Determination of the geographical origin of Slovenian black locust,lime and chestnut honey

The geographical origin of three Slovenian unifloral honey types (black locust, lime and chestnut) was investigated by analysis of some physico-chemical parameters, the elemental content using total reflection X-ray fluorescence spectrometry (TXRF) and the stable carbon and nitrogen isotope ratios using isotope ratio mass spectrometry (IRMS). The results were interpreted by chemometric methods. A total of 122 samples of Slovenian black locust, lime and chestnut honeys were collected from domestic beekeepers all over Slovenia for three years. Slovenia is a small country by area, but paedologically and climatically diverse, therefore offering interesting possibilities for studying geographical influences. The combination of the investigated parameters offers the possibility of distinguishing among samples of specific honey types from the four different Slovenian natural-geographical macroregions, namely the Alpine, Dinaric, Pannonnian and Mediterranean regions. Lime honey samples were 100% correctly classified, while the success rates for black locust and chestnut honeys were slightly lower at 98.2% and 94.6%, respectively.     

Dimensional changes of extracted and non-extracted small wood specimens of black locust ( Robinia pseudoacacia L.)

From straight grained heartwood of black locust (Robinia pseudoacacia L.), specimens, 3 cm×3 cm in cross section and 0.5 mm (or 10 mm) in axial direction, were cut and used for the determination of dimensional changes and the rate of tangential swelling. Mean radial, tangential and axial shrinkage was 5.30%, 6.67% and 0.16%, respectively, while the coefficient of anisotropy was 1.26. Half of the specimens for the determination of the rate of tangential swelling were extracted for 48 h with distilled hot water. The tangential dimensional change and the time taken to attain half maximum swelling in air-dry and oven-dry specimens were assessed according to a common technique. Extractive removal resulted in an increase of the total magnitude of tangential swelling in both air-dry and oven-dry specimens. However, no significant differences in time taken to attain half maximum swelling between air-dry and oven-dry specimens were observed after extraction. The rate of tangential swelling was lower in air-dry specimens than in oven-dry specimens after 30 min of immersion in water when were non-extracted and after 5 min of immersion in water when were extracted. Extracted air-dry specimens had a greater rate of tangential swelling than non-extracted air-dry specimens and the same occurred for oven-dry specimens. Extraction resulted in a higher diffusion coefficient for air-dry specimens. The diffusion coefficient calculated for non-extracted air-dry specimens (0.901×10^–4 cm²/min) showed that black locust is a difficult species to impregnate.     

Mycotoxins,trace elements,and phthalates in marketed rice of different origin and exposure assessment

ABSTRACT

The aim of this study was to determine levels of 11 mycotoxins, 10 trace elements, and 6 phthalates in rice samples from Serbian and Chinese market. Mycotoxins were not detected in any of the analysed rice samples. Results revealed similar median levels for following elements: Mn, 17.5 and 15.7 mg kg^?1; Fe, 2.47 and 2.12 mg kg^?1; Cu, 1.95 and 1.59 mg kg^?1 in marketed samples from Serbia and China, respectively. Median concentration of Ni in Serbian marketed samples was 1.9 times higher than in Chinese ones. The median levels (µg kg^?1) of phthalates ranged from 1.2 (benzylbutyl phthalate [BBP]) – 566 (di(2-ethyl-hexyl) phthalate [DEHP]) and 1.7 (BBP) – 348 (DEHP) in Serbian and Chinese marketed samples, respectively. The results were used to assess daily exposure of Serbian and Chinese adult consumers. The calculated target hazard quotients indicated that the potential risk attributable to the analysed contaminants in rice samples should not be of concern neither for the Serbian nor the Chinese consumers.     

