Effect of Sprouting on Proteins and Starch in Quinoa (Chenopodium quinoa Willd.)

Plant Foods for Human Nutrition - This study aims at understanding the relation among sprouting time (from 12 up to 72 h), changes in protein and starch components, and flour functionality...     

Nutritional and health benefits of quinoa (Chenopodium quinoa Willd.)

Quinoa (Chenopodium quinoa Willd.) is a plant species of the Chenopodiaceae family, which originated in the Andean region and can adapt to different types of soil and climatic conditions. It is a pseudo grain with high nutritional value as it is rich in proteins, lipids, fiber, vitamins, and minerals, and has an extraordinary balance of essential amino acids. Quinoa also contains a high amount of health-beneficial phytochemicals including saponins, phytosterols, phytoecdysteroids. It is known that quinoa has considerably positive effects on metabolic, cardiovascular, and gastrointestinal health in humans. Despite all these health benefits, quinoa is not widely consumed due to several reasons, such as high import costs of the grain and lack of knowledge regarding its benefits among consumers. As we believe that further research is needed to provide more information about quinoa, this review was prepared to investigate its basic compounds and health effects.     

Modelling photoperiod and temperature responses of flowering in quinoa (Chenopodium quinoa Willd.)

Two modelling approaches were used to quantify photoperiod and temperature responses of time from emergence to visible flower buds in nine quinoa (Chenopodium quinoa Willd.) cultivars. The first, non-interactive model, considers temperature and photoperiod responses as independent, and the threshold photoperiod, critical photoperiod, and base temperatures as constants. The second, interactive model, considers these attributes as variable, and allows for interaction between photoperiod and temperature responses. Controlled-environment experiments with a factorial combination of temperature and photoperiod provided information on responses, and data from field experiments were utilized in tests of the predictive capacity of the models.The two models were very similar in their goodness of fit and predictive capacity, but testing revealed that some assumptions about the interactive model were not fulfilled, whereas the non-interactive model is more consistent with the data. Both the models failed to predict dates of visible flower buds when average temperatures during the phase were >20°C; it is proposed that interaction between irradiance receipt and high temperature in controlled environments result in lower optimum temperatures there than in the field. Differences between field data and predicted values were eliminated when predictions were recalculated assuming no optimum for the temperature response.All nine cultivars examined are short-day plants. A juvenile sub-phase was observed in the six cultivars for which it was tested; and its duration was negatively associated with the latitude of origin of the lines (R² = 0.9, p < 0.05). Photoperiod sensitivity was negatively associated with the latitude of origin of the lines (R² = 0.55, p < 0.05) and positively associated with duration of the basic vegetative phase (minimal time between emergence and visible flower buds) (R² = 0.55, p < 0.05) using the non-interactive model. Photoperiod and temperature response parameters were not significantly associated with the latitude of origin for the interactive model (p > 0.05).     

Extrusion processing characteristics of quinoa (Chenopodium quinoa Willd.) var. Cherry Vanilla

Extrusion processing characteristics of Cherry Vanilla quinoa flour (Chenopodium quinoa Willd) were investigated using a three factor response surface design to assess the impact of feed moisture, temperature, and screw speed on the physicochemical properties of quinoa extrudates. Specific mechanical energy (SME) required to extrude this quinoa variety was higher (250–500 kJ/kg) than previously reported for quinoa. The following characteristics of the extrudates were observed: expansion ratio (1.17–1.55 g/cm³), unit density (0.45–1.02 g/cm³), water absorption index (WAI) (2.33–3.05 g/g), and water solubility index (WSI) (14.5–15.87%). This quinoa flour had relatively low direct expansion compared to cereal grains such as corn or wheat, suggesting that it is not well suited for the making of direct expanded products. The study further suggests that there is a need to understand the processing characteristics of new quinoa varieties for cultivation. Understanding extrusion and other quality traits in advance will help to select the appropriate varieties that would allow food processors to meet consumer needs.     

