Comparison of processing treatments on the composition and functional properties of rapeseed preparations (Brassica campestris L. var. toria)

Rapeseed preparations viz. rapeseed meal, concentrates and isolates were prepared using different processing treatments involving organic solvents, acids, alkali, steaming and boiling. Their antinutritional constituents and functional properties were studied in comparison to undefatted meal. Percent decrease in phytic acid and phenolic content was maximum in seeds boiled for 30 min and isolates, respectively. Isolate II prepared by sodium hexa-metaphosphate had minimum glucosinolates, maximum content of total proteins and much improved nitrogen solubility, emulsifying and foaming properties. Water absorption and fat absorption capacities were enhanced by boiling seeds prior to grinding and ammonia-methanol extraction, respectively. Viscosity decreased in all the treatments as compared to control.     

Glucosinolate profiles of international rapeseed lines (Brassica napus and Brassica campestris)

Seed samples from a range of international rapeseed lines (Brassica napus L and B campestris L) were analysed for glucosinolate content using high performance liquid chromatography (HPLC). This analytical method provided a total profile consisting of eight different glucosinolates, including those used to define the Canola standard. The data indicated that broad categories of distinct glucosinolate profiles existed among the seed lines analysed. Indole glucosinolate content, expressed as a percentage of total glucosinolate content, was higher in the low glucosinolate lines of B napus. The actual contents of all eight glucosinolates in the seed were variable, particularly gluconapin, glucobrassicanapin and progoitrin. The importance of this HPLC procedure in facilitating selection for high or low contents of individual glucosinolates is discussed.     

The response of proline metabolism to nitrogen deficiency in pods and seeds of French bean (Phaseolus vulgaris L cv Strike) plants

The objective of the present work was to determine the impact of nitrogen deficiency on proline metabolism in order to use this amino acid as a bioindicator of the N status of the pods and seeds of French bean (Phaseolus vulgaris L cv Strike) plants. We also identify the pathway of proline synthesis which is favoured under our experimental conditions. N was applied to the nutrient solution in the form of NH₄NO₃ at 1.45 mM (N1), 2.90 mM (N2) and 5.80 mM (N3, optimal level). Our results indicate that N deficiency is characterised by a decline in proline accumulation in both the pod and the seed, fundamentally because proline degradation is encouraged by stimulation of the enzyme proline dehydrogenase under these conditions. However, although the enzymes in charge of proline biosynthesis (ornithine‐δ‐aminotransferase and Δ¹‐pyrroline‐5‐carboxylate synthetase) vary in behaviour depending on the N status, this amino acid appeared to be synthesised mainly by the enzyme ornithine‐δ‐aminotransferase, suggesting predominance of the ornithine pathway over the glutamine pathway. Finally, under our experimental conditions, proline can be regarded as a good indicator of N deficiency, particularly in the seeds of French bean plants. © 2001 Society of Chemical Industry     

Effect of nitrogen source on oxalate accumulation in Setaria sphacelata (cv. Kazungula)

Setaria sphacelata (cv. Kazungula) was grown under controlled environment conditions on sand provided with mineral nutrient solutions containing nitrate, ammonium, urea, or nitrate plus ammonium as sole nitrogen sources. Growth in urea or ammonium resulted in small but significant decreases in oxalate concentrations of foliage compared with growth in nitrate, but nitrogen source had little effect on plant growth rates. Similar levels of potassium and total nitrogen were found in foliage from all treatments. Nitrate concentration was highest in leaves of plants supplied nitrate plus ammonium and lowest in leaves of plants supplied only ammonium as the nitrogen source. Nitrate reductase activity was virtually absent from new fully expanded leaves from all treatments, but readily detectable in young regrowth when highest activities were associated with the nitrate plus ammonium treatment and lowest with ammonium alone. Leaves continued to accumulate oxalate after reaching maturity and it is considered that anions other than nitrate must be responsible for the cation excess which prompts the synthesis of this oxalate. No diurnal variation in oxalate content of controlled environment or field grown Setaria sphacelata was observed.     

