scholarly journals The physical, chemical and functional characterization of starches from Andean tubers: oca (Oxalis tuberosa Molina), olluco (Ullucus tuberosus Caldas) and mashua (Tropaeolum tuberosum Ruiz & Pavón)

2013 ◽  
Vol 49 (3) ◽  
pp. 453-464 ◽  
Author(s):  
Beatriz Valcárcel-Yamani ◽  
Gerby Giovanna Rondán-Sanabria ◽  
Flavio Finardi-Filho

The physical, chemical, and functional properties of starches isolated from the Andean tubers oca (Oxalis tuberosa M.), olluco (Ullucus tuberosus C.) and mashua (Tropaeolum tuberosum R. & P.) were studied. The tubers were obtained from a local grocery. The morphology of the starch granules (size and shape) was studied with scanning electron microscopy (SEM), which revealed ellipsoid, oval, conical, pear-shaped and prismatic forms: ellipsoids and oval granules with lengths up to 54.30 µm in oca; with lengths up to 32.09 µm for olluco starch granules; and with predominantly truncated spherical or oval forms and smaller dimensions (up to 16.29 um) for mashua starch granules. Amylose contents were similar among the samples: 27.60% (oca), 26.49% (olluco) and 27.44% (mashua). Olluco starch had less swelling power, forming opaque, less firm gels. All three starch gels showed the same stability on refrigeration and presented high syneresis under freezing temperatures, with a variation of 40.28 to 74.42% for olluco starch. The starches cooked easily, with high peak viscosity. The low gelatinization temperatures and high stability during cooling make these starches suitable feedstock for use in formulations that require milder processing temperatures and dispense freezing storage.

2017 ◽  
Vol 21 (2) ◽  
pp. 33-42
Author(s):  
Omar Bellido-Valencia ◽  
Paul K. Huanca-Zúñiga ◽  
Luis A. Medina-Marroquín

Abstract Andean grains (i.e. quinoa, amaranth) have been increasingly studied in recent times, mainly due to the increase in international consumption. However, Andean tubers other than potatoes have not been so widespread and are mainly studied for their starch, previously extracted. This work studied the morphology of native starch in four of these crops (oca, olluco, isaño and aracacha), during cooking and the evolution of their internal temperature in relation to sensory acceptability. Using scanning electron microscopy, it was determined that the size of crude starch granules was between 9 μm to 38.2 μm for oca, 4.48 to 24.9 μm for olluco, 4.45 to 22.9 μm for isaño, and 5.36 to 23.8 μm for arracacha. Sensorially, it was determined that the optimum cooking temperature for arracacha was 89.1°C, 90.9°C for oca, 91°C for isaño, and 91.4 °C for olluco. All samples had optimal cooking times shorter than potato, with the isaño having the best heat transfer.


Author(s):  
Cristian José Esparza Bonilla ◽  
Cesar Iván ◽  
Flores Mancheno ◽  
Tatiana Elizabeth Sánchez Herrera

The objective of this research was to analyze the bromatological and microbiological composition of Andean tubers, to determine whether their state of maturation influences their composition. Mashwa (Tropaeolum tuberosum) and oca (Oxalis tuberosa) tubers were analyzed. Different degrees of maturation (tender, ripe) were considered. In each analysis, three treatments were carried out, using 100g of sample. The data were analyzed through a two-factor analysis of variance with several samples per group. The average values obtained from the bromatological data of tender mashwa were: 12.33% protein, 0.87% fat, 5.17% ash and 6.41% moisture. The values for mature mashwa were: 15.27% protein, 1.00% fat, 6.74% ash and 5.85% moisture. For tender oca, the values were: 7.47% protein, 0.65% fat, 4.59% ash and 7.03% moisture. Finally, the values for mature oca were 8.92% protein, 0.64% fat, 5.40% ash and 6.03% moisture. In terms of the microbiological evaluation, a minimal presence of the following aerobic bacteria was observed: Stapylococus aureos, coliforms, Eschericha coli. The results showed that the microbiological values ​​for Andean tubers (mashwa and oca) were within the safe parameters, so the tubers are suitable for consumption. Keywords: bromatological, microbiological, Tropaeolum tuberosum, Oxalis tuberosa, maturation. RESUMEN El objetivo de esta investigación fue analizar la composición bromatológica, microbiológica, y determinar si el estado de maduración influye en la composición de los tubérculos andinos. Los tubérculos analizados, mashwa (Tropaeolum tuberosum) y oca (Oxalis tuberosa), donde se considero diferentes grados de maduración (tierno, maduro), en cada análisis se empleo 3 tratamientos utilizando 100g de muestra. Los datos fueron analizados mediante el programa Excel con un análisis de varianza de dos factores con varias muestras por grupo. El promedio obtenido en los datos bromatológicos de mashwa tierna son: proteína de 12,33%, grasa 0,87%, ceniza 5,17% y humedad 6,41%, mashwa madura 15,27% de proteína, 1,00% de grasa, 6,74% de ceniza y 5,85% de humedad, para la oca tierna en proteína de 7,47%, grasa 0,65%, ceniza 4,59% y humedad 7,03%, oca madura son de 8,92% de proteína, 0,64% de grasa, 5,40% de ceniza y 6,03% de humedad. En el caso de la evaluación microbiológica se observó la presencia mínima de Bacterias Aerobias, Stapylococus Áureos, Coliformes, Eschericha Coli. Determinando que los valores microbiológicos para los tubérculos andinos (mashwa, oca) se encuentran dentro de los parámetros por lo que están libres de patógenos y son aptos para el consumo. Palabras claves: bromatológico, microbiológico, Tropaeolum tuberosum, Oxalis tuberosa, maduración.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Dorota Gałkowska ◽  
Teresa Witczak ◽  
Jarosław Korus ◽  
Lesław Juszczak

