection method. This development involved the assembly of a nanoporous platinum structure on a screen-printed carbon electrode (SPCE). The modified electrode was then employed as an amperometric sensing element in a flow injection analysis (FIA) manifold. The system was successfully applied to the rapid detection of reducing sugars in potatoes, without the need for sample preparation. Optimal signals were achieved in phosphate buffer (pH 7.4) at a flow rate of 0.5 mL min-1 and an applied potential of 0.6 V. Experimental results demonstrated the sensor's long-term stability and high selectivity for reducing sugars. This method provides high sample throughput due to a rapid response time of less than five seconds. Reducing sugar values determined were in good agreement with those recorded using a commercially available enzymatic assay kit.


Assuntos
Técnicas Eletroquímicas/métodos , Eletrodos , Análise de Injeção de Fluxo/métodos , Análise de Alimentos/métodos , Solanum tuberosum/química , Açúcares/análise , Carbono/química , Técnicas Eletroquímicas/instrumentação , Análise de Injeção de Fluxo/instrumentação , Análise de Alimentos/instrumentação , Frutose/análise , Sucos de Frutas e Vegetais/análise , Glucose/análise , Nanoestruturas/química , Platina/química , Propriedades de Superfície
12.
Food Chem ; 340: 127922, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32889211

RESUMO

This study aimed to evaluate the fermentation performance of a mixture of Lactobacillus spp. in cloudy apple juices from nine cultivars. The results showed that cultivar influenced most the properties of the fermented cloudy apple juice. The fermented cloudy apple juices made from Changfu had the highest viable bacterial count and acetic acid contents (6.37 × 108 CFU/mL and 2.67 mg/mL, respectively). It also had higher sensory score, second only to Huaniu. The highest total sugar consumption, utilising fructose, glucose, and sucrose (33.07 mg/mL), was seen with Golden Delicious. Qinguan fermented cloudy apple juice had the highest contents of lactic acid (6.74 mg/mL) and total esters (921.36 µg/L); d-limonene also detected in this fermented cloudy apple juice. Of the nine cultivars examined in this study, Changfu, Qinguan, and Golden Delicious were the most suitable for producing fermented cloudy apple juice with better taste, higher viable count and more intense aroma.


Assuntos
Alimentos e Bebidas Fermentados/microbiologia , Sucos de Frutas e Vegetais/análise , Sucos de Frutas e Vegetais/microbiologia , Malus , Ácido Acético/análise , Carga Bacteriana , Feminino , Fermentação , Alimentos e Bebidas Fermentados/análise , Humanos , Lactobacillus acidophilus , Lactobacillus fermentum , Lactobacillus plantarum , Masculino , Odorantes/análise , Açúcares/análise , Paladar , Compostos Orgânicos Voláteis/análise
13.
Phytochemistry ; 181: 112580, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33166752

RESUMO

Thirteen undescribed 24-methylene lanostane triterpenoids, named polyporenic acids E-M and fomitosides L-O, as well as seventeen known analogues, were isolated from the fruiting bodies of the mushroom Fomitopsis betulina. Their structures were determined using 1D, 2D NMR, IR, and HRESIMS. Fomitoside L and fomitoside N exhibited cytotoxicity against HL60 leukemia cells (IC50 = 15.8 and 23.7 µM, respectively). Among the known compounds, notable cytotoxicities against HL60 leukemia cells and selectivity with respect to MRC-5 healthy cells were noticed for dehydropachymic acid (IC50 = 10.9 µM, SI 8.6), pachymic acid (IC50 = 11.0 µM, SI 9.8), 3-epi-dehydrotumulosic acid (IC50 = 19.9 µM, SI 5.8) and 12α-hydroxy-3α-(3'-hydroxy-4'-methoxycarbonyl-3'-methylbutyryloxy)-24-methyllanosta-8,24 (31)-dien-26-oic acid (IC50 = 19.2 µM, SI 2.2).


Assuntos
Agaricales , Triterpenos , Ésteres , Humanos , Estrutura Molecular , Polyporales , Açúcares , Triterpenos/farmacologia
14.
Food Chem ; 340: 128100, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33059268

RESUMO

A strongly basic ion-exchange resin catalyst was reported to exhibit a high catalytic activity in transesterification to produce a bio-based surfactant, sugar ester under mild condition. However, the side-reactions to decompose the reactant and the product were found to occur. This study was aimed to improve the selectivity of sugar ester synthesis by newly focusing on the basicity of the resin. A weakly basic resin (Diaion WA20) with a lower mass transfer resistance suppressed the decompositions while maintaining synthesis rate. Controlling molar ratio of the reactants in the intraparticle reaction field also increased the reaction selectivity, 72.1% and product yield, 57.5%. Both values were drastically increased compared to the reported values with the strongly basic resin (selectivity 50.9%, yield 14.3%). This is the first knowledge to show a high catalytic activity of weakly basic resin. These results suggest that a more efficient continuous production process would be possible.


