Pinhão and corn starches are submitted to phosphating with sodium tripolyphosphate and their prop... more Pinhão and corn starches are submitted to phosphating with sodium tripolyphosphate and their properties are evaluated by thermogravimetry, differential scanning calorimetry, viscoamylography, X‐ray powder diffractometry, field emission gun‐scanning electron microscopy analysis. The phosphating process is divided into three steps to analyse the behaviour of the sample on exposure to phosphate groups. After the modification, there is a decrease in the transition temperatures and gelatinisation enthalpy of both starches. During the three phases of phosphating, small differences are observed in the thermal stability of the modified samples, but a lower value is obtained for corn starch after the third stage. The decrease in pasting temperature is accompanied by an increase in the peak viscosity of the starch suspensions, however, higher values for setback and breakdown are also recorded. The degree of relative crystallinity of the phosphated starches increases, and from microscopy it is possible to observe the presence of crystals of sodium tripolyphosphate during phosphating process.
Durante a producao de suco de maracuja ( Passiflora edulis ) e gerada grande quantidade de residu... more Durante a producao de suco de maracuja ( Passiflora edulis ) e gerada grande quantidade de residuos orgânicos, potencialmente utilizaveis como materia-prima na obtencao de coprodutos com aplicacao tecnologica e funcional na industria alimenticia. O objetivo deste estudo foi verificar a viabilidade de aplicacao da pectina extraida do albedo do maracuja como agente estabilizante em sorvetes convencionais. Para a realizacao deste trabalho a pectina foi extraida com acido nitrico, seguida de precipitacao etanolica e desidratacao em estufa a 40 oC. Foram preparadas sete amostras de sorvete, uma convencional (controle), tres com adicao de pectina e tres com reducao do percentual de gordura vegetal hidrogenada associado ao uso de pectina. Foram utilizadas pectinas comerciais de alta e de baixa metoxilacao, bem como a pectina extraida do maracuja nas formulacoes. Foram realizadas analises de viscosidade cinematica, incorporacao de ar ( overrun ) e do comportamento de derretimento em cada um...
Publicatio Uepg - Ciencias Exatas E Da Terra, Agrarias E Engenharias, 2005
A termogravimetria (TG) e a calorimetria exploratoria diferencial (DSC) sao tecnicas importantes,... more A termogravimetria (TG) e a calorimetria exploratoria diferencial (DSC) sao tecnicas importantes, e sao atualmente empregadas em pesquisa e controle de qualidade na area de alimentos. Neste estudo, atraves das tecnicas termoanaliticas TG e DSC bem como da espectroscopia de absorcao na regiao do infravermelho (FT-IR) e analises quimicas qualitativas e quantitativas, foram comparadas diferentes amostras comerciais de sacarina com um padrao, cujas perdas de massa e transformacoes fisicas e/ou quimicas foram acompanhadas pelas tecnicas citadas. Palavras-chave: TG, DSC, pureza, qualidade
A semente de pinhão, cultivada na região Sul do Brasil, é uma fonte não convencional de amido, se... more A semente de pinhão, cultivada na região Sul do Brasil, é uma fonte não convencional de amido, sendo esta uma alternativa para a minimização da exploração indevida das araucárias, espécie ameaçada de extinção. Assim, o objetivo deste estudo foi extrair e caracterizar o amido de pinhões cultivados em quatro cidades da região sul do Brasil (Bento Gonçalves, Colombo, Lages e Mafra). O amido foi extraído de maneira aquosa e caracterizado por meio de termogravimetria, calorimetria exploratória diferencial, análise viscoamilográfica, difratometria de raios X pelo método de pó e microscopia eletrônica de varredura. A partir da termogravimetria, observaram-se três perdas de massa, comuns a todas as amostras, e o amido de pinhões cultivados em Bento Gonçalves (RS) apresentou a maior estabilidade térmica. Já, por calorimetria foi identificado que o amido de pinhões colhidos em Mafra (SC) apresentou maiores temperaturas e entalpia de gelatinização. O amido de pinhões de Lages (SC) mostrou a ma...
Maize is the most important source of starch used for industrial applications. Its starch propert... more Maize is the most important source of starch used for industrial applications. Its starch properties can be improved by either single or double modification. Heat–moisture treatment (HMT) and acid modification are known to promote an increase in the levels of slowly digestible starch and resistant starch (RS). In this study, maize starch was treated by conventional HMT (with deionised water) using different organic acids (lactic, citric and acetic). The thermal, structural and pasting properties, morphology and digestibility were evaluated and compared to the native starch. The enthalpy of the native maize starch ranged from 10.30 to 8.78 J g −1 after heat treatment with acetic acid. The starches treated by HMT using lactic and citric acids did not show gelatinisation peaks. The relative crystallinity also decreased after acid–heat treatment, while conventional HMT did not present significant difference in relation to the native starch. The peak viscosity for the native starch was 1,805.5 mPa s. After HMT with acetic and lactic acid, this figure was 969.5 and 41.5 mPa s, respectively. The treated maize starch by HMT with citric acid did not show viscosity peaks in the RVA profile. The morphology of the starches was not strongly affected by acid–heat treatment. HMT increased the RS content; the treatments with lactic and citric acid produced the highest values, with a fivefold increase in relation to the native maize starch (8.45%). The results indicate a possible application for acid–heat treatment starches in functional foods with reduced viscosity.
In the previous study, the effect of chemical modification with sodium tripolyphosphate on the pr... more In the previous study, the effect of chemical modification with sodium tripolyphosphate on the properties of corn and pinhão starches was evaluated. However, physical modifications also confer specific characteristics on the starch, diversifying its application. Thus, in this study, thermal (thermogravimetry [TG], differential exploratory calorimetry [DSC]), structural (X‐ray powder diffractometry [XRD], Fourier‐transform infrared [FTIR]) and morphological (field emission gun‐scanning electron microscopy) properties of native and phosphated corn and pinhão starches are evaluated before and after ball milling treatment. In addition, wavelength dispersive X‐ray spectroscopy is applied as a new technique to measure the level of phosphorus and sodium. The incorporation of phosphate groups in starches is confirmed and phosphorus and sodium are reduced after milling. The doubly modified starches show lower moisture retention capacity and lower thermal stability. All treatments reduce the ...
Pinhão and corn starches are submitted to phosphating with sodium tripolyphosphate and their prop... more Pinhão and corn starches are submitted to phosphating with sodium tripolyphosphate and their properties are evaluated by thermogravimetry, differential scanning calorimetry, viscoamylography, X‐ray powder diffractometry, field emission gun‐scanning electron microscopy analysis. The phosphating process is divided into three steps to analyse the behaviour of the sample on exposure to phosphate groups. After the modification, there is a decrease in the transition temperatures and gelatinisation enthalpy of both starches. During the three phases of phosphating, small differences are observed in the thermal stability of the modified samples, but a lower value is obtained for corn starch after the third stage. The decrease in pasting temperature is accompanied by an increase in the peak viscosity of the starch suspensions, however, higher values for setback and breakdown are also recorded. The degree of relative crystallinity of the phosphated starches increases, and from microscopy it is...
– Inventado pelos chineses 250 a.C e atualmente definido como produto alimenticio, o sorvete agre... more – Inventado pelos chineses 250 a.C e atualmente definido como produto alimenticio, o sorvete agrega valor nutricional a dieta alimentar. Porem, o alto valor calorico de produtos providos de leite e gordura, alavancou o avanco da tecnologia pela industria alimenticia, proporcionando alternativas a elaboracao de alimentos mais saudaveis e ao reaproveitamento de residuos. Tendo em vista estes aspectos, o estudo teve como objetivo a elaboracao de um sorvete com teor reduzido de gordura, substituindo-a parcialmente por pectina extraida de residuos de maracuja como agente estabilizante. Para a realizacao deste trabalho foram preparadas quatro amostras de sorvete, uma com a formulacao base de aplicacao nos sorvetes convencionais, tres diferindo no percentual de gordura vegetal hidrogenada em relacao a de pectina. Foram utilizadas pectinas comerciais de alta e de baixa metoxilacao, bem como a pectina extraida do maracuja nas formulacoes. Analises de viscosidade cinematica, incorporacao de ar (overrun) e do comportamento de derretimento foram realizadas em cada uma das quatro diferentes amostras. Os resultados das analises mostraram que de modo geral, o emprego da pectina em conjunto a reducao no teor de gordura proporcionou ao sorvete melhor aeracao, aumento da viscosidade e melhor estabilidade durante o derretimento.
Unprocessed native starches are structurally too weak and functionally too restricted for applica... more Unprocessed native starches are structurally too weak and functionally too restricted for application in today's advanced food technologies. Processing is necessary to engender a range of functionality. Naturals or natives starches can be modified by using several methods physical, chemical, enzymatic or combined, according industrial purposes. In this work, native corn starch was hydrolyzed by hydrochloric acid solution and investigated by using thermoanalytical techniques (thermogravimetry - TG, differential thermal analysis - DTA and differential scanning calorimetry - DSC), as well as optical microscopy and X-ray diffractometry. After acid treatment at 30 and 50°C, a decrease of gelatinization enthalpy (ΔHgel) was verified. Optical microscopy and X-ray diffractometry allowed us to verify the granules contorn and rugosity typical of cereal starches.
Pinhão and corn starches are submitted to phosphating with sodium tripolyphosphate and their prop... more Pinhão and corn starches are submitted to phosphating with sodium tripolyphosphate and their properties are evaluated by thermogravimetry, differential scanning calorimetry, viscoamylography, X‐ray powder diffractometry, field emission gun‐scanning electron microscopy analysis. The phosphating process is divided into three steps to analyse the behaviour of the sample on exposure to phosphate groups. After the modification, there is a decrease in the transition temperatures and gelatinisation enthalpy of both starches. During the three phases of phosphating, small differences are observed in the thermal stability of the modified samples, but a lower value is obtained for corn starch after the third stage. The decrease in pasting temperature is accompanied by an increase in the peak viscosity of the starch suspensions, however, higher values for setback and breakdown are also recorded. The degree of relative crystallinity of the phosphated starches increases, and from microscopy it is possible to observe the presence of crystals of sodium tripolyphosphate during phosphating process.
Durante a producao de suco de maracuja ( Passiflora edulis ) e gerada grande quantidade de residu... more Durante a producao de suco de maracuja ( Passiflora edulis ) e gerada grande quantidade de residuos orgânicos, potencialmente utilizaveis como materia-prima na obtencao de coprodutos com aplicacao tecnologica e funcional na industria alimenticia. O objetivo deste estudo foi verificar a viabilidade de aplicacao da pectina extraida do albedo do maracuja como agente estabilizante em sorvetes convencionais. Para a realizacao deste trabalho a pectina foi extraida com acido nitrico, seguida de precipitacao etanolica e desidratacao em estufa a 40 oC. Foram preparadas sete amostras de sorvete, uma convencional (controle), tres com adicao de pectina e tres com reducao do percentual de gordura vegetal hidrogenada associado ao uso de pectina. Foram utilizadas pectinas comerciais de alta e de baixa metoxilacao, bem como a pectina extraida do maracuja nas formulacoes. Foram realizadas analises de viscosidade cinematica, incorporacao de ar ( overrun ) e do comportamento de derretimento em cada um...
Publicatio Uepg - Ciencias Exatas E Da Terra, Agrarias E Engenharias, 2005
A termogravimetria (TG) e a calorimetria exploratoria diferencial (DSC) sao tecnicas importantes,... more A termogravimetria (TG) e a calorimetria exploratoria diferencial (DSC) sao tecnicas importantes, e sao atualmente empregadas em pesquisa e controle de qualidade na area de alimentos. Neste estudo, atraves das tecnicas termoanaliticas TG e DSC bem como da espectroscopia de absorcao na regiao do infravermelho (FT-IR) e analises quimicas qualitativas e quantitativas, foram comparadas diferentes amostras comerciais de sacarina com um padrao, cujas perdas de massa e transformacoes fisicas e/ou quimicas foram acompanhadas pelas tecnicas citadas. Palavras-chave: TG, DSC, pureza, qualidade
A semente de pinhão, cultivada na região Sul do Brasil, é uma fonte não convencional de amido, se... more A semente de pinhão, cultivada na região Sul do Brasil, é uma fonte não convencional de amido, sendo esta uma alternativa para a minimização da exploração indevida das araucárias, espécie ameaçada de extinção. Assim, o objetivo deste estudo foi extrair e caracterizar o amido de pinhões cultivados em quatro cidades da região sul do Brasil (Bento Gonçalves, Colombo, Lages e Mafra). O amido foi extraído de maneira aquosa e caracterizado por meio de termogravimetria, calorimetria exploratória diferencial, análise viscoamilográfica, difratometria de raios X pelo método de pó e microscopia eletrônica de varredura. A partir da termogravimetria, observaram-se três perdas de massa, comuns a todas as amostras, e o amido de pinhões cultivados em Bento Gonçalves (RS) apresentou a maior estabilidade térmica. Já, por calorimetria foi identificado que o amido de pinhões colhidos em Mafra (SC) apresentou maiores temperaturas e entalpia de gelatinização. O amido de pinhões de Lages (SC) mostrou a ma...