Measurement of wood and bark particles acidity and their impact on the curing of urea formaldehyde resin during the hot pressing of mixed panels

In the manufacture of panels, pH value is an important property to measure, especially when a pH-dependent resin like urea-formaldehyde (UF) is used. It has been proven that UF cures very well and faster in an acidic environment. In this study the acidity (pH value and buffering capacity) of both outer and inner white birch bark particles as well as that of wood particles or fibres used together with those barks as reinforcement for the manufacture of three layers particleboards was measured. The results show a significant difference between the acidity of white birch bark and wood. Barks have a lower pH as well as higher acid and alkaline buffering capacities. It was also found that the pH value of inner white birch bark is lower than that of the outer part. The significant differences observed enabled to realize that inner bark should be separated from outer bark and used separately in mixed panels manufacture. The platen temperature should be reduced when the outer bark is used in the surface of mixed panels to avoid pre-cure or over-cure. This study confirms the linear relationship between the pH and the absolute and relative buffering capacities.     

Glycogen content, buffering capacity and resting pH in live muscles of pigs of different halothane genotypes (a pilot project)

The development of PSE (pale, soft and exudative) meat is characterized by a rapid decrease in pH post-mortem and/or a low ultimate pH. We investigated some physiological properties of the live muscle (the glycogen content, the non-bicarbonate buffering capacity and 'resting pH'), which could influence both the decrease in pH and the ultimate pH. Measurements were performed on three halothane genotypes, hal(N)hal(N), hal(N)hal(n) and hal(n)hal(n), with their known predispositions for PSE meat. It was demonstrated that the glycogen content in both the groups of double recessive and heterozygous individuals was higher than the levels in the group of homozygous dominant pigs. No difference was found in non-bicarbonate buffering capacity between the groups. The groups with the highest glycogen levels also had the lowest 'resting pH' values. The results indicate that measurement of glycogen content in vivo may be superior to the halothane test in detecting PSE-prone individuals. The lower pH values of carriers of the hal(n) gene further indicate that the characteristic rapid decrease after slaughter may not be as fast as generally accepted, as even very low pH values can be observed in the muscles of live pigs.     

Fumonisin contamination and fumonisin producing black Aspergilli in dried vine fruits of different origin

Aspergillus niger isolates are able to produce fumonisins in high quantities on agar media with a low water activity. Several agricultural products fit this criterion, including dried vine fruits, dates and figs. Data on the occurrence and role of this species in fumonisin contamination of agricultural products with high sugar content are needed to clarify the importance of A. niger in human health. The mycobiota and fumonisin contamination of various dried vine fruit samples collected from different countries were examined to clarify the role of black Aspergilli in fumonisin contamination of such products. All except two of the examined samples were contaminated with black Aspergilli. Species assignment of the isolates was carried out using sequence analysis of part of the calmodulin gene. The range of fumonisin isomers present in the raisin samples, and produced by A. niger isolates collected from dried vine fruits was also examined using reversed-phase high-performance liquid chromatography/electrospray ionization-ion trap mass spectrometry (RP-HPLC/ESI-ITMS). Among the 30 A. niger/A. awamori isolates identified, 20 were found to be able to produce fumonisins (average contamination: 5.16 mg/kg; range: 0.017-19.6 mg/kg). The average fumonisin content of the 7 dried vine fruit samples which were found to be contaminated by potential fumonisin producing black Aspergilli was 7.22 mg/kg (range: 4.55-35.49 mg/kg). The isolates produced several fumonisin isomers also present in the dried vine fruit samples, including fumonisins B_1-4, 3-epi-FB₃, 3-epi-FB₄, iso-FB₁, and two iso-FB_2,3 forms. Fumonisin B₁ was detected for the first time in A. niger cultures. Most of these isomers have previously only been identified in Fusarium species. Our data indicate that A. niger and A. awamori are responsible for fumonisin contamination of dried vine fruits worldwide. The observed levels of contamination are alarming and pose a new threat for food safety.     

