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1.
Quinoa (Chenopodium quinoa Willd) is a Latin American food staple readily available in large quantities in Peru, Bolivia and Ecuador. The outer husk of the grain is removed prior to consumption to reduce its bitter taste. At present, quinoa husks are considered as a by-product with no commercial value, despite its high content of triterpenoid saponins (20–30%). Due to this, the present work was undertaken to test if quinoa saponins have antifungal properties against Botrytis cinerea and if this activity is enhanced after alkaline treatment, since recent reports indicate that alkaline treatment of quinoa saponins increase their biological activity. Six products were tested against B. cinerea: (1) non-purified quinoa extract, (2) purified quinoa extract, (3) alkali treated non-purified quinoa extract, (4) alkali treated purified quinoa extract, (5) non-purified quinoa extract treated with alkali but without thermal incubation and (6) purified quinoa extract treated with alkali but without thermal incubation.

Untreated quinoa extracts showed minimum activity against mycelial growth of B. cinerea. Also, no effects were observed against conidial germination, even at 7 mg saponins/ml. However, when the saponin extracts were treated with alkali, mycelial growth and conidial germination were significantly inhibited. At doses of 5 mg saponins/ml, 100% of conidial germination inhibition was observed, even after 96 h of incubation. Fungal membrane integrity experiments based on the uptake of the fluorogenic dye SYTOX green showed that alkali treated saponins generate membrane disruption, while non-treated saponins had no effects.

The higher antifungal activity of alkaline treated saponins is probably due to the formation of more hydrophobic saponin derivatives that may have a higher affinity with the sterols present in cell membranes.  相似文献   


2.
Quantitative determinations of total and soluble proteins, total and free sugars, starch, total lipids, tanins, ash (Ca, Na, K, Fe, and P), and caloric value were carried out on quinoa flour.Results show that the amount of soluble proteins was higher than the standard value for wheat and maize and was very close to that of barley's. The yield of free sugars like glucose (4.55%), fructose (2.41%) and sucrose (2.39%) were also of importance.Iron and calcium levels were higher than the reported values for maize and barley. The same occurred for the caloric value (435.5 Kcal/100 g).The content of saponins was also examined since its effect on red blood cells of group A and O has been related as a potential problem of the Andes population.From the chemical analysis a more complete view about quinoa as human food was presented.  相似文献   

3.
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.  相似文献   

4.
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.  相似文献   

5.
陈宇宏  高颖  韩震  尹军峰 《茶叶科学》2022,42(5):705-716
茶皂素是一类在山茶科植物种子中含量丰富且具有特异生物活性的化合物,但不同种质茶叶籽中皂素含量及组成尚不清晰。以浙江省同一地区采集的21个茶树品种(系)的茶叶籽为试验材料,对茶叶籽的基本特征、皂素含量及组成进行测定和分析。结果表明,不同品种(系)的茶叶籽的百粒质量、壳仁比、皂素含量均有显著性差异(P<0.05)。紫外分光光度法和高效液相色谱法(HPLC)测得21个茶树品种(系)的茶叶籽的皂素含量范围分别为30.82%~48.16%和16.93%~31.82%,其中黄观音的茶叶籽皂素含量最高。利用高效液相色谱-四极杆-静电轨道阱质谱(UHPLC-Q-Exactive/MS)同时检测出68种茶叶籽皂素单体,其中Theasaponin E1的峰相对强度最大。正交偏最小二乘法判别分析(OPLS-DA)显示,21个品种(系)的茶叶籽以树型为依据被明显地划分为2组,组间差异单体物质有21种。结合相关性分析,高积累的Theasaponin E12、Camelliasaponin B1/B2、Theasaponin A5/A6、Camelliasaponin C1/C2和Assamsaponin G可能是灌木型种质资源有别于小乔木型、乔木型种质资源的重要特征物质。研究结果为生产茶叶籽皂素原料的选择和高值化利用奠定了基础。  相似文献   