A micromethod for the screening of individual seeds and cotyledons of Brassica napus and brassica campestris (rapeseed) for low sinapine content

The association of sinapine with the fishy or crabby odour present in eggs laid by certain brown egg laying hens when fed diets containing rapeseed meal indicates the desirability of removing sinapine from the original rapeseed. A method is presented whereby seeds and cotyledons of Brassica napus and B. campestris may be selected for low levels of sinapine. The method, based on microextraction, rapid chromatographic separation of sinapine and visual estimation of its fluorescence allows detection of 0.025 μg sinapine and enables 300-400 seed samples to be screened daily.     

Solvent effects on antioxidant properties of persimmon (Diospyros kaki L. cv. Daebong) seeds

The aim of this study was to investigate the antioxidant activities of persimmon seed extracts (PSE) using different solvents such as ethanol, methanol, acetone, and their aqueous 80% solvents. The EC₅₀ values of the extracts from absolute ethanol (EE) and methanol (ME) in 2, 2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical–scavenging assay were 49.71 and 51.15 μg mL^?1, respectively, while the EC₅₀ of butylated hydroxyanisole (BHA) was 70.82 μg mL^?1. However, the EC₅₀ value of reducing power for the absolute acetone extract (AE) was higher (210.06 μg mL^?1) than that of BHA (212.67 μg mL^?1). Although the absolute ME had the highest antioxidant activity, it exhibited the lowest total phenolics and flavonoids. In contrast, the antioxidant activities of the aqueous solvent extracts showed a good correlation with total phenolics and flavonoids when compared to the absolute solvent extracts. The results showed that PSE could potentially be used as an inexpensive source of natural antioxidant in food and pharmaceutical industries.     

摘薹对甘蓝型油菜籽粒品质性状的影响及其综合评价

为了探明摘薹对油菜籽粒品质性状的影响,本研究以21份甘蓝型油菜品系为材料,进行摘薹处理与正常收获,测定籽粒中饱和脂肪酸、不饱和脂肪酸、油份、蛋白质及硫苷含量变化。结果表明：摘薹后棕榈酸、硬脂酸、亚油酸、亚麻酸、蛋白质及硫苷含量表现为增加的趋势,油酸、油份含量表现为减少的趋势,芥酸、花生烯酸含量变化趋势并不明显。相关性分析表明,摘薹后油份与油酸呈极显著正相关,二者均与棕榈酸、硬脂酸、亚油酸、亚麻酸、蛋白质呈极显著负相关。主成分及隶属函数分析表明,摘薹后y15油菜品系籽粒综合性状最优良,y12、y10、y14、y6、y19、y11、y7、y13、y20、y3、y8品系次之,y4、y2、y9品系综合得分低于对照y21。     

Aflatoxins in sunflower seeds. Influence of fungicides and insecticides

The influence of ten commercial fungicides and insecticides on growth and formation of aflatoxin B₁ by Aspergillus parasiticus NRLL 2999 and A. parasiticus RC 12 was investigated in laboratory media and for sunflower seeds. Four of the five fungicides investigated in concentrations corresponding to commercial practice inhibited growth and toxin production in the laboratory media. The fifth compound appeared to stimulate growth but formation of aflatoxin B₁ could not be detected. Among the five insecticides investigated, one inhibited toxin formation but not growth and one inhibited growth as well as toxin formation. The results obtained in laboratory media could not be confirmed for sunflower seeds. Generally inhibition was much less and after prolonged incubation of sterile seeds inoculated with A. parasiticus spores, treated seeds even tended to develop higher levels of aflatoxin B₁ than the controls.     

The activity of myrosinase from broccoli (Brassica oleracea L. cv. Italica): influence of intrinsic and extrinsic factors

The potential of some intrinsic (MgCl2, ascorbic acid, pH) and extrinsic (temperature, pressure) factors for controlling/altering activity of myrosinase from broccoli was investigated in this paper. A combination of MgCl2 and ascorbic acid was found to enhance enzyme activity. Concentrations resulting in optimal activity were determined as 0.1 g/liter and 2 g/liter, respectively. Both in the absence and presence of this enzyme activator, the optimal pH was situated between 6.5 and 7, corresponding to the natural pH of fresh broccoli juice. At atmospheric pressure, the enzyme was optimally active at a temperature about 30 degrees C. Application of low pressure (50 to 100 MPa) slightly enhanced the activity while at higher pressure (300 MPa), the activity was largely reduced. Future work should focus on the extension of this work to real food products in order to take cellular disruption into account. In intact vegetable tissues, the enzyme myrosinase is present in compartments separated from its substrate, the glucosinolates. Hence, enzymatic hydrolysis can merely occur after cellular disruption. In this respect, processes such as cutting, cooking, freezing, or pressurizing of the vegetables will have a large effect on the glucosinolate hydrolysis by myrosinase. This work could then be the basis for controlling glucosinolate hydrolysis in food preparation and processing.     

Effect of processing on the texture and structure of raspberry (cv. Heritage) and blackberry (cv. Thornfree)

This paper reports separate studies of the effect of pre-treatments (CaCl₂, low methoxyl pectin (LMP), and combined solutions) and the effect of freezing method (at four different rates) and thawing mode (at two different rates) on objective parameters, structure and sensory characteristics of fresh raspberries and blackberries. After that, the effect of a complete freezing process combining the best pre-treatments with the best freezing/thawing conditions found for each fruit was investigated. Kramer Shear Cell (KSC), back extrusion, compression and multiple penetration tests were used to measure fruit texture objectively. For calcium and LMP pre-treatments, which were applied separately, texture parameters were significantly higher in samples treated at the highest concentrations (100 mM of CaCl₂ for both fruits and 0.3 and 3% of LMP for raspberry and blackberry, respectively) compared to fresh controls. Blackberry structure was more susceptible than raspberry structure to the effect of pre-treatments. For the combined pre-treatments, the highest texture parameters were found in the samples treated with CaCl₂ (100 mM) and LMP (0.1%) in the case of raspberries and CaCl₂ (100 mM) and LMP (3%) in the case of blackberries. Combined pre-treatment did not increase firmness with respect to that of samples treated only with calcium, which indicates that CaCl₂ preserved the raspberry structure more efficiently during processing. Fruits frozen by forced convection with liquid nitrogen vapour at –40 °C were significantly firmer. Raspberries should be thawed at 5 °C, whereas blackberries may be thawed at room temperature. Sensory analysis showed that the blackberry structure was more resistant to freezing. In both fruits, over the complete process parameter values were again highest in the samples treated with 100 mM CaCl₂, applied either separately or in combination with LMP. In raspberry, panellists detected no significant differences between sensory texture parameters of the different samples, and in blackberry, panellists found no significant differences between any of the sensory characteristics. Multiple penetration maximum force (F _MP) was the parameter that best expressed product firmness for both fresh and frozen raspberries, whereas compression slope (S _C) best reflected changes in blackberries. SEM mainly corroborated results from objective texture parameters.     

Cu胁迫对小白菜生理生化特性的影响

通过模拟盆栽实验,研究了不同浓度的Cu污染对小白菜生物量(分地上部分和地下部分).体内不同部位Cu的积累量、超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、硝酸还原酶(NR)活力等生理生化指标的影响,从而为蔬菜种植中的重金属防治、诊断提供科学理论依据.实验结果表明,Cu污染对小白菜的地上部分和地下部分的生物量都有明显的负作用,Cu在体内的富集量表现为根>叶>茎,对各种保护酶均有伤害和破坏作用,随着Cu处理浓度的增加,SOD、POD、NR活性均呈现出先上升后下降的趋势,而CAT则呈现出先下降后升高的趋势.     

The effect of nitrogen nutrition on the lysine content and protein composition of barley seeds

Increases in the total grain nitrogen of barley (cv. Julia and Bomi), resulting from increased N fertilisation, are accompanied by decreases in the relative lysine content of the grain proteins. Extraction of the grain proteins shows that the high-N grain have increased relative and total amounts of the lysine-poor storage protein (hordein) fraction. There are only small increases in the total amounts of the other more lysine-rich protein fractions (salt-soluble proteins and glutelin+residue proteins). There is also little or no effect on the amino acid compositions of the fractions. Consequently, it is concluded that the decreased relative lysine content of the whole grain is due to the increased synthesis of hordein. Further evidence for this hypothesis comes from similar studies with the high-lysine mutant, Risø 1508, in which the high-lysine character results from a decrease in the relative and total amount of hordein. The hordein fraction does not increase disproportionately with increasing grain N, nor does the relative lysine content of the grain decrease. There is no effect of grain N on the polypeptide compositions of the salt-soluble proteins of either line. However, in Bomi and Julia increased grain N does result in an increase in the relative amount of sulphur-poor ‘C’ hordein polypeptides in the hordein fraction. It is speculated that this results from limitation of S relative to N.     

