Staff Publications

Staff Publications

  • external user (warningwarning)
  • Log in as
  • language uk
  • About

    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

    We have a manual that explains all the features 

Current refinement(s):

Records 1 - 5 / 5

  • help
  • print

    Print search results

  • export

    Export search results

  • alert
    We will mail you new results for this query: keywords==Quinoa
Check title to add to marked list
Molecular characterization of Ecuadorian quinoa (Chenopodium quinoa Willd.) diversity : implications for conservation and breeding
Salazar, Juan ; Jaramillo Roman, Viviana ; Gutierrez, Bernardo ; Loo, E.N. van; Lourdes Torres, María de; Torres, Andrés Francisco - \ 2019
Euphytica 215 (2019)3. - ISSN 0014-2336
Breeding - Ecuador - Genetic diversity - Population structure - Quinoa - SSR

Quinoa (Chenopodium quinoa Willd.) is recognized as an important crop to improve global food security. It has gained international recognition because of the nutritional value of its seeds and its broad agronomic resilience. Although several studies have attempted to characterize the genetic diversity of quinoa, none have focused on evaluating germplasm from Ecuador; the latter considered a relevant subcenter of diversity for the species. In this study, 84 accessions representing the species’ cultivated range in the Ecuadorian Andes were characterized using 15 species-specific SSR markers. The extent of allelic richness (196 alleles) and genetic heterozygosity (H E = 0.71) detected for these accessions demonstrate that Ecuadorian quinoa is highly diverse. Phenetic analyzes structured Ecuadorian germplasm into 3 subgroups; each containing genotypes from all surveyed provinces. Average expected heterozygosity was high for all 3 subgroups (0.53 ≤ H E ≤ 0.72), and Nei-pairwise comparisons showed significant genetic divergence among them (0.31 ≤ Nei DST ≤ 0.84). The lack of a clear geographic pattern in the genetic structure of Ecuadorian quinoa led us to believe that the 3 reported subgroups constitute independent genetic lineages representing ancestral landrace populations which have been disseminated throughout Ecuador via informal seed networks. Nevertheless, a Wilcoxon test showed that at least one subgroup had been subject to intensive inbreeding and selection; and possibly corresponds to the local commercial variety INIAP-Tunkahuan. Our results show that ancestral quinoa diversity in Ecuador has prevailed despite the introduction of commercial varieties, and should be preserved for future use in breeding programs.

UAV based soil salinity assessment of cropland
Ivushkin, Konstantin ; Bartholomeus, Harm ; Bregt, Arnold K. ; Pulatov, Alim ; Franceschini, Marston H.D. ; Kramer, Henk ; Loo, Eibertus N. van; Jaramillo Roman, Viviana ; Finkers, Richard - \ 2019
Geoderma 338 (2019). - ISSN 0016-7061 - p. 502 - 512.
Hyperspectral - LiDAR - Quinoa - Remote sensing - Soil salinity - Thermography - UAV

Increased soil salinity is a significant agricultural problem that decreases yields for common agricultural crops. Its dynamics require cost and labour effective measurement techniques and widely acknowledged methods are not present yet. We investigated the potential of Unmanned Aerial Vehicle (UAV) remote sensing to measure salt stress in quinoa plants. Three different UAV sensors were used: a WIRIS thermal camera, a Rikola hyperspectral camera and a Riegl VUX-SYS Light Detection and Ranging (LiDAR) scanner. Several vegetation indices, canopy temperature and LiDAR measured plant height were derived from the remote sensing data and their relation with ground measured parameters like salt treatment, stomatal conductance and actual plant height is analysed. The results show that widely used multispectral vegetation indices are not efficient in discriminating between salt affected and control quinoa plants. The hyperspectral Physiological Reflectance Index (PRI) performed best and showed a clear distinction between salt affected and treated plants. This distinction is also visible for LiDAR measured plant height, where salt treated plants were on average 10 cm shorter than control plants. Canopy temperature was significantly affected, though detection of this required an additional step in analysis – Normalised Difference Vegetation Index (NDVI) clustering. This step assured temperature comparison for equally vegetated pixels. Data combination of all three sensors in a Multiple Linear Regression model increased the prediction power and for the whole dataset R2 reached 0.46, with some subgroups reaching an R2 of 0.64. We conclude that UAV borne remote sensing is useful for measuring salt stress in plants and a combination of multiple measurement techniques is advised to increase the accuracy.