Quinoa (Chenopodium quinoa Willd.) protein hydrolysates with in vitro dipeptidyl peptidase IV (DPP-IV) inhibitory and antioxidant properties

The potential of quinoa to act as a source of dipeptidyl peptidase IV (DPP-IV) inhibitory and antioxidant peptides was studied. A quinoa protein isolate (QPI) with a purity of 40.73 ± 0.90% was prepared. The QPI was hydrolysed at 50 °C for 3 h with two enzyme preparations: papain (P) and a microbial papain-like enzyme (PL) to yield quinoa protein hydrolysates (QPHs). The hydrolysates were evaluated for their DPP-IV inhibitory and oxygen radical absorbance capacity (ORAC) activities. Protein hydrolysis was observed in the QPI control, possibly due to the activity of quinoa endogenous proteinases. The QPI control had significantly higher DPP-IV half maximal inhibitory concentrations (IC₅₀) and lower ORAC values than QPH-P and QPH-PL (P < 0.05). Both QPH-P and QPH-PL had similar DPP-IV IC₅₀ and ORAC values. QPH-P had a DPP-IV IC₅₀ value of 0.88 ± 0.05 mg mL⁻¹ and an ORAC activity of 501.60 ± 77.34 μmol Trolox equivalent (T.E.) g⁻¹. To our understanding, this is the first study demonstrating the in vitro DPP-IV inhibitory properties of quinoa protein hydrolysates. QPHs may have potential as functional ingredients with serum glucose lowering properties.     

Nutritional quality of the protein in quinoa (Chenopodium quinoa,Willd) seeds

The nutritional quality of protein in quinoa seeds has been determined by amino acid assay and by animal feeding experiments. The amino acid composition of the protein in raw quinoa and washed quinoa show similar pattern. The first limiting amino acids were the aromatic amino acids thyrosine + phenylalanine giving a chemical score of 86 for protein in raw quinoa and 85 for protein in washed quinoa. Threonine was the next limiting amino acid followed by lysine. The amount of lysine and sulfur amino acids (methionine + cystine) was relatively high. In general, the content of essential amino acids in quinoa is higher than in common cereals. The animal experiments showed NPU values of 75.7, BV of 82.6 and TD value of 91.7 for the protein in raw quinoa. Results of the in-vitro enzymatic methods showed that the digestibility of the protein in quinoa is comparable to that of other high quality food proteins. The corresponding experiments carried out with samples of guinoa seeds, which have been processed to remove the saponins, showed that, the saponins do not exert any negative effect on the nutritive quality of the protein.     

Properties of starch and dietary fibre in raw and processed quinoa (Chenopodium quinoa,Willd) seeds

We investigated certain properties of starch in raw and in heat-treated samples of quinoa, properties that are of importance to the nutritional quality of an infant food currently being developed. Scanning electron microscopy of the starch in raw seeds showed polygonal granules (0.6 to 2.0 µm diameter) to be present both singly and as spherical aggregates. Thermograms (DSC) of the flours showed one transition phase for gelatinisation of the starch and another for the amylose-lipid complex. The gelatinisation temperature of the starch was 67°C. Cooked samples manifested the highest degree of gelatinisation (97%), followed by the drum-dried (96%) and autoclaved (27%) samples. Separation of the starch on a SEPHAROSE CL-2B column showed the quinoa starch to be affected by the heat treatment, manifesting changes in the degree and extent of degradation. The amylograph viscosity of the quinoa flour showed no distinct peak for pasting, but the viscosity remained constant after gelatinisation. Cooking and autoclaving modified the viscosity of the paste. The drum-dried sample manifested a higher initial viscosity at 25°C. Thein vitro digestibility of raw quinoa starch determined by incubation for 60 min with -amylase was 22%, while that of autoclaved, cooked and drum-dried samples was 32%, 45% and 73%, respectively. Saponins did not affect the digestibility of the starch, though they tended to increase the amylograph viscosity. The total dietary fibre content in the cooked sample (11.0%) was significantly lower than that in the autoclaved (13.2%), drum-dried (13.3%) or raw samples (13.3%), while the insoluble dietary fibre fraction in the samples did not change with heat treatment. However, as compared with that of raw quinoa, the soluble dietary fibre fraction was reduced significantly both by cooking (0.9%) and by autoclaving (1.0%).     

