Efeito de tratamentos enzimáticos e físico sobre a formação e características de amidos retrogradados
Carregando...
Data
2019-09-06
Autores
Villas-Boas, Flavia
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
Amido desramificado e retrogradado é resistente à ação das enzimas digestivas, sendo denominado amido resistente tipo 3 (AR3), enquanto amido lentamente digerido (ALD) é a fração digerida lentamente no intestino delgado resultando na liberação prolongada de glicose na corrente sanguínea. Ambos apresentam inúmeros benefícios à saúde, os quais têm sido amplamente relatados. O uso de diferentes técnicas que potencializem a formação do amido retrogradado conduz a diferentes características estruturais e físico-químicas do amido, bem como à sua digestibilidade. O presente trabalho teve como objetivo avaliar e comparar o efeito de diferentes tratamentos (enzimáticos e físico) precedendo a desramificação de amidos na formação de AR3 e ALD, bem como em suas características moleculares, cristalinas e físico-químicas. Para isso, amidos de batata-doce (SPS), mandioca (CAS) e milho com alto teor de amilose (HAS) foram submetidos à ação da α-amilase fúngica, α-amilase maltogênica, ou ultrassom em diferentes condições de tratamento. A cinética das hidrólises enzimáticas dos amidos foi estudada. Após tratamentos, os amidos foram desramificados com pululanase, autoclavados (121oC/30 min) e resfriados (4°C /24h) para potencializar a retrogradação. Os amidos modificados foram analisados quanto a digestibilidade in vitro e caracterizados estrutural e físico-quimicamente a partir de cromatografia de exclusão por tamanho de alta performance, difracção de raios-X, ressonância magnética do 13C, e calorimetria exploratória diferencial. Os dados de cinética de hidrólise foram bem ajustados para os modelos LOS e NLLS. O CAS foi o mais suscetível às enzimas, enquanto HAS, o mais resistente. Os tratamentos enzimáticos levaram à formação de até 65, 60,4 e 68% de AR3, enquanto o tratamento com ultrassom a teores de até 64,1, 62 e 69,5%, para SPS, CAS, e HAS, respectivamente. Ambos os tratamentos também levaram à formação de quantidades significativas de ALD. A redução do GP e proporção das cadeias longas da amilose aliada ao aumento na proporção de cadeias intermediárias (GP 13-30) potencializou a formação de AR3 cujo teor foi altamente correlacionado com a proporção de cadeias com GP 13-30, independentemente do amido ou tratamento. Para o HAS a força motriz na formação de AR3 foi a redução do GP das cadeias mais longas de amilose, enquanto para os amidos de raízes, a contribuição das cadeias intermediárias foi mais significativo. Altos coeficientes de correlação também foram encontrados entre AR3, cristalinidade relativa e mudança de entalpia (ΔH). Os amidos que tiveram maiores níveis de AR3 também tiveram maiores proporções de duplas hélices. Os resultados obtidos com este trabalho poderão nortear caminhos para o desenvolvimento de tecnologias viáveis para obtenção de amidos resistentes e sua aplicação em diferentes produtos alimentícios.