葡萄糖酸内酯处理对辣椒保鲜效果的研究

以苏椒5号为试材,研究了常温条件(15±5)℃下葡萄糖酸内酯(0.2%、0.6%、1.0%)处理对辣椒采后生理和品质的影响。实验结果表明,葡萄糖酸内酯能够显著地抑制辣椒贮藏前期的呼吸作用,降低贮藏期间辣椒的腐烂率和失重率,保持表皮绿色和较高的叶绿素含量,减缓VC的损失,诱导POD活性;本实验比较三种浓度的效果,以1.0%葡萄糖内酯处理的效果最好。      

Storage time effect on the rheology of refrigerated potato tissue (cv. Monalisa)

 Potato tubers were held in refrigerated storage and their firmness periodically sampled over a period of 140 days. At each sampling, the rheological properties uniaxial compression, shear, uniaxial tension, successive cycles of stress relaxation, creep compliance and texture profile analysis were determined, as was moisture content. Compression energy, maximum shear force, longitudinal tension stiffness and maximum tension deformation, stress relaxation parameters and moisture content were all significantly affected by storage time. Relaxed forces decreased consistently and linearly with time over a 140-day storage period, reflecting the decrease in cell turgor pressure resulting from the predominance of water loss through evaporation over water production. Longitudinal tension stiffness and maximum shear force increased linearly in the early stages, reflecting the increase in cell wall stiffness and elastic tissue behavior. Maximum tension deformation increased linearly with time reflecting the plastic deformation of the cell wall caused by growth in cell turgor pressure at early stages. Changes in the trends of rheological parameters over 140, 64 and 28 days evidenced the importance of extending the time period considered for rheological parameters of potato tissue. Received: 28 December 1999     

Simultaneous determination of neonicotinoid insecticides in sunflower-treated seeds (hull and kernel) by LC-MS/MS

A validated analytical method to determine seven neonicotinoids (dinotefuran, nitenpyram, thiamethoxam, clothianidin, imidacloprid, acetamiprid and thiacloprid) in sunflower seeds (hull and kernel) using HPLC coupled to electrospray ionisation mass spectrometry (ESI-MS) is presented. Sample clean-up based on a solid–liquid extraction, and the removal of lipid fraction, in the case of kernels, is proposed and optimised. Low limits of detection and quantification were obtained, ranging from 0.3 × 10^–3 to 1.2 × 10^–3 µg g^–1 and from 1.0 × 10^–3 to 4.0 × 10^–3 µg g^–1, with good precision, and recovery values ranged from 90% to 104% for hulls and kernels. The method was applied for the analysis of five thiamethoxam-dressed sunflower seeds and four non-treated seeds, where, besides thiamethoxam, residues of the other neonicotinoid, clothianidin, were also detected and confirmed via tandem mass spectrometry (LC-ESI-MS/MS). Finally, the presence of residues of thiamethoxam and clothianidin in collected sunflower seeds (hulls) coming from coated seeds confirmed the translocation of these neonicotinoids through the plant up to these seeds.     

Metabolic changes of biochemical constituents in developing fennel seeds (Foeniculum vulgare)

Fennel (Foeniculum vulgare) is the major spice/condimental crop of Haryana, generally used in India for preparing pickles and in vegetable cooking. Flowers were tagged at anthesis, fennel seeds (local variety) were collected at 1-week intervals after 40 days from anthesis for studying biochemical constituents. Moisture and protein contents decreased significantly with the advancement of seed development. Oil content ranged from 68 to 135·7 g kg^?1 (dry weight basis), which increased with seed development. The oil content was greater in mature seeds. The presence of phytate (11·35–13·10 mg g^?1) was also observed, which affects the availability of Zn and Fe. Fennel seeds were found to be a rich source of micro- and macroelements. Neutral detergent fibre, acid detergent fibre, cellulose and lignin contents increased significantly with the advancement of seed development. Oleic and linoleic fatty acids were found to be major fatty acids and variable proportions of different fatty acids were observed.     

油菜种子油体的观察和大小分析

研究油菜种子树脂半薄切片和超薄切片,发现胚子叶细胞被蛋白体和油体所充实,蛋白体为球状晶体蛋白体,油体大小差异较大,小油体呈球形,大油体呈椭球形。油体经分离和统计分析,表明小油体数量较多,平均直径为0．57μm;大油体数量较少,平均直径为2．39μm;不同大小油体的数量随着油体体积的增加而逐渐减少。     

Proximate and fatty acid composition changes in developing sandalwood (Santalum spicatum) seeds

Changes in the proximate composition of developing seeds of sandalwood (Santalum spicatum R Br) were quantified. The developing fruits were collected regularly over a period of 5 months commencing 14 days after flower opening. Rapid deposition of seed lipid began at about 91 days after flowering (DAF) at a level of 4 g kg⁻¹ and continued to about 396 g kg⁻¹ at 147 DAF. Protein and ash contents displayed similar trends to that of lipid with a corresponding decrease in moisture content. Fatty acid analysis of the seed oil demonstrated marked changes in composition during seed development. In particular, major increases in oleic and ximenynic acids were noted with corresponding decreases in the other fatty acids. © 1997 SCI.     

Effect of nitrogen fertilization on quality markers of strawberry (Fragaria × ananassa Duch. cv. Aromas)

BACKGROUND: Nitrogen is an indispensable element for fruit metabolism and low or excessive N levels can affect the accumulation of the most important components that contribute to the flavour and aroma of the fruit. Among them, sugars, acids and volatile compounds can be considered quality markers. The objective of this study was to evaluate the effect of N fertilization on these quality markers of the fruit at two harvest dates. RESULTS: Strawberry plants were grown in a hydroponic system and N was applied as Ca(NO₃)₂ at concentrations of 0.3, 3 and 6 mmol L^?1 in the nutrient solution. Total soluble solids, soluble carbohydrates, amino acids and organic acids and volatile compounds of the fruit were analyzed. The fruits produced at 3 and 6 mmol L^?1 N had higher contents of esters, soluble carbohydrates and amino acids. The hexanal content increased with the 6 mmol L^?1 dose. The effect of fertilization was more marked at the second harvest date. CONCLUSION: The availability of N in strawberry plants affected the accumulation of quality markers. The fruits expected to have the best flavour and aroma, with both high levels of soluble carbohydrate and esters and low levels of hexanal, were obtained with 3 mmol L^?1 nitrate in the solution. Copyright © 2009 Society of Chemical Industry     

The effect of the pre-treatments and the long and short-term frozen storage on the quality of raspberry (cv. Heritage)

Results are presented of the effect of pre-treatments before freezing followed by long and short-term frozen storage (12 months at –18 °C and 24 days suffering temperature fluctuations between –18 °C and –12 °C) on quality parameters of raspberry. Pre-treatments were carried out with calcium, low methoxyl pectin, a combined solution, and results compared with untreated control fruits. Kramer shear, back extrusion, compression, and multiple penetration tests were used to measure rheological behavior. One-hundred mM CaCl₂ reduced the long and short-term frozen storage induced loss of firmness. For long-term storage at –18 °C, a softening of the tissue became evident between 3 and 12 months and at each date test the stored fruits were firmer than those without storage. For short-term storage with fluctuations, the loss of firmness was evident between 0 and 24 days, and at all the testing dates the stored fruits were softer than those without storage. Results evidenced a higher cell damage in the short-term frozen storage. Coefficients of softening per day suffering fluctuation were determined, the highest values being given by Kramer shear energy and back extrusion maximum force (>1%). Short-term frozen storage affected physical and physico-chemical characteristics, increasing the saturation (r) and the anthocyanins and decreasing the ascorbic acid of the raspberries. In both storage conditions, pre-treatments reduced the drip loss, which correlated best with the Kramer shear energy. Panelists detected mainly time effect on the sensory firmness. For long-term, sensory firmness and juiciness gave the highest correlations with back extrusion maximum force, while for the short-term, sensory firmness and drip loss gave the highest correlations with the Kramer shear energy. SEM revealed different degrees of mechanical damage to structure, which accounted for rheological behavior of the fruits.