Physicochemical and functional properties of soluble dietary fiber from different colored quinoa varieties (Chenopodium quinoa Willd)

As it is well documented that the phytochemical composition and bioactive profile of quinoa are influenced by different phenotypes, we analyzed the physicochemical and functional characteristics of different quinoa soluble dietary fiber (SDF). SDF was prepared through ultrasound-assisted enzymatic extraction from three colored quinoa brans. After purification, the yield of SDF from white (W-SDF), red (R-SDF) and black quinoa bran (B-SDF) was 2.2%, 5.7% and 5.9%, respectively. Compared with R-SDF and B-SDF, W-SDF had a higher molecular weight (1.72 × 10⁶ Da) and lower zeta-potential (- 32.16 mV), although their monosaccharide composition and Fourier transform infrared spectroscopy (FT-IR) results showed no obvious differences. The transmission electron microscope (TEM) image suggested that R-SDF exhibited a more complex and loose structure than W-SDF and B-SDF. Moreover, R-SDF exhibited higher thermal stability, gel forming capacity, bile acid binding capacity, water-holding capacity and glucose adsorption capacity than those of B-SDF and W-SDF. Taken together, SDF extracted from quinoa especially from red quinoa might be a promising candidate for the development of novel functional food ingredients.     

Study of bitterness perception of quinoa (Chenopodium quinoa wild.) saponin extracts

The thresholds and behavior of bitterness perception over time were studied for quinoa saponins. The detection threshold was calculated in two ways using R-index values: linear equation (as previously used) and regression analysis (proposed hereby). Panelists were grouped depending on their bitterness sensitivity, and differences were found among dynamic panelist perceptions. At the threshold level, the sensation dynamic was lower than the caffeine threshold. By HPLC analysis, we identified three main types of saponins (A, B, and C), which positively correlated with the stimulus concentration. The saponin fractions were more related to the time-intensity parameters than the total saponins. Pearson's correlations showed that maximum intensity, total duration, area under the curve, and rising slope were best correlated with A, B, and C saponins. Interestingly, bitterness was perceived before chemical differentiation. It is important to study the saponin bitterness thresholds and perception, as they directly influence consumer choices and must be addressed before being used in quinoa products in the food industry.     

Genetic variability and interrelationship among various morphological and quality traits in quinoa (Chenopodium quinoa Willd.)

Evaluation of seed yield, morphological variability and nutritional quality of 27 germplasm lines of Chenopodium quinoa and 2 lines of C. berlandieri subsp. nuttalliae was carried out in subtropical North Indian conditions over a 2-year period. Seed yield ranged from 0.32 to 9.83 t/ha, higher yields being shown by four Chilean, two US, one Argentinian and one Bolivian line. Two lines of C. berlandieri subsp. nuttalliae exhibited high values for most of the morphological traits but were low yielding. Seed protein among various lines ranged from 12.55 to 21.02% with an average of 16.22 ± 0.47%. Seed carotenoid was in the range of 1.69–5.52 mg/kg, while leaf carotenoid was much higher and ranged from 230.23 to 669.57 mg/kg. Genetic gain as percent of mean was highest for dry weight/plant, followed by seed yield and inflorescence length. All morphological traits except days to flowering, days to maturity and inflorescence length exhibited significant positive association with seed yield. The association of leaf carotenoid with total chlorophyll and seed carotenoid was positive and highly significant. The path analysis revealed that 1000 seed weight had highest positive direct relationship with seed yield (1.057), followed by total chlorophyll (0.559) and branches/plant (0.520). Traits showing high negative direct effect on seed yield were leaf carotenoid (−0.749), seed size (−0.678) and days to flowering (−0.377). Total chlorophyll exerted strongest direct positive effect (0.722) on harvest index, followed by seed yield (0.505) and seed protein (0.245).     

