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1.
Molecules ; 28(6)2023 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-36985556

RESUMO

Triterpenoids are a group of secondary plant metabolites, with a remarkable pharmacological potential, occurring in the cuticular waxes of the aerial parts of plants. The aim of this study was to analyze triterpenoid variability in the fruits and leaves of three apple cultivars during the growing season and gain new insights into their health-promoting properties and fate during juice and purée production. The identification and quantification of the compounds of interest were conducted using gas chromatography coupled with mass spectrometry. The waxes of both matrices contained similar analytes; however, their quantitative patterns varied: triterpenic acids prevailed in the fruits, while higher contents of steroids and esterified forms were observed in the leaves. The total triterpenoid content per unit area was stable during the growing season; the percentage of esters increased in the later phases of growth. Antioxidative and anti-inflammatory properties were evaluated with a series of in vitro assays. Triterpenoids were found to be the main anti-inflammatory compounds in the apples, while their impact on antioxidant capacity was minor. The apples were processed on a lab scale to obtain juices and purées. The apple purée and cloudy juice contained only some of the triterpenoids present in the raw fruit, while the clear juices were virtually free of those lipophilic compounds.


Assuntos
Malus , Triterpenos , Malus/química , Antioxidantes/análise , Triterpenos/química , Cromatografia Gasosa-Espectrometria de Massas , Frutas/química , Ceras/química
2.
Food Chem ; 384: 132439, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35227999

RESUMO

The purpose of the study was to assess the effect of static and multi-pulsed high pressure processing (HPP) (300-600 MPa, 5-15 min) on the changes in the polyphenolic profile, polyphenoloxidase (PPO) and peroxidise (POD) activities and colour of apple juice. Content of (-)-epicatechin, procyanidin B2, phloretin isomers and phloridzin was detected using Triple-TOF-LC-MS/MS analysis. After HPP treatment, 1,2- disinapoyl-2-feruloylgentiobiose was detected, whereas sinapoyl glucose was degraded after applying 450 MPa and 600 MPa in single pulse, therefore indicating sensitivity of this compound to high pressure and/or polymerization caused by enzymatic reactions. The highest inactivation of PPO (95%) and POD (26%) was observed at 600 MPa. The multi-pulsed HPP (300 MPa × 3 pulses) resulted in higher reduction in oxidoreductive enzyme activity than higher pressure in single pulse (450 MPa). Statistical changes in the colour parameters were observed in pressurized samples, with the lowest ΔE values for 300 MPa × 3 pulses.


Assuntos
Malus , Catecol Oxidase/metabolismo , Cromatografia Líquida , Sucos de Frutas e Vegetais , Malus/metabolismo , Espectrometria de Massas em Tandem
3.
Molecules ; 27(3)2022 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-35164299

RESUMO

Blackcurrant juice (Ribes nigrum L.) was subjected to supercritical carbon dioxide (SCCD) at 10, 30, and 60 MPa for 10 min at 45 °C, as well as thermally treated at 45 and 85 °C for 10 min to determine the stability, antioxidant capacity (AC), and bioaccessibility (BAc) of vitamin C, total anthocyanins, and their individual monomers. An in vitro gastrointestinal digestion model completed with dialysis was used to assess BAc. The use of SCCD at each of the pressures applied improved the stability of vitamin C, total anthocyanins, and AC before in vitro digestion. As a result of digestion, the total content of vitamin C, anthocyanins, and AC decreased. The highest BAc of vitamin C was noted in fresh juice (FJ) (40%) and after mild heat treatment at 45 °C (T45) (46%). The highest BAc of total anthocyanins was also noted in the FJ (4.4%). The positive effect of the application of SCCD on the BAc of the delphinidin-3-O-glycosides was observed compared to T45 and thermal pasteurization at 85 °C (T85). Although SCCD did not significantly improve the BAc of vitamin C and total anthocyanins, the higher AC of SCCD samples after intestinal digestion (ABTS+• and DPPH•) and in dialysate (ABTS+•) compared to thermally treated was observed. The protocatechuic acid was detected by UPLC-PDA-MS/MS as the major metabolite formed during the digestion of delphinidin-3-O-rutinoside. This may indicate the influence of SCCD on improvement of the accessibility of antioxidants for digestion, thanks to which more metabolites with high antioxidant activity were released.