Effect of pre-treatment on in vitro gastric digestion of quinoa protein (Chenopodium quinoa Willd.) obtained by wet and dry fractionation
Opazo-Navarrete, M. ; Schutyser, M.A.I. ; Boom, R.M. ; Janssen, A.E.M. - \ 2018
International Journal of Food Sciences and Nutrition 69 (2018)1. - ISSN 0963-7486 - p. 1 - 11.
dry fractionation - in vitro gastric digestion - Quinoa - wet fractionation

Quinoa protein was isolated from quinoa seeds using wet fractionation that resulted in a protein isolate (QPI) with a high protein purity of 87.1% (w/dw) and a protein yield of around 54%, and a dry fractionation method delivered a quinoa protein concentrate (QPC) with a purity of 27.8% (w/dw) and yield of around 47%. The dry fractionation process only involves milling and sieving and keeps the protein in its natural, native state. The aim was to study the in vitro gastric digestibility of both protein. Attention was paid to thermal pre-treatment of QPI and QPC. QPC showed significantly higher (p < .05) digestibility than QPI samples. The results were interpreted with a simple double exponential model. The fraction of easily digested protein in QPC is higher than for QPI. The better digestibility of the QPC was explained by the prevention of the formation of large aggregates during pre-heating of the protein.

Effect of extraction pH on heat-induced aggregation, gelation and microstructure of protein isolate from quinoa (Chenopodium quinoa Willd)
Ruiz, Geraldine Avila ; Xiao, Wukai ; Boekel, Tiny van; Minor, Marcel ; Stieger, Markus - \ 2016
Food Chemistry 209 (2016). - ISSN 0308-8146 - p. 203 - 210.
Aggregation - Denaturation - Extraction - Gelation - Protein - Quinoa - Solubility

The aim of this study was to determine the influence of extraction pH on heat-induced aggregation, gelation and microstructure of suspensions of protein isolates extracted from quinoa (Chenopodium quinoa Willd). Quinoa seed protein was extracted by alkaline treatment at various pH values (pH 8 (E8), 9 (E9), 10 (E10) and 11 (E11)), followed by acid precipitation. The obtained protein isolates were freeze dried. The protein isolates E8 and E9 resulted in a lower protein yield as well as less protein denaturation. These isolates also had a higher protein purity, more protein bands at higher molecular weights, and a higher protein solubility in the pH range of 3-4.5, compared to the isolates E10 and E11. Heating the 10% w/w protein isolate suspensions E8 and E9 led to increased aggregation, and semi-solid gels with a dense microstructure were formed. The isolate suspensions E10 and E11, on the other hand, aggregated less, did not form self-supporting gels and had loose particle arrangements. We conclude that extraction pH plays an important role in determining the functionality of quinoa protein isolates.

Denaturation and in Vitro Gastric Digestion of Heat-Treated Quinoa Protein Isolates Obtained at Various Extraction pH
Ruiz, Geraldine Avila ; Opazo-Navarrete, Mauricio ; Meurs, Marlon ; Minor, Marcel ; Sala, Guido ; Boekel, Tiny van; Stieger, Markus ; Janssen, Anja E.M. - \ 2016
Food Biophysics 11 (2016)2. - ISSN 1557-1858 - p. 184 - 197.
Denaturation - Digestibility - Extraction pH - Heat processing - Protein - Quinoa

The aim of this study was to determine the influence of heat processing on denaturation and digestibility properties of protein isolates obtained from sweet quinoa (Chenopodium quinoa Willd) at various extraction pH values (8, 9, 10 and 11). Pretreatment of suspensions of protein isolates at 60, 90 and 120 °C for 30 min led to protein denaturation and aggregation, which was enhanced at higher treatment temperatures. The in vitro gastric digestibility measured during 6 h was lower for protein extracts pre-treated at 90 and 120 °C compared to 60 °C. The digestibility decreased with increasing extraction pH, which could be ascribed to protein aggregation. Protein digestibility of the quinoa protein isolates was higher compared to wholemeal quinoa flour. We conclude that an interactive effect of processing temperature and extraction pH on in vitro gastric digestibility of quinoa protein isolates obtained at various extraction pH is observed. This gives a first indication of how the nutritional value of quinoa protein could be influenced by heat processing, protein extraction conditions and other grain components.

Check title to add to marked list

Show 20 50 100 records per page

 
Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.