Agronomical and nutritional evaluation of quinoa seeds (Chenopodium quinoa Willd.) as an ingredient in bread formulations

Quinoa is an Andean seed crop of many potential uses. In 2009 a field trial was carried out to explore the potential for quinoa growing in climatic conditions of South Eastern Europe. Even under rainfed conditions, without fertilization, a seed yield as high as 1.721 t ha⁻¹ was obtained. Seed quality was remarkably good, with protein content ranging from 15.16 to 17.41 % on a dry weight basis, depending on whether seeds were processed. Amino acid and mineral composition revealed the potential of quinoa seeds as a valuable ingredient in the preparation of highly nutritious foods. Quinoa seeds had higher contents of most essential amino acids, especially lysine, than wheat flour. Dehulled quinoa seeds, devoid of saponins, were included into wheat bread formulations, with up to 20%, which resulted in a positive effect on the rheological characteristics of dough. Furthermore, protein content in bread was increased by around 2%. Sensory characteristics of breads were excellent also at the 20% supplementation level. The study of bread supplemented with quinoa seeds could enable the development of a range of new baking products with enhanced nutritional value.     

Effects of germination and kilning on the phenolic compounds and nutritional properties of quinoa (Chenopodium quinoa) and kiwicha (Amaranthus caudatus)

Quinoa (Chenopodium quinoa) and kiwicha (Amaranthus caudatus) are nutritious pseudocereals that originate from the Andean region. The aim of this research was to study the effect of germination and the subsequent kilning on the phenolic compounds and proximate composition in selected Peruvian varieties of quinoa (“Chullpi”) and kiwicha (“Oscar Blanco”). The germination process was carried out for 24, 48 and 72 h at 22 °C, and the kilning was performed with samples germinated for 72 h by drying the seeds at 90 °C for 5 min. Both processes increased the protein content of the samples. However, lipid content was reduced during germination. On the other hand, germination and kilning clearly increased the concentration of total phenolic compounds in both quinoa and kiwicha. Germination for 72 h either with or without kilning process resulted in a significant (p < 0.05) increase in the total content of phenolics compared to untreated materials, which was especially due to coumaric acid and a kaempferol tri-glycoside in quinoa and caffeoylquinic acid in kiwicha. Based on the results, germination and kilning may improve the nutritional quality of the Andean grains, encouraging the usage of the processed grains as ingredients in functional products for people with special gluten-free or vegetarian diets.     

Amino acid profile of the quinoa (Chenopodium quinoa Willd.) using near infrared spectroscopy and chemometric techniques

The high content of amino acids of the quinoa, especially essential amino acids (higher than other cereals) makes a food increasingly demanded by consumers. A total of twelve amino acids (arginine, cystine, isoleucine, leucine, lysine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine and valine) were analyzed in quinoa samples from Chile by near infrared spectroscopy (NIR) with direct application to the samples of a remote fiber-optic reflectance probe. The calibration results using modified partial least squares (MPLS) regression satisfactorily allowed the determination of the concentrations of this amino acid group with high multiple correlation coefficients (RSQ = 0.97–0.71) and low standard prediction errors (SEPC = 0.07–0.20). The prediction capacity (RPD) for the arginine, the cystine, the isoleucine, the lysine, the serine, the threonine, the tryptophan, the tyrosine and the valine ranged between 2.6 and 5.2, for the rest of amino acids were higher to 1.8, indicating that the NIRS equations obtained were applicable to unknown samples. It has confirmed that NIRS technology is a method that may be useful to replace the traditional methods for routine analysis of some amino acids.     

Digestibility of Quinoa (<Emphasis Type="Italic">Chenopodium quinoa</Emphasis> Willd.) Protein Concentrate and Its Potential to Inhibit Lipid Peroxidation in the Zebrafish Larvae Model

Quinoa protein concentrate (QPC) was extracted and digested under in vitro gastrointestinal conditions. The protein content of QPC was in the range between 52.40 and 65.01% depending on the assay used. Quinoa proteins were almost completely hydrolyzed by pepsin at pH of 1.2, 2.0, and 3.2. At high pH, only partial hydrolysis was observed. During the duodenal phase, no intact proteins were visible, indicating their susceptibility to the in vitro simulated digestive conditions. Zebrafish larvae model was used to evaluate the in vivo ability of gastrointestinal digests to inhibit lipid peroxidation. Gastric digestion at pH 1.2 showed the highest lipid peroxidation inhibition percentage (75.15%). The lipid peroxidation activity increased after the duodenal phase. The digest obtained at the end of the digestive process showed an inhibition percentage of 82.10%, comparable to that showed when using BHT as positive control (87.13%).     

