Geographical Origin Discrimination of Oolong Tea (TieGuanYin, <Emphasis Type="Italic">Camellia sinensis</Emphasis> (L.) O. Kuntze) Using Proton Nuclear Magnetic Resonance Spectroscopy and Near-Infrared Spectroscopy

A total of 90 oolong tea samples were collected from three different growing places in the Fujian province of China. Both proton nuclear magnetic resonance (¹H NMR) and near-infrared spectroscopy (NIR) were used to analyze the collected tea samples. With the aid of chemometric methods, differential components in ¹H NMR data and characteristic wavenumbers from NIR spectra were identified. Since NMR and NIR provide complementary information for tea samples, data fusion was carried out by combining ¹H NMR and NIR spectra of the collected tea sample. Experimental results showed that a better discrimination accuracy of geographical origins of oolong tea could be achieved by combining NMR and NIR data (86.2–95.8%), as compared to using NMR data (68.2–78.7%) or NIR data (80.0–89.3%) alone. The current data suggested that a combination of NMR and NIR methods could serve as an efficient way for geographical origin discrimination and qualitative control of oolong tea.     

傅里叶变换近红外光谱技术测定绿茶全氮量

建立准确性高、稳定性好的绿茶全氮量的偏最小二乘定量分析模型。在4 691～3 959、5 126～4 848 cm－1 波段区间内,光谱经过一阶导数与平滑处理后,模型的预测性能最好,外部验证集样品的预测值与实测值的预测均 方差（RMSEP）为0.092 5%,相关系数为0.993 9。根据嫩度等级,建立了绿茶全氮量子模型,提高了模型的预测 性能。嫩度为3 级的子模型预测结果最好,验证集样品的全氮量的预测值与实测值的RMSEP值最小,为0.037 9%, 相关系数为0.996 1。绿茶全氮量近红外光谱检测技术是一种绿色、快速、高效的新型分析技术,能够实现快速测定 绿茶全氮量,评价绿茶品质。     

Application of Fourier Transform Near Infrared Spectroscopy (FT-NIR) to thermally modified wood

A close relationship between the chemical changes and the NIR spectra of thermally modified beech wood makes clustering easy and provides a possibility for quality control.     

Application of Fourier Transform Near Infrared Spectroscopy (FT-NIR) to thermally modified wood

A close relationship between the chemical changes and the NIR spectra of thermally modified beech wood makes clustering easy and provides a possibility for quality control.     

Optimization for encapsulation of green tea (<Emphasis Type="Italic">Camellia</Emphasis><Emphasis Type="Italic">sinensis</Emphasis> L.) extract by spray drying technology

Green tea has been credited with providing a wide variety of health benefits like higher total antioxidant, cancer prevention, and anti-irritant etc. Microencapsulation technology is used to prevent antioxidant loss during processing which involves entrapment of active material into carrier material. The experiments were designed using response surface methodology based on three level two factor (green tea extract, 10–25 % and drying inlet air temperature, 120, 130 and 140°C) central composite design. The feed emulsion was prepared with green tea extract as core material and 40 % maltodextrin concentration as wall material with the ratio of core to wall (1:2) and it was fed into the spray dryer at varied drying inlet air temperature to get encapsulated green tea extract powder. The quality characteristics were analysed such as moisture content, total antioxidant activity and total phenolic content and the process conditions were optimized using desirability function methodology. At optimum spray drying condition moisture content, total antioxidant activity and total phenolic content were found to be 3.1 % w.b., 72.91 % free radical scavenging activity by DPPH method, 57.81 mg/g of dry matter, expressed as gallic acid equivalent respectively with desirability value of 0.92.     

Determination of Theanine and Catechin in <Emphasis Type="Italic">Camellia sinensis</Emphasis> (Kangra Tea) Leaves by HPTLC and NMR Techniques

Camellia sinensis is used to make special tea and also become a raw material for dietary supplements, health foods, and cosmeceuticals. Theanine (amino acid) and catechins (polyphenol) are most abundantly found in tea leaves. Theanine and catechins are also responsible for taste and flavor of tea products along with therapeutic and nutritional values. Hence, identification and quantification method for theanine and catechin has been developed using high performance thin layer chromatography (HPTLC) and NMR techniques. HPTLC method was validated for selectivity, sensitivity, accuracy, and precision. Theanine and catechin were quantified in three tea samples including randomly plucked tea leaves (HAR), authentically plucked tea leaves (HAN), and processed tea (HAT). Both theanine and catechin were found maximum in HAN as compared to HAR and HAT. The Validated HPTLC method is economical, rapid, and highly suitable for quantification of theanine and catechin. Moreover NMR studies were also used for the qualitative and quantitative estimation of theanine and catechin along with other important metabolites in C. sinensis samples.     

Rapid Determination of Antioxidant Compounds and Antioxidant Activity of Sudanese Karkade (<Emphasis Type="Italic">Hibiscus sabdariffa</Emphasis> L.) Using Near Infrared Spectroscopy

The extraction conditions applied in destructive analysis of Hibiscus sabdariffa L. (Hs) matrices before the measurement of antioxidant compounds may reduce their activities during isolation and purification due to decomposition. Hence, near infrared spectroscopic system was applied to determine these compounds. The calibration models developed by using partial least squares regression (PLSR) with 48 Hs samples and 24 unknown samples were used to confirm the robustness of the developed model. The results of calibration models effectively allowed the determination of the concentrations of total phenol content (TPC), total flavonoid content (TFC), total antioxidant content (TAC), ferric reducing antioxidant power (FRAP), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) with high correlation coefficients (0.85–0.91) and small standard error of cross-validation (RMSECV) ranged from 0.08 to 0.33. The prediction capacity (RPD) for TPC, TFC, TAC, FRAP, and DPPH ranged from 3.30 to 8.25, thus demonstrating that the near infrared spectroscopic (NIRS) equations developed were applicable to unknown samples. This study demonstrates that NIRS can be considered as a fast tool for the nondestructive determination of antioxidant compounds (phenolics and flavonoids) and antioxidant activity of the Hs.     

Estrogenic effects of various extracts from <Emphasis Type="Italic">Chamdanggui</Emphasis> (<Emphasis Type="Italic">Angelica gigas</Emphasis> Nakai) and <Emphasis Type="Italic">sogdan</Emphasis> (<Emphasis Type="Italic">Phlomis umbrosa</Emphasis> Turcz)

The various extracts from chamdanggui (Angelica gigas Nakai) and sogdan (Phlomis umbrosa Turcz) were evaluated for estrogenic activity and characterized according to HPLC profile. Chamdanggui and sogdan were individually extracted with 4 solvents (hot water, 70% ethanol, n-butanol, and dichloromethane) of differing polarities. Estrogenic activity was determined by E-screen using an estrogen-dependent MCF-7 BUS cell. Although almost all extracts showed estrogenic effects in a concentrationdependent manner, the hot water extract from chamdanggui (250 μg/mL) had the higher effect (138%). Among 90 fractions using HPLC separation of the hot water extract from chamdanggui, fraction 21 and 28 produced the highest estrogenic effects of 178 and 163% at 10 μg/mL, respectively. The results imply that the hot water extract from chamdanggui could be useful as an alternative hormone replacement therapy.     

Effect of glasswort (<Emphasis Type="Italic">Salicornia herbacea</Emphasis> L.) and rice (<Emphasis Type="Italic">oryza sativa</Emphasis> L.) on quality of <Emphasis Type="Italic">Ganjang</Emphasis> (Korean Soy Sauce)

Four types of meju were made from 100%(w/w) defatted soybean (DFS), a mixture of 80%(w/w) defatted soybean, and 20%(w/w) glasswort (DFS-G), a mixture of 80%(w/w) defatted soybean and 20%(w/w) rice (DFS-R), and a mixture of 60%(w/w) defatted soybean, 20%(w/w) glasswort, and 20%(w/w) rice (DFS-GR). Four types of Korean traditional soy sauce were prepared from the 4 types of meju. Mineral and antioxidant contents in the soy sauce made of DFS-G and DFS-GR were significantly higher than others. Citric, malic, succinic, lactic, and pyroglutamic acid contents in soy sauce made of DFS-R and DFS-GR were 1.3–1.5 times higher than others. Total nitrogen and free amino acid contents in soy sauce were correlated with DFS concentration in the meju. The bacterial community in the non-fermented meju-making ingredients was replaced largely by Bacillus sp. in the fermented meju. The use of glasswort and rice in the meju-making process did not alter the bacterial community responsible for the fermentation of meju.     

Tyramine production of technological important strains of <Emphasis Type="Italic">Lactobacillus</Emphasis>, <Emphasis Type="Italic">Lactococcus</Emphasis> and <Emphasis Type="Italic">Streptococcus</Emphasis>

The aim of this paper was to study the biogenic amines (histamine, tyramine, putrescine, cadaverine, agmatine, spermine and spermidine) production of selected technological important lactic acid bacteria (strains of the genera Lactococcus, Lactobacillus and Streptococcus). Three methods (ion-exchange chromatography (IEC), PCR and cultivation method with pH indicator) were used. Within the 39 strains of lactic acid bacteria tested, the production of tyramine (formed by tyrosine decarboxylase) was detected in eight strains (3 strains of Lactococcus lactis subsp. lactis, three strains of Lactococcus lactis subsp. cremoris, 1 strain of Streptococcus thermophilus and 1 strain of Lactobacillus delbrueckii subsp. bulgaricus). The other tested biogenic amines were not detected. Cultivation in decarboxylation broth seems to be the least accurate method for the detection of biogenic amines due to enhanced risk of false-positive reactions. Therefore, in order to detect bacteria producing biogenic amines, the combination of PCR and chromatographic methods (e.g. IEC) can be recommended.     

Determination of Pear Internal Quality Attributes by Fourier Transform Near Infrared (FT-NIR) Spectroscopy and Multivariate Analysis

This paper attempted the feasibility to determine firmness and soluble solid content (SSC) in intact pears using Fourier transform near infrared (FT-NIR) spectroscopy coupled with multivariate analysis. Principal component analysis and independent component analysis were employed comparatively to extract latent vectors from the original spectra data. Extreme learning machine (ELM) was performed to calibrate regression model. Some parameters of ELM model were optimized according to the lowest root mean square error of cross-validation in the calibration set. Moreover, the root mean square error of prediction of the calibration model was finally corrected for making it more closed to the true prediction error due to the effect of reference measurement error existing in the pear sample attribute value on the prediction error of the model. Experimental results showed that the $ R_p^2 $ and ratio performance deviation (RPD) in the prediction set were achieved as follows: $ R_p^2 $ ?=?0.81 and RPD?=?2.28 for the firmness model when ICs?=?6 and $ R_p^2 $ ?=?0.91 and RPD?=?3.43 for the SSC model when ICs?=?5. This study demonstrates that the predictive precision of the calibration model can be effectively enhanced in measurement of firmness and SSC in intact pears by use of FT-NIR spectroscopy combined with appropriate chemometrics methods.     

Thermal inactivation kinetics of quality-related enzymes in cauliflower (<Emphasis Type="Italic">Brassica oleracea</Emphasis> var. <Emphasis Type="Italic">botrytis</Emphasis><Emphasis Type="Bold">)</Emphasis>

Thermal inactivation of quality-related enzymes in both cauliflower crude enzyme extracts and fresh tissue samples was studied in temperature range 50–100 °C. For crude enzyme extracts, several parameters, reaction rate constants (k) and activation energy (E _a) as well as decimal reduction time (D) and (z) values, were used to characterize the thermal stability. The rates of inactivation were found to follow first-order inactivation kinetics. Activation energies varied between 101.18 and 208.42 kJ mol⁻¹ with z values of 10.59–24.09 °C. The examined kinetics indicated that lipoxygenase was the most heat resistant followed by peroxidase, polyphenol oxidase, pectin methyl esterase and ascorbic acid oxidase. Furthermore, the obtained results from the blanched fresh tissues indicated that inactivation of lipoxygenase secured disappearing of any other enzyme activities. Therefore, this study recommends using lipoxygenase as an indicator enzyme to optimize the thermal treatments of cauliflower products.     

Changes in major polyphenolic compounds of tea (<Emphasis Type="Italic">Camellia sinensis</Emphasis>) leaves during the production of black tea

The objective of this study was to quantify the polyphenolic compounds present in tea samples during black tea processing, and to determine the correlation between the contents of individual catechins and theaflavins. Nine monomeric and four dimeric compounds were identified and quantified by HPLC. During black tea processing, the catechins content decreased, whereas the gallic acid content increased. The decrease in the catechins-in particular, the cis-catechins-was due to the formation of dimeric theaflavins. In the present study, we found a significant negative correlation between the changes in the catechins and theaflavins contents during black tea processing. Theaflavin-3-gallate showed the strongest correlations with the cis-catechins ((?)-epigallocatechin: r=0.713; (?)-epicatechin: r=0.755; (?)-epigallocatechin gallate: r=0.681; and (?)-epicatechin gallate: r=0.771).     

Effects of suni-bug (<Emphasis Type="Italic">Eurygaster</Emphasis> spp.) damage on size distribution of durum wheat (<Emphasis Type="Italic">Triticum durum</Emphasis> L.) proteins

Wholemeal samples were obtained from five durum wheat cultivars at two different bug (Eurygaster spp.) damage levels (medium and high damage). The samples were incubated (60 and 120 min) and used in size exclusion high performance liquid chromatography (SE-HPLC) analyses. The results showed that the amount of larger polymeric protein (TP1) and smaller polymeric protein (TP2) obtained from total (sodium dodecyl sulfate soluble) proteins decreased significantly in the bug-damaged samples, while the amount of total larger monomeric proteins (TP3) increased. The polymeric/monomeric protein ratio of all cultivars decreased at 60 min of incubation with increasing damage level. For all cultivars, the ratio of unextractable polymeric protein (UPP%) significantly decreased at 60 min of incubation except cv. Diyarbakir. The results suggested that bug protease caused depolymerization and/or disaggregation of polymeric proteins to lower their average molecular size. The changes in protein structure as determined using SE-HPLC supported by the decreases in gluten content and gluten index values which decreased with suni-bug damage. Deteriorative effects of bug damage on durum wheat quality were found to be quite similar to those on bread wheats.     

Heavy metal contents and chemical compositions of atlantic (<Emphasis Type="Italic">Scomber scombrus</Emphasis>), blue (<Emphasis Type="Italic">Scomber australasicus</Emphasis>), and chub (<Emphasis Type="Italic">Scomber japonicus</Emphasis>) mackerel muscles

The heavy metal contents and chemical compositions among mackerel species were investigated. Atlantic and chub mackerel had higher mercury, but lower lead than blue mackerel. Chub mackerel had the highest crude fat (18.62%) and the lowest moisture (58.29%), whereas blue mackerel had the highest moisture (70.10%) and the lowest crude fat (2.89%). Atlantic and blue mackerel had total saturated fatty acids (SFA)>polyunsaturated fatty acids (PUFA)>monounsaturated fatty acids (MUFA), whereas chub mackerel had PUFA>SFA>MUFA. The main SFA of the 3 mackerels were 16:0 and the main PUFAs were 22:6n-3 and 20:5n-3. The total amino acid contents in Atlantic, blue, and chub mackerel were 190.63, 169.49, and 172.97 mg/g, respectively. The major amino acids of the 3 mackerels were glutamic acid, aspartic acid, lysine, and leucine.     

<Emphasis Type="Italic">Lactobacillus acidophilus</Emphasis> fermented yam (<Emphasis Type="Italic">Dioscorea opposita</Emphasis> Thunb.) and its preventive effects on gastric lesion

This study was carried out to find the possibility of fermenting yam (Dioscorea opposita Thunb.) with Lactobacillus acidophilus and the protective role on stomach lesion of rats. The solutions of raw and extracted yam used were 2 and 6%, and they were fermented by L. acidophilus at 37°C for 0, 12, 24, and 36 h. At intervals (0, 12, 24, and 36 h), viscosity, titratable acidity (TA), allantoin, and diosgenin were examined. In the results, it was observed the most desirable data at 12 h with 6% fermented raw yam (FRY) without any change in the content of allantoin and diosgenin. In the animal study by rats (Sprague-Dawley), the inhibition ratios on gastric lesion were 53.41% in FRY. Based on these data, it confirmed that raw yam powder fermented by L. acidophilus would be a functional food with the supplement of viable cells and nutraceutical component of allantoin and diosgenin.     