6.
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%).  相似文献   

7.
To avoid predation, holothuroids produce feeding-deterrent molecules in their body wall and viscera, the so-called saponins. Five tropical sea cucumber species of the family Holothuriidae were investigated in order to study their saponin content in two different organs, the body wall and the Cuvierian tubules. Mass spectrometry techniques (MALDI- and ESI-MS) were used to detect and analyze saponins. The smallest number of saponins was observed in Holothuria atra, which contained a total of four congeners, followed by Holothuria leucospilota, Pearsonothuria graeffei and Actinopyga echinites with six, eight and ten congeners, respectively. Bohadschia subrubra revealed the highest saponin diversity (19 congeners). Saponin mixtures also varied between the two body compartments within a given animal. A semi-quantitative approach completed these results and showed that a high diversity of saponins is not particularly correlated to a high saponin concentration. Although the complexity of the saponin mixtures described makes the elucidation of their respective biological roles difficult, the comparisons between species and between body compartments give some clues about how these molecules may act as predator repellents.  相似文献   

8.
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.  相似文献   

9.
The edible seeds of the quinoa plant contain small quantities of alcohol-soluble protein which, after peptic-tryptic digestion, are unable to agglutinate K562(s) cells. When separated by affinity chromatography on sepharose-6B coupled with mannan, peptic-tryptic digest separated in two fractions. Fraction B peptides (about 1% of total protein) were shown to agglutinate K562(s) cells at a very low concentration, whereas peptides in fraction A and in the mixed fraction A+B were inactive, suggesting that fraction A contains protective peptides that interfere with the agglutinating activity of toxic peptides in fraction B.  相似文献   

10.
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.  相似文献   

11.
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.  相似文献   

12.
Due to its high nutritional value, quinoa has recently been attracting worldwide attention. The composition and secondary structure of proteins isolated from quinoa varieties from other countries have been determined, but proteins from Chinese quinoa varieties have not been described. The aim of this research was to determine the composition and secondary structure of proteins isolated from six different quinoa varieties from China. In all varieties, the protein content was 69.62–73.14%. The fat content and ash content were all less than 2%. The starch content was 20.67–23.12%. The amino acid composition and secondary structures of quinoa protein isolates (QPIs) purified from six Chinese quinoa varieties were investigated by using a combination of amino acid analysis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and Fourier transform infrared spectroscopy (FTIR). The results revealed that QPIs, with molecular weights ranging from 10.0 kDa to 50.0 kDa, were rich in essential amino acids. In addition, glutamic acid was the most abundant amino acid found in the quinoa protein isolates. The remaining amino acid contents were balanced, except for tryptophan. The secondary structures of QPIs have been quantified by the deconvolution of the amide I band of the FTIR spectrum of QPIs. The main secondary structure in quinoa isolate protein was the β-sheet (from 30.86% to 36.88%). These results will be promising guides for the use of QPIs in food processing and additives.  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

15.
Strategies for reducing plasma cholesterol have been focused on reducing the absorption or synthesis of cholesterol. The aim of this study was to correlate the content of flavonoids and saponins in black bean (Phaseolus vulgaris L.) seed coats extracts with a potential effect in lowering cholesterol absorption by the inhibition of cholesterol micellar solubility. Extracts with different flavonoids and saponins concentration were obtained from a Box-Behnken design used to optimize extraction temperature, stirring time and solvent composition. Major flavonoids and saponins were quantified by HPLC-PDA-ELSD and confirmed through mass spectrometry. Contrary to the flavonoid content, saponins were correlated to the inhibitory effect of cholesterol micelle solubility as an approach to a potential reduction of cholesterol absorption. Extracts with the highest saponin content strongly inhibited cholesterol micellization with values of 55.4?±?1.9 %, while stigmasterol used as control, only reached 12?±?2.3 % at the same concentration (5 mg/ml). The optimal extracting conditions for saponins were 25 °C, during 3 h in 85 % aqueous-methanol. Correlations of inhibitory effect of cholesterol micellar solubility with the content of each identified saponin suggested that the reduction of cholesterol micellization depends on the C-22 substitution of saponins.  相似文献   