Assuntos
Ésteres/química , Ácidos Graxos/química , Resinas de Troca Iônica/química , Açúcares/química , Catálise , Esterificação
15.
Bioresour Technol ; 320(Pt A): 124293, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33120065

RESUMO

In this study, five acid or alkali catalyzed ethylene glycol (EG) organosolv pretreatments were proposed and compared for sugar production from bagasse. The results showed that compared with single EG/H2O pretreatment, the EG/H2O-HCl pretreatment was more efficient for both hemicellulose (~99.3%) and lignin (~67.1%) remove due to the synergistic effect of HCl and EG. The EG/H2O-NaOH pretreatment was also beneficial for lignin remove (~90.9%), but it was weak for hemicellulose degradation (~28.8%). Both EG/H2O-HCl and EG/H2O-NaOH pretreatments have good capacity to reserve the cellulose in pretreated solids. Following enzymatic saccharification, the largest glucose recovery yield from EG/H2O-HCl pretreatment was 94.3%, a slightly higher than this from EG/H2O-NaOH pretreatment (92.5%). However, its xylose recovery yield was only 77.3%, significantly lower than that of EG/H2O-NaOH pretreatment (93.5%). Besides, a certain amount of lignin also can be recovered from above acid or alkali catalyzed organosolv pretreatments through diluting or acidizing the pretreated liquids.


Assuntos
Álcalis , Saccharum , Catálise , Celulose , Etilenoglicol , Hidrólise , Lignina , Açúcares
16.
Bioresour Technol ; 320(Pt A): 124284, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33137640

RESUMO

Biohydrogen production in Microbial Electrolysis Cell (MEC) had inspired the researchers to overcome the challenges associated towards sustainability. Despite microbial community and various substrates, economical cathode catalyst development is most significant factor for enhancing hydrogen production in the MEC. Hence, in this study, the performance of MEC was investigated with a sugar industry effluent (COD 4200 ± 20 mg/L) with graphite anode and modified Nickel foam (NF) cathode. Nickel molybdate (NiMoO4) coated NF achieved a higher hydrogen production rate 0.12 ± 0.01 L.L-1D-1 as compared to control under favorable conditions. Electrochemical characterizations demonstrated that the improved catalytic activity of novel nanocatalyst with lower impedance favoring faster hydrogen evolution kinetics. The MEC with the novel catalyst performed with 58.2% coloumbic efficiency, 20.36% cathodic hydrogen recovery, 11.96% overall hydrogen recovery and 54.38% COD removal efficiency for a 250 mL substrate during 5 days' batch cycle. Hence, the potentiality of modified cathode was established with the real time industrial effluent highlighting the waste to wealth bio-electrochemical technology.


Assuntos
Fontes de Energia Bioelétrica , Níquel , Eletrodos , Eletrólise , Hidrogênio , Molibdênio , Açúcares
17.
Zhongguo Zhong Yao Za Zhi ; 45(22): 5511-5517, 2020 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-33350213

RESUMO

Evaporative light scattering detector(ELSD) and charged aerosol detector(CAD) methods were established in this study for the content determination of four kinds of sugars in Zhusheyong Yiqi Fumai(YQFM), and the factors affecting the accuracy of CAD methods were discussed. HPLC-ELSD chromatographic separation was performed on a Shodex Asahipak NH2 P-50 column with acetonitrile-water(75∶25)as the mobile phase, with a flow rate of 0.8 mL·min~(-1), drift tube temperature of 80 ℃. The analysis by HPLC-CAD was performed on the same column with acetonitrile-water as mobile phase for gradient elution, with a flow rate of 0.8 mL·min~(-1), a neb temperature of 45 ℃, and power function(PF) of 1.3. The samples of YQFM were detected by ELSD and CAD respectively. It was found that YQFM was composed of fructose, glucose, sucrose and maltose. The linear relationship of the two methods was good, and the recoveries, reproducibility and stability of these four kinds of sugars measured by the two methods satisfied the requirements of methodology. Both CAD and ELSD detectors were accurate and reliable in detecting saccharides components in YQFM. In addition, it was revealed in this study for the first time that the PF parameter of CAD had an important influence on the accuracy of sugar determination and acted as the key parameter of CAD method. It was also found that for CAD, a non-linear detector, there was no significant difference between the results of linear regression and logarithmic regression.