A New Multiplexed Real-Time PCR Assay to Detect <Emphasis Type="Italic">Campylobacter jejuni</Emphasis>, <Emphasis Type="Italic">C. coli</Emphasis>, <Emphasis Type="Italic">C. lari</Emphasis>, and <Emphasis Type="Italic">C. upsaliensis</Emphasis>

A new rapid method based on real-time PCR was developed to detect four thermophilic Campylobacter species (Campylobacter jejuni, Campylobacter coli, Campylobacter lari, and Campylobacter upsaliensis) in food samples. The assay targeted the bipA gene for C. upsaliensis and C. lari, whereas the gene encoding the ATP-binding protein CJE0832 was used to detect C. coli and C. jejuni. These genes were chosen for this assay due to their low variability and mutation rate at a species level. The multiplex PCR showed 100% inclusivity for all 25 thermophilic Campylobacter strains tested and 100% exclusivity for 38 non-targeted strains belonging to closely related species. The newly developed real-time PCR could detect down to 10² genomes/reaction and displayed efficiency above 97% for all species except for C. upsaliensis (90.1%). The method proved to be a reliable tool for food analysis, showing 100% sensitivity, 96% efficiency, and 92.45% specificity when validated against the gold standard method UNE-EN ISO 10272:2006 using 200 diverse food samples (meat, fish, fruits and vegetables, and raw milk). In artificially spiked samples, the detection limit of the method was 10 cfu/g in salad, 5 cfu/g in turkey meat, and 1 cfu/g in the rest of meat samples tested. Consequently, the newly designed molecular tool represents a quick and safe alternative to obtain reliable results concerning the presence/absence of the main thermophilic Campylobacter in any food sample.     

Quantification of anthocyanins in black carrot extracts (<Emphasis Type="Italic">Daucus carota</Emphasis> ssp.<Emphasis Type="Italic"> sativus</Emphasis> var.<Emphasis Type="Italic"> atrorubens</Emphasis> Alef.) and evaluation of their color properties

Pigment composition of 15 black carrot cultivars (Daucus carota ssp. sativus var. atrorubens Alef.) was screened by HPLC-MS. Up to seven cyanidin glycosides, five of which were acylated with hydroxycinnamic and hydroxybenzoic acids, were identified and quantified in the roots by HPLC-DAD. Contents of individual compounds indicated great differences in the potential of anthocyanin accumulation both between different cultivars and carrots of the same cultivar. Total anthocyanin amounts ranged from 45.4 mg/kg dry matter to 17.4 g/kg dry matter. To the best of our knowledge, this is the first report on the quantification of individual anthocyanins in roots of different black carrot cultivars. The determination of color properties in the extracts under various pH conditions proved black carrot anthocyanins to be applicable as natural food colorants also for low-acid food commodities, whereas a considerable loss of color was noted under nearly neutral conditions. Additionally, relatively high saccharide contents were found in almost all cultivars which may be disadvantageous when coloring concentrates are produced from carrot roots.     

Molecular diagnostics of Lemon Myrtle (<Emphasis Type="Italic">Backhousia citriodora</Emphasis> versus <Emphasis Type="Italic">Leptospermum citratum</Emphasis>)

‘Lemon Myrtle’ is becoming increasingly popular in Europe both for use in cuisine and phytotherapy. However, this common name covers two completely different species, Backhousia citriodora F. Muell. and Leptospermum citratum Challinor, Cheel & A.R.Penfold. These species differ with respect to secondary compounds and even can cause, if mixed up and applied in high dose, toxic effects. We describe how the two species can be discriminated microscopically making use of differences in the morphology of leaf pavement cells and the relative size of palisade parenchyma. Based on the large subunit of ribulose-1,5-bisphosphate carboxylase oxygenase (rbcL) as molecular marker, the phylogenetic position of the two species within the Myrtaceae could be clarified. This sequence information was used to develop a simple assay to discriminate the two species even in dried and highly fragmented mixtures as typically occurring in commercial samples. This assay utilises the occurrence of single-nucleotide exchanges between those species that produce different fragments when the rbcL amplificates are restricted with Sac II.