UHPLC-ESI-QTOF-MS phenolic profiling and antioxidant capacity of bee pollen from different botanical origin

In this work, bee pollen samples from different botanical origin were investigated for antioxidant capacity. Thereafter, a phenolic profiling was produced through a mass spectrometric untargeted metabolomic approach. Marked differences were identified in TPC, ranging from 4.2 (Magnolia) to 29.6 mg g⁻¹ GAE (Lamium). Wide differences were also recorded in antioxidant capacity (ORAC, ABTS and DPPH assays). Untargeted profiling allowed annotating 467 compounds with flavonoids being the most frequent class of phenolics followed by phenolic acids, tyrosols, lignans and other. OPLS-DA clearly discriminated the most represented floral families (Umbelliferae, Rosaceae and Fabaceae), suggesting, thus, that botanical origin leaves a characteristic phenolic signature in pollen. Overall, 35 phenolics accounted for most of the discrimination, with flavonoids being the most represented class. Despite the fact that further research is needed, the phenolic profile of bee pollen is a promising tool to investigate the botanical origin.     

Comparative responses in plain black tea quality parameters of different tea clones to fermentation temperature and duration

The amounts of black tea theaflavins, brightness, and sensory evaluations varied with clones in the order clone 6/8>SC12/28>S15/10, while thearubigins and total colour changed in the reverse order. The rates of change of these plain tea quality parameters varied in all clones causing significant (P⩽ 0.05) fermentation duration and clone interactions. Thus, the total amount and rate of development of each quality parameter is unique to a clone and a change in fermentation duration for optimal quality parameter achievement in one clone cannot be extrapolated to another clone. Although processing of black tea at low fermentation temperatures improved black tea quality, there was no significant difference between fermenting at 15 and 20°C. Long fermentation duration and high temperature favoured production of more intense coloured black teas with high thearubigin levels, which were less bright and had lower theaflavin levels. There were significant (P⩽ 0.05) interactions between fermentation duration and temperature in all the plain black tea parameters development indicating that their rates of formation and amounts formed varied with time at different temperatures. Clones 6/8 and SC12/28 plain tea quality parameters were more sensitive to temperature and duration changes than clone S15/10. Thus there are clones, which can withstand high temperature and long fermentation duration without drastic impairment of their plain black tea quality parameters.     

黄酒中糖和无机元素成分与黄酒口味品质的定量关系研究

为在黄酒中的糖、无机元素成分与口味品质间建立一种定量关系,以明确各种糖和无机元素成分对口味的影响。采用阴离子交换色谱-积分脉冲安培检测法测定38个黄酒样品中糖,ICP-MS检测无机元素,与感官评分一起进行回归分析。结果表明,在建立的多元回归方程中,无机元素的相关系数较好,R2=0.7209,而与糖之间的相关系数较低,R2=0.2467。     

赤水河流域不同地区酱香型白酒矿质元素特征分析及产地辨识初探

该文利用电感耦合等离子体-质谱测定了赤水河流域五个不同地区酱香型白酒中14种矿质元素的含量,并利用主成分分析（PCA）和偏最小二乘法判别分析（PLS-DA）对其进行特征分析和产地初辨。检测结果显示,Al、Fe、Zn、Rb、Sr 5种元素的含量在四川古蔺地区显著高于贵州茅台镇核心地区、习水地区、遵义市区、金沙地区（P＜0.05）。主成分分析（PCA）结果表明,四川古蔺地区酱香型白酒单独聚为一类,与贵州各地区分类效果明显,而贵州各地区酱香型白酒分类效果不明显。偏最小二乘判别分析法（PLS-DA）结果表明,Rb、Mg、Zn、Sr、Nb 5种元素为判别四川古蔺地区与贵州各地区酱香型白酒的重要分类变量。     

基于矿物元素和稳定同位素技术不同产地陈皮鉴别研究

为开展不同产地陈皮中矿物元素含量和稳定同位素比值的影响,并建立产地溯源模型,采集我国4个地区(广东、福建、四川和重庆)共160份陈皮样品,用电感耦合等离子体质谱法测定陈皮中21种矿物元素的含量,用元素分析质谱法测定陈皮中4种稳定同位素比值,研究不同产地陈皮中矿物元素含量、稳定同位素比值差异并进行产地溯源。结果表明,除Zn外,其余20种矿物元素的含量、4种稳定同位素的比值在4个地区间均存在显著差异(P＜0.05) ,陈皮样品中含量最高的是K,其次是Ca,最低的是Y。对160个陈皮样品的矿物元素含量和稳定同位素比值进行主成分分析法(PCA)、偏最小二乘判别分析法(PLS-DA)、正交偏最小二乘判别分析法(OPLS-DA)和交叉验证的结果表明,矿物元素、稳定同位素可以对不同产地来源的陈皮样品进行鉴别,线性判别(LDA)交叉验证准确率为93.8%,通过VIP值筛选得出产地鉴别的关键因子是Cu、K、Ga、Ni、Y、Ba、La、Nd、V、Cr、Rb、Fe、Mn、Co及δ18^O。综上,利用矿物元素结合稳定同位素技术可以有效地鉴别陈皮的地理来源,这项技术的应用可以为判断陈皮的产地和真实性提供可靠的技术支持。     