Assuntos
Carboidratos , Açúcares , Aerossóis , Cromatografia Líquida de Alta Pressão , Luz , Reprodutibilidade dos Testes , Espalhamento de Radiação
18.
An Acad Bras Cienc ; 92(3): e20191258, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33206801

RESUMO

We investigated the changes in the physical structure of cellulose recovered from soybean and rice hulls treated with the ionic liquids 1-butyl-3-methylimidazolium chloride ([bmim][Cl]) and 1-butyl-3-methylimidazolium acetate ([bmim][Ac]). The characterization was carried out by a combination of thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Regenerated cellulose from soybean hull showed loss of crystallinity and high structural disruption caused by both ionic liquid treatments as compared to the untreated material. In contrast, rice hull presented only a small structural disruption when treated with [bmim][Ac] and was practically unaffected by [bmim][Cl], showing that this biomass residue is recalcitrance towards physico-chemical treatments, possibly as a consequence of its high composition content in silica. These results suggest the use of soybean hull as a substrate to be treated with ionic liquids in the preparation of lignocellulosic hydrolysates to be used in second-generation ethanol production, whereas other methods should be considered to treat rice hull biomass.


Assuntos
Líquidos Iônicos , Oryza , Biomassa , Soja , Açúcares
19.
PLoS One ; 15(11): e0241491, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33152049

RESUMO

The quality attributes of jujube fruit can be directly and indirectly affected by abiotic stresses associated with climate change. Increased temperature and drought are among the most important factors challenging sustainable jujube production in the temperate semi-arid region in northwest China. The main objective of the present study was to understand the effects of elevated air temperature and drought stress on sugar and acid accumulation and coloration of jujube fruits. The content of soluble sugar, organic acid and pigments of traditional jujube "Linwuchangzao" under different atmospheric temperatures and drought stresses were analyzed during three different fruit ripening stages. The elevated temperature (1.5-2.5° C than normal temperature) significantly increased the fruit sugar content, sugar-acid ratio, anthocyanins, flavonoids and carotenoids content. Under the drought stress where the soil moisture was 30% -50% of the field capacity, sugar content, anthocyanin, flavonoid and carotenoid content of the fruit were significantly reduced at the same temperature, but the chlorophyll and organic acid content increased. No significant interaction of Temperature x Drought was observed for all the analyzed quality parameters. The current results showed that the fruit quality of jujube variety "Lingwuchangzao" could be improved when the atmospheric temperature increases by 2° C in this region. However, drought stress had a negative impact on the fruit's sugar-acid ratio and pigment content. The present results also showed that the synthesis and accumulation of anthocyanins in jujube fruit were positively correlated with sugar content and related enzyme activities, especially Phenylalanine Ammonia-lyase (PAL) activity. This study, therefore, provides novel information for understanding the influence of growth environment on the quality properties of jujube fruits. This knowledge will help develop appropriate crop management practices for jujube production in arid and semi-arid areas in northwest China.


Assuntos
Antocianinas/metabolismo , Secas , Frutas/fisiologia , Estresse Fisiológico , Temperatura , Ziziphus/enzimologia , Ziziphus/fisiologia , Análise de Variância , Ácidos Carboxílicos/análise , Umidade , Solo , Solubilidade , Açúcares/análise
20.
PLoS One ; 15(11): e0242602, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33216800

RESUMO

AIM: The main cause of childhood overweight/obesity is an imbalance between energy intake and energy expenditure. The objective was to determine whether the intake by Spanish schoolchildren of sugars from habitually consumed foods and drinks can be related to overweight/obesity. METHODS: Subjects The study included 657 schoolchildren between 7-10 years from educational centers in Southern Spain. These children live under the influence of the Mediterranean diet. Design Participants completed an encoded questionnaire with three sections: a) data on sex, age, educational center, school year, and life/family habits, among others; b) semi-quantitative food frequency questionnaire related to the previous 12 months; and c) information on anthropometrics and physical activities. RESULTS: Obesity was observed in 10.9% of the children. The daily activity questionnaire showed a mean energy expenditure of 8.73 (1.33) MJ/day. The study considered foods that supply carbohydrates in any form (total carbohydrates, starch, total sugars, added sugars, and free sugars). The likelihood of overweight/obesity was significantly greater with a higher intake/day of total sugars, starch, added sugars, and free sugars. The likelihood of normal weight was significantly greater with lower energy expenditure in sedentary activities (OR = 3.03), higher energy expenditure in sports activities (OR = 1.72), and higher total activity/day measured as METs (OR = 8.31). CONCLUSIONS: In this population, overweight/obesity was influenced by the physical activity of the children and by their intake of energy, total sugars, starch, added sugars, and free sugars. Further studies are warranted to verify this observation and explore the implications for public health policies.


Assuntos
Carboidratos da Dieta/análise , Açúcares da Dieta/análise , Ingestão de Energia/fisiologia , Metabolismo Energético/fisiologia , Exercício Físico/fisiologia , Obesidade Pediátrica/epidemiologia , Bebidas , Índice de Massa Corporal , Criança , Estudos Transversais , Dieta Mediterrânea , Carboidratos da Dieta/efeitos adversos , Açúcares da Dieta/efeitos adversos , Comportamento Alimentar , Feminino , Humanos , Masculino , Inquéritos Nutricionais , Obesidade Pediátrica/prevenção & controle , Prevalência , Espanha/epidemiologia , Açúcares/efeitos adversos , Açúcares/análise , Inquéritos e Questionários
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA