Functional properties of proteins isolated from phorbol ester-free physic nut (Jatropha curcas L.) seed cake

Phorbol ester-free physic nut (Jatropha curcas L.) seed cake is a nutritious protein source. Functional properties of the protein isolates obtained from various protein precipitation methods were investigated. Proteins isolated from the seed cake by ammonium sulfate gave the highest yield. The solubility of all proteins increased with increasing pH with their maximum and minimum solubility at pH of 12.0 and 4.0, respectively. The protein prepared by ethanol provided the maximum water holding capacity (3.34 mL water/g protein). The oil binding capacities of all proteins were 1.96–2.03 mL oil/g protein. The protein precipitated by ethanol showed higher emulsion activity and stability than that precipitated by acetone and ammonium sulfate. The protein obtained from ammonium sulfate gave the highest foam capacity, while the protein from acetone had the highest foam stability. Different functional properties of the proteins were achieved by various protein precipitation methods. The protein isolate obtained from each method could serve as a food ingredient applied to food products requiring a specific functional property.     

Isoelectric protein precipitation from mild-acidic extracts of de-oiled sunflower (<Emphasis Type="Italic">Helianthus annuus</Emphasis> L.) press cake

Sunflower protein extraction using sodium chloride solutions allows high extraction yields at pH ~6 while preventing oxidation and covalent binding of phenolic compounds to the proteins, which usually occurs under alkaline conditions. Since protein solubility is enhanced at high NaCl concentrations, isoelectric precipitation had to be adapted in the present study besides developing subsequent desalting steps. Precipitation losses decreased from 62 to 31% with increasing NaCl (0.6–2.0 mol/L) and protein concentrations of the solution (6–14 mg/mL) and decreasing pH of precipitation (pH 4.5–3.0). Maximum yields were achieved at low temperature (8 °C) and upon instant acid addition. After adsorptive removal of co-extracted phenolics from the protein extracts, overall protein yields were considerably higher after precipitation at pH 3.5 compared with 4.5, but only slightly higher after washing of the precipitates. The physico-chemical properties of the protein isolates did not differ significantly except for the marked protein denaturation upon precipitation at pH 3.5. From the proposed process, light-coloured protein isolates of high purity (>98%) are obtained, which are suitable for food use.     

Oil composition of coriander (<Emphasis Type="Italic">Coriandrum sativum </Emphasis>L.) fruit-seeds

Coriander (Coriandrum sativum L.) seeds were extracted with chloroform/methanol (2:1, v/v) and the amount of total lipid was 28.4% of seed weight. The major fatty acid was petroselinic acid (65.7% of the total fatty acid methyl esters) followed by linoleic acid. Chromatography on a silica column with solvent of increasing polarity yielded 93.0% neutral lipids, 4.14% glycolipids, and 1.57% phospholipids. Thin-layer chromatography on silica gel was used to obtain major neutral lipid subclasses. Fatty acid profile of neutral lipid subclasses, triacylglycerols, and sterol content were determined using gas-liquid chromatography. Six triacylglycerol molecular species were detected but one component (C54:3) corresponding to tripetroselinin, and/or dipetroselinoyl oleoyl glycerol comprised more than 50% of the total triacylglycerols. Sterol content was estimated to be at a high level (5186 µg g^-1 oil). Stigmasterol, #-sitosterol, ƕ-avenasterol, and campesterol were found to be the sterol markers. Phospholipid subclasses were separated by high-performance liquid chromatography on a silica column by gradient elution from isooctane/2-propanol (6:8, v/v) to isooctane/2-propanol/water (6:8:0.6, v/v/v) with detection at 205 nm. The major individual phospholipid subclasses were phosphatidylcholine followed by phosphatidylethanolamine, phosphatidylinositol, and phosphatidylserine.     

Cold-adapted structural properties of trypsins from walleye pollock (<Emphasis Type="Italic">Theragra chalcogramma</Emphasis>) and Arctic cod (<Emphasis Type="Italic">Boreogadus saida</Emphasis>)

Complementary DNA clones encoding trypsins were isolated from pyloric ceca of cold-adapted fish, walleye pollock (Theragra chalcogramma) (WP-T) and Arctic cod (Boreogadus saida) (AC-T). The isolated full-length cDNA clones of WP-T and AC-T were 852 and 860 bp, respectively, and both cDNAs were contained an open reading frame of 726 bp. WP-T and AC-T seemed to be synthesized as preproenzyme that contains a signal peptide, an activation peptide, and a mature trypsin. Although the amino acid sequence identities of WP-T and AC-T to that of bovine trypsin were 64 and 63%, respectively, they completely conserved the structural features for catalytic function of trypsin. On the other hand, WP-T and AC-T possessed the four Met residues (Met135, Met145, Met175 and Met242) in their molecules and the deletion of Tyr151 and substitution of Pro152 for Gly in their autolysis loops when aligned with the sequences of tropical-zone fish and bovine trypsins. In addition, the contents of charged amino acid residues at the N-terminal regions (positions 20–50) of WP-T and AC-T were extremely higher than those of other fish and bovine trypsins. Moreover, one amino acid (Asn72) and two amino acids (Asn72 and Val75) coordinating with Ca²⁺ in bovine trypsin were exchanged for another amino acids in WP-T (His) and AC-T (His and Glu), respectively, and the contents of negative charged amino acids at their Ca²⁺-binding regions were lower than those of tropical-zone fish and bovine trypsins. Therefore, it was considered that these structural characteristics of WP-T and AC-T are closely related to their lower thermostability.     

Volatile flavor composition of <Emphasis Type="Italic">gamguk</Emphasis> (<Emphasis Type="Italic">Chrysanthemum indicum</Emphasis>) flower essential oils

The volatile composition of the essential oil from fresh gamguk (Chrysanthemum indicum) flowers was investigated. The volatile constituents were extracted by the hydro distillation method. Volatile compositional changes of gamguk prepared via different drying methods (shade- and freeze-drying methods) were also determined. Total 36, 63, and 55 volatiles constituents were confirmed in the essential oil from fresh and shade-, and freeze-dried flowers. Ketones were predominant in the volatiles of gamguk flowers (%): fresh, 43.8; shade dried, 30.3; and freeze dried, 36.1. Camphor was the most abundant volatile component in all samples, and the content of borneol was also remarkable. The content of camphor was higher in fresh sample than those of dried samples while borneol concentration was significantly increased in the dried samples.     

Purification of <Emphasis Type="Italic">S</Emphasis>-Alk(en)yl alka/enethiosulfinates of garlic (<Emphasis Type="Italic">Allium sativum</Emphasis> L.) by using recycling preparative HPLC

S-Alk(en)yl alka/enethiosulfinates formed in crushed garlic were purified by using recycling preparative HPLC. Allyl 2-propenethiosulfinate and methyl methanethiosulfinate were effective separated because no other thiosulfinates were coeluted with them. Allyl methanethiosulfinate and methyl 2-propenethiosulfinate, trans-1-propenyl methanethiosulfinate and methyl trans-1-propenethiosulfinate, (cis)- and (trans)-1-propenyl 2-propenethiosulfinate were eluted as 1 peak, respectively, and further separated by using additional kinds of column. Since the quantity of trans-1-propenyl trans-1-propenethiosulfinate (PPTHS) was small in garlic, PPTHS was isolated from a mixture of blanched onion homogenate and garlic alliinase and purified. Purified thiosulfinates can be employed for the study of antimicrobial activity, flavor, and greening of garlic.     

Fractioned High Pressure Extraction of Anthocyanins from Elderberry (<Emphasis Type="Italic">Sambucus nigra</Emphasis> L.) Pomace

Fractionated high pressure extractions from dry and in natura elderberry pomace were performed in order to obtain anthocyanin rich extracts. Experiments were carried out using CO₂ supercritical fluid extraction followed by enhanced solvent extraction (ESE) with CO₂/EtOH–H₂O mixtures (1–100%, v/v), to obtain anthocyanin rich fractions in the second step, at 313 K and ~20 MPa. Higher extract yields, anthocyanin contents and antioxidant activities occurred by the presence of water, both in the raw material and in the solvent mixture. The CO₂ dissolved in the ESE solvent mixture favored either anthocyanin contents or antioxidant activities, which were not directly related. Comparing to the literature data for elderberries and grapes, these fractions had higher anthocyanins contents. From these results, an added economical value to this agroindustrial residue is proposed, using solvents and techniques “generally regarded as safe” in the food and pharmaceutical industries.     

Fruit quality of Italian pomegranate (<Emphasis Type="Italic">Punica granatum</Emphasis> L.) autochthonous varieties

Pomegranate is getting an increasing attention for its health-promoting effects. Collection and characterization of plants of local sources has been performed, and five accessions have been propagated and cultivated in a collection field for extra situ investigations. Accessions differ for pomological traits and chemical composition. Three of them, MG1, MG2, and MG3, belong to typology with low-medium acidity and high sugar content, while the other two, Tordimonte A and B, belong to typology with high acidity. In the juice and in the peels’ extract of Tordimonte A accession a high level of punicalin has been found through chromatographic determinations, while the presence of punicalagin was found in the juice of accession MG1. The accessions MG1, MG2, and MG3 seem particularly suitable for direct commercialization of fruits due to the fruit traits and quality (sweet varieties), while Tordimonte A and B could be valuable for juice processing (sour varieties).     

Effects of processing and storage on the stability of free and esterified carotenoids of red peppers (<Emphasis Type="Italic">Capsicum annuum</Emphasis> L.) and hot chilli peppers (<Emphasis Type="Italic">Capsicum frutescens</Emphasis> L.)

The stability of non-esterified carotenoids and carotenoid esters in paprika and chilli powder as affected by various processing treatments and storage conditions were studied. For this purpose, freshly harvested chilli and paprika pods were minced, immediately heated at 80, 90 and 100 °C for 5 and 10 min, respectively, and lyophilised. Alternatively, thermal treatment prior to mincing was applied. Processing resulted in a 25–34% loss of the initial carotenoid contents in chilli and 20–53% in paprika. Degradation of individual non-esterified carotenoids, mono- and diesters was monitored, generally showing an increased processing stability of mono- and diesters compared to their non-esterified counterparts. Capsanthin, capsorubin, zeaxanthin and β-cryptoxanthin mono- and diesters esterified with saturated fatty acids displayed similar stabilities, whereas susceptibility of the non-esterified pigments to degradation differed considerably. During storage over 4 months at ambient temperature pigment contents dropped by 16.7 and 9.6% in chilli and by 39.7 and 38.8% in paprika powders with and without illumination, respectively.     

<Emphasis Type="Italic">In vitro</Emphasis> characterization study of <Emphasis Type="Italic">Bacillus mojavensis</Emphasis> KJS-3 for a potential probiotic

The identification and characterization of Bacillus mojavensis KJS-3 was performed by in vitro tests. A 16S rDNA sequence and phylogenetic tree demonstrated that this isolate belongs to the B. mojavensis group. B. mojavensis KJS-3 supplies nutrients by synthesizing several vitamins. B. mojavensis KJS-3 produces α-amylase and protease. B. mojavensis KJS-3 is cultured well under aerobic conditions without gas production. B. mojavensis KJS-3 allows for assimilation of cholesterol and bile salt hydrolase activity. Finally, adhesion experiments using Caco-2 cells revealed that the adherence of B. mojavensis KJS-3 to Caco-2 cells was approximately 51.2±8.14%.     

Antioxidant synergism between fruit juice and <Emphasis Type="Italic">α</Emphasis>-tocopherol. A comparison between high phenolic black chokeberry (<Emphasis Type="Italic">Aronia melanocarpa</Emphasis>) and high ascorbic blackcurrant (<Emphasis Type="Italic">Ribes nigrum</Emphasis>)

Black chokeberry juice (Aronia melanocarpa, Elliot), blackcurrant juice (Ribes nigrum, Ben Lomond) and α-tocopherol were found to protect phosphatidyl choline against oxidation in a peroxidating liposome system as evidenced by lag phases for formation of conjugated dienes. When present together, black chokeberry juice and α-tocopherol showed a clear synergistic effect on the length of the lag phase, while effects of blackcurrant juice and α-tocopherol were additive. The concentration of total phenolics in black chokeberry juice was six times higher than in blackcurrant juice (gallic acid equivalents). Ascorbic acid corresponded to 1% of total phenolics in black chokeberry juice and 10% in blackcurrant juice. Based on the length of the lag phase, the phenolics present in black chokeberry were on an average, twice efficient as scavengers of lipid peroxyl radicals as phenolics in blackcurrant. Black chokeberry was by HPLC analysis of peroxidating liposomes, in contrast to blackcurrant, found to protect α-tocopherol efficiently against oxidation to the end of the lag phase. The phenolics present in black chokeberry juice were concluded to be more efficient in regenerating or protecting α-tocopherol than ascorbic acid or the phenolics in blackcurrant. As for the phenolics, this was further evidenced by ranking of their radical scavenging activity as studied by ESR-spectroscopy.     

