Sapogenin Content Research Articles

Ultrasound-assisted Co-extraction and characterization of saponin-rich Co-extracts from fenugreek seeds (Trigonella foenum-graecum L.) and quinoa husk (Chenopodium quinoa Willd.) and their hydrolysates

The co-extraction of steroidal and triterpenoid saponins, followed by hydrolysis to produce sapogenin-rich extracts, offers an efficient strategy to enhance the multi-bioactive potential of extracts. The resulting chemical composition modifications, including the presence of other co-extracted or co-hydrolyzed compounds, must also be considered. In this study, ultrasound-assisted co-extraction of fenugreek seeds and quinoa husk using methanol and 50% aqueous methanol was conducted to obtain extracts and co-extracts with varying proportions of steroidal and triterpenoid saponins, in ratios of 0:100, 25:75, 50:50, 75:25, and 100:0, respectively. Aqueous methanol produced the highest extraction yields (15–25%) and saponin contents (40–70%) in the extracts and co-extracts. The conversion by microwave-assisted acid hydrolysis of saponins to sapogenins was more efficient for triterpenoid saponins, leading to a higher triterpenoid sapogenin content in all co-extracts, accounting for over 70% of the total sapogenins. The co-extracts also contained other bioactive compounds, such as phenolic compounds (3–4 g/100 g), with their content being favored by the presence of fenugreek. Hydrolysis altered the overall composition of the saponin-rich co-extracts, enriching the resulting hydrolyzed products in both types of sapogenins, along with fatty acids, carbonyls, non-protein nitrogen compounds and organic acids, while reducing monoglycerides, removing carbohydrates and significantly modifying the phenolic profile by eliminating many original phenolic compounds and generating new ones. Therefore, co-extraction and post-extraction hydrolysis of fenugreek and quinoa allowed the combination of triterpenoid and steroidal saponins or sapogenins into single products, along with other specific compounds from both sources.

Queen of all herbs (Asparagus racemosus): an assessment of its botany, conventional utilization, phytochemistry and pharmacology

Shatavari (Asparagus racemosus), a member of the Asparagaceae family, is vital in Ayurveda since it may prevent and treat hundreds of ailments. It is known as "herb's queen."Its bioactive constituents include steroidal glycosides, saponins (primarily Shatavarins I, II, III and IV), polyphenols, flavonoids, alkaloids (racemosol) and vitamins. Shatavari is a popular shrub in folk and Ayurvedic medicine due to its sapogenin content, which is the precursor to many pharmacologically active steroids. Most of its components are medicinal, but roots, stems and leaves are the most essential. Shatavari "Rasayanas" boost immunity and infection resistance. Due to its phytochemicals, it is used to cure several illnesses. Due to its phytochemicals, it is used to cure several illnesses. Shatavari has many medicinal properties such as anti-spasmodic, anti-oxidant, anti-diabetic, anti-allergic, anti-malarial, protective, anti-neoplastic activities, immune response enhancement, anti-arthritic, anti-inflammatory, anti-periodic, anti-ulcerogenic action, immune modulatory antistress, anti-diarrheal, antidepressant infections, tuberculosis and so on. Commercial Shatavari extract medications are anti-leprotic, anti-abortifacient, antibacterial, antipyretic and analgesic. Shatavari root, leaf, flower and stem extracts treat dyspepsia, mental disorders, cough, bronchitis, throat and female reproductive system issues.

Extraction and analysis of ruscogenins from butcher’s broom (Ruscus aculeatus L.) rhizomes using HPLC

Butcher’s broom (Ruscus aculeatus L.) is a plant with valuable chemical composition and many medical applications. The underground rhizomes of the plant contain steroidal saponins, compounds with proven therapeutic effects and used mostly in treating venous insufficiency. The research aimed to optimise the extraction of saponins from butcher’s broom rhizomes to obtain the highest possible content of active compounds in the dry extract. The extraction was carried out in five variants using pure water or a mixture of water and ethanol as solvents in different potions. Three samples of butcher’s broom rhizomes from Albania, Bulgaria, and Germany were examined for the presence of highest level of sapogenin active ingredient. Results show that Albanian sample has the highest percentage of ruscogenins, and hence Albanian butcher’s broom rhizomes were chosen for the extraction of active ingredient by alcoholic solution with different concentration. The sapogenin content in the extracts was determined by the pharmacopoeial method using high performance liquid chromatography (HPLC). A strong, positive correlation was found between ethanol concentration and the content of ruscogenins in the dry extract. The most efficient variant of the extraction turned out to be the use of 50% ethanol as a solvent, where 304 mg of ruscogenins were obtained from 50 g of the raw material.

