NMR characterization of saccharides in Italian honeys of different floral sources

The saccharide profiles of 5 different botanical species in 86 Italian honey samples were investigated by 1H and 1H-13C NMR spectroscopy. Nineteen saccharides were identified in the aqueous extracts, namely, fructose, glucose, gentiobiose, isomaltose, kojibiose, maltose, maltulose, melibiose, nigerose, palatinose, sucrose, turanose, erlose, isomaltotriose, kestose, maltotriose, melezitose, raffinose, and maltotetraose. PCA performed on NMR spectral regions, in particular between 4.400 and 5.700 ppm and the fructose signal at 4.050 ppm, revealed a partial sample grouping. The score contribution plots derived from PCA performed using the mean values for the buckets of the anomeric region for each floral source allowed the identification of saccharides characterizing different honeys. OPLS-DA models were further evaluated to confirm the previous findings. OPLS-DA models were also built to highlight differences between polyfloral and high mountain polyfloral honeys and between high mountain polyfloral and rhododendron honeys, both collected at high altitude; S-plots highlighted the characteristic saccharides.     

Antioxidant capacity of honeys from various floral sources based on the determination of oxygen radical absorbance capacity and inhibition of in vitro lipoprotein oxidation in human serum samples

Honeys from seven different floral sources were analyzed for in vitro antioxidant capacity and total phenolic content. Antioxidant capacity was measured by the oxygen radical absorbance capacity (ORAC) assay and by monitoring the formation of conjugated dienes as an index of the inhibition of copper-catalyzed serum lipoprotein oxidation. ORAC values ranged from 3.1 to 16.3 micromol Trolox equivalent/g honey. The darkest colored honeys, such as buckwheat honey, had the highest ORAC values. A linear correlation was observed between phenolic content and ORAC activity of the investigated honeys (p < 0.0001, R (2) = 0.9497). The relationship between the ORAC activity and inhibition of lipoprotein oxidation by the honeys yielded a correlation coefficient of 0.6653 (p = 0.0136). This work shows that honey may be used as a healthy alternative to sugar in many products and thereby serve as a source of dietary antioxidants.     

Usefulness of amino acid composition to discriminate between honeydew and floral honeys. Application to honeys from a small geographic area

With the aim of finding methods that could constitute a solid alternative to melissopalynological and physicochemical analyses to determine the botanical origin (floral or honeydew) of honeys, the free amino acid content of 46 honey samples has been determined. The honeys were collected in a small geographic area of approximately 2000 km(2) in central Spain. Twenty-seven honey samples were classified as floral and 19 as honeydew according to their palynological and physicochemical analyses. The resulting data have been subjected to different multivariant analysis techniques. One hundred percent of honey samples have been correctly classified into either the floral or the honeydew groups, according to their content in glutamic acid and tryptophan. It is concluded that free amino acids are good indicators of the botanical origin of honeys, saving time compared with more tedious analyses.     

Protein analysis of honeys by fast protein liquid chromatography: application to differentiate floral and honeydew honeys

Fast protein liquid chromatography on a Superdex 75 HR column has been applied to analyze the proteins of 29 honeys, 12 of floral origin and 17 from honeydew. The molecular masses were comprised between 13100 and 94000 Da. Seven peaks have been separated; four of them were present in all of the honeys, and three were only present in some honeys. Direct observation of the chromatograms of the floral and honeydew honeys did not reveal any information about their botanical origins. However, both types of honeys can be distinguished with the percentages of the areas of four of the seven chromatographic peaks obtained.     

Amino acid composition and antioxidant capacity of Spanish honeys

The amino acid composition of 53 honey samples from Spain, consisting of 39 floral, 5 honeydew, and 9 blend honeys, has been determined. Physicochemical characteristics, polyphenolic content, amino acid composition, and estimation of the radical scavenging capacity against the stable free radical DPPH of the honey samples were analyzed. The resulting data have been statistically evaluated. The results showed that pH, acidity, net absorbance, electrical conductivity, and total polyphenolic contents of the honeys showed a strong correlation with the radical scavenging capacity. The correlation between the radical scavenging capacity of honey and amino acid contents was high with 18 of the 20 amino acids detected, with correlation values higher than those obtained for polyphenolic content. These results suggest that the amino acid composition of honey is an indicator of the sample's scavenging capacity.     

Antimutagenic effect of various honeys and sugars against Trp-p-1

Honey has been used since ancient times as a flavorful sweetener and for its therapeutic and medicinal effects. Consumers' demand for natural, healthy products has driven renewed interest in honey's health benefits. The commonly encountered food mutagen, Trp-p-1, has been demonstrated to be mutagenic in bacteria and carcinogenic in animals. Chemically, honey is quite complex. Honey is comprised primarily of sugars; however, it contains many other potentially biologically active components, such as antioxidants. Sugars have been reported to display both mutagenic and antimutagenic effects in different systems; antioxidants often display antimutagenic activity. Little information exists about potential antimutagenic effects of honey. Antimutagenicity of honeys from seven different floral sources against Trp-p-1 was tested via the Ames assay and compared to that of a sugar analogue and to individually tested simple sugars. All honeys exhibited significant inhibition of Trp-p-1 mutagenicity; most demonstrated a linear correlation between percentage inhibition and log transformed honey concentration from 10 microg/mL to 20 mg/mL. Each displayed significant degrees of inhibition of mutagenicity above concentrations of 1 mg/mL, with individual variations in degree of effectiveness. Buckwheat honey displayed the greatest inhibition at 1 mg/mL, with slightly less effectiveness at higher concentrations. A sugar analogue demonstrated a pattern of inhibition similar to that of the honeys, with enhanced antimutagenicity at concentrations greater than 1 mg/mL. Glucose and fructose were also similar to honeys and were more antimutagenic than maltose and sucrose.     

Sources of antioxidant activity in Australian native fruits. Identification and quantification of anthocyanins

Selected native Australian fruits, muntries (Kunzea pomifera F. Muell., Myrtaceae), Tasmanian pepper berry (Tasmanian lanceolata R. Br., Winteraceae), Illawarra plum (Podocarpus elatus R. Br. ex Endl., Podocarpaceae), Burdekin plum (Pleiogynium timorense DC. Leenh, Anacardiaceae), Cedar Bay cherry (Eugenia carissoides F. Muell., Myrtaceae), Davidson's plum (Davidsonia pruriens F. Muell. var. pruriens, Davidsoniaceae), and Molucca raspberry (Rubus moluccanus var. austropacificus van Royen, Rosaceae), were evaluated as sources of antioxidants by 2,2-diphenyl-1-picrylhydrazyl and ferric reducing antioxidant power assays and compared with blueberry (Vaccinum spp. cv. Biloxi). The total reducing capacity of five fruits was 3.5-5.4-fold higher than that of blueberry, and the radical scavenging activities of muntries and Burdekin plum were 1.5- and 2.6-fold higher, respectively. The total phenolic level by Folin-Ciocalteu assay highly correlated with the antioxidant activity. Therefore, systematic research was undertaken to identify and characterize phenolic complexes. In the present study we report on the levels and composition of anthocyanins. The HPLC-DAD and HPLC/ESI-MS-MS (ESI = electrospray ionization) analyses revealed simple anthocyanin profiles of one to four individual pigments, with cyanidin as the dominating type. This is the first evaluation of selected native Australian fruits aiming at their utilization for the development of novel functional food products.     

Quantification of saccharides in multiple floral honeys using fourier transform infrared microattenuated total reflectance spectroscopy

Fourier transform infrared (FTIR) spectroscopy with microattenuated total reflectance (mATR) sampling accessory and chemometrics (partial least squares and principal component regression) was used for the simultaneous determination of saccharides such as fructose, glucose, sucrose, and maltose in honey. Two calibration models were developed. The first model used a set of 42 standard mixtures of fructose, glucose, sucrose, and maltose prepared over the range of concentrations normally present in honey, whereas the second model used a set of 45 honey samples from various floral and regional sources. The developed models were validated with different data sets and verified by high-performance liquid chromatography (HPLC) measurements. The R (2) values between the FTIR-mATR predicted and HPLC results of the different sugars were between 0.971 and 0.993, demonstrating the predictive ability and accuracy of the procedure.     

Honeys from different floral sources as inhibitors of enzymatic browning in fruit and vegetable homogenates

Honeys from different floral sources were evaluated for their antioxidant content and for their ability to inhibit enzymatic browning in fruits and vegetables. Antioxidant contents of honeys vary widely from different floral sources, as do their abilities to protect against enzymatic browning. Polyphenol oxidase (PPO) activity was reduced over a range of approximately 2-45% in fruit and vegetable homogenates, corresponding to a reduction in browning index by 2.5-12 units. Soy honey was particularly effective when compared to clover honey, which had a similar antioxidant content. When compared to commercial inhibitors of browning, honeys were less effective; however, in combination they added to the effectiveness of metabisulfite and ascorbic acid. Honey has great potential to be used as a natural source of antioxidants to reduce the negative effects of PPO browning in fruit and vegetable processing.     

Identification and quantification of aroma-active components that contribute to the distinct malty flavor of buckwheat honey

Characteristic aroma components of buckwheat honey were studied by combined sensory and instrumental techniques. Relative aroma intensity of individual volatile components was evaluated by aroma extract dilution analysis (AEDA) of solvent extracts and by gas chromatography-olfactometry (GCO) of decreasing headspace samples (GCO-H). Results indicated that 3-methylbutanal, 3-hydroxy-4,5-dimethyl-2(5H)-furanone (sotolon), and (E)-beta-damascenone were the most potent odorants in buckwheat honey, with 3-methylbutanal being primarily responsible for the distinct malty aroma. Other important aroma-active compounds included methylpropanal, 2,3-butanedione, phenylacetaldehyde, 3-methylbutyric acid, maltol, vanillin, methional, coumarin, and p-cresol.     

Dietary sources and antioxidant effects of ergothioneine

Ergothioneine is a native membrane-impermeable thiol compound that is specifically accumulated in cells via the organic cation transporter OCTN1. In humans, OCTN1 and ergothioneine have been implicated in the etiopathogenesis of autoimmune disorders. However, available evidence about dietary sources and the functional role of ergothioneine in human physiology is scarce. Here, we analyzed the ergothioneine content in common foods using liquid chromatography tandem-mass spectrometry. Additionally, we assessed the protective potency of ergothioneine against various oxidative stressors in OCTN1-expressing cells in comparison with the main intracellular thiol antioxidant glutathione by evaluating cell viability with the MTT reduction assay. Only some food contained ergothioneine with highest concentrations detected in specialty mushrooms, kidney, liver, black and red beans, and oat bran. Ergothioneine exhibited cell protection only against copper(II)-induced toxicity but was far less potent than glutathione, indicting that ergothioneine is not involved in the intracellular antioxidant thiol defense system.     

Determination of antioxidant properties of aroma extracts from various beans

Aroma extracts from fresh soybeans, mung beans, kidney beans, and azuki beans were prepared using simultaneous steam distillation and solvent extraction (SDE) under mild conditions (55 degrees C and 95 mmHg). Extracts were examined for antioxidative activities in two different assays. The aroma extracts isolated from all beans inhibited the oxidation of hexanal for nearly one month at a level of 250 microL/mL. Mung bean and soybean extracts inhibited malonaldehyde (MA) formation from cod-liver oil by 86% and 88%, respectively, at the 250 microL/mL level. Azuki and kidney bean extracts inhibited MA formation from cod-liver oil by 76% and 53%, respectively, at the 250 microL/mL level. The antioxidative activities of mung bean and soybean extracts were comparable with that of the natural antioxidant, alpha-tocopherol (vitamin E).     

超临界CO2萃取生姜中抗氧化活性物质的工艺研究

随着天然抗氧化剂需求的增加,生姜中抗氧化活性物质提取的研究日益深入.本研究采用超临界二氧化碳(SC-CO2)萃取这一新型的分离技术对生姜中的抗氧化成分进行富集.通过生姜的含水率、粒度作为单因素,而对于影响萃取工艺的萃取温度、压力、时间三个因素进行正交试验分别进行了研究,同时以萃取量和添加到油脂中的过氧化值(POV)变化为指标,确定各工艺参数对萃取效果的影响.结果表明:应用10%以下含水率的片状生姜原料,采用60℃、24 MPa、140 min的操作工艺,可以获得较大量的具有较高抗氧化活性的生姜提取物.     

Identification of botanical biomarkers in Argentinean Diplotaxis honeys: flavonoids and glucosinolates

To select and establish floral biomarkers of the botanical origin of Diplotaxis tenuifolia honeys, the flavonoids and glucosinolates present in bee-deposited nectar collected from hive combs (unripe honey) and mature honey from the same hives fron which the unripe honey samples were collected were analyzed by LC-UV-PAD-ESI-MS(n). Glycosidic conjugates of the flavonols quercetin, kaempferol, and isorhamnetin were detected and characterized in unripe honey. D. tenuifolia mature honeys contained the aglycones kaempferol, quercetin, and isorhamnetin. The differences between the phenolic profiles of mature honey and freshly deposited honey could be due to hydrolytic enzymatic activities. Aliphatic and indole glucososinolates were analyzed in unripe and mature honeys, this being the first report of the detection and characterization of glucosinolates as honey constituents. Moreover, these honey samples contained different amounts of propolis-derived flavonoid aglycones (1765-3171 μg/100 g) and hydroxycinnamic acid derivatives (29-1514 μg/100 g). Propolis flavonoids were already present in the freshly deposited nectar, showing that the incorporation of these compounds to honey occurs at the early steps of honey production. The flavonoids quercetin, kaempferol, and isorhamnetin and the glucosinolates detected in the samples could be used as complementary biomarkers for the determination of the floral origin of Argentinean Diplotaxis honeys.     