Maize is the most important source of starch used for industrial applications. Its starch propert... more Maize is the most important source of starch used for industrial applications. Its starch properties can be improved by either single or double modification. Heat–moisture treatment (HMT) and acid modification are known to promote an increase in the levels of slowly digestible starch and resistant starch (RS). In this study, maize starch was treated by conventional HMT (with deionised water) using different organic acids (lactic, citric and acetic). The thermal, structural and pasting properties, morphology and digestibility were evaluated and compared to the native starch. The enthalpy of the native maize starch ranged from 10.30 to 8.78 J g −1 after heat treatment with acetic acid. The starches treated by HMT using lactic and citric acids did not show gelatinisation peaks. The relative crystallinity also decreased after acid–heat treatment, while conventional HMT did not present significant difference in relation to the native starch. The peak viscosity for the native starch was 1,805.5 mPa s. After HMT with acetic and lactic acid, this figure was 969.5 and 41.5 mPa s, respectively. The treated maize starch by HMT with citric acid did not show viscosity peaks in the RVA profile. The morphology of the starches was not strongly affected by acid–heat treatment. HMT increased the RS content; the treatments with lactic and citric acid produced the highest values, with a fivefold increase in relation to the native maize starch (8.45%). The results indicate a possible application for acid–heat treatment starches in functional foods with reduced viscosity.
In the previous study, the effect of chemical modification with sodium tripolyphosphate on the pr... more In the previous study, the effect of chemical modification with sodium tripolyphosphate on the properties of corn and pinhão starches was evaluated. However, physical modifications also confer specific characteristics on the starch, diversifying its application. Thus, in this study, thermal (thermogravimetry [TG], differential exploratory calorimetry [DSC]), structural (X‐ray powder diffractometry [XRD], Fourier‐transform infrared [FTIR]) and morphological (field emission gun‐scanning electron microscopy) properties of native and phosphated corn and pinhão starches are evaluated before and after ball milling treatment. In addition, wavelength dispersive X‐ray spectroscopy is applied as a new technique to measure the level of phosphorus and sodium. The incorporation of phosphate groups in starches is confirmed and phosphorus and sodium are reduced after milling. The doubly modified starches show lower moisture retention capacity and lower thermal stability. All treatments reduce the ...
Pinhão and corn starches are submitted to phosphating with sodium tripolyphosphate and their prop... more Pinhão and corn starches are submitted to phosphating with sodium tripolyphosphate and their properties are evaluated by thermogravimetry, differential scanning calorimetry, viscoamylography, X‐ray powder diffractometry, field emission gun‐scanning electron microscopy analysis. The phosphating process is divided into three steps to analyse the behaviour of the sample on exposure to phosphate groups. After the modification, there is a decrease in the transition temperatures and gelatinisation enthalpy of both starches. During the three phases of phosphating, small differences are observed in the thermal stability of the modified samples, but a lower value is obtained for corn starch after the third stage. The decrease in pasting temperature is accompanied by an increase in the peak viscosity of the starch suspensions, however, higher values for setback and breakdown are also recorded. The degree of relative crystallinity of the phosphated starches increases, and from microscopy it is...
– Inventado pelos chineses 250 a.C e atualmente definido como produto alimenticio, o sorvete agre... more – Inventado pelos chineses 250 a.C e atualmente definido como produto alimenticio, o sorvete agrega valor nutricional a dieta alimentar. Porem, o alto valor calorico de produtos providos de leite e gordura, alavancou o avanco da tecnologia pela industria alimenticia, proporcionando alternativas a elaboracao de alimentos mais saudaveis e ao reaproveitamento de residuos. Tendo em vista estes aspectos, o estudo teve como objetivo a elaboracao de um sorvete com teor reduzido de gordura, substituindo-a parcialmente por pectina extraida de residuos de maracuja como agente estabilizante. Para a realizacao deste trabalho foram preparadas quatro amostras de sorvete, uma com a formulacao base de aplicacao nos sorvetes convencionais, tres diferindo no percentual de gordura vegetal hidrogenada em relacao a de pectina. Foram utilizadas pectinas comerciais de alta e de baixa metoxilacao, bem como a pectina extraida do maracuja nas formulacoes. Analises de viscosidade cinematica, incorporacao de ar (overrun) e do comportamento de derretimento foram realizadas em cada uma das quatro diferentes amostras. Os resultados das analises mostraram que de modo geral, o emprego da pectina em conjunto a reducao no teor de gordura proporcionou ao sorvete melhor aeracao, aumento da viscosidade e melhor estabilidade durante o derretimento.
Unprocessed native starches are structurally too weak and functionally too restricted for applica... more Unprocessed native starches are structurally too weak and functionally too restricted for application in today's advanced food technologies. Processing is necessary to engender a range of functionality. Naturals or natives starches can be modified by using several methods physical, chemical, enzymatic or combined, according industrial purposes. In this work, native corn starch was hydrolyzed by hydrochloric acid solution and investigated by using thermoanalytical techniques (thermogravimetry - TG, differential thermal analysis - DTA and differential scanning calorimetry - DSC), as well as optical microscopy and X-ray diffractometry. After acid treatment at 30 and 50°C, a decrease of gelatinization enthalpy (ΔHgel) was verified. Optical microscopy and X-ray diffractometry allowed us to verify the granules contorn and rugosity typical of cereal starches.
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