Assuntos
Antocianinas/análise , Antioxidantes/análise , Ácido Ascórbico/análise , Sucos de Frutas e Vegetais/análise , Ribes/química , Dióxido de Carbono/química
4.
Food Chem ; 370: 131023, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34509942

RESUMO

The influence of high pressure homogenization (HPH) at 100-150 MPa performed by multiple passes below 35 °C on carrot juice quality and stability was studied. The highest reduction in microorganisms (by 2.47 log) was noted at 150 MPa with 5 passes of the juice through the homogenizer. The PPO and POD's residual activity increased after HPH; PG was at the same level, while PME activity increased or decreased depending on the process parameters used. HPH treatment resulted in a decrease in the apparent dynamic viscosity, turbidity and colour parameters. Five passes at 150 MPa caused an increase in the carotenoid content, especially 9-Z-ß-carotene (by 154%) while the TPC did not change significantly. Carrot juice treatment at 150 MPa with 5 passes may extend its shelf-life by 3 days when stored at 4 °C.


Assuntos
Daucus carota , Carotenoides , Manipulação de Alimentos , Conservação de Alimentos , Pressão
5.
Foods ; 9(12)2020 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-33302360

RESUMO

The development of functional beverages often requires a compromise between the palatability and high content of bio-active compounds. The purpose of this study was to elaborate on the fruit-herbal beverages with defined pro-health functions and evaluate their consumer acceptance. The beverages contained 80% of juices obtained from the fruits of aronia, rugosa rose, acerola, sea buckthorn, and cranberry. Each beverage was supplemented with different plant extracts which enhanced the designed functions of the beverage. The beverages were sweetened with sugar or with steviol glycosides, and were preserved by thermal pasteurization. The main groups of bio-active compounds and antioxidant capacity using ABTS, DPPH, and ORAC methods were analysed before and after pasteurization. The sensory acceptance was tested by 60 adult consumers who assessed the desirability of taste, odour, colour, and overall quality. Each beverage contained substantial amounts of polyphenols, including anthocyanins; rosehip-acerola and sea buckthorn beverages were also sources of vitamin C and carotenoids. All these components were stable under thermal treatment. Rosehip-acerola beverages had the highest antioxidant capacity, which was measured using all three methods exhibited. The highest level of consumer acceptance and willingness to purchase went to aronia beverages, while the sea buckthorn gained the lowest. There was no significant difference between the acceptance of beverages sweetened with sugar and stevia. Women and the 25- to 34-year-old consumer group rated the overall acceptability of the beverages slightly higher, although this was not reflected in their inclination to buy them. Attitude toward proper body mass and health had no influence on overall acceptance and willingness to complete the purchases. The main motivation for purchasing the functional beverages was their sensory acceptance, even if the consumers were informed of their potential health benefits.

6.
Molecules ; 25(15)2020 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-32756431

RESUMO

The aim of the study was to investigate the effect of high-pressure processing (HPP) and thermal processing (TP) on the bioaccessibility of vitamin C and anthocyanins as well as changes in the antioxidant capacity (AC) using ABTS+• and DPPH• tests on blackcurrant (Ribes nigrum L.) puree during the steps in the digestive process. The puree was subjected to HPP at 200, 400, and 600 MPa for 5 min (room temperature) or TP at 85 °C for 10 min. The controls were untreated puree (P) and fruit crushed in a mortar (M). All the samples were digested in a static in vitro digestion model, including the mouth, stomach, and small intestine, and subjected to dialysis. The vitamin C, anthocyanin, and antioxidant capacity were monitored at each step of the digestion process. The potential bioaccessibility of the antioxidants studied was calculated in relation to the undigested sample. TP and HPP enabled a high content of vitamin C, anthocyanins, and AC to be maintained. After simulated digestion in the small intestine, a significant decrease was observed in the vitamin C and anthocyanins (approximately 98%) content. However, a high stability (approximately 70%) of both compounds was noted at the gastric stage. HPP and TP significantly affected the potential bioaccessibility of vitamin C and anthocyanins, although the bioaccessibility of both compounds in the samples treated using HPP was higher than when using TP. Moreover, the potential bioaccessibility of vitamin C after HPP treatment (400 and 600 MPa) was higher than the bioaccessibility calculated for the M and P control samples. TP and HPP treatment negatively affected anthocyanin bioaccessibility after dialysis. The most favorable pressure was 400 MPa, as it allowed maintaining the best antioxidant activity after digestion.


