Browsing by Autor "Cinthia Carola Rojas"

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Comparison of the Chemical Composition of Six Canihua (Chenopodium pallidicaule) Cultivars Associated with Growth Habits and after Dehulling
(Multidisciplinary Digital Publishing Institute, 2023) Jenny Mérida-López; Sander Jonathan Pérez; R. Morales; Jeanette Purhagen; Björn Bergenståhl; Cinthia Carola Rojas
The canihua (Chenopodium pallidicaule) is a native Andean crop that stands out for its high content of protein, fiber, and minerals and that has a good fatty acid profile. We studied six canihuas cultivars, which were compared according to their proximate, mineral, and fatty acid composition. Based on the form of stems, termed growth habit, they belonged to two groups: decumbent (Lasta Rosada, Illimani, Kullaca, and Cañawiri) and ascending (Saigua L24 and Saigua L25). Dehulling is an important process applied to this grain. However, there is no information about how it affects the chemical composition of the canihua. Dehulling resulted in two levels, whole and dehulled canihua. The highest protein and ash contents were in whole Saigua L25 (19.6 and 5.12 g/100 g, respectively), and the highest fat content was found in dehulled Saigua L25, while the whole grains of Saigua L24 presented the highest fiber content (12.5 g/100 g). Dehulling mainly affected the macro-minerals content, while micro-minerals were only slightly linked to the dehulling. The growth habit influenced the C18:1 and C18:3 contents. In conclusion, the canihua had a nutritional composition influenced by each variety, strongly influenced by dehulling, and to a lesser extent by growth habit.
Enzymatic hydrolysis of Canna indica, Manihot esculenta and Xanthosoma sagittifolium native starches below the gelatinization temperature
(Wiley, 2012) Daysi Perez‐Rea; Cinthia Carola Rojas; Sergio Carballo; Wilson Aguilar; Björn Bergenståhl; Lars Nilsson
Abstract The susceptibility to enzymatic hydrolysis of starch extracted from raw roots of Canna indica , Manihot esculenta and Xanthosoma sagittifolium , grown in Bolivia, were studied below the gelatinization temperature. The granule size and amylose content were as followed: C. indica > M. esculenta > X. sagittifolium . The hydrolysis showed a rapid rate at the initial stage, followed by a progressive decrease thereafter. At 30, 40 and 50°C, during the initial stage, the rate of hydrolysis was observed to be influenced by the size of the granules, being the highest for the small sized granules X. sagittifolium , followed by the medium sized granules M. esculenta and the lowest rate was for the large sized granules C. indica starch. During the slow phase, A‐type M. esculenta and B‐type C. indica showed higher hydrolysis rates than A‐type X. sagittifolium . At 60°C, a positive correlation was found between the amylose content and the rate of hydrolysis among the starches. Microscopic observations showed a pattern of attack by the enzyme towards C. indica starch granules, suggesting that high amylose content is concentrated around the hilum.
Fermented and extruded quinoa (Chenopodium quinoa): Physicochemical properties and in vitro mineral accessibility
(Elsevier BV, 2026) Jenny Mérida-López; Raquel Antezana-Gomez; Vanesa Castro-Alba; Jeanette Purhagen; Cinthia Carola Rojas; Daysi Perez-Rea
Quinoa is an Andean grain with high nutritional potential. This study evaluated the synergistic impact of a sequential, two-step fermentation followed by- on quinoa flour (QF) properties, with a primary focus on enhancing in vitro mineral accessibility and characterizing associated physicochemical changes. QF, and -QF fermented with Lactobacillus plantarum were extruded at 14% and 16% feed moisture. In vitro assays assessed mineral accessibility. Both fermentation and extrusion enhanced the accessibility of iron, zinc, and calcium. Extrusion alone improved de accessibility of Fe, Zn, and Ca by 31 – 78%, while a combined processing method of fermentation and extrusion enhanced accessibility by 160 – 445%. The extrusion process gelatinized the starch, thus altering the water absorption, and the pasting-, and solubility properties. The color parameters were also affected by both the extrusion and fermentation processes and the combination of both processes. In conclusion, fermentation and extrusion improved QF characteristics, yielding extrudates with enhanced mineral accessibility and modified pasting properties (gelatinization), with a great potential for new and innovative food applications. • Both fermentation and extrusion processes enhance the mineral accessibility in quinoa. • Integrating fermentation with extrusion yielded the highest mineral accessibility. • Starch structure and flour properties can be altered through both fermentation and extrusion.
