Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Artigo em Inglês | MEDLINE | ID: mdl-21854298

RESUMO

This article reports the results of a survey and an exposure study, based on a probabilistic approach, concerning red juice-based and red soft drink products in Italy. It highlights the fact that the estimates of both the consumption rates and colorant intakes are related to the hypotheses of scenarios. In fact, the study estimates that, on average, consumers of red soft drinks consume 53.1 L year(-1), ranging from 39.1 to 70.7 L of soft drink products under one scenario, or 21.3 L, and from 12.7 and 35.9 L under another hypothesis; while 9.5 L of red juice-based drinks are consumed per year, ranging from 7.0 to 12.5 L, under one scenario, or on average 6.9 L, and ranging from 3.2 to 17.7 L under another scenario. The amount of colorant in a red beverage ranged from 10.9 mg l(-1) in a red soft drink up to 55.9 mg l(-1) in a red juice-based product. The risk evaluation process showed that in all cases the intake of E129 was always lower than the acceptable daily intake. The exposure assessment showed high average intakes of Allura Red in the worst-case scenario, on average, 6.5 and 13.9 mg day(-1), up to 25.0 and 33.0 mg day(-1) at the 95th percentile, for juice-based and soft drinks respectively. The most realistic scenario estimated a weighted average daily intake of Allura Red, on average from about 0.3 to 0.5 mg day(-1) at the 95th percentile, and from 0.4 to 0.6 mg day(-1) for the 95th percentile, from juice-based and soft drinks, respectively. Actually, the highest colorant intake was estimated in a 'health' juice-based drink. The intake of E129 significantly increased with a high level of colorant (>40 mg l(-1)).


Assuntos
Compostos Azo/análise , Bebidas/análise , Cor , Exposição Ambiental , Cromatografia Líquida de Alta Pressão , Humanos , Itália , Probabilidade , Medição de Risco , Espectrofotometria Ultravioleta
2.
Artigo em Inglês | MEDLINE | ID: mdl-24779619

RESUMO

Despite growing demand by consumers for healthy beverages, artificial colours are still widely used. Levels of anthocyanins and artificial colours were determined by HPLC with UV-Vis detection in red orange juices and other red beverages (nectar, juice-based, health, carbonated and sports drinks). The contribution of pigments to the visible colour of the beverage was calculated. Red orange juice samples contained about 34 mg l(-1) of anthocyanins, which were responsible for about 92% of the visible colour. Red juice-based drinks, containing from 0% to 30% of red orange, berry, grape or pomegranate juices, had low levels of anthocyanins (about 7 mg l(-1)) and high levels of E129 (about 32 mg l(-1)), which were responsible for about 90.7% of the colour of these beverages. Red health drinks, enriched with vitamins and polyphenols, contained from 3% to 50% of red fruit juices. Also in this case the E129 levels were higher (about 22 mg l(-1)) than anthocyanins (about 9 mg l(-1)), and were responsible for the colour of the beverages (76.1%). High levels of artificial colours were found in red orange carbonated drinks, but in comparable amounts with those found in the other beverage samples, while anthocyanins were only present in trace amounts. Although all of the beverages claimed to contain red fruits on the labels, no correlation was found between the level of anthocyanins and the declared percentage of red fruits. These labels generally conformed with the requirements of the law, but food product labels can often be misleading to consumers about the real characteristics of the product.


Assuntos
Bebidas/análise , Cor , Corantes de Alimentos/análise , Rotulagem de Alimentos , Frutas , Pasteurização , Antocianinas/análise , Bebidas Gaseificadas/análise , Cromatografia Líquida de Alta Pressão , Itália
3.
Artigo em Inglês | MEDLINE | ID: mdl-19680977

RESUMO

This paper reports the results of a 5-year study to evaluate pesticide levels, derived from orchard activities, on Italy's most common orange cultivar (Citrus sinensis, L. Osbeck, cv. Tarocco). Using a Bayesian approach, the study allowed both the qualitative (number) and quantitative distributions (amount) of pesticides to be determined with its own probability value. Multi-residue analyses of 460 samples highlighted the presence of ethyl and methyl chlorpyrifos, dicofol, etofenprox, fenazaquin, fenitrothion, imazalil, malathion and metalaxil-m. A total of 30.5% of samples contained just one pesticide, 2.16% two pesticides and 0.65% of samples had three pesticides present simultaneously. The most common residue was ethyl chlorpyrifos followed by methyl chlorpyrifos. Estimated daily intake (EDI) values for ethyl and methyl chlorpyrifos, as well as the distance from the safety level (non-observed adverse effect level, NOAEL), were calculated. The risk was differentiated (1) to take account of the period of actual citrus consumption (180 days) and (2) to discriminate the risk derived from eating oranges containing a certain level of chlorpyrifos from unspecified pesticides. The most likely EDI values for ethyl chlorpyrifos derived from Italian blood orange consumption are 0.01 and 0.006 mg/day calculated for 180 and 365 days, respectively. Considering the probability of the occurrence of ethyl chlorpyrifos, these EDI values are reduced to 2.6 x 10(-3) and 1.3 x 10(-3) mg/day, respectively. For methyl chlorpyrifos, the most likely EDI values are 0.09 and 0.04 mg/day, respectively; considering the probability of its occurrence, the EDI values decrease to 6.7 x 10(-3) and 3.4 x 10(-3) mg/day, respectively. The results confirmed that levels of pesticides in Italian Tarocco oranges derived from a known controlled chain of production are safe.