Assuntos
Antioxidantes/química , Ribes/química , Antocianinas/análise , Antocianinas/isolamento & purificação , Ácido Ascórbico/análise , Ácido Ascórbico/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Digestão , Frutas/química , Frutas/metabolismo , Pressão Hidrostática , Ribes/metabolismo , Espectrofotometria , Temperatura
7.
Molecules ; 25(17)2020 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-32825691

RESUMO

Furocoumarins are a group of plant phytoalexins exhibiting various bioactive properties; the most important of which are photosensitization and alteration of P450 cytochrome activity. Supercritical fluid extraction with carbon dioxide has been proposed as a green alternative for an organic solvent extraction of the furocoumarins. Four plant matrices rich in furocoumarins were extracted with CO2 at a temperature of 80 °C and pressure of 40 MPa, as these conditions were characterized by the highest solubility of furocoumarins. The extracts collected were analyzed using the HPLC method and the results obtained were used for the mathematical modeling of the observed phenomena. The total content of the furocoumarins in the matrices was 4.03-26.45 mg g-1 of dry weight. The impact of the process parameters on the solubility was consistent with the Chrastil equation. The broken plus intact cell model proved to be suitable to describe extraction curves obtained. The research proved the possibility of supercritical carbon dioxide utilization for the extraction of the furocoumarins from plant material and provided valuable data for prospective industrial-scale experiments.


Assuntos
Dióxido de Carbono/química , Cromatografia com Fluido Supercrítico/métodos , Furocumarinas/análise , Furocumarinas/isolamento & purificação , Fármacos Fotossensibilizantes/análise , Fármacos Fotossensibilizantes/isolamento & purificação , Plantas/química , Fenômenos Fisiológicos Celulares , Furocumarinas/química , Cinética , Fármacos Fotossensibilizantes/química , Plantas/classificação
8.
Food Chem ; 307: 125549, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31648175

RESUMO

The aim of this study was to determine the influence of static and multi-pulsed hydrostatic pressure processing (HPP) treatments on the polyphenolic profile, oxidoreductase activity, colour, and browning index of carrot juice. Phenolic acids, flavonoids, lignans and other polyphenols were the predominant polyphenols detected with Triple-TOF-LC-MS/MS. The highest concentration of ferulic acid, didymin, dihydro-p-coumaric acid, sesaminol and matairesinol isomers were found among all the compounds detected. After HPP treatment, irrespective of the pressures applied, new simple polyphenols like oleuropein, 4-vinylsyringol, isocoumarin, and 4-hydroxybenzaldehyde were detected. Both phenomena could be attributed to the release of bounded phenolic compounds after applying HPP, as well as enzymatic degradation and/or condensation. The highest inactivation of polyphenoloxidase (PPO) enzymes (57%) was obtained at 300 MPa × 3 pulses, and peroxidase (POD) enzymes (31%) at 600 MPa working in static mode. Significant changes in the colour parameters and browning index were observed in all HPP-treated juices.


Assuntos
Catecol Oxidase/metabolismo , Daucus carota/química , Polifenóis/análise , Pressão Sanguínea , Cromatografia Líquida , Cor , Daucus carota/enzimologia , Espectrometria de Massas em Tandem
9.
Molecules ; 23(11)2018 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-30373258