The aim of this work was to analyze selected physical, chemical, thermal, and rheological properties of starches isolated from different spelt wheat varieties. The analyzed starches contained from 22.5 to 24.6 g/100 g of amylose and from 45.9 to 50.6 mg/100 g of phosphorus. Ranges of characteristic gelatinization temperatures, TO, TP, and TE, were 55.7–58.5°C, 61.1–62.6°C, and 67.4–68.2°C, respectively, while gelatinization enthalpy ranged from 8.87 to 9.96 J/g. The pasting curves showed significant differences in pasting characteristics of the starches. The values of maximum viscosity (ηmax) and viscosity after cooling (η50) determined for the starch pastes were in the range of 82.3–100.7 B.U. and 149.3–172.7 B.U., respectively. The starch pastes demonstrated non-Newtonian, shear thinning flow behaviour and thixotropy phenomenon. After cooling the resulting starch gels were characterized by different viscoelastic properties, with a dominance of elastic features (G′>G′′). The starches exhibited different tendency to retrogradation, with its degree (R=ΔHR/ΔHG) in the range of 21.1–37.4%.


Author(s):  
Paolino Ninfali ◽  
Anna Panato ◽  
Federica Bortolotti ◽  
Laura Valentini ◽  
Pietro Gobbi

This review focuses on the combination of optical microscopy (OM) and Environmental Scanning Electron Microscopy-Energy Dispersive Spectroscopy (ESEM-EDS) in the anatomical and functional characterization of the cereal caryopsis in order to drive the technology of transformation as well as to save the nutrients in the flours and their derived products. With OM, we analyzed caryopsis sections stained with Azan Trichrome, Periodic Acid Shiff (PAS) and Toluidine blue staining. These techniques allowed the characterization of the aleuronic layers with their protein globoids and starch granules of variable dimensions in the endosperm. Fluorescence OM allowed to evidence phenolic compounds and soluble fibers, in particolar the β-glucan of oat and barley, with the aid of the dye Calcoflour white. ESEM-EDS does not require fixation or embedding of the samples, and the structures are visualized under natural conditions. By means of ESEM-EDS, we localized protein globoids, the germ with the depleted layer (which connects the germ to the endosperm) and the starch granules with their qualitative elemental composition. Referring to nutrition, microscopic analysis highlights the higher bioaccessibility of einkorn wheat starch granules during digestion. At the technological level, barley and oat are more suitable than einkorn for pearling and malting, due to their thicker and more robust cell walls.


2021 ◽  
Vol 10 (3) ◽  
pp. e30310310118
Author(s):  
Joiciana Cardoso Arruda de Souza ◽  
Jéssica Franco Freitas Macena ◽  
Ivo Henrique Pinto Andrade ◽  
Geany Peruch Camilloto ◽  
Renato Souza Cruz

Mango agribusiness is an expanding activity in Brazil and produces a large volume of waste that are not reused. Mango seeds are one of the residues from fruit processing, and are a potential starch source. In the food industry, starch is used as a functional ingredient, allowing the preservation of important characteristics of foods. The objectives of this study were to extract starch from mango seed, and to characterize it in terms of its physicochemical, technological and rheological properties. Starch extraction involved washing, cutting, and milling the mango seeds. The extraction yield was 53.89% and the starch granules presented spherical to irregular ellipsoidal shapes with superficial grooves and average size of 20 µm. It had an initial paste temperature of 75.3 °C and a maximum viscosity of 706 BU at 88.1 ºC. The rate of syneresis, 1.51%, was considered low, which indicates a starch with good stability at low temperatures. In the texture profile it was found that there was a significant difference (p ≤ 0.05) in the texture profile of gels with sodium chloride, sucrose and citric acid added. The gel with emulsifier showed no significant difference in any of the parameters analyzed (hardness, cohesiveness and gumminess). The properties of the starch indicated great potential for use in food products.


2020 ◽  
Vol 477 (7) ◽  
pp. 1261-1286 ◽  
Author(s):  
Marie Anne Richard ◽  
Hannah Pallubinsky ◽  
Denis P. Blondin

Brown adipose tissue (BAT) has long been described according to its histological features as a multilocular, lipid-containing tissue, light brown in color, that is also responsive to the cold and found especially in hibernating mammals and human infants. Its presence in both hibernators and human infants, combined with its function as a heat-generating organ, raised many questions about its role in humans. Early characterizations of the tissue in humans focused on its progressive atrophy with age and its apparent importance for cold-exposed workers. However, the use of positron emission tomography (PET) with the glucose tracer [18F]fluorodeoxyglucose ([18F]FDG) made it possible to begin characterizing the possible function of BAT in adult humans, and whether it could play a role in the prevention or treatment of obesity and type 2 diabetes (T2D). This review focuses on the in vivo functional characterization of human BAT, the methodological approaches applied to examine these features and addresses critical gaps that remain in moving the field forward. Specifically, we describe the anatomical and biomolecular features of human BAT, the modalities and applications of non-invasive tools such as PET and magnetic resonance imaging coupled with spectroscopy (MRI/MRS) to study BAT morphology and function in vivo, and finally describe the functional characteristics of human BAT that have only been possible through the development and application of such tools.


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