The Experts below are selected from a list of 231 Experts worldwide ranked by ideXlab platform
Flavio Diniz Soares - One of the best experts on this subject based on the ideXlab platform.
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volatile and non volatile chemical composition of the white guava fruit psidium guajava at different stages of maturity
Food Chemistry, 2007Co-Authors: Flavio Diniz Soares, Talita Pereira, Marcia Ortiz Maio Marques, A MonteiroAbstract:Abstract The effect of the maturation stages on the chemical composition and volatile compounds of the white Guava ( Psidium guajava ) Cv. Cortibel was investigated during three different stages. The stages were characterized by evolution of color, pH, titratable acidity, sugars, soluble solids, vitamin C and volatile components. The fruits were stored at 24 °C and air humidity of 74% for 13 days. The volatile extracts were obtained using Headspace Technique and analyzed using gas chromatograph/mass spectrometry (GC/MS) system. The titratable acidity and sugars decreased. The pH level and amount of vitamin C increased throughout progress of maturation. The behavior of volatile compounds of fruits in the three stages of maturation was: in immature fruits and those in their intermediate stage of maturation, were predominantly the aldehydes such as ( E )-2-hexenal and ( Z )-3-hexenal. In mature fruits, esters like Z -3-hexenyl acetate and E -3-hexenyl acetate and sesquiterpenes caryophyllene, α-humulene and β-bisabollene are present.
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volatile and non volatile chemical composition of the white guava fruit psidium guajava at different stages of maturity
Food Chemistry, 2007Co-Authors: Flavio Diniz Soares, Talita Pereira, Marcia Ortiz Maio Marques, Alcilene Rodrigues MonteiroAbstract:Abstract The effect of the maturation stages on the chemical composition and volatile compounds of the white Guava ( Psidium guajava ) Cv. Cortibel was investigated during three different stages. The stages were characterized by evolution of color, pH, titratable acidity, sugars, soluble solids, vitamin C and volatile components. The fruits were stored at 24 °C and air humidity of 74% for 13 days. The volatile extracts were obtained using Headspace Technique and analyzed using gas chromatograph/mass spectrometry (GC/MS) system. The titratable acidity and sugars decreased. The pH level and amount of vitamin C increased throughout progress of maturation. The behavior of volatile compounds of fruits in the three stages of maturation was: in immature fruits and those in their intermediate stage of maturation, were predominantly the aldehydes such as ( E )-2-hexenal and ( Z )-3-hexenal. In mature fruits, esters like Z -3-hexenyl acetate and E -3-hexenyl acetate and sesquiterpenes caryophyllene, α-humulene and β-bisabollene are present.
Lars Porskjaer Christensen - One of the best experts on this subject based on the ideXlab platform.
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effect of packing materials and storage time on volatile compounds in tea processed from flowers of black elder sambucus nigra l
European Food Research and Technology, 2008Co-Authors: Karl Kaack, Lars Porskjaer ChristensenAbstract:The effect of cultivar, packaging materials and storage time at 20 °C on volatile compounds in tea processed by gentle air-drying of flowers from the black elder cultivars Sampo, Sambu and Samyl was determined. Elderflower tea samples packed in bags of paper at normal pressure and in bags of plastic and aluminium at 99% vacuum were stored for up to 21 months and investigated for volatile compounds. Volatile compounds emitted from elderflower tea samples were collected by dynamic Headspace Technique (purge and trap) and analysed by GC–FID and GC–MS. A total of 56 volatile compounds were identified and quantified, including 10 aldehydes, 7 ketones, 21 alcohols, 1 phenol, 3 esters, 4 heterocycles, and 8 hydrocarbons being derivatives of fatty acids, amino acids, shikimic acid and/or of terpenoid origin. Packaging material and storage time had a significant effect on the content of volatile compounds and 15 volatile compounds disappeared partially or completely during processing and/or storage. Tea processed from flowers of the cultivars Sampo and Sambu and packed in plastic and aluminium bags had a satisfactory flavour and content of volatile compounds at least up to 3 months or more after processing, whereas all tea samples processed from Samyl had an unpleasant grassy off-flavour. The content of important volatile compounds with grassy notes such as hexanal, heptanal, and (Z)-3-hexen-l-ol were at the same level in all cultivars. However, the content of important elderflower volatiles with flowery, fruity and/or sweet notes such as linalool, hotrienol, and cis- and trans-rose oxide were significantly lower in Samyl compared to Sampo and Sambu, which to some extent may explain the differences in tea flavour between the stored elderflower tea samples.