Crop water use indicators to quantify the flexible phenology of quinoa (Chenopodium quinoa Willd.) in response to drought stress

Models can play an important role in agricultural planning and management. Thermal time accumulation is a common way of describing phenological development in crop models, but the sensitivity of this concept to water stress is rarely quantified. The effect of pre-anthesis droughts on the timing of anthesis and physiological maturity was assessed for quinoa (Chenopodium quinoa Willd.) var. ‘Santa Maria’, with the help of two field experiments (2005–2006 and 2006–2007) in the central Bolivian Altiplano. Various treatments with different sowing dates and irrigation applications were considered. To evaluate the effect of drought stress on crop development, drought stress during the first 60 days after sowing was assessed with three different stress indicators: the number of days that the soil water content of the root zone was above a threshold, the average relative transpiration, and the sum of daily actual transpiration, standardized for reference evapotranspiration (∑(T_a/ET₀)). The best indicator to quantify the effect of pre-anthesis drought stress on phenological development was ∑(T_a/ET₀) cumulated until 60 days after sowing. This indicator showed a significant logarithmic relation with the time to anthesis and time to physiological maturity. Correlations of the drought stress indicator with thermal time accumulation were better than with calendar time accumulation. Due to an effect of post-anthesis droughts, the correlations of the drought stress indicator with the time to anthesis were stronger than with the time to physiological maturity. It was also demonstrated that deficit irrigation can contribute to a better agricultural planning due to a better control of the phenological development of quinoa. The proposed relations can be used for modeling phenological development of quinoa in drought prone regions and for efficient deficit irrigation planning.     

甘薯(Ipomoea batatas(L.) Lam.)试管苗种质保存技术研究进展

甘薯种质资源的大田种植保存面临着严重的病毒感染以及病虫害、自然灾害的影响.由茎尖分生组织培养成无病毒苗并进行试管保存,是当前既经济又实用的方法.     

Chemical and Nutritional Evaluation of Protein-Rich Ingredients Obtained through a Technological Process from Yellow Lupin Seeds (Lupinus luteus)

Plant Foods for Human Nutrition - In recent years, interest in plant-based proteins has been rising due to ethical and sustainability issues. In this context, the production of protein concentrates...     

Distribution and prevalence of nematodes (Scutellonema bradys and Meloidogyne spp.) on marketed yam (Dioscorea spp.) in West Africa

The distribution, population density and incidence of plant parasitic nematodes and associated damage to yam (Dioscorea spp.) tubers obtained from market stalls in the West African countries of Benin, Burkina Faso, Côte d’Ivoire, Ghana, Mali, Nigeria and Togo was determined during the tuber storage periods in 2002 and 2003. A total of 527 yam tuber samples, exhibiting typical nematode (Scutellonema bradys) damage symptoms, were collected and assessed for S. bradys densities. In addition 25,318 tubers on sale in markets were assessed for visual symptoms (except in Nigeria) of nematode damage (S. bradys and Meloidogyne spp.). S. bradys was present in all countries assessed, with greatest (P ≤ 0.05) mean population densities occurring in tubers in Benin (397 g⁻¹), followed by Nigeria (248 g⁻¹) and lowest in Togo (28 g⁻¹). When analysed by agroecological zone, the greatest (P ≤ 0.05) mean S. bradys density was observed in the mid altitude savannah (890 g⁻¹), followed by the southern guinea savannah (488 g⁻¹). S. bradys occurred in lower (P ≤ 0.05) densities on Dioscorea alata (57 g⁻¹) than other yam species, while Dioscorea rotundata was the most abundant yam species encountered. There was considerable variation in S. bradys density between cultivars within country and in some cases between countries. From some cultivars no S. bradys were recovered, even though they presented symptoms of damage. Tubers from Ghana had the greatest (P ≤ 0.05) proportion of tubers visually affected by S. bradys (7.53%), when analysed across yam species and Mali the least (0.28%), while the highest proportion of galled tubers (due to Meloidogyne spp.) was observed in Mali (14.4%) on D. rotundata (19.6%). S. bradys infection, based on visible symptoms, was more evident on D. rotundata (3.8%) than D. alata (0.6%), although 5.18% of yams in the group comprising the unidentified yam species had the greatest mean proportion of visually affected tubers. On market stalls, D. alata (4.73%) and D. rotundata (3.35%) were most affected by visible galling due to Meloidogyne spp.     