Functional properties of starch cultivars of two Andean grains grown in Bolivia: Amaranth (Amaranthus caudatus) and canihua (Chenopodium pallidicaule)
(Elsevier BV, 2024) Jenny Mérida-López; Cinthia Carola Rojas; Björn Bergenståhl; Jeanette Purhagen
Macromolecular Geometries Determined with Field-Flow Fractionation and their Impact on the Overlap Concentration
(American Chemical Society, 2008) Cinthia Carola Rojas; Karl‐Gustav Wahlund; Björn Bergenståhl; Lars Nilsson
In this paper we aim to understand the size/conformation relationship in waxy barley starch, a polydisperse and ultrahigh molar mass biomacromolecule. Characterizations are performed with asymmetrical flow field-flow fractionation (AsFlFFF). Furthermore, we study the effect of homogenization on the molar mass, rms radius (r rms) and hydrodynamic radius (r h). For the untreated sample, the macromolecules are elongated objects with low apparent density. As a result of homogenization, molar mass, and r rms decrease, while r h remains unaffected. The process also induces an increase, and scaling with size, of apparent density as well as changes in conformation, represented qualitatively by r rms/ r h. Finally, results from AsFlFFF are compared with viscosimetry and discussed in terms of concentration and close-packing in relation to macromolecular shape and conformation. Hence, the results show that AsFlFFF and our novel methodology enable the determination of several physical properties with high relevance for the solution behavior of polydisperse macromolecules.
Nutritional Composition of Six Amaranth (Amaranthus caudatus) Andean Varieties
(2023) Jenny Mérida-López; Sander Jonathan Pérez; Björn Bergenståhl; Jeanette Purhagen; Cinthia Carola Rojas
Amaranthus caudatus is a nutrient-rich Andean pseudocereal with wide genetic variability. Six productive varieties (Oscar Blanco, Pucara, Tomina, Cotahuasi, Barbechos, and Guindo Criollo) were compared by proximate, mineral, and fatty acid composition. The proximal content showed certain singularities in the varieties. Barbechos and Guindo Criollo stood out for their fat content (9.50% and 9.01%, respectively), while Tomina stood out for their carbohydrate content (72.6%), and Pucara and Oscar Blanco for their fiber content (4.59% and 4.48%, respectively). The mineral content presented differences, highlighting the Ca content for Pucara (108 mg/100 g), and Tomina with micro-minerals (Zn, Mn, Fe, and Cu, 4.67, 5.90, 9.13 and 1.03 mg/100 g, respectively). All varieties showed high tricosanic acid (C23:0) content, and Cotahuasi was highlighted for its high linoleic acid (C18:2) content. Multivariate analysis showed negative correlations between proteins and carbohydrates, and between fat and fiber in their proximal content, as well as between Fe and Na for their mineral content, and C18:1 and C18:2 for the fatty acids. Although certain differences were found, the total nutritional composition tended to have minor differences between the investigated varieties.
SIMULTANEOUS DETERMINATION OF GLUCOSE, MALTOSE AND SUCROSE IN STARCH OF SIX VARIETIES OF CASSAVA
(2006) Cinthia Carola Rojas; Baboo M. Nair; Adelina Herbas; Björn Bergenståhl
An enzymatic method has been developed to simultaneously determine glucose, maltose and sucrose in tubers The principle of the method is based on an enzymatic cleavage of these disaccharides and specific measurement the resulting glucose using an enzymatic procedure described by Holm (3). The study comprises two parts; the first one includes modifications of the pretreatment method to minimize errors due to ethanol used to precipitate polymeric material interfering with the activity of α-glucosidase and invertase. In the second part the usability of the method has been probed by employing it on six samples of cassava that come from Chapare-Bolivia.
Size, structure and scaling relationships in glycogen from various sources investigated with asymmetrical flow field-flow fractionation and 1H NMR
(Elsevier BV, 2011) Céline Fernandez; Cinthia Carola Rojas; Lars Nilsson
Water and Thermal Properties Characterized in Phases of Wheat Flour Dough during Thawing and Baking Conditions
(2019) Sander Jonathan Pérez; Cinthia Carola Rojas; Ann‐Charlotte Eliasson; Malin Sjöö
Phase separation of dough is based on the thermodynamic incompatibility of its components. The studies on phase-separated systems allow to model, understand, and develop foods. Model dough systems made with water and wheat flour were disassembled into their main structural phases, i.e. liquid, gel, gluten and starch phases, by ultracentrifugation, and further characterized with differential scanning calorimetry (DSC) and microscopy. The study of phase separation, water properties and thermal transitions in phases showed that wheat flour doughs are mainly characterized by the volume fractions of liquid, gel and gluten. The different samples of flours were highly affected by flour combinations. The freezable water (FW) of each separated phase influenced the water properties of the whole dough. The FW is further related to starch thermal behaviour of dough systems at baking temperatures. The methods used here were therefore found relevant from a baking perspective for initial characterizing of flours and dough.