The most important bioactive components of cold pressed oil from different pumpkin (Cucurbita pepo L.) seeds

The composition and content of certain bioactive components of the cold pressed oil obtained from six samples of pumpkin seeds (Cucurbita pepo L.) cultivated in Serbia were analyzed by GC and GC/MS. The composition and content of fatty acids, tocopherols and phytosterols, and the total content of squalene were determined. The results indicate oil's excellent quality, with high contents of monounsaturated fatty acids (37.1 ± 0.70–43.6 ± 0.69 g/100 g of total fatty acids), total tocopherols (38.03 ± 0.25–64.11 ± 0.07 mg/100 g of oil), sterols (718.1 ± 6.1–897.8 ± 6.8 mg/100 g of oil) and especially squalene (583.2 ± 23.6–747 ± 16 mg/100 g of oil). High content of squalene, phytosterols and monounsaturated fatty acids recommend the use of this type of the oil in the nutritional and medical purposes.     

Variability of vitamin E content in pumpkin seeds (Cucurbita pepo L)

Pumpkin (Cucurbita pepo L.) seed oil is a common salad oil which is produced in the southern parts of Austria, Slovenia and Hungary. It is dark green and has a high content of free fatty acids. Due to its colour, the oil cannot be used for cooking. The content of vitamin E, especially-tocopherol, is very high. The oil content of the pumpkin seed is about 50%. The seed itself can be eaten. Therefore a pumpkin variety with high vitamin E content is desirable. The aim of this work was to find a variety ofCucurbita pepo which has a high oil yield and a high vitamin E content. A total of 100 breeding lines were tested for their tocopherol content. The tocopherols and tocotrienols are extracted with hexane and analysed by NP-HPLC/FLD with hexane/dioxan (96/4) as eluent, with fluorescence detection at 292/335 nm. The/gg-tocopherol content, which is about 5–10 times as much as that of -tocopherol varies over a broad range (41–620 mg/kg dry pumpkin seeds).- and-tocopherol are found at low levels.     

Analysis of giant pumpkin (Cucurbita maxima) drying kinetics in various technologies of convective drying

The paper analyses the results of the research on drying a variety of giant pumpkin (Justynka – 957). The research involved drying kinetics of pumpkin as well as changes in the volume of 10 mm pumpkin cubes, dried at the temperature of 80 °C, using free (natural) convection and in the forced convection in the tunnel dryer, with the drying factor speed of 1.2 m s⁻¹ and in the fluid bed dryer. Drying kinetics of pumpkin pieces dried in the tunnel dryer, fluid bed dryer and during two-stage initial drying in the tunnel, and in the fluid bed dryer were examined. Measurements results were used to verify the theoretical models of drying kinetics of the first period taking volume shrinkage into consideration, and the second period of the examined processes.     

Lipid classes,fatty acid composition and triacylglycerol molecular species in the kernels of pumpkin (Cucurbita spp) seeds

The lipids extracted from the kernels of pumpkin (Cucurbita spp) seeds of three cultivars were classified by thin layer chromatography into six fractions: steryl esters (SEs, 0.5–1.2%), triacylglycerols (TAGs, 92.7–93.4%), free fatty acids (FFAs, 2.9–3.5%), sn‐1,3‐diacylglycerols (1,3‐DAGs, 0.4–0.9%), sn‐1,2‐diacylglycerols (1,2‐DAGs, 0.7–0.9%) and phospholipids (PLs, 1.5%). Fatty acids derivatised as methyl esters were analysed by gas chromatography with flame ionisation detection. Molecular species and fatty acid distributions of TAGs, isolated from the total lipids in the kernels, were analysed by a combination of argentation thin layer chromatography (TLC) and gas chromatography. A modified argentation TLC procedure, developed to optimise the separation of the complex mixture of total TAGs, provided 11 different groups of TAGs, based on both the degree of unsaturation and the total chain length of fatty acid groups. With a few exceptions, SM₂ (5.8–20.1%), S₂D (8.8–11.2%), M₃ (6.7–24.8%), SMD (6.8–16.7%), M₂D (16.7–23.6%), SD₂ (4.6–15.1%) and MD₂ (4.9–18.6%) were the main TAG components. These results suggest that there are significant differences (P < 0.05) not only in fatty acid distributions of acyl lipids but also in molecular species of TAGs among the three cultivars. The differences in pumpkin cultivars could be appreciable, based on the distribution of molecular species in TAGs. However, pumpkin seed kernels could be utilised successfully as a source of edible oils for human consumption. Copyright © 2004 Society of Chemical Industry     

Color stability of pumpkin (Cucurbita moschata, Duchesne ex Poiret) puree during storage at room temperature: Effect of pH, potassium sorbate, ascorbic acid and packaging material

The color stability of pumpkin (Cucurbita moschata, Duchesne ex Poiret) puree of pH 4.00 and 5.00 containing potassium sorbate (KS), ascorbic acid (AA) or their mixture, packaged in polyethylene and in polyvinyl chloride-polyvinylidene chloride copolymer (PCPC) bags, was analyzed throughout the storage at 25 °C. Color changes were measured through lightness (L), redness (a), yellowness (b). Changes in a and b were mathematically modeled. In general, lightness, redness and yellowness diminished with storage time. The presence of KS diminished color loss of purees packed in PCPC bags and increased the discoloration of purees contained in polyethylene suggesting, in the first case, that KS oxidation diminished the available oxygen protecting carotenoids oxidation, and in the second case, the existence of a coupled oxidation between KS and carotenoids helped by the oxygen presence. Addition of AA to a puree of pH 4.00 containing KS and packed in polyethylene minimized the losses of redness and yellowness; probably as a consequence of the antioxidant action of AA. The increase in pH from 4.00 to 5.00 in the presence of KS significantly minimized color degradation of puree packed in PCPC. From the point of view of improving color stability, a convenient formulation could be a puree of pH 5.00 preserved with KS and packed in PCPC.     

Roasting effects on fatty acid distribution of triacylglycerols and phospholipids in the kernels of pumpkin (Cucurbita spp) seeds

In this study, changes in fatty acid distributions of pumpkin seeds (Cucurbita spp) in the course of the roasting process were investigated. Whole pumpkin seeds were exposed to microwaves for 6, 12, 20 or 30 min at a frequency of 2450 MHz. The kernels were separated from the seeds, and the lipid components and the fatty acid distributions of triacylglycerols (TAGs) and phospholipids (PLs) were analysed by a combination of thin layer chromatography and gas chromatography. Major lipid components were TAGs, free fatty acids (FFAs) and PLs, while steryl esters and diacylglycerols were also present in minor proportions. The greatest PL losses (p < 0.05) were observed in phosphatidyl ethanolamine, followed by phosphatidyl choline or phosphatidyl inositol. With a few exceptions, significant differences (p < 0.05) in fatty acid distributions occurred when the seeds were microwaved for 20 min or more. Nevertheless, the positional characteristics of fatty acid distributions in the TAGs were still retained after 20 min of roasting: unsaturated fatty acids were predominantly concentrated in the sn‐2‐position, and saturated fatty acids primarly occupied the sn‐1‐ or sn‐3‐position. These results suggest that no significant changes in fatty acid distribution of TAGs and PLs would occur within 12 min of microwave roasting, thus ensuring that a good‐quality product would be obtained. Copyright © 2005 Society of Chemical Industry     

New vitamin E isomers (gamma-tocomonoenol and alpha-tocomonoenol) in seeds,roasted seeds and roasted seed oil from the Slovenian pumpkin variety ‘Slovenska golica’

The Štajerska region in north-eastern Slovenia and the Styria region in southern Austria have a long tradition of growing pumpkins (Cucurbita pepo L.) as an oil crop. GC-MS determination of the free and esterified minor compounds in oil of roasted pumpkin seeds from the Slovenian C. pepo L. variety ‘Slovenska golica’ revealed the presence of two previously unreported compounds: alpha-tocomonoenol and gamma-tocomonoenol. Using the GC-MS data, reference samples (Crude Palm Oil) and tocopherol and tocotrienol standards it was possible to assign and quantify alpha-tocomonoenol (17.6 ± 0.6 μg/g) and gamma-tocomonoenol (118.7 ± 1.0 μg/g) compounds in roasted ‘S. golica’ seed oil using HPLC. The concentrations of alpha-tocopherol and gamma-tocopherol were 77.9 ± 1.9 μg/g and 586.0 ± 4.6 μg/g, respectively. Surprisingly the gamma-tocotrienol concentration found was only 6.9 ± 0.2 μg/g. Analysis of the seeds from which the oil was pressed showed the initial gamma-tocotrienol amount was even lower (1.6 ± 0.1 and 2.2 ± 0.1 μg/g in the ground and roasted seeds, respectively) than in the roasted seed oil.     

Cold-induced ethylene in relation to chilling injury and chilling sensitivity in the non-climacteric fruit of zucchini (Cucurbita pepo L.)

Zucchini is a non-climacteric fruit which is harvested immature on reaching about 18 cm in length. In the present paper we compare fruit quality parameters in different zucchini cultivars with the production of ethylene and the expression of two ethylene biosynthesis genes (CpACS1 and CpACO1) throughout postharvest storage at 4, 12 and 20 °C. In fruit stored at 12 or 20° ethylene production and expression of CpACS1 and CpACO1 genes remained very low throughout the whole storage period. Ethylene production was also low at 4 °C, but was induced rapidly upon transfer to 20 °C for a minimum of 4 h. The expression of both CpACS1 and CpACO1 genes was also induced by storage at 4 °C. This cold-induced ethylene is not necessary for triggering chilling injury (CI) symptoms in zucchini, since they were already evident in the cold chambers before rewarming of the fruit and, therefore, before the burst of ethylene. However, the level of the cold-induced ethylene was lower in those cultivars that were more tolerant to CI, and it fell in response to temperature conditioning treatments that alleviate CI symptoms.     

Characterisation of phenolic components present in raw and roasted wattle (Acacia victoriae Bentham) seeds

The effect of roasting on the phenolic components of Australian wattle (Acacia victoriae Bentham) seed was investigated. Wattle seeds were roasted at 200 °C for 5–30 min and ground to flour, which were then extracted with 70% acetone. The total phenolic and flavonoid contents of the extracts were determined, and the phenolic components were analysed by reverse phase-high performance liquid chromatography (RP-HPLC) coupled with an on-line post-column reaction system to determine the active antioxidant peaks. The major peaks were then purified by preparative HPLC and identified by gas chromatography–mass spectrometry (GC–MS) analysis. Roasting of wattle seeds resulted in significant increases in its soluble phenolic content. The concentration of total phenolics and flavonoids in the seeds roasted for 30 min was more than nine and four times higher, respectively, than that in the raw seeds. The major phenolic acids present in wattle seeds were found to be succinic and gallic acids, the concentration of which increased by up to 10-fold as a result of roasting.     

Determination of oligosaccharide contents in 19 cultivars of chickpea (Cicer arietinum L) seeds by high performance liquid chromatography

The extraction procedure of oligosaccharides from chickpea seeds was optimized and sufficient extraction was achieved with 50% of ethanol-water in a ratio of 10:1 for solvent to defatted chickpea meal at 50 °C for 30 min. Under the optimal extraction conditions, the contents of oligosaccharides in 19 cultivars of chickpea seeds were determined by HPLC. The results showed that the main α-galactooligosaccharides (α-GOS) in chickpea seeds were raffinose, stachyose, verbascose and an unknown glycoside, which was isolated, purified, and identified as ciceritol. Ciceritol, the main sugar in all the chickpea samples, accounted for about 50% of the total α-GOS. There were considerable variations in the levels of α-GOS and sucrose between species, especially verbascose which could only be detected in 7 samples. With the highest amount of α-GOS and a low amount of sucrose, the 171 was the best choice for obtaining α-GOS for use as a prebiotic in functional foods.     

Isolation and purification of a novel antioxidant protein from the water extract of Sundakai (Solanum torvum) seeds

Reactive oxygen species (ROS) at physiological concentrations may be required for normal cell function. Excessive production of ROS can be detrimental to cells, because ROS can cause oxidative damage to lipids, proteins, and DNA. Herein, we describe the isolation and purification of a novel antioxidant protein the water extract of dried, powdered Sundakai (Solanum torvum [Solanaceae]) seeds. Sundakai belongs to the Solanaceae family, a small shrub, which is distributed widely in India, Malaya, China, Phillipines and tropical America. Fifty percent of ammonium sulphate-precipitated crude water extract was fractionated on a Sephadex G100 column, which yielded two peaks, PI and PII. Peaks PI and PII inhibited lipid peroxidation up to 40% and 89%, respectively in linolenic acid micelles. Rechromatographing of peak PII on Sephadex G100 yielded a single peak, indicating the homogeneity of the purified protein. SDS–PAGE analysis indicated the molecular weight of the purified protein to be ∼28 kDa. The purified protein, at 0.8 μM, inhibited deoxyribose degradation induced by generation of hydroxyl radicals by 90% and scavenged DPPH (1,1-diphenyl-2-picrylhydrazyl) radicals by 76%. The reducing power and chelating power of the purified protein, at 0.8 μM, were found to be 72% and 85%, respectively. The protein, at 0.8 μM, also offered significant protection to calf thymus DNA damage induced by H₂O₂ (1 mM). Therefore, the present study demonstrates, for the first time, a novel protein from the water extract of Sundakai seeds as an excellent antioxidant.     

罗汉果种仁油脂的提取及其性质研究

首次对罗汉果种仁油脂进行提取。并对其性质做了初步的研究。用索氏提取法对研碎的种仁及种籽(含种仁)分别进行油脂提取,再通过实验测定油的密度、水分、酸价、过氧化值、皂化值、碘价,并对其进行了红外光谱和质谱分析。实验结果表明:罗汉果种仁含有48.5%油脂,油脂中含不饱和脂肪较多,并含有大量的角鲨烯,具有较高的开发价值。     

Isolation and characterisation of collagens from the skin,scale and bone of deep-sea redfish (Sebastes mentella)

To make more effective use of underutilised resources, collagens from skin, scale and bone (SKC, SCC and BOC) of deep-sea redfish were isolated with acetic acid and characterised for their potential in commercial applications. The abundant ash and fat in the materials could be removed effectively by EDTA and hexane treatment in 24 h, with high recoveries of protein. The yield of SKC (47.5%) was significantly higher than that of SCC and BOC (6.8% and 10.3%, respectively). The denaturation temperatures of SKC, SCC and BOC were 16.1 °C, 17.7 °C and 17.5 °C, respectively, which were lower than those of most other fish species. The amino acid profiles of these collagens were similar with a low imino acid content, which might be the reason for the low denaturation temperature. All the collagens were type I mainly and maintained their triple helical structures well with slight molecular structure differences. SKC possessed a higher degree of intermolecular cross-linking and molecular order, but the extent of peptide chain unwinding was also higher, due to the existence of fewer hydrogen bonds, compared to SCC and BOC.     

Effect of cooking and sterilisation on the composition of amino acids in immature seeds of flageolet bean (Phaseolus vulgaris L.) cultivars

The aim of the work was to evaluate the amino acid content and protein quality in products of immature bean seeds with a dry matter content of 40%. The investigation included raw seeds, fresh seeds after cooking to consumption consistency and seeds after canning. Raw seeds of the cultivar Alamo contained more amino acids in 100 g fresh matter than the seeds of the cultivars Flaforte and Mona. Cooking and sterilisation brought about decreases in the content of all the amino acids in the investigated cultivars; 1–50% and 9–60% respectively. Higher losses being noted in sterilised seeds. If the results were expressed in 16 g N, the differences in amino acid content were much smaller. The amino acid content of Mona was lower than that of the remaining cultivars. The cooking of seeds did not bring about changes in relation to the raw material (except tyrosine which showed a decrease 35–45%); however, sterilisation affected the content of most amino acids (from −45 to +17%). Compared with the standard (FAO/WHO/UNU, 2007), the limiting amino acid was cystine with methionine (amino acid score 70–83). Of the seeds prepared for consumption, sterilised bean seeds had a higher EAA index value, while of the cultivars, the seeds of Alamo had the highest value (147–162).     

超高效液相色谱-串联质谱法测定食品包装材料中全氟辛酸及其盐类物质

建立了超高效液相色谱-串联质谱(UPLC-MS/MS)结合加速溶剂萃取测定食品包装材料中全氟辛酸及其盐类物质(PFOA)的方法.采用甲醇作为溶剂,加速溶剂提取法提取食品包装材料中的PFOA,提取液经0.2 μm有机滤膜过滤后,以甲醇、水为流动相,梯度洗脱,经UPLC分离后用多级反应监测(MRM)方式测定.用两个子离子的...     

Influence of temperature and pH on the degradation of deoxynivalenol (DON) in aqueous medium: comparative cytotoxicity of DON and degraded product

Deoxynivalenol (DON), a toxic fungal metabolite, is stable under different processing conditions; however, its stability in aqueous medium at different temperatures and low pH (1–2) (present in the gastrointestinal tract) has not been investigated. In the present study, DON standard was used to study the influence of temperature and pH on DON stability in aqueous medium, the characterisation of the degraded product, and the comparative toxicity profile of the degraded and the parent compound. The results suggest that standard DON was unstable at 125–250°C showing 16–100% degradation whereas DON at pH 1–3 had 30–66% degradation, with a concomitant increase in the formation of a degraded product. Further ESI-MS characterisation of the dominant precursor ion of the HPLC eluate of the DON-degraded product was found to be m/z 279, resembling the known metabolite DOM-1. The degraded product of DON was reconfirmed as DOM-1 by comparison with standard DOM-1 and both gave a similar λ_max at 208 nm. Comparative studies of both standard DOM-1 and the degraded product of DON showed no cytotoxicity up to 6400 ng ml^–1 while significant cytotoxicity was observed for DON (400 ng ml^–1). The results suggest that a highly acidic environment (pH 1–2) could be responsible for the de-epoxydation of DON leading to the formation of DOM-1.     

Accumulation and species distribution of selenium in Se-enriched bacterial cells of the Bifidobacterium animalis 01

Bifidobacterium animalis 01 (B. animalis 01) could absorb 16.7–39.6% of inorganic selenium in the medium and transform most of it into organic selenium. Most of the organic selenium (50.7–63.0%) was found in the protein fraction, 9.62–18.7% in the polysaccharide fraction, 0.273–0.754% in the nucleic acid fraction, and 20.8–30.9% in other components. Furthermore, the selenium content of different protein extractions was in the following order: Alkaline-soluble protein-bound Se (46.5–53.4%) > Water-soluble protein-bound Se (27.4–30.8%) > Salt-soluble protein-bound Se (7.79–11.9%) > Alcohol-soluble protein-bound Se (not detected). Additionally, the molecular mass of most proteins or protein subunits containing selenium was about 10–20 kDa. Analysis by LC–MS showed that selenomethionine (SeMet) is the major selenocompound in protein.     

Characterisation of the chemical composition and in vitro anti-inflammation assessment of a novel lotus (Nelumbo nucifera Gaertn) plumule polysaccharide

Lotus plumule has been recognised as an anti-inflammatory agent. A novel lotus plumule polysaccharide (LPPS) was prepared, characterised and cultured with splenocytes from non-obese diabetes (NOD) and BALB/c mice (as a control) to further evaluate its anti-inflammatory effects in this study. The results showed the molecular weights of LPPS respectively distributed at 391 kDa (89.8 ± 0.5%) and 5 kDa (10.1 ± 1.5%) using HPLC analysis. The neutral sugar composition in LPPS comprised xylose (33.4 ± 10.0%), glucose (25.7 ± 1.6%), fructose (22.0 ± 15.0%), galactose (10.5 ± 3.3%), and fucose (8.1 ± 3.5%). LPPS administrations at appropriate concentrations significantly (P < 0.05) increased interleukin (IL)-10, IL-6, tumour necrosis factor (TNF)-α secretions by splenocytes from both NOD and BALB/c mice at ages of 15, 22 and 26 weeks, respectively. However, LPPS administrations markedly (P < 0.05) increased secretion ratios of anti-/pro-inflammatory (IL-10/IL-6) cytokines by splenocytes. The present study suggests that LPPS may have potential to treat type 1 diabetes via its potent anti-inflammatory activity.     

Chromatographic separation and physicochemical properties of collagen species in the skin of deep-sea redfish (Sebastes mentella)

Type I collagen (PSC-I) and type V collagen (PSC-V) were directly separated by DEAE-cellulose chromatography without salt precipitation from the skin of deep-sea redfish after limited pepsin digestion. The yields of PSC-I and PSC-V were 79.4% and 8.4%, respectively. The denaturation temperature of PSC-V (17.8 °C) was significantly higher than that of PSC-I (15.9 °C), as a result of its higher total content of imino acid (17.1%) and hydroxylation degree of proline and lysine (44.7%) than those of PSC-I (14.7% and 35.8%). However, the intrinsic viscosity and viscosity transition temperature span of PSC-I (14.4 dL/g and 8 °C) were considerably higher than those of PSC-I (13.5 dL/g and 5 °C), which could be attributed to its greater extent of triple helix and more intermolecular crosslinks as shown by SDS-PAGE pattern and infrared spectra.