采用微波消解-ICP-AES法分析不同产地大枣中无机元素的组成及其含量

采用微波消解-ICP-AES法探索不同产地、不同栽培品种大枣中无机元素的组成及含量,结果表明在所测定的19种无机元素中,不同产地、不同栽培品种大枣中普遍含有元素K、Ca、Mg、Na、Fe、B、Sr、Al、Zn、Mn、Mo、Cu;在所检测的37批样品中,有36批样品中检出有害重金属元素Pb,其平均含量可达2.62μg/g;所有样品均未检出有害元素As、Cd、Cr、Hg。依据各样品中测定元素的含量,采用主成分分析法,选择前4个因子(F1~F4)对大枣营养保健价值进行了综合评价,其综合评价函数为F=0.19936F1+0.18240F2+0.17396F3+0.10946F4。结果显示,产自陕西彬县的晋枣品种、河南内黄的扁核酸枣品种以及山东荷泽的核桃纹品种综合排序分列1、2和3位,表明从无机元素角度考虑以上三个产地所产大枣品质较好。本研究为药食两用大枣资源营养及保健价值的进一步发现及安全性评价提供了一定的数据支撑,为大枣适宜栽培区域、栽培品种的选择提供了借鉴。     

采用微波消解-ICP-AES法分析不同产地大枣中无机元素的组成及其含量

采用微波消解-ICP-AES法探索不同产地、不同栽培品种大枣中无机元素的组成及含量,结果表明在所测定的19种无机元素中,不同产地、不同栽培品种大枣中普遍含有元素K、Ca、Mg、Na、Fe、B、Sr、Al、Zn、Mn、Mo、Cu;在所检测的37批样品中,有36批样品中检出有害重金属元素Pb,其平均含量可达2.62μg/g;所有样品均未检出有害元素As、Cd、Cr、Hg。依据各样品中测定元素的含量,采用主成分分析法,选择前4个因子（F1^F4）对大枣营养保健价值进行了综合评价,其综合评价函数为F=0.19936F1+0.18240F2+0.17396F3+0.10946F4。结果显示,产自陕西彬县的晋枣品种、河南内黄的扁核酸枣品种以及山东荷泽的核桃纹品种综合排序分列1、2和3位,表明从无机元素角度考虑以上三个产地所产大枣品质较好。本研究为药食两用大枣资源营养及保健价值的进一步发现及安全性评价提供了一定的数据支撑,为大枣适宜栽培区域、栽培品种的选择提供了借鉴。      

不同产地栀子32种矿物元素含量分析与产地鉴别

目的? 建立不同产地栀子矿物元素的分析方法和评价体系,结合计量学方法,探讨栀子产地鉴别的可行性。方法? 采用电感耦合等离子体质谱法(ICP-MS)和电感耦合等离子体原子发射光谱法(ICP-AES)对国内5个主产区75份栀子中32种矿物元素的含量进行测定,并采用方差分析、主成分分析、逐步判别分析等方法进行统计与评价。结果? 栀子中32种矿物元素的含量在产地间差异显著(P?0.05);Pb、Cd、Hg、Cu、As等重金属含量均在安全限度以内;广西玉林栀子的综合加权值最高(5.61),表明基于矿物元素角度评价,该产地品质较好;逐步筛选出Na、Mg、P、K、Ca、Sc、Mn、Sr、Sn、Ba 10种矿物元素构建产地鉴别函数,判别模型的初始分组和交叉验证正确率均为100%。结论? 不同产地栀子矿物元素的分布各具特征且差异显著,逐步判别分析是栀子产地鉴别的有效方法。     

Dimensional changes of extracted and non-extracted small wood specimens of black locust (<Emphasis Type="Italic">Robinia pseudoacacia</Emphasis> L.)