Debranched and retrograded starch is resistant to the action of digestive enzymes, being called resistant starch type 3 (RS3), while slowly digested starch (SDS) is the slowly digested fraction in the small intestine resulting in prolonged glucose release into the bloodstream. Both starches present numerous health benefits, which have been widely reported. The use of different techniques that enhance the formation of retrograded starch leads to different structural and physicochemical characteristics of starch, as well as its digestibility. The objective of the present work was to evaluate and compare the effect of different treatments (enzymatic and physical) preceding starch debranching on the formation of RS3 and SDS, as well as their molecular, crystalline and physicochemical characteristics. For this purpose, sweet potato (SPS), cassava (CAS), and high amylose maize (HAS) starches were subjected to the action of fungal α-amylase, maltogenic α-amylase, or ultrasound, under different treatment conditions. The enzymatic hydrolysis kinetic of the starches was studied. After the treatments, these starches were debranched with pullulanase, autoclaved (122°C/30 min), and cooled (4°C/24 h) in order to enhance the retrogradation. Modified starches were analysed regarding to in vitro digestibility and structurally characterized by high performance size exclusion chromatography, X-ray diffraction, 13C magnetic resonance, and differential scanning calorimetry. Hydrolysis kinetic data were well adjusted for the LOS and NLLS models. CAS was the most susceptible to enzymes, while HAS was the most resistant. Enzymatic treatments led to the formation of up to 65, 60.4 and 68% of RS3, while ultrasound treatment led to contents up to 64.1, 62 and 69.5% for SPS, CAS, and HAS, respectively. Both treatments also led to formation of significant amount of SDS. The DP reduction and amylose long chains proportion combined with the increase in intermediate chain amount (DP 13-30) potentiated RS3 formation, whose content was highly correlated with the proportion of DP 13-30 chains, regardless of starch or treatment. For HAS, the driving force in the formation of RS3 was the DP reduction of longer amylose chains, while for root starches the contribution of intermediate chains was more significant. High correlation coefficients were also found among RS3, crystallinity, and enthalpy change (ΔH). Starches that had higher levels of RS3 also had higher proportion of double helices. The results obtained with this work may guide ways for the development of viable technologies to obtain resistant starches and their application in different products.
Debranched and retrograded starch is resistant to the action of digestive enzymes, being called resistant starch type 3 (RS3), while slowly digested starch (SDS) is the slowly digested fraction in the small intestine resulting in prolonged glucose release into the bloodstream. Both starches present numerous health benefits, which have been widely reported. The use of different techniques that enhance the formation of retrograded starch leads to different structural and physicochemical characteristics of starch, as well as its digestibility. The objective of the present work was to evaluate and compare the effect of different treatments (enzymatic and physical) preceding starch debranching on the formation of RS3 and SDS, as well as their molecular, crystalline and physicochemical characteristics. For this purpose, sweet potato (SPS), cassava (CAS), and high amylose maize (HAS) starches were subjected to the action of fungal α-amylase, maltogenic α-amylase, or ultrasound, under different treatment conditions. The enzymatic hydrolysis kinetic of the starches was studied. After the treatments, these starches were debranched with pullulanase, autoclaved (122°C/30 min), and cooled (4°C/24 h) in order to enhance the retrogradation. Modified starches were analysed regarding to in vitro digestibility and structurally characterized by high performance size exclusion chromatography, X-ray diffraction, 13C magnetic resonance, and differential scanning calorimetry. Hydrolysis kinetic data were well adjusted for the LOS and NLLS models. CAS was the most susceptible to enzymes, while HAS was the most resistant. Enzymatic treatments led to the formation of up to 65, 60.4 and 68% of RS3, while ultrasound treatment led to contents up to 64.1, 62 and 69.5% for SPS, CAS, and HAS, respectively. Both treatments also led to formation of significant amount of SDS. The DP reduction and amylose long chains proportion combined with the increase in intermediate chain amount (DP 13-30) potentiated RS3 formation, whose content was highly correlated with the proportion of DP 13-30 chains, regardless of starch or treatment. For HAS, the driving force in the formation of RS3 was the DP reduction of longer amylose chains, while for root starches the contribution of intermediate chains was more significant. High correlation coefficients were also found among RS3, crystallinity, and enthalpy change (ΔH). Starches that had higher levels of RS3 also had higher proportion of double helices. The results obtained with this work may guide ways for the development of viable technologies to obtain resistant starches and their application in different products.
Descrição
Palavras-chave
Amido, Amilólise, Digestibilidade, Estruturas molecular e cristalina, Ultrassom, Starch, Amylolysis, Digestibility, Molecular and crystalline structures, Ultrasound