RESUMO

Apple pomace, a byproduct of juice production, is a rich source of bioactive compounds and nutrients. Supercritical fluid extraction was proposed as a method for a fast and selective extraction of hydrophobic compounds with a pharmaceutical potential from this matrix. Chromatographic analysis showed that the pomace contained significant amounts of such substances, the most abundant of them were ursolic acid, oleanolic acid, and ß-sitosterol. The solubility was chosen as a primary factor for a selection of the extraction conditions; the best results were acquired for a temperature of 80 °C and a pressure of 30 MPa. The equation proposed by Chrastil was applied for the description of the impact of the process parameters on the solubility of the analytes; the obtained values of coefficients of determination were satisfactory, despite the fact that the equation was developed for binary systems. The extraction curves obtained during the experiments were used for the description of the process kinetics using the Broken plus Intact Cell model. The impact of the temperature, pressure, and flow rate of carbon dioxide on the mass transfer phenomena was investigated. The data obtained allowed the prediction of the extraction curve for the process conducted on the larger scale.


Assuntos
Dióxido de Carbono , Cromatografia com Fluido Supercrítico , Malus/química , Fitosteróis/química , Extratos Vegetais/química , Triterpenos/química , Dióxido de Carbono/química , Cromatografia Gasosa , Cromatografia com Fluido Supercrítico/métodos , Modelos Teóricos , Solventes
10.
Food Chem ; 268: 279-286, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30064759

RESUMO

The impact of supercritical carbon dioxide (SCCD) (10-60 MPa/45 °C/30 min) and subsequent 10 weeks storage at 4 °C on polyphenol oxidase (PPO), peroxidase (POD) activities, phenolic profile, vitamin C, sugars, physicochemical properties of cloudy apple juices was investigated. No significant changes in sugars and total polyphenols were observed, whereas significant degradation (≈28%) of vitamin C and individual polyphenols (≈18%) was noted after SCCD treatment. After 4 weeks storage only 34% of vitamin C was retained and no vitamin C was detected after this time. Ten weeks of storage caused hydrolysis of sucrose in 15%, whereas degradation of individual polyphenols ranged from 43 to 50% depending on the pressure applied. The highest pressure was applied the highest retention of polyphenols was observed. The lightness of juice significantly increased by 15% after SCCD and decreased during storage. Moreover, the synergistic effect of both enzymes with chlorogenic acid and catechol was found.


Assuntos
Catecol Oxidase/metabolismo , Manipulação de Alimentos/métodos , Sucos de Frutas e Vegetais/análise , Malus/química , Peroxidases/metabolismo , Compostos Fitoquímicos/análise , Ácido Ascórbico/análise , Dióxido de Carbono/química , Cromatografia Líquida de Alta Pressão , Temperatura Baixa , Malus/metabolismo , Valor Nutritivo , Fenóis/análise , Polifenóis/análise , Especificidade por Substrato , Fatores de Tempo
11.
J Food Sci Technol ; 54(3): 832-841, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28298698

RESUMO

This study was aimed at monitoring changes in the quality of strawberry purée preserved by high pressure processing (HPP) and thermal pasteurization (TP) during cold storage (6 °C) and determining its optimal storage period. The storage period of strawberry purée treated at 500 MPa, 50 °C, 15 min based on microbiological changes was 12 weeks. During this period, purée lost 32% of polyphenols, 73% of anthocyanins and entire vitamin C. Color changes described as dE increased up to 5.05 whereas the overall sensory quality decreased by 3 points on a 9-point scale. Under similar storage conditions, TP-preserved purée lost only 28% of polyphenols and 54% of anthocyanins, and entire vitamin C. Color changes were more visible (dE = 7.21) compared to the HPP sample whereas the overall sensory quality decreased only by 2 points. Recommended cold shelf-life for the HPP product was estimated at 6 weeks, during which period HPP-preserved purée had higher content of polyphenols and colour parameters compared to TP purée.

12.
Int J Mol Sci ; 18(2)2017 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-28134807

RESUMO

Anthocyanins are a group of phenolic compounds responsible for red, blue and violet colouration of many fruits, vegetables and flowers. The high content of these pigments is important as it influences directly their health promoting properties as well as the sensory quality of the product; however they are prone to degradation by, inter alia, elevated temperature and tissue enzymes. The traditional thermal methods of food preservation cause significant losses of these pigments. Thus, novel non-thermal techniques such as high pressure processing, high pressure carbon dioxide and high pressure homogenization are under consideration. In this review, the authors attempted to summarize the current knowledge of the impact of high pressure techniques on the stability of anthocyanins during processing and storage of fruit and vegetable products. Furthermore, the effect of the activity of enzymes involved in the degradation of these compounds has been described. The conclusions including comparisons of pressure-based methods with high temperature preservation techniques were presented.