Influence of light intensity,fertilizers and salinity on oxalate and mineral concentration of two vegetables (Chenopodium album L. and Chenopodium amaranthicolor L.)

The effect of light intensity on the synthesis of oxalate and cation concentration in leaves, stems and roots ofC. amarànthicolor L. was investigated. It appears that oxalic acid is synthesized in leaves from metabolites of both photosynthetic and non-photosynthetic origin. In roots the effect of light on the oxalic acid synthesis was different to that of leaves and stems. Cation uptake seems to increase with increase in oxalic acid production.The influence of applications of superphosphate (single) urea, calcium ammonium nitrate, potassium chloride and salinity on the oxalate production and cation make up ofC. album L. was also studied. All the nutrients except at low levels of calcium ammonium nitrate depressed slightly the oxalate synthesis in leaves. The influence of the applications of sodium chloride and potassium chloride was more pronounced although the higher levels of both of these salts gave almost an equal yield of oxalic acid. These results suggest that the soil nutrients can only partly regulate the oxalic acid production in this plant. The findings also support the belief that chloride or the other anions, if available, are absorbed, compete for cations and depress the oxalate synthesis.

---

Zusammenfassung Untersucht wurde der Einflu der Lichtintensität auf die Oxalatsynthese und die Kationenkonzentration in Blättern, Stengeln und Wurzeln von Chenopodium amaranthicolor L. Es scheint, da in den Blättern die Oxalsäure aus Metaboliten synthetisiert wird, die sowohl photosynthetischen als auch nicht photosynthetischen Ursprungs sein können. Der Einflu des Lichtes auf die Oxalsäuresynthese in den Wurzeln weicht von dem in den Blättern und Stengeln ab. Die Kationenaufnahme scheint mit der Zunahme der Oxalsäureproduktion anzústeigen.Des weiteren wurde der Einflu von Superphosphat, Harnstoff, Kalkammon-Salpeter, Kaliumchlorid und Natriumchlorid auf die Oxalatbildung und die Kationenaufnahme bei Chenopodium album untersucht. Alle hier angeführten Nährstoffe, mit Ausnahme der geringsten Gabe Kalkammon-Salpeter, wirkte depressiv auf die Oxalatsynthese in den Blättern. Natrium- und Kaliumchlorid hatten den stärksten Einflu, wobei zwischen diesen beiden Salzen kein Unterschied bestand. Diese Ergebnisse legen den Gedanken nahe, da die Bodennährstoffe nur teilweise die Oxalsäureproduktion in dieser Pflanze regulieren. Auerdem stützen sie die Annahme, da Chloride oder andere Anionen, sofern sie verfügbar sind, absorbiert werden und als Konkurrenten um die Kationen auftreten und sich somit auf die Oxalatsynthese hemmend auswirken.

---

---

Professor of biochemistry     

Response of Potato (Solanum tuberosum L.) Germplasm to Water Stress Under In Vitro Conditions

Chile is center of origin and diversity of potato (Solanum tuberosum L.). Potato yield is affected under water stress conditions, so development of varieties with better tolerance to this stress is desirable. In this study we determined the differential response of INIA-Chile potato germplasm to water stress under in vitro assays with polyethylene glycol. One-hundred-and-fourty-nine genotypes were evaluated. Polyethylene glycol 4.8 % w/v was able to distinguish genotype response by considering the morphological variables (plantlet height, leaf and root number) and fresh and dry weight. Through multivariate statistical analysis, and in comparison with their respective controls without treatment, genotypes were clustered with high (74 – 79 %), intermediate (29 – 94 %), low (29 – 57 %), and very low (4– 28 %) water stress tolerance. The high-tolerance-response cluster was mainly made up of Chilean potato landraces. These results highlight the importance of this germplasm in food security, which could be directly cultivated and/or be used as progenitors to produce new varieties with increased tolerance to water-deficit stress.