Identification of a new flavanol glucoside from barley (<Emphasis Type="Italic">Hordeum vulgare</Emphasis> L.) and malt

(2R,3S)-Catechin-7-O-#-D-glucopyranoside is isolated from barley (Hordeum vulgare L.) and malt for the first time. For identification, the glucoside was isolated from acetone-water extracts of malt by polyamide clean-up and semi-preparative HPLC. The structure was elucidated by various NMR techniques, fast atom bombardment mass spectrometry and UV and circular dichroism spectroscopy. The investigation of 20 different barley varieties and the corresponding malts by HPLC with UV and coulometric electrode array detection revealed that the amount of the glucoside increases during malting. In contrast, the content of the monomeric (+)-catechin decreases and (-)-epicatechin was not detected.     

Characterization and functional properties of watermelon (<Emphasis Type="Italic">Citrullus lanatus</Emphasis>) seed protein isolates and salt assisted protein concentrates

Watermelon (Citrullus lanatus) seed meal contains significant amount of extractable protein which can be used as nutritional and functional ingredients in food formulations. Alkali (0.1 M) and NaCl (0.5 M) were used to prepare protein isolates and concentrates from the defatted watermelon seed meals. Protein isolates reported protein yield of 35.15–38.27% and protein content (79.05–83.79%) which was significantly (p≤0.05) higher than the protein concentrates. SDS-PAGE of protein isolates and concentrates showed major polypeptides in the range of 74.72–110.42 kDa. Also, in vitro pepsin digestibility showed that most of the proteins were readily digested within 30 min of hydrolysis. Amino acids were dominated by arginine, aspartic, and glutamic acid. DSC results indicated that protein concentrates had significantly (p≤0.05) higher denaturation temperatures than protein isolates. The functional properties of concentrates in terms of solubility and surface properties were better than respective isolates. The results indicated that NaCl extracted proteins had comparatively better functional properties but their yield is significantly lower than respective protein isolates.     

Effect of γ-irradiation on the physicochemical and sensory properties of walnuts (<Emphasis Type="Italic">Juglans regia</Emphasis> L.)

The present study evaluated physicochemical and sensory quality parameters of walnuts as a function of irradiation dose in order to determine dose levels causing minimal undesirable changes to walnuts. Physicochemical parameters including peroxide value (PV), hexanal content, fatty acid composition, volatile compounds and sensory parameters including color, texture, odor and taste were determined for unirradiated and irradiated walnuts at radiation doses of 1.0, 1.5, 3.0, 5.0 and 7.0 kGy. PV increased from 1.1 to 3.0 meq O₂/kg walnut oil while the hexanal content increased from 3.80 to 34.3 mg/kg walnut after irradiation at a dose of 7.0 kGy. Of the fatty acids determined, stearic and palmitic acids concentration increased while oleic acid decreased with irradiation dose. Polyunsaturated fatty acids were unaffected by irradiation. Volatile compounds such as aldehydes, ketones, alcohols and hydrocarbons increased after irradiation indicating enhanced lipid oxidation. Color parameter L*, a* and b* remained unaffected by irradiation. Sensory analysis showed that taste was the most sensitive of all sensory attributes for the evaluation of walnut quality. Based on taste and odor scores, walnuts remained organoleptically acceptable at doses ≤3.0 kGy.     

Aromatic characterization and enological potential of 21 minor varieties (<Emphasis Type="Italic">Vitis vinifera</Emphasis> L.)

The homogenization of international wine market led to a gradual impoverishment of the genetic pool. In fact, in several Spanish Quality Demarcations, the most frequent international varieties are replacing the local ones. As a result, minor varieties, perfectly adapted to the local environmental conditions, are nowadays at risk of extinction. The study of minor varieties could provide useful inputs to satisfy the demand for new and interesting wine products. This work aims at filling a gap in the existing literature, focusing on the aromatic potential of minor varieties. Here, the study of glycosidic volatile compounds and the evaluation of the influence of several variables on aroma composition were considered. Fifty-one glycosidic compounds were identified and quantified. The results revealed differences for glycosidic compounds according to cultivars, berry color, clone and sample origin. The inclusion or not of the cultivars in Quality Demarcation was also discussed. Moreover, the synthesis of some compounds involved in these differentiations seems to have a genetic component. The characterization of aromatic potential of several minor varieties, achieved for the first time, revealed that some of these (Argamusa, Quigat, Pampolat girat, Excursach, Gorgollasssa or Mandón) could represent an excellent option for winemaking and commercial offer diversification strategies, besides being important for these cultivars conservation.     