Assuntos
Antocianinas/química , Frutas/química , Pressão , Verduras/química , Enzimas/metabolismo , Temperatura
13.
Curr Microbiol ; 73(6): 773-780, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27565144

RESUMO

The number of people who cannot consume dairy products due to intolerance or allergies to food components is increasing. Consumers are increasingly searching for alternative, nondairy beverages which have an advantageous effect on the body and which stimulate gut microflora. Previous studies have shown that Streptococcus thermophilus TKM3 KKP 2030p can be an efficient starter culture for the fermentation of plant material and can also ensure an acceptable sensory profile and a high number of lactic acid bacteria during 4 week cold storage. The aim of this study was to determine the relative gene expression of the L-lactate dehydrogenase gene (ldhL) in selected strain using the RT qPCR technique at particular time points. The gene expression experiments were conducted in laboratory broth (LABm) and fruit-cereal (OBPromOat) matrix with a beta-glucan additive. Levels of gene relative expression in the selected strain in these two media were correlated with the amount of L-lactate produced. The results showed that the plant matrix stimulated stronger ldhL gene expression in the first 4 h of the experiment (although the synthesis of L-lactate was less than in laboratory broth). This study broadens existing knowledge of the transcriptional mechanisms which arise from the adaptation of the analyzed strain to different habitats during L-lactate synthesis. This could contribute to the development of new alternative food products for people who show intolerance to milk proteins or lactose.


Assuntos
Avena/microbiologia , Proteínas de Bactérias/genética , Bebidas/microbiologia , Aditivos Alimentares/metabolismo , L-Lactato Desidrogenase/genética , Musa/microbiologia , Streptococcus thermophilus/enzimologia , beta-Glucanas/metabolismo , Avena/metabolismo , Proteínas de Bactérias/metabolismo , Bebidas/análise , Fermentação , Aditivos Alimentares/análise , Regulação Bacteriana da Expressão Gênica , L-Lactato Desidrogenase/metabolismo , Musa/metabolismo , Streptococcus thermophilus/genética , Streptococcus thermophilus/metabolismo , beta-Glucanas/análise
14.
Food Microbiol ; 60: 92-103, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27554150

RESUMO

Ayran is a traditional Turkish milk drink which is fermented and salted. Inadequate production and storage conditions contribute to its variable organoleptic quality and stability during shelf-life. A thorough physico-chemical, nutritional and microbial characterization of artisanal Ayran was carried out in order to standardize its overall quality without altering its original traits. Ayran microbial ecosystem was largely dominated by Streptococcus thermophilus (ST) and Lactobacillus delbrueckii subsp. bulgaricus (LDB). High counts of other lactic acid bacteria species, including Lactobacillus helveticus (LH), Lactobacillus fermentum (LF), and Lactobacillus paracasei (LP), were also found. Selected LDB, LP and LH strains grew well in milk displaying fast acidification and high proteolysis, differently from ST and LF strains that did not cause noticeable changes. A selected autochthonous three-strain culture (TSC), composed of one strain of LDB, LP and ST, was applied for the pilot-scale production of traditional Ayran. The Ayran produced with this TSC resulted in the most extensive shelf-life (one month) and in the best terms of its nutritional and sensory quality nevertheless altering its typical pleasant yogurt and cottage cheese notes. This TSC is at disposal of SMEs who need to standardize the overall quality of this traditional fermented milk, preserving its typical traits.


Assuntos
Produtos Fermentados do Leite/análise , Produtos Fermentados do Leite/microbiologia , Qualidade dos Alimentos , Armazenamento de Alimentos/normas , Animais , Técnicas de Tipagem Bacteriana , Biodiversidade , Lactobacillus/classificação , Lactobacillus/genética , Lactobacillus/isolamento & purificação , Viabilidade Microbiana , Tipagem Molecular , Projetos Piloto , Proteólise , Streptococcus thermophilus/genética , Streptococcus thermophilus/isolamento & purificação , Paladar , Turquia , Iogurte/análise , Iogurte/microbiologia
15.
Molecules ; 20(11): 20614-41, 2015 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-26610440

RESUMO

Ursolic acid (UA) is a natural terpene compound exhibiting many pharmaceutical properties. In this review the current state of knowledge about the health-promoting properties of this widespread, biologically active compound, as well as information about its occurrence and biosynthesis are presented. Particular attention has been paid to the application of ursolic acid as an anti-cancer agent; it is worth noticing that clinical tests suggesting the possibility of practical use of UA have already been conducted. Amongst other pharmacological properties of UA one can mention protective effect on lungs, kidneys, liver and brain, anti-inflammatory properties, anabolic effects on skeletal muscles and the ability to suppress bone density loss leading to osteoporosis. Ursolic acid also exhibits anti-microbial features against numerous strains of bacteria, HIV and HCV viruses and Plasmodium protozoa causing malaria.


Assuntos
Triterpenos/química , Triterpenos/farmacologia , Animais , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Encéfalo/efeitos dos fármacos , Coração/efeitos dos fármacos , Humanos , Fígado/efeitos dos fármacos , Extratos Vegetais/biossíntese , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Ácido Ursólico
16.
Pol J Microbiol ; 64(4): 351-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26999955

RESUMO

Given the importance of spoilage caused by Alicyclobacillus acidoterrestris for the fruit juice industry, the objective of this work was to study the germination and inactivation of A. acidoterrestris spores induced by moderate hydrostatic pressure. Hydrostatic pressure treatment can induce the germination and inactivation of A. acidoterrestris spores. At low pH, spore germination of up to 3.59-3.75 log and inactivation of 1.85-2.04 log was observed in a low pressure window (200-300 MPa) applied at 50 degrees C for 20 min. Neutral pH suppressed inactivation, the number of spores inactivated at pH 7.0 was only 0.24-1.06 log. The pressurization temperature significantly affected spore germination and inactivation. The degree of germination in apple juice after pressurization for 30 min with 200 MPa at 20 degrees C was 2.04 log, with only 0.61 log of spores being inactivated, while at 70 degrees C spore germination was 5.94 log and inactivation 4.72 log. This temperature strongly stimulated germination and inactivation under higher (500 MPa) than lower (200 MPa) pressure. When the oscillatory mode was used, the degree of germination and inactivation was slightly higher than at continuous mode. The degree of germination and inactivation was inversely proportional to the soluble solids content and was lowest in concentrated apple juice.


Assuntos
Alicyclobacillus/fisiologia , Viabilidade Microbiana , Esporos Bacterianos/fisiologia , Bebidas/microbiologia , Microbiologia de Alimentos , Pressão Hidrostática , Temperatura , Fatores de Tempo
17.
J Agric Food Chem ; 62(46): 11264-9, 2014 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-25376304

RESUMO

A high level of sweetness and health-promoting properties make steviol glycosides an interesting alternative to sugars or artificial sweeteners. The radical oxygen species scavenging activity of these compounds may influence the stability of labile particles present in food. Model buffer solutions containing steviol glycosides, a selected food antioxidant (vitamin C or anthocyanins), and preservative were analyzed during storage. The addition of steviol glycosides at concentrations of 50, 125, and 200 mg/L increased the stability of both ascorbic and dehydroascorbic acid (degradation rates decreased up to 3.4- and 4.5-fold, respectively); the effect was intensified by higher sweetener concentrations and higher acidity of the solutions. Glycosides used alone did not affect the stability of anthocyanins; however, they enhanced the protective effect of sugars; half-life times increased by ca. 33% in the presence of sucrose (100 g/L) and by ca. 52% when both sucrose (100 g/L) and glycosides (total 200 mg/L) were used. Steviol glycosides concentrations remained stable during experiments.


