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.

Efficient production of pullulan by Aureobasidium pullulans grown on mixtures of potato starch hydrolysate and sucrose

Abstract Pullulan is a natural exopolysaccharide with many useful characteristics. However, pullulan is more costly than other exopolysaccharides, which limits its effective application. The purpose of this study was to adopt a novel mixed-sugar strategy for maximizing pullulan production, mainly using potato starch hydrolysate as a low-cost substrate for liquid-state fermentation by Aureobasidium pullulans. Based on fermentation kinetics evaluation of pullulan production by A. pullulans 201253, the pullulan production rate of A. pullulans with mixtures of potato starch hydrolysate and sucrose (potato starch hydrolysate:sucrose = 80:20) was 0.212 h−1, which was significantly higher than those of potato starch hydrolysate alone (0.146 h−1) and mixtures of potato starch hydrolysate, glucose, and fructose (potato starch hydrolysate:glucose:fructose = 80:10:10, 0.166 h−1) with 100 g L−1 total carbon source. The results suggest that mixtures of potato starch hydrolysate and sucrose could promote pullulan synthesis and possibly that a small amount of sucrose stimulated the enzyme responsible for pullulan synthesis and promoted effective potato starch hydrolysate conversion effectively. Thus, mixed sugars in potato starch hydrolysate and sucrose fermentation might be a promising alternative for the economical production of pullulan.

Characterization and Optimization of Natural Maltodextrin-based Niosome.

Natural maltodextrin, due to their outstanding merits, have received more and more attention in the field of drug delivery systems. In particular, maltodextrin seem to be the most promising materials in the preparation of niosome carriers. This study aimed to optimize and characterize the formulation of natural maltodextrin-based niosome. The natural maltodextrin was made from cilembu sweet potato starch which used partial starch hydrolysis method by α-amylase enzyme. Proniosome and niosome formulations used three various concentration of surfactant (sorbitan monostearat) which about 5 mmol, 7.5 mmol, and 10 mmol for formula 1 (F1), formula 2 (F2), and Formula 3 (F3) respectively. In addition, physical and chemical characterizations had been done to characterize maltodextrin, proniosome, and niosome. The Dextrose Equivalent (DE) value of natural maltodextrin was 7.99+0.11. Furthermore, the vesicle size of proniosome was in the range of 5μ to 13μ. The entrapment percentages of piroxicam in niosome formulations were 72.5+1.1%,, 76+1.7 %, and 77.5+1.9 % for FI, F2 and F3 respectively. It can be concluded that the result provided an indication of natural maltodextrin from Cilembu sweet potato starch are potentialy carrier in the proniosome preparation which can be used for producing niosomes.

Formulation of Diclofenac Sodium tablets using Tapioca starch powder- A promising binder.

Formulation research is oriented towards increasing safety and efficacy of existing drug molecule through novel concepts of drug delivery. Diclofenac is a semi-synthetic NSAID used as analgesic and anti-inflammatory. An attempt was made to identify the use of a natural product tapioca starch as binding agent in the formulation of Diclofenac tablets. To establish two other commonly used disintegrating agents potato starch and maize starch were selected and formulated for comparison. Different formulations were prepared by using above three disintegrants in the concentration of 20mg per tablet. The tablets were prepared by wet granulation technique. All the formulations were subjected to in in-vitro evaluation and the results were compared. The formulation containing tapioca starch powder showed good dissolution characteristics, within the Pharmacopoeial limits and comparative to potato and maize starch.

Inmovilización de bacillus licheniformis y Saccharomyces cerevisiae para la producción de etanol a partir de almidón de papa / Inmobilization of bacillus licheniformis and Saccharomyces cerevisiae for ethanol production from potato starch