Identification of TLC markers and quantification by HPLC-MS of various constituents in noni fruit powder and commercial noni-derived products

The composition of noni (Morinda citrifolia) products has been investigated. TLC profiles of several commercial juices and capsules were compared. 3-Methyl-1,3-butanediol was identified as a typical marker in noni juices. The presence of sorbic acid (E200) was detected in one juice declared as additive free. Quantitative data have been obtained by HPLC-MS. A method for the quantification of characteristic noni constituents, such as iridoid glucosides, scopoletin, rutin, fatty acid glucosides, and anthraquinones, was developed and validated. The separation was performed on a C18 column with a gradient of acetonitrile in water containing 0.1% formic acid. Detection was carried out with ESI-MS in the negative ion mode. Significant differences were observed between the products. Asperulosidic acid, deacetylasperulosidic acid, and rutin were present in all samples analyzed, but their concentrations differed considerably between the products. Fatty acid glucosides, noniosides B and C, were present in capsules and most juices. Scopoletin was mainly found in juices. The anthraquinone alizarin, which has been reported from roots and leaves, was not detected in the samples investigated.     

Determination of antioxidant potential of volatile extracts isolated from various herbs and spices

Antioxidant activities of volatile extracts isolated from thyme, basil, rosemary, chamomile, lavender, and cinnamon were evaluated by two independent assays: the aldehyde/carboxylic acid assay and the conjugated diene assay. The volatile extracts were prepared from dried herbs and spices using liquid-liquid continuous extraction following steam distillation under reduced pressure (55 degrees C and 95 mmHg). The antioxidant activities of the extracts decreased in the following order in both of the lipophilic assay systems: thyme > basil > rosemary > chamomile > lavender and cinnamon. Thyme and basil extracts inhibited the oxidation of hexanal for 40 days at the levels of 10 microg/mL and 50 microg/mL, respectively. The extracts of thyme and basil were effective in retarding methyl linoleate deterioration at 40 degrees C, with activity increasing with concentration in the range 10-200 microg/mL. At a concentration of 50 microg/mL, thyme extract was similar in antioxidant activity to BHT and alpha-tocopherol in the conjugated diene assay. The antioxidant potentials of the volatile extracts used in this study were accurately measured by the lipophilic systems, such as the aldehyde/carboxylic acid assay and the conjugated diene assay.     

Flavor authentication studies of alpha-ionone, beta-ionone, and alpha-ionol from various sources

In addition to the already available information on the authenticity of alpha- (1) and beta-ionone (2) from plant tissues, there is an interest in the stable isotope data of 1 and 2 available by synthesis from citral and acetone, as European Union regulations, in contrast to the United States and other countries, do not allow a product to be declared as 'natural' that has been chemically synthesized (e.g., by using a natural catalyst) from natural educts. Analyses performed by on-line capillary gas chromatography-isotope ratio mass spectrometry in the combustion and pyrolysis modes (HRGC-C/P-IRMS) as well as by elemental analyzers (EA-C/P-IRMS) measuring delta(13)C(V)-PDB and delta(2)H(V)-SMOW values provide for the first time isotope data of such 'natural' 1 and 2 as well as of synthetic and 'ex plant' alpha-ionol (3). The isotope data recorded for synthesized 1 and 2 reflected the influence of the origin of the used citral, whereas that of acetone was less remarkable. For instance, 'natural' 1 ex citral from lemongrass showed, as expected for a C4 plant, an enriched delta(13)C(V)-PDB value of -18.5 per thousand. In addition, the use of synthetic citral resulted in an enriched delta(2)H(V)-SMOW value of -43 per thousand, whereas with citral ex Litsea cubeba and ex lemongrass values of -242 and -232 per thousand, respectively, were recorded. IRMS analyses of 'natural' 2 revealed delta(13)C(V)-PDB and delta(2)H(V)-SMOW values that were nearly identical to that recorded for 'natural' 1. As to both 1 and 2, variations of synthesis conditions led to distinct changes in the delta(13)C(V)-PDB but not the delta(2)H(V)-SMOW values. Synthetic 3 showed delta(13)C(V)-PDB and delta(2)H(V)-SMOW values of -24.5 and -184 per thousand, respectively. These data differed from those found in raspberry fruit under study (n = 8), that is, ranging from -33.6 to -36.6 per thousand for delta(13)C(V)-PDB and from -200 to -225 per thousand for delta(2)H(V)-SMOW. The values determined additionally for 1 and 2 in raspberry fruit samples ranged from -30.3 to -35.1 per thousand and from -176 to -221 per thousand for delta(13)C(V)-PDB and delta(2)H(V)-SMOW, respectively, and thus corresponded to the already known literature information.     