Selenium uptake and species distribution in selenium-enriched bean (<Emphasis Type="Italic">Phaseolus vulgaris</Emphasis> L.) seeds obtained by two different cultivations

In this work, bean plants were cultivated in two different ways using two modes of selenium supplementation in the form of sodium selenate. Each group consisted of the same four cultivars. Group A plants were grown in soil and twice foliarly sprayed at an interval of 10 days with an aqueous solution of 10 mg Se L⁻¹ at flowering time. Group B plants were hydroponically cultivated after the maternal seeds were soaked in nutrient solution containing the same Se content as used for foliar fertilisation. Bean seeds obtained from group A plants accumulated much more Se (around 2 μg g⁻¹ dry weight) than those seeds obtained from group B plants (around 0.6 μg g⁻¹ dry weight). No differences in Se content within each group were found. After enzyme hydrolysis, 85±7% of soluble selenium was found in group A and 65±2% of soluble Se in group B with respect to the total Se content in seeds. In bean seed supernatants SeMeSeCys, SeMet and two unknown species were found. These four species together represented 79±8 and 53±9% of the Se mass fraction of group A and group B, respectively. No differences in the presence of selenium species were found between the four cultivars and cultivation conditions.     

Nutritional and health-related compounds in sprouts and seeds of soybean (<Emphasis Type="Italic">Glycine max</Emphasis>), wheat (<Emphasis Type="Italic">Triticum aestivum.L</Emphasis>) and alfalfa (<Emphasis Type="Italic">Medicago sativa</Emphasis>) treated by a new drying method

Nutritional and health-related compounds of alfalfa, wheat and soybean seeds dried by new drying process called the DIC process (controlled instantaneous pressure release) were evaluated, before and after sprouting. Vitamins (A, B₁, B₂, B₆, C and E), minerals (Fe, Mg, Ca, K, Mn, Na, Cu and Zn) and phytoestrogens (genistein and daidzein ) content were determined. Alfalfa, soybean and wheat seeds dried by DIC showed similar content of biological compounds to seeds dried by traditional processes. Sprouting DIC-seeds significantly increased the levels of vitamins, minerals and phytoestrogens, improving their nutrititional value and health quality compared to fresh products. The increase of 1250-fold and 10-fold of the initial vitamin A and vitamin C content, respectively, of alfalfa seeds due to sprouting is remarkable. Sprouts from DIC-seeds showed a significantly higher vitamin A content than sprouts obtained from seeds dried by other methods. Soybean sprouts obtained from DIC-seeds showed a significant increase in free phytoestrogens, quantified as genistein (70.34LJ.8 mg kg^-1 d.w.) and daidzein (109.17.3ᆥ.3 mg kg^-1 d.w.).     

Coriander (<Emphasis Type="Italic">Coriandrum sativum</Emphasis> L.) seed oil improves plasma lipid profile in rats fed a diet containing cholesterol

Coriander (Coriandrum sativum L.) seed oil (COR) is a promising oil with high levels of bioactive compounds. Very little information, however, is available on the effect of administration of COR on different aspects of plasma lipid profile in experimental animals. In view of the important implications, the effect of administration of COR and oil blend [a mixture of soybean oil, coriander oil and sunflower oil (4:2:4, w/w/w; Blend)] on the profile of plasma lipids was investigated in 24 male albino rats placed on a cholesterol-rich (1%) basal diet as compared to rats on a cholesterol-free basal diet. Coriander seed oil and Blend were analyzed for composition of fatty acid, sterol and tocopherol. The levels of bioactive compounds (sterols and tocopherols) were higher in COR than in the Blend. In addition, the antiradical potential of COR and Blend was measured and the results showed that COR had stronger radical scavenging activity than Blend. In the biological experiment, rats were divided into four diet groups. The negative control group (control) consumed the basal diet (BD) only, which contained wheat starch, casein and cellulose, as well as mineral and vitamin mixtures. To the BD were added 1 g/100 g cholesterol (Chol/group), or both (Chol/COR group) and (Chol/Blend group). The groups did not differ before the experiment, which lasted 60 days. Plasma total lipids (TL), triacylglycerols (TAG), total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C) and high-density lipoprotein-cholesterol (HDL-C) were measured at day 15, 30, 45 and 60 during the experiment period. Generally, COR and Blend-supplemented diets decreased the levels of TL, TC, TAG and LDL-C in plasma. In addition, significant increase in the levels of HDL-C was observed for Chol/COR and Chol/Blend groups. The results demonstrated that COR, and to a relatively lesser degree Blend, have hypocholesterolemic properties in rats fed a cholesterol-rich diet.