16.
The effect of 40 h solid-state fermentation with Rhizopus oligosporus on selected parameters of white and coloured quinoa was studied, as compared to standard (30 h) product and cooked seeds.The reducing power (RP) and the activity against synthetic free radicals of standard tempe were higher by on average 140% (white) and 64% (coloured quinoa) than that of cooked seeds. The OH scavenging activity was increased by more than 7 fold (white), and over 2 fold (coloured quinoa). Prolongation of the fermentation caused further improvement in this potential, on average by 27% (OH, RP) and 24% (DPPH, ABTS+ assays). The soluble phenols i.e. vanillic acid, protocatechuic acid and rutin levels in 40 h tempe were significantly higher than in cooked quinoa. Fermented products contained 470% (white) and on average 150% (coloured quinoa) more riboflavin and 100% more thiamine (white quinoa) than cooked seeds. The levels of total protein, free amino acids and proteins releasable during the in vitro digestion, were improved as a result of 40 h fermentation. The essential amino acids profile of quinoa tempe was consistent with the reference pattern.The prolonged tempe-type fermentation of quinoa can be recommended as a method of the value-added food production.  相似文献   

17.
A new gluten-free bread formulations composed of quinoa, buckwheat, rice flour and potato starch were developed in the present study. Rheological characteristics of the bread batter with increasing amount of quinoa were determined; storage (G′) and loss modulus (G″) values were also measured for investigation of viscoelastic properties. To evaluate the quality of breads; technological and physical (bake loss %, specific volume, texture, microstructure, color), chemical (protein, moisture, ash) and sensory properties were determined. All batter formulations independent of the quinoa amount exhibited pseudoplastic behavior, and G′ values were found to be higher than G″ values in expressing the solid like characteristics of the batter. Amount of quinoa flour addition did not present significant difference on bake loss%, specific volume and protein content (p>0.05); however, 25% quinoa flour bread displayed better results with its higher sensory scores and softer texture. Quinoa and buckwheat flour mixture therefore will be a good alternative for conventional gluten-free bread formulations.  相似文献   

18.
大豆皂甙最新研究概况   总被引:20,自引:2,他引:20  
详细地论述了大豆皂甙的化学结构、在大豆中的分布以及含量。大豆皂甙种类包括有A、B、E系列以及最近发现的DDMP型系列,而DDMP大豆皂甙是大豆中的真正皂甙存在形式,由于不稳定较易降解生成通常所称的B或E系列大豆皂甙。本文还综述了大豆皂甙的最新生理功能进展,包括大豆皂甙的抗癌活性、抗HIV活性以及DDMP皂甙的抗氧化活性等。  相似文献   

19.
目的通过测定比较普通人参、西洋参和长芦人参、西洋参的总皂苷及单体皂苷Re、Rg1、Rb1的含量,以阐明长芦人参、西洋参主要成分含量的品质特点。方法采用比色法测定总皂苷含量;采用高效液相色谱法测定人参单体皂苷Re、Rg1、Rb1的含量。结果比色法测定的线性范围为15.0~75.0μg,相关系数r=0.9929;平均回收率为100.09%,RSD为0.86%(n=6)。单体皂苷Re、Rg1、Rb1与生长年份成正相关。结论长芦人参、西洋参的总皂苷含量高于普通人参、西洋参,单体皂苷含量随着年份的增长而增加。  相似文献   

20.
Patients suffering from coeliac disease have to avoid traditional cereals-based products and depend on the availability of gluten-free alternatives. The gluten-free bread matrix and its foam stability are strongly affected by the choice of ingredients. In this study, the impact of quinoa white flour on bread quality parameters, in particular volume, has been investigated. The pseudocereal proved to be a suitable substrate for dough aeration using yeast, since considerably more glucose and a higher activity of α-glucosidase were found in comparison to rice and corn flour. Consequently, quinoa white flour was used to replace 40–100% of the rice and corn flour in a gluten-free control recipe. As a result, quinoa white flour enhanced the specific volume by 33%, which was related to the absence of bran components and the increased α-glucosidase activity. The significance of the latter was proven by separately adding sucrose and fungal amyloglucosidase to the control recipe. Moreover, the crumb featured homogeneous and finely distributed gas bubbles and the taste was not compromised. Thus, it was possible to improve the quality of gluten-free bread by using quinoa white flour, which might be a relief for coeliac patients.  相似文献   

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