Determination of tea components with antioxidant activity

Levels of essential elements with antioxidant activity, as well as catechins, gallic acid, and caffeine levels, in a total of 45 samples of different teas commercialized in Spain have been evaluated. Chromium, manganese, selenium, and zinc were determined in the samples mineralized with HNO(3) and V(2)O(5), using ETAAS as the analytical technique. The reliability of the procedure was checked by analysis of a certified reference material. Large variations in the trace element composition of teas were observed. The levels ranged from 50.6 to 371.4 ng/g for Cr, from 76.1 to 987.6 microg/g for Mn, from 48.5 to 114.6 ng/g for Se, and from 56.3 to 78.6 ng/g for Zn. The four major catechins [(-)-epigallocatechin gallate (EGCG), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), and (-)-epicatechin (EC)], gallic acid (GA), and caffeine were simultaneously determined by a simple and fast HPLC method using a photodiode array detector. In all analyzed samples, EGCG ranged from 1.4 to 103.5 mg/g, EGC from 3.9 to 45.3 mg/g, ECG from 0.2 to 45.6 mg/g, and EC ranged from 0.6 to 21.2 mg/g. These results indicated that green tea has a higher content of catechins than both oolong and fermented teas (red and black teas); the fermentation process during tea manufacturing reduces the levels of catechins significantly. Gallic acid content ranged from 0.039 to 6.7 mg/g; the fermentation process also elevated remarkably gallic acid levels in black teas (mean level of 3.9 +/- 1.5 mg/g). The amount of caffeine in the analyzed samples ranged from 7.5 to 86.6 mg/g, and the lower values were detected in green and oolong teas. This study will be useful for the appraisal of trace elements and antioxidant components in various teas, and it will also be of interest for people who like drinking this beverage.     

香椿老叶中活性物质提取及其抗氧化活性的研究

该文对香椿老叶抗氧化活性物质的提取工艺进行了研究,筛选出纯化用大孔吸附树脂,并对该树脂纯化出的活性物质进行了抗氧化活性研究。结果表明,最佳提取工艺为60％乙醇、60℃、料液比1∶30、提取4 h;筛选出最优纯化树脂AB-8,经该树脂纯化后物质具有很强的抗氧化活性,总还原力为(863.59±13.90)mg/g,1,1-二苯基苦基苯阱(DPPH)自由基清除能力和三价铁还原抗氧化能力测试(FRAP)均呈现明显的剂量依赖性关系,显著高于相同浓度的2,4二叔丁基甲基苯酚(BHT)(P<0.01),与同浓度的维生素C相当。     

不同来源豌豆分离蛋白高水分挤压特性

高水分挤压技术（水分含量40%～80%）制备的植物基肉制品具有更接近动物肉质构品质的特征,其中,以豌豆蛋白为原料的应用备受关注。然而,不同来源的豌豆分离蛋白（pea protein isolate, PPI）品质功能特性差异明显,高水分挤压特性尚不明确,这不利于豌豆蛋白在植物基肉制品中的开发应用。为探究PPI原料品质及冷却成型温度对高水分挤出物品质的影响,该研究选取了5种商业PPI,探究其组分含量、粒径、溶解性、凝胶性等差异,并探究了在不同冷却成型温度条件下（65、90 ℃）的高水分挤压特性。结果表明,PPI的原料品质、冷却成型温度与挤出物的质地品质密切相关,溶解度高（21.24%～25.51%）且凝胶性强（0.84 N～1.14 N）的PPI更有利于纤维结构的形成（组织化度>1.5）,同时发现,较低的冷却成型温度下,溶解度与组织化度呈显著正相关（P<0.05）,提高冷却成型温度后,PPI挤出物结构更加致密,能够显著提高PPI挤出物的弹性（P<0.05）,溶解度与组织化度呈显著正相关（P<0.05）,凝胶强度与组织化度呈极显著正相关（P<0.01）。该研究为豌豆蛋白在高水分挤压植物基肉制品产品创制中的应用提供支撑。