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analysis of aroma compounds from carrots by dynamic Headspace Technique using different purging and cutting methods
Developments in food science, 2006Co-Authors: Stine Kreutzmann, Lars Porskjaer Christensen, Merete Edelenbos, Anette Kistrup Thybo, Mikael Agerlin PetersenAbstract:Abstract The aim of the present study was to evaluate which purging and cutting method that gives the best relationship between sensory quality and the release of carrot volatiles. Volatile compounds from carrots (cv. Eskimo and cv. Nairobi) were collected from shreds and half-moon cuttings by dynamic Headspace sampling using dry (no water added) and wet purging (water added and blended). Headspace samples were analysed by GC-MS. Monoterpenes, sesquiterpenes and irregular terpenes accounted for more than 98% of the total mass of the volatiles. Dry purging had a significant effect on the total volatile mass compared to wet purging, resulting in higher Headspace concentrations of major volatile compounds. However, sensory analysis revealed that there were no significant differences between the sensory scores for the used descriptors.
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changes in volatile compounds of carrots daucus carota l during refrigerated and frozen storage
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Frank Kjeldsen, Lars Porskjaer Christensen, Merete EdelenbosAbstract:Carrots (Daucus carota L.) of cv. Bolero and cv. Carlo were processed into shreds and stored for up to 4 months at −24 °C (frozen storage), or the roots were stored for up to 4 months at 1 °C (refrigerated storage) followed by processing into shreds. Volatiles from the carrot shreds were collected by dynamic Headspace Technique and analyzed by GC-FID, GC-MS, GC-MS/MS, and GC-O to determine the volatile composition and aroma active components of carrots stored under different temperature conditions. A total of 52 compounds were quantified, of which mono- and sesquiterpenes accounted for ∼99% of the total volatile mass. Major volatile compounds were (−)-α-pinene, β-myrcene, (−)-limonene, (+)-limonene, (+)-sabinene, γ-terpinene, p-cymene, terpinolene, β-caryophyllene, α-humulene, and (E)- and (Z)-γ-bisabolene. A considerable increase in the concentration of mono- and sesquiterpenes was observed during refrigerated storage, whereas the concentration of terpenoids was around the same level during frozen storag...
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olfactory and quantitative analysis of volatiles in elderberry sambucus nigra l juice processed from seven cultivars
Journal of the Science of Food and Agriculture, 2001Co-Authors: Karina Jensen, Lars Porskjaer Christensen, Merete Hansen, Ulla Jorgensen, Karl KaackAbstract:Aroma compounds emitted from elderberry juices processed from seven cultivars were collected by the dynamic Headspace Technique and analysed by GC–FID and GC–MS. Forty aroma compounds were identified and quantified, including nine compounds which had not previously been detected in elderberry juice. Significant differences were found among cultivars in the concentration levels of 30 compounds. The sensory characteristics of the individual aroma compounds in elderberry juice were determined by a GC-sniffing Technique, and the compounds were grouped according to their odour. The characteristic elderberry odour is due to dihydroedulan and β-damascenone, of which the former occurs in relatively high concentrations in the Headspace of elderberry juice. The fruity group consisted of aliphatic alcohols and aldehydes and aromatic esters, of which 1-pentanal, 2-methyl-1-propanol, 2- and 3-methyl-1-butanol, 1-octanal, 1-octanol and methyl and ethyl benzoate contributed with fruity notes. In the flowery group, 1-nonanal, nerol oxide and (Z)- and (E)-rose oxide contributed with characteristic elder flower odour, whereas other flowery notes were associated with hotrienol, linalool and α-terpineol. Fresh and grassy odours were correlated with 1-hexanal, (E)-2-hexen-1-al, (Z)-3-hexen-1-ol, (E)-2-hexen-1-ol and (E)-2-octen-1-al of the grassy group, whereas 1-octen-3-ol and 1-octen-3-one of the agrestic group contributed significantly with the characteristic aroma of mushrooms. © 2000 Society of Chemical Industry
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olfactory and quantitative analysis of aroma compounds in elder flower sambucus nigra l drink processed from five cultivars
Journal of Agricultural and Food Chemistry, 2000Co-Authors: Ulla Jorgensen, Karina Jensen, Lars Porskjaer Christensen, Merete Hansen, Karl KaackAbstract:Fresh elder flowers (Sambucus nigra L.) were extracted with an aqueous solution containing sucrose, peeled lemon slices, tartaric acid, and sodium benzoate to make elder flower syrup. Aroma compounds emitted from the elder flower syrup were collected by the dynamic Headspace Technique and analyzed by GC−FID and GC−MS. A total of 59 compounds were identified, 18 of which have not previously been detected in elder flower products. The concentrations of the identified volatiles were measured in five elder cultivars, Allesoe, Donau, Sambu, Sampo, and Samyl, and significant differences were detected among cultivars in the concentration levels of 48 compounds. The odor of the volatiles was evaluated by the GC-sniffing Technique. cis-Rose oxide, nerol oxide, hotrienol, and nonanal contributed to the characteristic elder flower odor, whereas linalool, α-terpineol, 4-methyl-3-penten-2-one, and (Z)-β-ocimene contributed with floral notes. Fruity odors were associated with pentanal, heptanal, and β-damascenone. Fres...
Alcilene Rodrigues Monteiro - One of the best experts on this subject based on the ideXlab platform.