From straight grained heartwood of black locust (Robinia pseudoacacia L.), specimens, 3 cm×3 cm in cross section and 0.5 mm (or 10 mm) in axial direction, were cut and used for the determination of dimensional changes and the rate of tangential swelling. Mean radial, tangential and axial shrinkage was 5.30%, 6.67% and 0.16%, respectively, while the coefficient of anisotropy was 1.26. Half of the specimens for the determination of the rate of tangential swelling were extracted for 48 h with distilled hot water. The tangential dimensional change and the time taken to attain half maximum swelling in air-dry and oven-dry specimens were assessed according to a common technique. Extractive removal resulted in an increase of the total magnitude of tangential swelling in both air-dry and oven-dry specimens. However, no significant differences in time taken to attain half maximum swelling between air-dry and oven-dry specimens were observed after extraction. The rate of tangential swelling was lower in air-dry specimens than in oven-dry specimens after 30 min of immersion in water when were non-extracted and after 5 min of immersion in water when were extracted. Extracted air-dry specimens had a greater rate of tangential swelling than non-extracted air-dry specimens and the same occurred for oven-dry specimens. Extraction resulted in a higher diffusion coefficient for air-dry specimens. The diffusion coefficient calculated for non-extracted air-dry specimens (0.901×10^–4 cm²/min) showed that black locust is a difficult species to impregnate.

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Dimensionsveränderungen extrahierter und nicht-extrahierter kleiner Holzproben von Robinie (Robinia pseudoacacia L.)

Zusammenfassung Von Robinienkernholz (Robinia pseudoacacia L.) mit senkrecht verlaufenden Fasern, wurden Proben 3 cm×3 cm im Querschnitt und 0,5 mm (oder 10 mm) in axialer Richtung geschnitten und zur Bestimmung dimensionaler Veränderungen und der tangentialen Quellenrate verwendet. Die mittlere radiale, tangentiale und axiale Schrumpfung betrug 5,30%. 6,67% und 0,16%, wobei der Anisotropie-Koeffizient 1,26 betrug. Die Hälfte der Proben zur Bestimmung der radialen Quellung wurde 48 Stunden lang mit heißem destillierten Wasser extrahiert. Die tangentiale dimensionale Veränderung und die benötigte Zeit, um ein halb-maximales Quellen bei Luft- und Ofentrocknung zu erreichen wurde gemäß einer bekannten Methode geschätzt. Die Entfernung der Extraktstoffe führte zu einer Zunahme der Gesamtgröße der tangentiellen Schwellung sowohl der luft- als auch der ofengetrockneten Proben. Es wurden jedoch keine signifikanten Unterschiede in der Zeit nach der Extraktion beobachtet, die benötigt wurde, um die halb-maximale Schwellung zwischen luft- und ofengetrockneten Proben zu erreichen. Die Rate der tangentiellen Schwellung war bei luftgetrockneten Proben niedriger als bei ofengetrockneten Proben nach 30-minütigem Eintauchen in Wasser. Extrahierte luftgetrocknete Proben hatten eine größere Rate tangentieller Schwellung als nicht-extrahierte luftgetrocknete Proben, das gleiche gilt für ofengetrocknete Proben. Die Extraktion führte zu einem höheren Diffusionskoeffizienten bei luftgetrockneten Proben. Der berechnete Diffusionskoeffizient von nicht-extrahierten luftgetrockneten Proben (0,901×10^–4 cm²/min) zeigte, dass Robinien eine schwierig zu imprägnierende Spezies sind.

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Part of Doctoral thesis of Mr. Stergios Adamopoulos titled: "Anatomical characteristics and technical properties of black locust wood (Robinia pseudoacacia L.)". Aristotelian University, Thessaloniki, 2001.