Microwave-Assisted Acid Hydrolysis vs. Conventional Hydrolysis to Produce Sapogenin-Rich Products from Fenugreek Extracts.

The acid hydrolysis of saponins is commonly performed by conventional heating to produce sapogenin-rich products of bioactive interest, but alternative hydrolysis methods and their impact on bioactivity have been unexplored. We compared the conventional method with microwave-assisted acid hydrolysis (MAAH) of a commercial saponin-rich extract from a typical saponin source, fenugreek, focusing on the study of temperature (100, 120, 130, 140, 150 °C) and time (10, 20, 30, 40 min) of hydrolysis. The impact of these factors was assayed on both the sapogenin yield and the bioactivity of the hydrolyzed products, specifically their antioxidant and lipase inhibitory activities. The highest sapogenin content (34 g/100 g extract) was achieved by MAAH at 140 °C and 30 min, which was higher than conventional hydrolysis at both reference conditions (100 °C, 60 min, 24.6 g/100 g extract) and comparative conditions (140 °C, 30 min, 17 g/100 g extract) (p < 0.001). Typical steroid artifacts from sapogenins were observed in very small amounts, regardless of the method of hydrolysis. Antioxidant activity of MAAH hydrolyzed extracts (around 80% DPPH inhibition) was barely affected by time and temperature, but pancreatic lipase inhibitory activity was higher (>65%) at lower MAAH temperature (<130 °C) and time (<30 min) of hydrolysis. MAAH is shown as a valid alternative to produce selective sapogenin-rich extracts from fenugreek with minor impact on their bioactivities, and whose magnitude can be modulated by the hydrolysis conditions.

Characterization of Saponins from Differently Colored Quinoa Cultivars and Their In Vitro Gastrointestinal Digestion and Fermentation Properties.

Quinoa contains rich saponins, which are removed during processing and cause ecological waste. We extracted saponins from quinoa (SEQ) in black, white, and red cultivars and compared their composition by spectrophotometric assay and high-performance liquid chromatography analysis combined with acid hydrolysis. The digestion and fermentation properties of SEQ were investigated using an in vitro model. Our results showed that acid hydrolysis released sapogenins, mainly phytolaccagenin (PA), hederagenin (HD), and oleanolic acid from SEQ. Varying from SEQ in red, SEQ in black and white had a similar composition and content of sapogenins. Gastrointestinal digestion did not release sapogenins from SEQ but reduced the antioxidant activity of SEQ. Gut microbiota from human feces released PA and HD from SEQ. Reciprocally, SEQ in black significantly increased the growth of Lactobacillus spp. and Bifidobacterium spp., while reducing the growth of Shigella spp. The present study provides guidance for further investigation about the bioactivities of saponins from quinoa.

Effect of Fertilizers on the Sapogenin Yields of Dioscorea composita in Puerto Rico

Seedlings of Dioscorea composita were treated with various combinations of ammonium sulfate, superphosphate, and potassium sulfate over a 3-year period. The tubers of the resulting plantings were tested for sapogenin content. Complete fertilization increased the sapogenin yields significantly as compared with an untreated control. Incomplete combinations or single-nutrient treatments did not significantly increase yields and, in some cases, decreased them. Yield increases were associated with increased fresh and dry weight. Although no significant effects of fertility on percentage of sapogenin were found, tubers in unfertilized plots contained the highest sapogenin in percentage.

Brief Review on Shatavari (Asparagus racemosus) and Its Medicinal Uses

Asparagus racemosus is another name for shatavari. It belongs to the family asparagaceae. It is an adaptable plant as well. The adaptation of human body to mental and physical stress is said to be achieved by the help of adaptogenic herbs like these.&#x0D; Shatavari is an ayurvedic medicine staple that is made available in the form of analeptic for the wellbeing and vitality of person.&#x0D; It is popular among all therapeutic plants due to various active biochemicals present in it such as steroidal glycosides, saponins (Shatavarins I, II, III, and IV), flavonoids, polyphenols, vitamins and alkaloids (racemosol). Shatavari extracts from its different parts like roots, flowers, leaves and stems are effective in treating female organs which are involved in reproduction.&#x0D; For centuries, ayurvedic medicine has employed shatavari. However, there haven't been enough human trials to recommend it for any medical problem. It is, however, safe to consume it in modest doses, and doing so will allow you to benefit from its antioxidant and immune-boosting properties.&#x0D; Except for being an indigenous medicinal plant which known to be important for its sapogenin content which is the precursor of many active pharmacological steroids, it also has many medicinal uses like antioxytoxic (shatavarin four),spasmodic to uterus, hypertensive as well as hypoglycemic activity, anticoagulant activity, antiviral activity, anticancer and antidysentric activity. In ayurvedic medicine asparagus racemosus is considered as tonic specific to females .Despite of being a herb which is rejuvenating it is used in infertility cases of females, increases libido , enhances ovulation as well as folliculogenesis, also increases lactation.

CRISPR/Cas9-Mediated Targeted Mutagenesis of CYP93E2 Modulates the Triterpene Saponin Biosynthesis in Medicago truncatula.

In the Medicago genus, triterpene saponins are a group of bioactive compounds extensively studied for their different biological and pharmaceutical properties. In this work, the CRISPR/Cas9-based approach with two single-site guide RNAs was used in Medicago truncatula (barrel medic) to knock-out the CYP93E2 and CYP72A61 genes, which are responsible for the biosynthesis of soyasapogenol B, the most abundant soyasapogenol in Medicago spp. No transgenic plants carrying mutations in the target CYP72A61 gene were recovered while fifty-two putative CYP93E2 mutant plant lines were obtained following Agrobacterium tumefaciens-mediated transformation. Among these, the fifty-one sequenced plant lines give an editing efficiency of 84%. Sequencing revealed that these lines had various mutation patterns at the target sites. Four T0 mutant plant lines were further selected and examined for their sapogenin content and plant growth performance under greenhouse conditions. The results showed that all tested CYP93E2 knock-out mutants did not produce soyasapogenols in the leaves, stems and roots, and diverted the metabolic flux toward the production of valuable hemolytic sapogenins. No adverse influence was observed on the plant morphological features of CYP93E2 mutants under greenhouse conditions. In addition, differential expression of saponin pathway genes was observed in CYP93E2 mutants in comparison to the control. Our results provide new and interesting insights into the application of CRISPR/Cas9 for metabolic engineering of high-value compounds of plant origin and will be useful to investigate the physiological functions of saponins in planta.

Analysis of saponin composition and comparison of the antioxidant activity of various parts of the quinoa plant (Chenopodium quinoa Willd.).

Quinoa plant is a valuable food crop because of its high nutritional and functional values. Total saponin content, sapogenins, polyphenol, and flavonoid contents and antioxidant activities were analyzed in various parts of quinoa plants, including sprout, seeds, bran, pericarp, leave, stem, and root. Quinoa seeds (QS) had significantly higher sapogenin content than quinoa stem (QT), quinoa leaves (QL), and quinoa roots (QR). Quinoa saponin was mainly composed of phytolaccagenic acid. Quinoa root (QR) had the highest amount of total saponin (13.39 g 100 g−1), followed by quinoa bran. The highest total phenolic content (30.96 mg GAE 100 g−1) and total flavonoid content (61.68 mg RE 100 g−1) were observed in quinoa root extract and 1‐month‐old sprout extract, respectively. Quinoa sprouts showed better antioxidant activity than fully grown parts of the quinoa plant. Overall, root and sprout had a higher antioxidant capacity compared to other parts of the quinoa plant, suggesting the potential use of quinoa root and sprout as a nutraceutical ingredient in the health food industry.

Supercritical CO2 extraction of steroidal sapogenins from fenugreek (Trigonella foenum-graecum L.)seed

Supercritical CO2 extraction was applied on fenugreek (Trigonella foenum-graecum L., Fabaceae) seeds with the aim to define optimal process conditions to obtain the maximal extract yields content of steroidal sapogenins. Central composite rotatable design (CCRD) combined with response surface methodology (RSM) was applied to determine optimal process conditions defined by the influence and interaction of pressure, temperature and time of extraction through consumption of SC CO2. Optimization experiments revealed that the pressure of 24.73 MPa, the temperature of 38.?C and the consumption of SC CO2 of 19.24 g/gDM were the best process conditions enabling the maximal yield of extract and gain of the highest content of sapogenins. The optimal values of pressure and temperature defined SC CO2 density of 885.47 kg/m3, which provided the maximal yield of the extract with the highest content of steroidal sapogenins. The achieved yield of extract at these conditions was 0.073g/gDM, with 0.774 mg/gDM diosgenin, 0.477 mg/gDM protodioscin, 0.713 mg/gDM sarsapogenin and 0.205 mg/gDM oleanolic and ursolic acid with a significant quantity of 2.475 mg/gDM in the obtained extract.

Assessment of Fatty Acid, Proximate and Quantitative Phytochemical Compositions of Matured Stem of Costus afer (Bush Cane).

This study estimated the fatty acid, proximate and quantitative phytochemical compositions of Costus afer matured stem collected from Choba campus of University of Port Harcourt, in Choba community, Rivers State. This was carried out using standard procedures of analysis (fatty acid and proximate) as well as gas chromatographic method (quantitative phytochemical analysis). The fatty acid analysis of the plant stem revealed high contents of linolenic acid (32.26%), linoleic acid (25.89%) and palmitic acid (25.48%) and moderate levels of oleic acid (7.11%) and stearic acid (6.36%) while myristic acid, palmitoleic acid, arachidonic acid, behenic acid and lignoceric acid was low and caprylic acid, capric acid, lauric acid, margaric acid, arachidonic acid, erucic acid were absent. The results of the proximate composition of the stem of Costus afer indicated that total carbohydrate composition of Costus afer stem was the highest (54.98%) while crude fat had the lowest value of 1.15%. The moisture content had a moderate value of 22.15% while total ash (4.60%), crude protein (7.72%) and crude fibre (9.40%) values were low. The gas chromatographic analysis of the stem indicated that the total alkaloid composition was 70.59mg/100g with high compositions of papaverine (44.72%), methyl morphine (23.24%), morphine (17.92%) and narcotine (14.11%). The total flavonoids concentration was 28.29mg/100g. Myricetin (69.79%) had the highest value with moderate levels of quercetin (14.88%) and kaempferol (9.78%). The total composition of saponin was 2.87mg/100g. The sapogenin content of the stem (39.20%) was the highest with moderate levels of diosgenin (26.13%), saponine (22.12%) and tigonine (9.76%) while gitogenin value (2.28%) was observed to be low. The analysis of the plant stem showed the presence of glycosides (22.35mg/100mg) made up mainly of costugenin (65.60%), digitoxin (18.73%), digoxin (6.28%), salicin (4.76%) and low levels of ouabain (1.95%) and kaemferol-3-rhamnoside (1.08%). The study has shown that matured stems of Costus afer can contribute greatly towards meeting human nutritional requirements and suggest the possibility of its use in folklore medicine.&#x0D; Keywords: Costus afer, phytochemicals, proximate composition, fatty acids.

Production of sapogenins (stigmasterol and hecogenin) from genetically transformed hairy root cultures of Chlorophytum borivilianum (Safed musli)

Chlorophytum borivilianum belonging to the family Liliaceae, is distributed in the pantropical regions of India and South Africa. The sapogenins (stigmasterol and hecogenin) of C. borivilianum are well known for their appetizing and aphrodisiac properties. The present study involves enhancing the sapogenin content in C. borivilianum by genetic transformations with Agrobacterium rhizogenes strains (MTCC 2364 and 532, PRT Gus). A maximum transformation frequency of 98% was obtained with Agrobacterium rhizogenes MTCC 2364 strain with rhizome explants after a co-cultivation period of 48 h. Two potential rhizoclones (2364a and 2364b) were selected for the production of stigmasterol and hecogenin. The maximum production of stigmasterol (83.952 ± 0.01 mg/g) was seen in 2364b rhizoclone, whereas, the highest accumulation of hecogenin (81.52 ± 0.02 mg/g) was observed in 2364a rhizoclone. The C. borivilianum hairy root cultures obtained in this study provide a continuous and sustainable production of stigmasterol and hecogenin on a commercial scale.

Next-generation sequencing of representational difference analysis products for identification of genes involved in diosgenin biosynthesis in fenugreek (Trigonella foenum-graecum)

Main conclusionRepresentational difference analysis of cDNA was performed and differential products were sequenced and annotated. Candidate genes involved in biosynthesis of diosgenin in fenugreek were identified. Detailed mechanism of diosgenin synthesis was proposed.Fenugreek (Trigonella foenum-graecum L.) is a valuable medicinal and crop plant. It belongs to Fabaceae family and has a unique potential to synthesize valuable steroidal saponins, e.g., diosgenin. Elicitation (methyl jasmonate) and precursor feeding (cholesterol and squalene) were used to enhance the content of sterols and steroidal sapogenins in in vitro grown plants for representational difference analysis of cDNA (cDNA-RDA). To identify candidate genes involved in diosgenin biosynthesis, differential, factor-specific libraries were subject to the next-generation sequencing. Approximately 9.9 million reads were obtained, trimmed, and assembled into 31,491 unigenes with an average length of 291 bp. Then, functional annotation and gene ontogeny enrichment analysis was performed by aligning all-unigenes with public databases. Within the transcripts related to sterol and steroidal saponin biosynthesis, we discovered novel candidate genes of diosgenin biosynthesis and validated their expression using quantitative RT-PCR analysis. Based on these findings, we supported the idea that diosgenin is biosynthesized from cycloartenol via cholesterol. This is the first report on the next-generation sequencing of cDNA-RDA products. Analysis of the transcriptomes enriched in low copy sequences contributed substantially to our understanding of the biochemical pathways of steroid synthesis in fenugreek.

GC-MS Profiling of Triterpenoid Saponins from 28 Quinoa Varieties (Chenopodium quinoa Willd.) Grown in Washington State.

Quinoa (Chenopodium quinoa Willd) contains 2 to 5% saponins in the form of oleanane-type triterpenoid glycosides or sapogenins found in the external layers of the seeds. These saponins confer an undesirable bitter flavor. This study maps the content and profile of glycoside-free sapogenins from 22 quinoa varieties and 6 original breeding lines grown in North America under similar agronomical conditions. Saponins were recovered using a novel extraction protocol and quantified by GC-MS. Oleanolic acid (OA), hederagenin (HD), serjanic acid (SA), and phytolaccagenic acid (PA) were identified by their mass spectra. Total saponin content ranged from 3.81 to 27.1 mg/g among the varieties studied. The most predominant sapogenin was phytolaccagenic acid with 16.72 mg/g followed by hederagenin at 4.22 mg/g representing the ∼70% and 30% of the total sapogenin content. Phytolaccagenic acid and the total sapogenin content had a positive correlation of r2 = 0.88 (p < 0.05). Results showed that none of the varieties we studied can be classified as "sweet". Nine varieties were classified as "low-sapogenin". We recommend six of the varieties be subjected to saponin removal process before consumption. A multivariate analysis was conducted to evaluate and cluster the different genotypes according their sapogenin profile as a way of predicting the possible utility of separate quinoa in food products. The multivariate analysis showed no correlations between origin of seeds and saponin profile and/or content.

Sapogenin content variation in Medicago inter-specific hybrid derivatives highlights some aspects of saponin synthesis and control.

In the Medicago genus, saponins are a complex mixture of triterpene glycosides showing a broad spectrum of biological properties. Here we analyzed the variation in the sapogenin content and composition of inter-specific hybrid Medicago sativa×Medicago arborea derivatives to highlight the pattern of this variation in plant organs (leaves/roots) and the possible mechanisms underlying it. In Sativa Arborea Cross (SAC) leaves and roots, saponins and sapogenins were evaluated using chromatographic methods. Phenotypic correlations between sapogenin content and bio-agronomic traits were examined. Expression studies on β-amyrin synthase and four cytochromes P450 (CYPs) involved in sapogenin biosynthesis and sequence analysis of the key gene of the hemolytic sapogenin pathway (CYP716A12) were performed. Chromatographic analyses revealed a different pattern of among-family variation for hemolytic and nonhemolytic sapogenins and saponins and for the two organs/tissues. Different correlation patterns of gene expression in roots and leaves were found. Diachronic analysis revealed a relationship between sapogenin content and gene transcriptional levels in the early stages of the productive cycle. The results suggest that there are different control mechanisms acting on sapogenin biosynthesis for leaves and roots, which are discussed. A key role for medicagenic acid in the control of sapogenin content in both the tissues is proposed and discussed.

Medicago truncatula CYP716A12 Is a Multifunctional Oxidase Involved in the Biosynthesis of Hemolytic Saponins

Saponins, a group of glycosidic compounds present in several plant species, have aglycone moieties that are formed using triterpenoid or steroidal skeletons. In spite of their importance as antimicrobial compounds and their possible benefits for human health, knowledge of the genetic control of saponin biosynthesis is still poorly understood. In the Medicago genus, the hemolytic activity of saponins is related to the nature of their aglycone moieties. We have identified a cytochrome P450 gene (CYP716A12) involved in saponin synthesis in Medicago truncatula using a combined genetic and biochemical approach. Genetic loss-of-function analysis and complementation studies showed that CYP716A12 is responsible for an early step in the saponin biosynthetic pathway. Mutants in CYP716A12 were unable to produce hemolytic saponins and only synthetized soyasaponins, and were thus named lacking hemolytic activity (lha). In vitro enzymatic activity assays indicate that CYP716A12 catalyzes the oxidation of β-amyrin and erythrodiol at the C-28 position, yielding oleanolic acid. Transcriptome changes in the lha mutant showed a modulation in the main steps of triterpenic saponin biosynthetic pathway: squalene cyclization, β-amyrin oxidation, and glycosylation. The analysis of CYP716A12 expression in planta is reported together with the sapogenin content in different tissues and stages. This article provides evidence for CYP716A12 being a key gene in hemolytic saponin biosynthesis.

Ruminal metabolism in sheep of saponins from Yucca schidigera.

Fifty-five mg per kg live weight of crystallized Yucca schidigera saponins, corresponding to 26 mg/kg live weight of sapogenins, was given daily intraruminally to two lambs for 11 consecutive days. Neither of the lambs showed any sign of toxicity throughout the experimental period. One lamb was killed 5 h after the last dose and GC-MS analysis of the free and conjugated sapogenin content samples of liver, and of the contents of the rumen, omasum, abomasum, duodenum, jejunum, ileum, colon and rectum, of faecal samples collected before dosing started, and of parts of the administered Yucca saponin were performed. The Yucca material contained mainly sarsasapogenin and smilagenin saponins. Ingested saponins were quickly hydrolysed in the rumen to free sapogenins and, in part, epimerized at C-3 to afford episapogenins. The absorption of free sapogenins appeared to occur in the jejunum. The metabolism of Yucca saponins was identical to that of Narthecium ossifragum saponins, and it is suggested that Yucca saponins could replace N. ossifragum saponins for toxicity studies on the latter plant.

Physical, morphological and chemical characteristics, oil recovery and fatty acid composition of Balanites aegyptiaca Del. kernels.

Balanites aegyptiaca Del. kernels were chemically, physically and morphologically characterized. Crude oil (49.0%) and crude protein (32.4%) were the two major constituents of the kernels. Phytic acid content was relatively high compared to other legumes. In contrast, antitryptic activities of the kernel flours were very low. Sapogenin contents of the full fat, defatted and testa flours were 1.5, 2.7 and 3.0%, respectively. The hardness of the kernel was found to be about 10.4 x 10(5) N/m2, which was somewhat high. The morphological structure of the kernel using a scanning electron microscope revealed that the protein matrix was embedded in a lake of oil droplets. Oil recovery, as a function of pressing time, pressure, temperature and particle size was investigated. With increasing temperature up to 70 degrees C at 400 bar, for 120 min, an oil recovery of 79.4% was obtained. Using an expeller at 115 degrees C, about 85% of the kernel oil was recovered. The reduction of particle size had a negative effect on oil recovery under the same conditions. The fatty acid composition was not affected by the pressing temperature up to 115 degrees C. The total amount of the unsaturated fatty acids was found to be up to 74.8% (50 degrees C) and 75.1% (115 degrees C) of the total fatty acids content.

Occurrence of sapogenins in leaves and seeds of quinoa (Chenopodium quinoa Willd)

Seeds of the Andean seed crop quinoa usually contain saponins in the seed coat. Saponins give a bitter taste sensation and are a serious antinutritional factor. Therefore selection of sweet genotypes with a very low saponin content in the seeds is a main breeding goal. However, selection for sweet genotypes is retarded by cross-pollination. Early identification of sweet and bitter quinoa genotypes before anthesis would speed up breeding considerably. The ability to distinguish sweet and bitter genotypes was investigated in a glasshouse and in a field experiment. In the glasshouse experiment the content of sapogenins was determined in leaves of sweet and bitter quinoa genotypes at successive stages of plant development and finally in the seeds. Detectable amounts of sapogenins were found earliest 82 days after sowing in leaves of both sweet and bitter quinoa genotypes. The total sapogenin content in leaves of sweet and bitter genotypes increased during plant development but remained lower than the content found in the seeds. The sapogenin content in seeds of sweet genotypes varied from 0.2 to 0.4 g kg−1 dry matter and in seeds of bitter genotypes from 4.7 to 11.3 g kg−1 dry matter. The difference in sapogenin content between leaves and seeds was much higher in bitter genotypes than in sweet genotypes. Hederagenin was the major sapogenin found in leaves, and oleanolic acid in seeds. In the field experiment it was found that the content of sapogenins in the leaves of F2 plants of crosses between both quinoa types did not differ between sweet and bitter genotypes. The obtained results demonstrated that sweet genotypes could not be selected before anthesis on the basis of the sapogenin content in the leaves. © 2000 Society of Chemical Industry

Recovery and characterization of Balanites aegyptiaca Del. kernel proteins. Effect of defatting, air classification, wet sieving and aqueous ethanol treatment on solubility, digestibility, amino acid composition and sapogenin content.

In order to find alternative protein sources in African regions where protein deficiency in nutrition is prevailing, solubility, in-vitro digestibility, amino acid composition and chemical score of Balanites aegyptiaca Del. kernel proteins were investigated as a function of different processing steps including defatting, air classification, wet sieving and aqueous ethanol treatment. Air classification delivered a fine fraction of 58.1% of the total protein. Applying a wet sieving process, a protein concentrate of 72.9% protein content was achieved but the recovery was very low (35.6%). However, in case of isoelectric precipitation followed by aqueous ethanol treatment both protein content (78.2%) and recovery (53.7%) were high. Data concerning the chemical score revealed, that lysine content of the defatted kernel flour amounted to 74.2% of the recommended FAO/WHO standard level. In-vitro protein digestibility was found to be higher than of legume proteins. The digestible protein of the full fat flour, defatted flour, air classified and wet sieved fine fractions and protein concentrate were 91.9, 93.7, 82.0, 86.4 and 94.2%, respectively. The sapogenin content per 100 g protein of the investigated protein preparations was significantly lower (46% to 62%) than of the initial material (oilcake).