Assuntos
Antocianinas/química , Ácido Ascórbico/química , Diterpenos do Tipo Caurano/análise , Glucosídeos/análise , Extratos Vegetais/análise , Stevia/química , Estabilidade de Medicamentos , Meia-Vida
18.
Food Microbiol ; 38: 179-91, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24290642

RESUMO

Matsoni, a traditional Georgian fermented milk, has variable quality and stability besides a short shelf-life (72-120 h at 6 °C) due to inadequate production and storage conditions. To individuate its typical traits as well as select and exploit autochthonous starter cultures to standardize its overall quality without altering its typicality, we carried out a thorough physico-chemical, sensorial and microbial characterization of traditional Matsoni. A polyphasic approach, including a culture-independent (PCR-DGGE) and two PCR culture-dependent methods, was employed to study the ecology of Matsoni. Overall, the microbial ecosystem of Matsoni resulted largely dominated by Streptococcus (S.) thermophilus and Lactobacillus (Lb.) delbrueckii subsp. bulgaricus. High loads of other lactic acid bacteria species, including Lb. helveticus, Lb. paracasei and Leuconostoc (Leuc.) lactis were found to occur as well. A selected autochthonous multiple strain culture (AMSC) composed of one Lb. bulgaricus, one Lb. paracasei and one S. thermophilus strain, applied for the pilot-scale production of traditional Matsoni, resulted the best in terms of enhanced shelf-life (one month), sensorial and nutritional quality without altering its overall typical quality. This AMSC is at disposal of SMEs who need to exploit and standardize the overall quality of this traditional fermented milk, preserving its typicality.


Assuntos
Produtos Fermentados do Leite/química , Produtos Fermentados do Leite/microbiologia , Lactobacillales/isolamento & purificação , Lactobacillales/metabolismo , Valor Nutritivo , Paladar , Animais , Bovinos , Fermentação , Conservação de Alimentos , Armazenamento de Alimentos , Humanos , Lactobacillales/classificação , Lactobacillales/genética
19.
Rocz Panstw Zakl Hig ; 59(4): 437-43, 2008.
Artigo em Polonês | MEDLINE | ID: mdl-19227255

RESUMO

The aim of the study was to investigate the microbiological decontamination of coriander and caraway when HPP technology was applied in elevated temperature in helium atmosphere. The HPP and heat treatment was conducted for 30 minutes at 800 and 1 000 MPa and temperature range was 60 - 121 degrees C. Contamination with aerobic mesophilic bacteria was decreased by about 2 logarithmic cycles. Total elimination of coliform and yeast and moulds was observed. The efficacy of HPP treatment under helium atmosphere depended on the content of the water in tested samples. It can be concluded that high pressure treatment under atmosphere of helium, combination of proper high pressure and time improved the microbiological quality of spices.


Assuntos
Bactérias/crescimento & desenvolvimento , Contaminação de Alimentos/prevenção & controle , Manipulação de Alimentos/métodos , Conservação de Alimentos/métodos , Especiarias/microbiologia , Contagem de Colônia Microbiana , Qualidade de Produtos para o Consumidor , Microbiologia de Alimentos , Humanos , Pressão Hidrostática
20.
J Chromatogr A ; 992(1-2): 199-203, 2003 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-12735476

RESUMO

During the GC analysis of apple aroma essence using a capillary column with polar stationary phases, i.e., bonded/crosslinked polyethylene glycol (HP-Innowax) and acid-modified polyethylene glycol (FFAP) the phenomenon of changing the elution order of some compounds was observed ("cross-over phenomenon"). The elution order within two pairs of closely eluting compounds: 2-methylbutyl acetate/pentan-3-ol (internal standard) and trans-2-hexen-1-al/2-methylbutan-1-ol differed between samples introduced onto the column with direct injection and with static headspace method. Experiments carried out on standard solutions of investigated compounds in water-acetone mixtures of gradually reduced water ratio (99:1 to 0:100) proved that changes of elution times leading first to co-elution and subsequently to reversion of elution order of compounds within both pairs depended on the amount of water in the injected sample. The same effect was observed while the amount of water was diminished by reducing the sample volume introduced into the column.


Assuntos
Cromatografia Gasosa/instrumentação , Cromatografia Gasosa/métodos , Compostos Orgânicos/isolamento & purificação , Água/análise
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