Browsing by Subject "amaranth"

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  • Ramos Diaz, Jose Martin; Rinnan, Åsmund; Jouppila, Kirsi Leena (2019)
    Amaranth (Amarantus caudatus), quinoa (Chenopodium quinoa) and kañiwa (Chenopodium pallidicaule) are Andean grains that are gaining interest as nutritious gluten-free alternatives to conventional cereals. Near infrared (NIR) imaging was applied to extrudates containing 20, 35% and 50% amaranth, quinoa and kañiwa in order to study the spatial distribution of fibre and protein along the cross-sectional area. The results were contrasted with existing physical measurements (e.g., sectional expansion, stiffness) and textural data obtained from sensory profiling and temporal studies (i.e., temporal dominance of sensation, TDS). Score distribution in PCA plots was directly associated to fibre (PC1) and protein (PC2) due to spectral wavelength specificity (fibre: 1028 nm; protein: 1470 nm). Partial Least Squares regression model (PLS) showed that evenly distributed protein structures are strongly linked to desirable TDS textural properties such as crispiness and crunchiness, while protein clumps were linked to undesirable properties such as roughness. In contrast, fibre was found to reduce roughness. PLS could not explain accurately changes in physical attributes, and sensory data from profiling tests had to be omitted from computing due to lack of fit. This study shows that NIR hyperspectra imaging could help elucidate the chemical background of physical and particularly temporal dominant attributes.
  • Sundarrajan, Lakshminarasimhan (Helsingfors universitet, 2014)
    Amaranth, quinoa, kañiwa and lupine are good sources of protein, fat, dietary fibre and bioactive compounds. The literature review deals with the nutritional properties and the stability of bioactive compounds and the effect of extrusion cooking on amaranth, quinoa, kañiwa and lupine. The main aim of this study was to (1) chemically characterize amaranth, quinoa, kañiwa and lupine, and (2) to determine the effect of extrusion cooking on the nutritional properties and the stability of bioactive compounds. Extrudates were processed using twin screw extruder at two different extrusion temperatures (140 and 160 °C) containing two different contents of tested flour mixtures (20 and 50%). The raw materials and the extrudates were stored at -18 °C and chemically characterized to determine fatty acid composition, tocopherol composition and total phenolic acid content. Fatty acid composition was determined using GC while tocopherol composition was detected using HPLC. The total phenolic acid content was analyzed using Folin-Ciocalteu method. The protein and dietary fibre content in lupine accounted for 29 and 50 g/100 g d.m., respectively. The extrudates containing 50% lupine and processed at 140 °C possessed higher content of oleic, linoleic and linolenic fatty acids. At higher content of tested flours, extrusion cooking at 160 °C resulted in better retention of unsaturated fatty acids in the extrudates of amaranth, kañiwa and quinoa. Higher extrusion temperatures resulted in lower retention of tocopherols in all the extrudates. The total phenolic acid resulted in higher contents in the extrudates of kañiwa when compared to other extrudates. At higher seed contents of tested flours (%), higher retention of total phenolic acid was achieved during extrusion cooking at 140 °C in the extrudates of amaranth, quinoa and kañiwa. This study showed that extrusion conditions could be optimized in order to obtain lesser effects on the nutritional properties and better retention of bioactive compounds. The research study provides supportive information for obtaining gluten-free cereal snack products with lower glycemic index.
  • Ramos Diaz, Jose Martin (Helsingfors universitet, 2012)
    Malnutrition is a common problem in Peruvian highlands and in Bolivia. Amaranth, quinoa and kañiwa are pseudocereals cultivated in these areas and regarded as good sources of protein and non-saturated fatty acids. The literature review deals with the nutritional and technological properties of amaranth, quinoa and kañiwa. The aim of this investigation was to: (1) prepare gluten free corn-based extrudates containing amaranth, quinoa and kañiwa (20% of solids), (2) study the effects of independent extrusion variables on the physical properties of the extrudates and (3) evaluate lipid stability during storage by measuring hexanal production. Extrudates were made in 4 separate trials using a small scale co-rotating twin screw extruder. Experiments were performed using Box-Behnken?s experimental design in which independent extrusion variables were water content of mass (15, 17 and 19%), screw speed (200, 350 and 500 rpm) and temperature of the die (150, 160 and 170 °C). Samples were collected and their physical properties were analyzed (sectional expansion index, hardness and water content). Ground and whole extrudate samples were stored in open headspace vials at 11 and 76% RH for a week (exposure time) before being sealed and stored for 0, 2, 5 and 9 weeks at room temperature in the absence of light. Hexanal content was analyzed using headspace gas chromatography. The highest sectional expansion index (SEI) and the lowest hardness were achieved when the water content of mass was 15%, screw speed 500 rpm and temperature of the die 160 °C. Extrudates containing amaranth had the highest SEI (7.6) while extrudates containing quinoa and kañiwa had SEIs of 6.1 and 5.1, respectively. Pure corn extrudates (reference sample) had the lowest SEI (4.5). Extrudates containing kañiwa and pure corn extrudates presented the lowest (28 N/mm) and highest hardness (89 N/mm), respectively. In storage studies, ground extrudates (except samples containing quinoa) showed comparatively higher hexanal production than whole extrudates exposed to 11 and 76% RH. Whole extrudates exposed to 76% RH showed very low hexanal production during storage. This study proved that it was possible to add amaranth, quinoa and kañiwa to extruded corn snacks and achieve higher expansion than that of pure corn extrudates. Indeed, the results obtained from the evaluation of lipid oxidation during storage suggest a remarkable stability of whole extrudates after being exposed to high relative humidity. Further studies on lipid stability for longer storage would be highly desirable.
  • Ramos Diaz, Jose Martin; Kirjoranta, Satu; Tenitz, Seppo; Penttilä, Paavo A; Serimaa, Ritva; Lampi, Anna-Maija; Jouppila, Kirsi (2013)
    Amaranth (Amaranthus caudatus), quinoa (Chenopodium quinoa) and kañiwa (Chenopodium pallidicaule) are pseudocereals regarded as good gluten-free sources of protein and fiber. A co-rotating twin screw extruder was used to obtain corn-based extrudates containing amaranth/quinoa/kañiwa (20% of solids). Box–Behnken experimental design with three independent variables was used: water content of mass (WCM, 15–19%), screw speed (SS, 200–500 rpm) and temperature of the die (TEM, 150–170 °C). Milled and whole samples were stored in open headspace vials at 11 and 76% relative humidity (RH) for a week before being sealed and stored for 9 weeks in the dark. Hexanal content was determined by using headspace gas chromatography. Extrudates containing amaranth presented the highest sectional expansion index (SEI) (p < 0.01) while pure corn extrudates (control) presented the lowest SEI and greatest hardness (p < 0.01). SEI increased with increasing SS and decreasing WCM. In storage, whole extrudates exposed to 76% RH presented the lowest formation of hexanal. This study proved that it was possible to increase SEI by adding amaranth, quinoa and kañiwa to pure corn flour. The evaluation of lipid oxidation suggested a remarkable stability of whole extrudates after exposure to high RH.