Se evaluó un sistema discontinuo secuencial compuesto por células de Bacillus licheniformis y Saccharomyces cerevisiae para producción de etanol, utilizando en la segunda fase del proceso, un hidrolizado de almidón de papa, obtenido con el uso de células de B. licheniformis. Ambos microorganismos fueron inmovilizados en matriz de alginato de calcio al 3,2 por ciento y 2,5 por ciento (p/v), observando que a estas concentraciones se retiene la mayor cantidad de células (26x106 y 10x107 UFC/g) y permite la difusión de los productos, obteniendo 3,3 g/L de azúcares reductores y 642 UA/L (unidades amilolíticas) para B. licheniformis y 0,866 por ciento (v/v) de etanol con S. cerevisiae. Mediante un diseño factorial 22 se seleccionaron las condiciones de operación a escala de reactor para la producción del hidrolizado, encontrando que al cultivar a B. licheniformis con 3 v.v.m. y 150 r.p.m. se produjeron 3,7 g/L de azúcares reductores y 669 UA/L a las 4 horas de proceso. El hidrolizado se caracterizó por cromatografía HPLC determinando que es rico en oligómeros, dextrinas y que tiene baja concentración de glucosa y maltosa. El uso del hidrolizado para la producción de etanol, generó porcentajes bajos (0,47por ciento y 0,74 por ciento v/v), tanto en células libres como inmovilizadas, respectivamente.

We evaluated a sequential discontinuous system composed by Bacillus licheniformis and Saccharomyces cerevisiae forethanol production. For the second phase of the process potato starch hydrolyzed were used, which was obtained from B. licheniformis cells. Both microorganisms were immobilized in a calcium alginate matrix of 3,2% and 2,5% (w/v), where was observed that these concentrations retained the majority of the cells (26x106 and 10x107 UFC/g) and alloweddissemination of its products, gaining 3.3 g/L of reducing sugars and 642 AU/L (units Amylolytic) for B. licheniformis and 0,866% (v/v) ethanol with S. cerevisiae. By means of a 22 factorial design were selected operating conditions at a reactor scale for production of hydrolyzed, finding that by cultivating B. licheniformis with 3 v.v.m. and 150 r.p.m. there were 3.7 g/L of reducing sugars and 669 AU/L after 4 hours of the process. The hydrolyzed was characterized using HPLC chromatography, which determined that it is rich in oligomers and dextrin, and it has low concentration of glucose andmaltose. The use of hydrolyzed for ethanol production, generated low percentages (0,47% and 0,74% v/v) in free and immobilized cells respectively.

Production and characterization of glucoamylase from fungus Aspergillus awamori expressed in yeast Saccharomyces cerevisiae using different carbon sources

Glucoamylase is widely used in the food industry to produce high glucose syrup, and also in fermentation processes for production beer and ethanol. In this work the productivity of the glucoamylase of Aspergillus awamori expressed by the yeast Saccharomyces cerevisiae, produced in submerged fermentation using different starches, was evaluated and characterized physico-chemically. The enzyme presented high specific activity, 13.8 U/mgprotein or 2.9 U/mgbiomass, after 48 h of fermentation using soluble starch as substrate. Glucoamylase presented optimum activity at temperature of 55ºC, and, in the substratum absence, the thermostability was for 1h at 50ºC. The optimum pH of activity was pH 3.5 - 4.0 and the pH stability between 5.0 and 7.0. The half life at 65ºC was at 30.2 min, and the thermal energy of denaturation was 234.3 KJ mol-1. The hydrolysis of different substrate showed the enzyme's preference for the substrate with a larger polymerization degree. The gelatinized corn starch was the substratum most susceptible to the enzymatic action.

A glucoamilase é amplamente utilizada na indústria de alimentos no processamento do amido para a produção de xarope com alto teor de glicose e também muito empregada nos processos de fermentação para produção de cerveja e etanol. Neste trabalho a glucoamilase de Aspergillus awamori expressa em Saccharomyces cerevisiae produzida sob fermentação líquida foi avaliada quanto à produtividade em diferentes amidos e caracterizada físico-quimicamente. A enzima apresentou alta atividade específica de 13,8 U/mg proteína e de 2,9 U/mg biomassa ao final de 48 h de fermentação em meio contendo amido solúvel. A glucoamilase apresentou temperatura ótima de atividade a 55ºC, e temperatura de desnaturação térmica na ausência de substrato por 1h a 50ºC. O pH ótimo de atividade foi na faixa de 3,5 - 4,0 e a estabilidade ao pH entre os valores 5,0 e 7,0. A meia vida a 65ºC foi 30,2 min., e a energia de desnaturação foi de 234.3 KJ mol-1. A hidrólise em diferentes substratos mostrou a preferência da enzima pelos substratos com maior grau de polimerização, sendo o amido de milho gelatinizado o substrato preferencial à ação enzimática.