Assuntos
Citrus sinensis/química , Resíduos de Praguicidas/análise , Contaminação de Alimentos/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Humanos , Itália , Método de Monte Carlo , Medição de Risco , Estatística como Assunto , Fatores de Tempo
4.
J Food Sci ; 73(9): C625-31, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19021792

RESUMO

5-Hydroxymethylfurfural (HMF) is the most important intermediate product of the acid-catalyzed dehydration reaction of hexoses and/or Maillard reaction; furthermore, it is the most used index to evaluate thermal damages or ageing in food products. Usually its degradation reactions, being very slow, are neglected. This study reports the findings concerning the degradation kinetics of HMF, in honeys of different floral origin at a temperature between 25 and 50 degrees C. The results highlighted higher degradation rates (k(HMF) (degradation)) compared to the corresponding formation rates (k(HMF) (formation)) in chestnut and citrus samples. Similar k-values were found in multifloral honey. Moreover, the reaction of HMF degradation was characterized by lower activation energy (E(a)) values compared to E(a) formation values. The final concentration of HMF in honey, during storage at room temperature, should be ascribed to high sugar concentration. The fluctuation of HMF in honeys could depend on the equilibrium between the accumulation and the degradation processes. This can affect the validity of HMF as storage index in some honeys, above all during the analysis of those honeys whose legislation is too restrictive (citrus) or in chestnut honey analysis where it does not accumulate.


Assuntos
Furaldeído/análogos & derivados , Mel/análise , Citrus , Flores , Frutose/análise , Furaldeído/metabolismo , Glucose/análise , Mel/normas , Concentração de Íons de Hidrogênio , Cinética , Lactonas/análise , Nozes
5.
J Agric Food Chem ; 48(6): 2291-5, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10888539

RESUMO

This paper describes a procedure for recovering hesperidin from the waste water of orange juice processing, namely, yellow water, by concentration of diluted extracts on styrene-divinylbenzene resin. Turbid raw material flowing out from centrifuges of essential oil separation contains considerable amount of hesperidin ( approximately 1 g/L) mainly associated with solid particles. Yellow water was treated with calcium hydroxide until pH 12 to solubilize hesperidin, filtered, neutralized at pH 6, and loaded on resin up to saturation. Desorption with 10% ethanol aqueous solutions at different NaOH concentrations (0.23-0.92 M) assured high concentration of hesperidin in selected fractions (10-78 g/L), from which it precipitated in high yield and purity immediately after acidification at pH 5. Best results were obtained using 0.46 M NaOH as eluent: 71.5% of the adsorbed hesperidin was desorbed in 300 mL, with an overall 64% yield of isolated product at 95.4% purity (HPLC). These experiments can constitute a useful starting point for an industrial application.


Assuntos
Citrus , Manipulação de Alimentos , Hesperidina/isolamento & purificação , Resíduos/análise , Água/análise , Poliestirenos , Resinas Sintéticas
6.
J Agric Food Chem ; 47(10): 4391-7, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10552823

RESUMO

This paper describes a new procedure for obtaining hesperidin from the waste orange peel of the citrus industry. It is based on the adsorption of dilute extracts of hesperidin on a styrene-divinylbenzene (SDVB) resin and the desorption in much more reduced volumes by means of alkaline eluents. Hesperidin immediately precipitates with good yield and high purity after acidification of the concentrated solutions, thus overcoming disadvantages due to the high dilution. Different experiments were carried out to examine operating conditions in each phase of the process. Hesperidin was extracted from peel with an aqueous saturated Ca(OH)(2) solution, allowing precipitation of calcium pectates from colloidal pectins that can interfere in the subsequent phases of adsorption and separation of hesperidin. The clear extracts were neutralized to optimize adsorption on resin. The most effective eluent was 0.5 N NaOH solution containing 10% ethanol. Recycling of the crystallization liquor improved the yield and purity of the product and reduced the acid amount required for neutralizing fresh alkaline extracts. Resin must be washed after each adsorption-desorption cycle and regenerated after five cycles. Results can constitute a useful starting point for an industrial application. A flow scheme of the process is also reported.


Assuntos
Citrus/química , Indústria Alimentícia , Hesperidina/isolamento & purificação , Resinas de Troca Iônica , Adsorção , Indústria Alimentícia/métodos , Humanos , Estireno , Compostos de Vinila
7.
J Agric Food Chem ; 47(6): 2255-61, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10794619

RESUMO

Aqueous glucose/phenylalanine (0.1 M with respect to each reactant) systems were heated in an autoclave for 30 min at 140 degrees C, in the presence of hexanal (0.04, 0.1, and 0.2 M) or FeCl(2) (0.01 M). Results show that hexanal significantly inhibited color development at pH 5 and 6 and led to an increase of 5-(hydroxymethyl)furfural. Iron addition had similar effects at pH 5, but only small effects at pH 6. The reaction routes proposed give key roles to the alpha-dicarbonyl compounds, to the Strecker aldehyde, and to the Schiff base formed by the reaction between hexanal and phenylalanine.


Assuntos
Aldeídos/química , Compostos Ferrosos/química , Glucose/química , Fenilalanina/química , Furaldeído/análogos & derivados , Furaldeído/análise , Reação de Maillard , Espectrofotometria/métodos
8.
J Agric Food Chem ; 46(2): 464-470, 1998 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-10554264

RESUMO

Extraction, resolution, and determination of the trans-hydroxycinnamic acids (caffeic, p-coumaric, ferulic, and sinapic) were performed in 82 orange juices derived from the most important blood and blond varieties grown in Italy. Soluble solids, acidity, and anthocyanins were also determined. Hydroxycinnamic acids were more abundant in blood orange than in blond juices. Ferulic acid was the major component in all cases, but the distribution of the four acids was typical in each variety. Discriminant analysis of the experimental results showed that these acids could be used as markers of blood and blond varieties. The statistical model was used to recognize some mixtures of blood and blond juices.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA