Chemical investigation of Erythrina variegata Linn. seed proteins

Proteins were extracted from deoiled seeds of Erythrina variegata Linn., a potential source of non-conventional seed, in aqueous solutions of various pHs or by different concentrations of NaCl, KCl, CaCl₂ and MgSO₄ at pH 7.0. Nitrogen contents of the seeds and deoiled seeds showed good protein content. Fractionation of protein was done to separate albumin, globulin, prolamine and glutelin. Amino acid analysis of the total protein isolates (TPI) and the fractions isolated (except prolamine) identified 17 amino acids, most of which were essential. The molecular weights of TPI and the fractions were determined by SDS–PAGE electrophoresis. The results showed that TPI was composed of twelve bands, eight for globulin, nine for prolamine and six for glutelin. Studies on surface structure of the proteins and seed flour by scanning electron microscopy (SEM) are also included.     

Isolation and chemical evaluation of carob (Ceratonia siliqua L.) seed germ

The present investigation was undertaken in order to study the influence of the dehusking procedure on the germ meal composition of carob (Ceratonia siliqua L.) seeds and also to investigate its detailed composition and nutritive value. Meals of carob seed germ were obtained by acid treatment or boiling water treatment of the whole seeds. These procedures allowed to separation of the tight-fitting brown coat of the seed and the removal of the endosperm. Results indicated that the carob germ meal composition could be affected by the isolation procedures. Small reductions were observed in protein and lipid contents in germ meals from acid extraction. The analysis of the carob germ meal (containing fine fragments of husk and endosperm), which could be really obtained industrially, showed the following composition: moisture 8.3%, ash 6.5%, lipids (neutral and polar) 6.6% containing ∼21% of polar lipids, crude proteins 54.7% and energy value 17.5 kJ/g.     

Analytical nutritional characteristics of seed proteins in six wild Lupinus species from Southern Spain

The nutritional characteristics of seed proteins of Spanish wild populations of Lupinus angustifolius, L. cosentinii, L. gredensis, L. hispanicus, L. luteus and L. micranthus have been studied. Protein contents in this genus ranged from 23.8% in L. gredensis to 33.6% in L. luteus. On the one hand, L. cosentinii showed the most balanced amino acid composition, being only deficient in lysine. On the other hand, L. gredensis showed the worst amino acid composition. The in vitro protein digestibility (IVPD) was high in all species examined, ranging from 82.3% in L. gredensis to 89.0% in L. cosentinii. In addition to the amino acid composition and IVPD, other nutritional parameters, such as amino acid score, calculated biological value, predicted protein efficiency ratio or protein digestibility corrected amino acid score, were studied. These data yielded L. luteus, L. hispanicus and L. cosentinii as the species with seed proteins with the best nutritional properties, similar to those observed in other legumes with recognised high quality proteins, such as soybean. Results confirm the importance of studying wild populations of cultivated and non-cultivated Lupinus species as sources of seeds with good nutritional characteristics.     

Nutritional characteristics of seed proteins in 15 Lathyrus species (fabaceae) from Southern Spain

The nutritional characteristics of seed proteins of 15 Spanish Lathyrus species have been analyzed. Protein contents in studied Lathyrus ranged from 17.7% in Lathyrus sativus to 25.6% in L. tingitanus with a 22.4% average protein content in studied Lathyrus. Among essential amino acids the most abundant were Leu, Lys, Phe, Thr and Val. Also, all species contained Lys above FAO recommendations. On the contrary, all species were limiting in Trp ranging from 0.5% to 0.8% content and were also limiting in sulphur containing amino acids, Met and Cys. In vitro protein digestibility (IVPD) in studied Lathyrus ranged from 76.0% in L. pratensis to 86.5% in L. annuus, with an average IVPD of 80.5%. Nutritional parameters, such as protein efficiency ratio, corresponded to high quality proteins. Protein digestibility corrected amino acid score was similar to the observed in other legumes such as lentil or peanut. An analysis of similarity based on the profile of seed protein amino acid composition showed, in the cluster generated, correlation with the taxonomic classification of these species according to morphological characters. Results confirm the interest of studying wild populations of cultivated and non-cultivated Lathyrus species as source of seeds with good nutritional characteristics.     

Emulsifying and foaming properties of Phaseolus vulgaris and coccineus proteins

Protein isolates from two Phaseolus cultivars, common bean (Phaseolus vulgaris L.) and scarlet runner bean (Phaseolus coccineus L.), were prepared by wet extraction methods (isoelectric precipitation – 4000 rpm, ultrafiltration, extraction with NaCl 2%, and isoelectric precipitation – 9900 rpm). The protein isolates were characterized by sodium dodecyl sulfate–polyacrylamide gel electrophoresis and then evaluated for their solubility. The emulsion stability of emulsions produced at pH 7.0 and 5.5 with 1% or 2% or 3% w/v protein isolate was evaluated by average droplet size diameter, viscosity and creaming measurements. Emulsions with 1% protein content were unstable through storage. Emulsions with 3% w/v protein isolate concentration, extracted by ultrafiltration at pH 5.5 from both cultivars, were flocculated; this was more pronounced for coccineus isolates. The foaming properties, for the respective foams, were investigated. Foams with 1% w/v protein showed little foaming ability Ultrafiltration isolates produced more foam, which was especially stable at pH 5.5.     

Isolation,fractionation, and some chemical studies on Kleinhovia hospita Linn. seed protein

Protein was extracted from the seeds of Kleinhovia hospita Linn., which is being a nonconventional source. Extraction of K. hospita seed protein at various pH values in aqueous solution and at pH 7, different salt concentrations were done. Fractionation of protein from seeds was performed to separate albumin, globulin, prolamin, and glutelin. The amino acid compositions of total protein isolate (TPI) and the fractions were determined. A total of 15 amino acids were identified including 9 essential amino acids. Gel filtration by Sephadex G-100 revealed the presence of three components in the TPI. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis analysis of TPI and fractions showed different polypeptide bands having molecular weights ranging from 12 to 42 kDa approximately. Scanning electron microscopic study of TPI and fractions revealed the surface topology of the protein.     

Evaluation and characterisation of Citrullus colocynthis (L.) Schrad seed oil: Comparison with Helianthus annuus (sunflower) seed oil

The physicochemical properties, fatty acid, tocopherol, thermal properties, ¹H NMR, FTIR and profiles of non-conventional oil extracted from Citrullus colocynthis (L.) Schrad seeds were evaluated and compared with conventional sunflower seed oil. In addition, the antioxidant properties of C. colocynthis seed oil were also evaluated. The oil content of the C. colocynthis seeds was 23.16%. The main fatty acids in the oil were linoleic acid (66.73%) followed by oleic acid (14.78%), palmitic acid (9.74%), and stearic acid (7.37%). The tocopherol content was 121.85 mg/100 g with γ-tocopherol as the major one (95.49%). The thermogravimetric analysis showed that the oil was thermally stable up to 286.57 °C, and then began to decompose in four stages namely at 377.4 °C, 408.4 °C, 434.9 °C and 559.2 °C. The present study showed that this non-conventional C. colocynthis seed oil can be used for food and non-food applications to supplement or replace some of the conventional oils.     

Characterisation of proteins from date palm sap (Phoenix dactylifera L.) by a proteomic approach

The proteins contained in juice tapped from date palm (Phoenix dactylifera L.), from Deglet Nour variety, were analysed by the application of two-dimensional electrophoresis (2DE). Identification was carried out by mass spectrometry analyses. The SDS–PAGE patterns showed more than 100 spots of which 52 spots were identified. A proportion of the identified proteins were related to Saccharomyces cerevisiae that may belong to the natural microflora of date palm sap. These proteins are principally involved in glycolysis. While other proteins were assigned to be vegetable proteins, probably a mixture of proteins from the vascular system, which have several biological functions within the palm tree. Thus, we found enzymes involved in stress and defence reactions, in glycolysis, and photosynthesis reactions. Other enzymes are associated with carbohydrates and proteins metabolisms.     

Evaluation of aglianico grape skin and seed polyphenol astringency by SDS–PAGE electrophoresis of salivary proteins after the binding reaction

SDS–PAGE electrophoresis and densitometry analysis were carried out to evaluate the reactivity of Aglianico red grape skin and seed polyphenols with human salivary proteins in order to find a method able to assess their astringency. Analysis of the supernatant obtained after a tannin/human salivary protein binding assay and sensorial analysis showed that four proteins, lactoferrin, PRPbg1, PRPbg2 and α-amylase, were the proteins best able to distinguish tannin solutions characterised by different levels of astringency.     

Studies on seed characteristics and chemical composition of three morphotypes of Mucuna urens (L.) Medikus – Fabaceae

Seed characteristics and nutrient composition of three morphotypes of big-grained Mucuna urens (L.) Medikus were studied. Results showed that 100-seed weight ranged from 3200.2 to 4700.9 g, cotyledon weight per seed (23.2–26.6 g) and testa weight per seed (9.0–21.2 g). The testa constituted 43.7%, 28.1% and 44.7% of the average seed weight for morphotypes 1, 2 and 3, respectively. The cotyledon also constituted 56.3%, 71.9% and 55.3% of the average seed weight for morphotypes 1, 2 and 3, respectively. Nutrient composition analyses showed that the three morphotypes of M. urens are good sources of crude protein (19.97–20.57 g 100 g⁻¹), carbohydrate (72.39–75.49 g 100 g⁻¹) and fat (1.84–5.05 g 100 g⁻¹). Other nutritional components, including ascorbic acid, calcium and phosphorus are present in the three morphotypes in moderate amounts. The iron content of the M. urens is low. The three morphotypes contain appreciable amounts of essential amino acid. The oxalate content is low. The variations observed in the seed characteristics and nutrient compositions are suspected to be due to genotype. Genetic improvement of this plant is recommended to remove the itching hair trait so as to encourage its cultivation.     

Antioxidant activity of seed polyphenols in fifteen wild Lathyrus species from South Spain

Antioxidant activity of seed phenolics was studied in the following Lathyrus species: Lathyrus hirsutus, Lathyrus filiformis, Lathyrus sativus, Lathyrus cicera, Lathyrus angulatus, Lathyrus sphaericus, Lathyrus annuus, Lathyrus clymenum, Lathyrus pratensis, Lathyrus ochrus, Lathyrus aphaca, Lathyrus latifolius, Lathyrus setifolius, Lathyrus tingitanus and Lathyrus amphicarpos. Phenolic contents ranged from 3.8 mg/g meal in L. setifolius to 29.2 mg/g meal in L. sphaericus. In general, non-cultivated Lathyrus species contained higher phenolic contents than cultivated ones. A negative correlation between seed size and phenolic contents was observed and was related to the higher proportion of hulls in the smaller seeds. L. annuus possessed phenolics with highest specific antioxidant activity. These phenolics were more than two times more antioxidant than equivalent amounts of phenolics extracted from commercial chickpea, lupin or soy. On the other hand, L. aphaca possessed the highest antioxidant activity per mg of flour extract. This antioxidant activity was twice that observed in same amounts of extracted flours from commercial chickpea, lupin or soy. Results show that studied Lathyrus species are rich in phenolic compounds with higher antioxidant activity than phenolics of widely consumed legumes such as soy, chickpea or lupin. In conclusion, Lathyrus may represent an interesting source of phenolic compounds with high antioxidant activity that may be useful as natural antioxidants and contribute to revalorize the cultivation of these legumes.     

Characteristics and composition of Washingtonia filifera (Linden ex André) H. Wendl. seed and seed oil

Characteristics of seeds and oil extracted from Washingtonia filifera seeds are evaluated. The percentage composition of the W. filifera seeds is: ash 1.37%, oil 16.30%, protein content 3.46%, total carbohydrate 77.19% and moisture 3.22%. The major nutrients (mg/100 g of seeds) found in the seeds are: potassium (67.33), magnesium (34.35), calcium (187.85) and phosphorus (23.26). Physicochemical properties of the oil include: iodine value 67.33 g/100 g of oil; saponification value, 191.63 mg KOH/g of oil; refractive index (25 °C), 1.469; unsaponifiable matter, 0.83%; acidity, 0.41%; p-anisidine value, 0.87; peroxide value, 7.60 mEq O₂/kg of oil; carotenoid content 14.8 mg/100 g and the chlorophyll content = 0.13 mg/100 g. W. filifera seed oil shows some absorbance in the UV-B and UV-C ranges with potential use as a broad spectrum UV protectant. The oil contains high levels of oleic acid (40.60%) followed by lauric acid (17.87%), linoleic acid (16.26%), myristic acid (11.43%) and palmitic acid (9.23%). The triacylglycerols (TAGs) with equivalent carbon number ECN 44 (20.47%) are dominant, followed by TAGs ECN 46 (16.71%), TAGs ECN 42 (15.43%) and TAGs ECN 48 (15.41%). The DSC melting curves reveal that: melting point = 2.25 °C and melting enthalpy = 82.34 J/g. γ-Tocotrienol is the major tocol (72%) with the rest being δ-tocotrienol and α-tocotrienol. The results of the present analytical study show that W. filifera seed oil could be used in cosmetic, pharmaceutical and food products.     

Supercritical CO2 cell breaking extraction of Lycium barbarum seed oil and determination of its chemical composition by HPLC/APCI/MS and antioxidant activity

The extraction parameters for oil extraction from Lycium barbarum seed including extraction pressure, temperature and time were optimized using an orthogonal test design. The optimum conditions for supercritical CO₂ extraction were as follows: extraction pressure, 30 MPa; extraction temperature, 45 °C; dynamic extraction time, 60 min; CO₂ flow, 25 kg/h. The oil yield under the conditions proposed was 19.28 g/100 g. The effect of cell wall breakage pretreatment was investigated by supercritical CO₂ rapid depressurization, and results indicated this pretreatment could result in a rapid and efficient extraction. A sensitive fluorescent reagent 2-(11H-benzo[a]carbazol-11-yl) ethyl 4-methylbenzenesulfonate (BCETS) was utilized as pre-column labeling regent to determine fatty acids (FA) from Lycium barbarum seed oils obtained by different extraction methods. The main FA were: C18:2, C18:1, C16, C20:6, C18:3, and C20. The oil from L. barbarum seed exhibited excellent antioxidant activity in 2,2-diphenyl-1-picrylhydrazyl（DPPH）radical scavenging assay and β-carotene bleaching test, and its antioxidant activity compared well with the references ascorbic acid and α- tocopherol.     

Kaempferol acetylated glycosides from the seed cake of Camellia oleifera

The seed cake is a big by-product after crushing cooking oil from the seeds of Camellia oleifera Abel. Chemical investigation on the seed cake of C. oleifera led to the isolation of two new kaempferol acetylated glycosides (1 and 2). In addition, five kaempferol glycosides (3–7) and their aglycone, kaempferol (8), were also obtained, in addition to gallic acid (9). Their structures were determined by the detailed spectroscopic analysis and acidic hydrolysis. The new compounds were characterised as kaempferol-3-O-[4′′′′-O-acetyl-α-l-rhamnopyranosyl-(1→6)]-[β-d-glucopyranosyl-(1→2)]-β-d-glucopyranoside (1) and kaempferol-3-O-[4′′′′-O-acetyl-α-l-rhamnopyranosyl-(1→6)]-[β-d-xylopyranosyl-(1→2)]-β-d-gluco-pyranoside (2), respectively. The DPPH radical scavenging activity of all the isolated compounds was described.     

Effect of heat,rutin and disulfide bond reduction on in vitro pepsin digestibility of Chinese tartary buckwheat protein fractions

Protein fractions (albumin, globulin, prolamin and glutelin) were extracted from defatted tartary buckwheat flour. The in vitro pepsin digestibilities of the four protein fractions were different, and albumin was more susceptible to pepsin hydrolysis. The native structure of the four protein fractions may be destroyed by heat treatment, and the digestibilities were all improved significantly (P < 0.05). Adding rutin to the digestion mixture of the four fractions did not cause a decrease in pepsin digestibility, although it did cause a significant increase in certain instances (P < 0.05). Treatment with β-mercaptoethanol (2-ME) only caused a higher initial proteolysis rate and did not increase the final digestibility distinctly except for prolamin. After pepsin digestion, the remaining proteins of unhydrolyzed albumin, globulin, prolamin and glutelin (untreated) shared some similarities. They also exhibited a minor band at 20,000 Da and a broad band at 10,000–14,000 Da.     

Short-term toxicological evaluation of Terminalia catappa, Pentaclethra macrophylla and Calophyllum inophyllum seed oils in rats

The purpose of this study was to evaluate the toxicological effects of feeding the oils of Calophyllum inophyllum, Pentaclethra macrophylla and Terminalia catappa to rats. The effects on physical appearance, feed intake, weight gain, plasma and tissue cholesterol and triacyglycerol levels in rats with 5% of the oils in normal rat feed were determined. Weekly monitoring of the rats showed good physical appearance and steady weight gain, with no mortality recorded for the period of the study. Haematological analysis of the rats indicated that they were not anaemic. Histopathotogical examination of the sections of the heart, liver, kidney and spleen revealed moderate (T. catappa oil) to severe fatty change and necrosis in the liver. Glomerulonephrotic changes in the kidneys of rats fed with T. catappa oil were moderate, while it was severe in the group fed with P. macrophylla oil. Severe myocardiac necrosis as well as atherosclerotic clefts in vasa vasori was observed in the vasa vasori of the hearts of rats fed with P. macrophylla oil. This change was moderate in the heart of rats fed with C. inophyllum, while no such observation was made in the group fed with T. catappa oil. There was a significant difference in the plasma cholesterol levels of the rats fed with C. inophyllum and T. catappa oils when compared with the control rats, while those fed with P. macrophylla oil had no significant difference. The oil of T. catappa appears more suitable for consumption than the oils from C. inophyllum and P. macrophylla. Fatty acid analysis of the oils showed that they have high amounts of unsaturated fatty acids with linoleic and oleic acids as the major ones.     

Physico-chemical, amino acid composition, functional and antioxidant properties of roe protein concentrates obtained from Channa striatus and Lates calcarifer

Roe protein concentrates prepared from Channa striatus (CRPC) and Lates calcarifer (LRPC) were investigated for physico-chemical characteristics, amino acid composition, functional properties and antioxidant activity. Channa and Lates roes yielded 20.7% and 22.5% of protein concentrates possessing 90.2% and 82.5% protein, respectively. Major differences were not observed in each of the amino acids except leucine in CRPC and LRPC. The solubility of protein was 3.93-54.6% and 1.6-55.5% over a pH range of 2-12 in CRPC and LRPC, respectively. Water absorption, oil absorption, foam capacity, stability and emulsifying capacity were found to be higher in CRPC than in LRPC. Antioxidant activity determined by the radical scavenging activity and ferric reducing power was higher in CRPC. SDS-PAGE of both roe protein concentrates showed protein bands of 170, 95 and 55 kDa. Moisture sorption isotherms of protein concentrates indicated their hygroscopic nature.     

Application of Kluyveromyces marxianus, Lactobacillus delbrueckii ssp. bulgaricus and L. helveticus for sourdough bread making

The application of Kluyveromyces marxianus (IFO 288), Lactobacillus delbrueckii ssp. bulgaricus (ATCC 11842) and Lactobacillus helveticus (ATCC 15009) as starter cultures for sourdough bread making was examined. Production of lactic and acetic acids, bread rising, volatile composition, shelf-life and organoleptic quality of the sourdough breads were evaluated. The amount of starter culture added to the flour, the dough fermentation temperature and the amount of sourdough used were examined in order to optimise the bread making process. The use of mixed cultures led to higher total titratable acidities and lactic acid concentrations compared to traditionally made breads. Highest acidity (3.41 g lactic acid/kg of bread) and highest resistance to mould spoilage were observed when bread was made using 50% sourdough containing 1% K. marxianus and 4% L. delbrueckii ssp. bulgaricus. The use of these cultures also improved the aroma of sourdough breads, as shown by sensory evaluations and as revealed by GC–MS analysis.     

Influence of Botrytis cinerea infection on Champagne wine proteins (characterized by two-dimensional electrophoresis/immunodetection) and wine foaming properties

Proteins are implicated in the foam stabilization of Champagne wines. They may have a grape, yeast, bacteria or fungal origin. Botrytis cinerea is a widespread fungal pathogen, which is the causal agent for gray mold. The first part of this work showed the deleterious effect of the presence of this fungus on the foaming properties of a champenois base wine. Foamability and foam stability were reduced, respectively, by 47.7% and 33.3% in the botrytized wine, as compared to the healthy wine. In a second part, SDS–PAGE and two-dimensional electrophoresis (2-DE), coupled with immunodetection, were used to study (thoroughly) the protein patterns of both wines. With 2-DE and silver-staining detection, the disappearance of numerous spots, located in an acidic pH range, was observed. Indeed, the number of spots detected was about two times more abundant in the healthy wine than in the botrytized one, suggesting that a proteolysis occurred. On the other hand, the presence of new proteins, likely fungal proteins, proteins secreted by the plant as a response to B. cinerea infection, or even protein fragments resulting from partial proteolysis, was detected in the botrytized wine. All these modifications of the wine protein content were undoubtedly due to the presence of B. cinerea and this might be a reason for the loss of foaming properties of Champagne base wines, though no relationship between these two phenomena can be established from the results obtained.