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volatile and non volatile chemical composition of the white guava fruit psidium guajava at different stages of maturity
Food Chemistry, 2007Co-Authors: Flavio Diniz Soares, Talita Pereira, Marcia Ortiz Maio Marques, Alcilene Rodrigues MonteiroAbstract:Abstract The effect of the maturation stages on the chemical composition and volatile compounds of the white Guava ( Psidium guajava ) Cv. Cortibel was investigated during three different stages. The stages were characterized by evolution of color, pH, titratable acidity, sugars, soluble solids, vitamin C and volatile components. The fruits were stored at 24 °C and air humidity of 74% for 13 days. The volatile extracts were obtained using Headspace Technique and analyzed using gas chromatograph/mass spectrometry (GC/MS) system. The titratable acidity and sugars decreased. The pH level and amount of vitamin C increased throughout progress of maturation. The behavior of volatile compounds of fruits in the three stages of maturation was: in immature fruits and those in their intermediate stage of maturation, were predominantly the aldehydes such as ( E )-2-hexenal and ( Z )-3-hexenal. In mature fruits, esters like Z -3-hexenyl acetate and E -3-hexenyl acetate and sesquiterpenes caryophyllene, α-humulene and β-bisabollene are present.
A Monteiro - One of the best experts on this subject based on the ideXlab platform.
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volatile and non volatile chemical composition of the white guava fruit psidium guajava at different stages of maturity
Food Chemistry, 2007Co-Authors: Flavio Diniz Soares, Talita Pereira, Marcia Ortiz Maio Marques, A MonteiroAbstract:Abstract The effect of the maturation stages on the chemical composition and volatile compounds of the white Guava ( Psidium guajava ) Cv. Cortibel was investigated during three different stages. The stages were characterized by evolution of color, pH, titratable acidity, sugars, soluble solids, vitamin C and volatile components. The fruits were stored at 24 °C and air humidity of 74% for 13 days. The volatile extracts were obtained using Headspace Technique and analyzed using gas chromatograph/mass spectrometry (GC/MS) system. The titratable acidity and sugars decreased. The pH level and amount of vitamin C increased throughout progress of maturation. The behavior of volatile compounds of fruits in the three stages of maturation was: in immature fruits and those in their intermediate stage of maturation, were predominantly the aldehydes such as ( E )-2-hexenal and ( Z )-3-hexenal. In mature fruits, esters like Z -3-hexenyl acetate and E -3-hexenyl acetate and sesquiterpenes caryophyllene, α-humulene and β-bisabollene are present.
Talita Pereira - One of the best experts on this subject based on the ideXlab platform.
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volatile and non volatile chemical composition of the white guava fruit psidium guajava at different stages of maturity
Food Chemistry, 2007Co-Authors: Flavio Diniz Soares, Talita Pereira, Marcia Ortiz Maio Marques, A MonteiroAbstract:Abstract The effect of the maturation stages on the chemical composition and volatile compounds of the white Guava ( Psidium guajava ) Cv. Cortibel was investigated during three different stages. The stages were characterized by evolution of color, pH, titratable acidity, sugars, soluble solids, vitamin C and volatile components. The fruits were stored at 24 °C and air humidity of 74% for 13 days. The volatile extracts were obtained using Headspace Technique and analyzed using gas chromatograph/mass spectrometry (GC/MS) system. The titratable acidity and sugars decreased. The pH level and amount of vitamin C increased throughout progress of maturation. The behavior of volatile compounds of fruits in the three stages of maturation was: in immature fruits and those in their intermediate stage of maturation, were predominantly the aldehydes such as ( E )-2-hexenal and ( Z )-3-hexenal. In mature fruits, esters like Z -3-hexenyl acetate and E -3-hexenyl acetate and sesquiterpenes caryophyllene, α-humulene and β-bisabollene are present.
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volatile and non volatile chemical composition of the white guava fruit psidium guajava at different stages of maturity
Food Chemistry, 2007Co-Authors: Flavio Diniz Soares, Talita Pereira, Marcia Ortiz Maio Marques, Alcilene Rodrigues MonteiroAbstract:Abstract The effect of the maturation stages on the chemical composition and volatile compounds of the white Guava ( Psidium guajava ) Cv. Cortibel was investigated during three different stages. The stages were characterized by evolution of color, pH, titratable acidity, sugars, soluble solids, vitamin C and volatile components. The fruits were stored at 24 °C and air humidity of 74% for 13 days. The volatile extracts were obtained using Headspace Technique and analyzed using gas chromatograph/mass spectrometry (GC/MS) system. The titratable acidity and sugars decreased. The pH level and amount of vitamin C increased throughout progress of maturation. The behavior of volatile compounds of fruits in the three stages of maturation was: in immature fruits and those in their intermediate stage of maturation, were predominantly the aldehydes such as ( E )-2-hexenal and ( Z )-3-hexenal. In mature fruits, esters like Z -3-hexenyl acetate and E -3-hexenyl acetate and sesquiterpenes caryophyllene, α-humulene and β-bisabollene are present.
