Formación de almidón retrogradado relacionado a niveles de amilosa en el almidón de papa (Solanum tuberosum) y chuño / Retrograded starch formation dependent on amylose level of potatoe starch (Solanum tuberosum) and chuño

INTRODUCCIÓN: la papa es el tubérculo más importante producido a nivel mundial como producto alimenticio. Una de las formas ancestrales de conservación de la papa en los países andinos es la obtención de un producto llamado chuño, obtenido a partir de las denominadas papas amargas. Existen pocos datos respecto a la composición química y nutricional del chuño y sobre los cambios producidos en el almidón durante su elaboración en el proceso de congelado-secado en condiciones específicas de temperatura y exposición a rayos ultravioleta. OBJETIVO: el objetivo del trabajo fue realizar una revisión bibliográfica respecto a cambios producidos en la relación de amilosa y amilopectina, la composición de almidón aislado de papa y la modificación de las características de este almidón en el proceso de elaboración de chuño. METODOLOGÍA: La revisión bibliográfica se ha realizado con la recopilación de tres fuentes referenciales de estudios realizados sobre el chuño y su proceso de elaboración, artículos sobre la estructura del almidón de papa y otros tubérculos del mismo género, artículos de otros productos alimenticios del Altiplano boliviano y peruano, y finalmente la influencia de los cambios de la estructura del almidón en el incremento de la formación de almidón retrogradado. RESULTADOS: la revisión bibliográfica realizada, señala que el proceso de elaboración de chuño eleva el porcentaje de amilosa en el contenido total de almidón, lo cual está relacionado a procesos de exposición a radiación UV y a cambios de temperaturas muy drásticos, que van entre -13,5 ºC y 16 ºC. Este proceso llevaría a la activación de enzimas, como amilasas, para la catálisis de reacciones de ruptura de enlaces como principal ruta del proceso; sin embargo, se podrían evaluar otras causas. CONCLUSIONES: el mayor porcentaje de amilosa permitiría la obtención de altos porcentajes de almidón retrogradado.

INTRODUCTION: the potato is the most important tuber produced worldwide as a food product. One of the ancestral ways of preserving pootatoes in the Andean countries is a product called chuño (traditional Andean freeze and sun-dried potato), obtained from the so-called bitter potatoes. There are few data regarding the chemical and nutritional composition of chuño and the changes produced in the starch during its preparation in the freeze-drying process under specific conditions of temperature and exposure to ultraviolet rays. OBJECTIVE: the objective of this article was to do a bibliographic review regarding changes produced in the amylose and amylopectin ratio, the composition of isolated potato starch and the modification of the characteristics of this starch in the process of making chuño. METHODOLOGY: the literature review methodology has the compilation of three reference sources of studies carried out on chuño and its production process, articles about the structure of potato starch and other tubers, research on other food products from the Bolivian and Peruvian of Altiplano and finally the influence of the changes in starch structure in relation to the increasing of retrograde starch formation. RESULTS: the results show that the process of making chuño increases the percentage of amylose in the total starch content, which is related to the processes of exposure to UV radiation and very drastic temperature changes, ranging between -13, 5 ºC and 16 ºC. This process would lead to the activation of enzymes, such as amylases, for the catalysis of bond breaking reactions as the main route of the process; however, other causes could be evaluated. CONCLUSIONS: the higher percentage of amylose would allow the obtaining of high percentages of retrograded starch.

Retrogradation of heat-gelatinized rice grain in sealed packaging: investigation of moisture relocation

Abstract The aggregation of water molecules inside heat-gelatinized rice grain due to retrogradation of the grain was investigated by textural change and scanning electron microscopy (SEM) analysis of cooked grains after storage at 11 °C in a sealed package. Relaxation tests using a disc-type tip showed an increase in hardness (strength) of the cooked grain as the degree of retrogradation increased with increasing storage time, measured by the α-amylase-iodine method. SEM analysis of the vacuum-dried cooked rice grain showed a gradual increase in crevices, which further developed into holes at the center of the granule with increasing storage time. The results suggest that the disruption of hydrogen bonds between water and starch molecules is the first step for the retrogradation of gelatinized rice grain stored in a hermetic environment to avoid drying, resulting in its increased hardness, followed by the aggregation of starch molecules with subsequent water extrusion.

Physicochemical Properties of Cassava Starch Retrograded in Alcohol.

Starch is an important excipient employed in the pharmaceutical industry but irrespective of its source, the native starch is undesirable for many applications because of its inability to withstand processing conditions and hence the need for it modification in order to improve its desired properties. The objective of this study was to extract, modify by retrogradation in alcohol and evaluate starch obtained from Manihot esculentum as a pharmaceutical excipient. The starch was extracted then modified by retrogradation using alcohol for a period of 0, 24, 48 and 96 hrs. The granular morphology, amylose and amylopectin fractions, ash value, true density, powder porosity, swelling capacity, hydration capacity, moisture sorption capacity, bulk density, tapped density, Carr’s index, Hausner’s ratio, angle of repose, X-ray diffractography, elemental and proximate analysis were used for the physicochemical characterizations and was subsequently compared with native Manihot esculentum starch. Starch obtained by retrogradation showed decrease in angle of repose, moisture sorption capacity, moisture content, water solubility index and showed increase swelling capacity, hydration capacity and crystallinity as compared to the native starch. In conclusion, retrograded starch showed better pharmaceutical potentials than the native starch as evident to its improved physicochemical properties.

Fibra de casca de laranja como substituto de gordura em pão de forma / Citrus peel fiber and its application as a fat substitute in loaf brad

Os subprodutos da indústria de frutas possuem alta qualidade nutricional, de forma que sua transformação em ingredientes para aplicação em produtos alimentícios é de grande importância. No presente estudo, foram avaliados os efeitos da substituição total da gordura em pães de forma através da utilização de fibra de casca de laranja (0 a 5%), um subproduto industrial. A adição da fibra de laranja foi combinada ao uso de α-amilase (10 a 50ppm), através de um planejamento experimental fatorial completo 22. Para fins de comparação, foi elaborada uma formulação controle, sem fibras, sem enzimas e com 2% de gordura. A qualidade dos pães foi avaliada através de análises de vida útil (por índice de retrogradação, DSC), volume, cor, atividade de água e análise sensorial. A fibra de laranja, associada ao uso de enzimas, contrapôs os possíveis efeitos negativos causados pela ausência da gordura, para as concentrações de fibra e enzima estudadas, permitindo a obtenção de pães isentos de gordura e com fibras. A presença de 2,5% de fibra de laranja combinada ao uso de 30ppm de α-amilase gerou um pão com volume 23% maior ao alcançado pela amostra controle e com índice de aceitação em torno de 80%.

Food industry byproducts have high nutritional quality, so that its transformation into ingredients for use in food products is of great importance. This study aimed to analyze the effects of total fat replacement in loaf bread, by adding orange peel fiber (0-5%), an industrial byproduct. The use of citrus fiber was combined with the addition of α -amylase (10 to 50ppm), by using a complete experimental factorial design (22). A formulation containing 2% of fat, without citrus fiber and enzyme was used as control. The breads quality was measured by analyzing shelf life (by Retrogradation Index determination), volume, crumb color, water activity and sensorial parameters. The citrus fiber in association with the addition of α-amylases neutralized the potential negative effects that the removal of fat could cause, considering the ranges of fiber and enzyme studied, allowing to obtain fat-free breads with fibers. The presence of 2.5% of citrus fiber combined with the use of 30ppm of α-amylase increased the volume of breads by 23%, comparing with the control formula, and had an acceptance index of around 80%.

Estrutura dos grânulos de amido e sua relação com propriedades físico-químicas: [revisão] / Starch granules structure and its regards with physicochemical properties: [review]

Devido aos escassos trabalhos brasileiros sobre a estrutura dos grânulos de amido, o objetivo desta revisão foi demonstrar os avanços atuais na elucidação da arquitetura e da estrutura química desse polímero. Muitas pesquisas sobre a avaliação da relação existente entre a estrutura molecular do amido e seu comportamento em algumas propriedades físico-químicas sugerem que diversas características estruturais, tais como teor de amilose, distribuição de comprimento das cadeias de amilopectina e grau de cristalinidade no grânulo, estejam intimamente relacionadas a eventos associados à gelatinização e retrogradação, como inchamento do grânulo, lixiviação de amilose e/ou amilopectina, perda da estrutura radial (birrefringência), supra-molecular (cristalinidade) e molecular e recristalização. O foco principal desta revisão foi a compilação de estudos a fim de obter melhor entendimento da estrutura e das características dos componentes do amido e sua relação com propriedades físico-químicas, principalmente no que diz respeito à gelatinização e retrogradação, as quais apresentam grande importância nutricional e tecnológica.

Due to poor Brazilians work on the structure of starch granules, the purpose of this review was to demonstrate the advances in current understanding of architecture and chemical structure of this polymer. Many studies evaluating the relationship between the molecular structure of starch and its behavior in some physicochemical properties, suggest that several structural features, such as amylose content, amylopectin chain length distribution and the degree of crystallinity in the granule, are closely related to the events associated with gelatinization and retrogradation as starch granule swelling, amylose and/or amylopectin leaching, loss of radial structure (birefringence), supra-molecular (crystallinity) and molecular order, and recrystallization. The main focus of this review was to make a compiler of studies in order to gain better understanding of the granule structure and characteristics of starch components and physicochemical properties (gelatinization and retrogradation) that could play a significant role in improving the quality of different food products.

Evaluación de l retrogradación del almidón en harina de yuca precocdda / Evaluatin of staarch retrogradation in cassava flour from precooked parenchyma / Avaliação a retrrogradação do amido em farinha de mandioca precozida

Las modificaciones del almidón, que ocurren durante el proceso de elaboración de harina de yuca precocida, se evaluaron utilizando técnicas como calorimetría diferencial de barrido (CDB), difracción de rayos X, comportamiento al empastamiento y capacidad de formación de complejo con yodo. La harina precocida se obtuvo a partir de trozos de parénquima de yuca cocinados en vapor o en agua a ebullición, los cuales fueron posteriormente almacenados a 5 ºC o a -20 ºC por 24 h. La temperatura utilizada durante el periodo de almacenamiento del parénquima cocinado no es un factor significativo en los resulta dos de retrogradación del almidón. La entalpía de fusión y cristalinidad del almidón retrogradado de la harina proveniente del parénquima cocinado en vapor fue ligeramente mayor, comparado con la elaborada a partir de parénquima cocinado en agua a ebullición para el periodo de almacenamiento a 5 ºC. Por otra parte, en el periodo de almacenamiento a -20ºC, el método de cocción no tuvo efecto significativo sobre la entalpía de fusión del almidón retrogradado, la cristalinidad y el índice del valor azul.

Starch modifications during the processing of precooked cassava flour was monitored using techniques as differential scanning calorimetry (DSC), pasting behaviour, wide angle X-ray diffraction and iodine binding capacity. Cassava flour was obtained from parenchyma pieces cooked either in steam or in boiling water and then stored either at 5 ºC or at -20 ºC for 24 h. The temperature during the rest period of the cooked parenchyma was not a significant factor in the starch retrogradation results. For a rest period at 5 ºC, flour from parenchyma cooked in steam presented a slightly higher melting enthalpy of retrograded starch and crystallinity as compared to that from parenchyma cooked in boiling water. Whereas for conditioning period at -20 ºC, the cooking method had no significant effect on the enthalpy of retrogradation, crystallinity and blue value index.

As modificações do amido durante o processo de elaboração de farinha de mandioca precozida, foram avaliadas utilizando as técnicas de calorimetria diferencial de varredura (CDV), difração de raios X, comportamento no empastamento e capacidade de formação de complexo de iodo. A farinha precozida obteve-se de troços do parênquima da mandioca cozidos com vapor o em água em ebulição, os quais foram armazenados depois a 5 ºC ou -20 ºC por 24 h . A temperatura do armazenamento do parênquima cozido no foi um factor significativo nos resulta dos de retrogradação do amido. A entalpia de fusão e cristalinidade do amido retrogradado da farinha proveniente do parênquima cozido no vapor foi levemente maior, do que aquela elaborada do parênquima cozido em água em ebulição e armazenada a 5 ºC. Além disso, o método de cozimento não teve efeito significativo na entalpia de fusão do amido retrogradado, na cristalinidade o no índice de valor azul (IVA).