Effect of pH on betalain–anthocyanin mixture in bayberry juice: influences on pigments,colour, and antioxidant capacity

Betalains (mainly betanin, isobetanin, and phyllocactin) extracted from red–purple pitaya were blended with Chinese bayberry juice (rich in anthocyanins) to explore variation trends of two natural pigments in one system. The mixture showed higher anthocyanin contents at pH 4, 4.5, and 5. In this process, redness and colour saturation were also maintained to a greater extent compared to the control. The coexisting betalains and anthocyanins increased colour acceptability of the juice matrix and expanded the pH tolerance range. Interestingly, colour change (ΔE) showed the opposite trend. Besides, betalains showed the function of improving the antioxidant activity of juice matrix at pH 3, 4, and 4.5, which confirmed their biological activity. Betalain-added bayberry juice obtained a satisfactory ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging capacity for 62.52% at pH 5.     

Characterization of volatile compounds in ten Piper species cultivated in Hainan Island,South China

The volatile compounds of 10 Piper species cultivated in Hainan Island, China, have been investigated. Eighty compounds were profiled after headspace–solid phase microextraction (HS–SPME) with gas chromatography–mass spectrometry (GC–MS). Mean Bray–Curtis similarity value was only 22.78 ± 1.98% among the different Piper species. The volatile compounds were largely grouped as hydrocarbons, aldehydes, alcohols, acids, ketones, esters, and phenols. The main compounds comprised benzaldehyde, cinnamaldehyde, β-caryophyllene, ocimene, lavandulol, myrcene, cubebene, terpinene, linalool, α-caryophyllene, β-elemene, and germacrene. Principal component analysis revealed that Piper laetispicum, Piper longum, Piper hainanense, Piper betle, and Piper flaviflorum were characterized by high contents of β-caryophyllene, α-caryophyllene, germacrene, and β-pinene. Piper puberulum and Piper cathayanum were associated with high contents of linalool, myrcene, and germacrene D. On the other hand, Piper pseudofuligineum and Piper retrofractum were related with high contents of ocimene. Finally, Piper auritum was associated with high content of cinnamaldehyde. Volatile profiling of Piper species by HS–SPME–GC–MS and the interrelationship investigated among the volatiles can be used as a roadmap for future resource utilization or biotechnological applications.     

Polycyclic aromatic hydrocarbons in traditionally smoked meat products from the Baltic states

A total of 77 traditionally smoked meat samples produced in Latvia, Lithuania, and Estonia were tested for the occurrence of four EU regulated polycyclic aromatic hydrocarbons (PAHs). Levels of PAHs exceeding the EU maximum levels for benzo[a]pyrene and for the sum of four PAHs (PAH4) were detected in 46% and 48% of the samples originating from Latvia. The detected BaP levels in smoked meats ranged from 0.05 to 166 μg kg^?1, while the PAH4 content ranged from 0.42 to 628 μg kg^?1. The mean dietary exposure to PAHs was estimated at the levels of 5.4 ng BaP/kg bw/day and 36 ng PAH4/kg bw/day. The margin of exposure (MOE) approach was utilised to assess the risks to Latvian consumers due to PAHs and the obtained MOEs were in a range of 7205–24,434, thus indicating a potential concern for consumer health for specific population groups.     

The UPLC–ESI–QqQLIT–MS/MS method for quantitative determination of phytochemicals in ethanolic extracts of different parts of eight Ficus species: Development and validation

Ficus and validation of the ultra performance liquid chromatography–electrospray ionization hybrid triple quadrupole–linear ion trap–tandem mass spectrometry (UPLC–ESI–QqQ_LIT–MS/MS) method in a multiple-reaction monitoring (MRM) mode for the quantitative determination of 19 phytochemicals. The chromatographic separation of targeted phytochemicals was performed using the Waters ACQUITY UPLC BEH? C18 column (1.7 μm, 2.1 mm × 50 mm) with 0.1% formic acid with water and acetonitrile as a mobile phase at a flow rate of 0.25 mL/min. The validation parameters showed the overall recoveries from 95.78?101.44% (RSD ≤ 3.25%), precision (intra-day: RSD ≤ 2.96%; inter-day: RSD ≤ 2.89%), linearity (R² ≥ 0.9982), limit of detection (8.60 × 10^–10?2.18 × 10^–6 mg/mL), and the limit of quantitation (2.60 × 10^–9–6.63 × 10^–6 mg/mL) in the concentration range from 0.5 to 1000 × 10^–6 mg/mL. This method was successfully applied in ethanolic extracts of different parts (fruits, leaves, and barks) of selected eight Ficus species. Quinic acid was predominant followed by rutin and chlorogenic acid among the studied nineteen phytochemicals. Ficus benjamina showed the maximum total content in fruits and leaves. The UPLC–ESI–QqQ_LIT–MS/MS method combined with principal component analysis (PCA) was successfully used for Ficus species discrimination on the basis of the contents of 15 compounds. The UPLC–ESI–QqQ_LIT–MS/MS method combined with PCA could be used for quality control.     

Erythromycin residue in honey from the Southern Marmara region of Turkey

Honey samples, collected from the Southern Marmara region of Turkey, were analysed for erythromycin residues by liquid chromatography–mass spectrometry using electrospray ionization in the positive ion mode (LC–ESI–MS). Fifty samples, comprising chestnut, pine, linden and multi-flower honeys, were collected directly from hives and analyzed. The limit of detection and quantification were 6 and 20 ng g^?1, respectively, and recovery ranged from 85 to 89%. Four of the honey samples (8%) were found to be contaminated with erythromycin residues at concentrations ranging from 50 to 1776 ng g^?1. An erythromycin-fortified cake feeding assay was also performed in a defined hive to test the transfer of erythromycin residue to the honey matrix. In this test hive, the residue level in the honey, 3 months after dosing, was approximately 28 ng g^?1.     

Determination of malachite green and crystal violet in processed fish products

This paper presents analysis of malachite green (MG) and crystal violet (CV) residues in processed fish products. Samples were homogenized and extracted with ammonium acetate buffer and acetonitrile. The extracted residues were partitioned into dichloromethane, in situ oxidized to chromic forms with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, and cleaned up on neutral alumina and propylsulfonic acid cation-exchange solid-phase extraction (SPE) cartridges. MG and CV were determined at 618 and 588 nm using HPLC with a visible detector (LC–VIS) and confirmed by LC–electrospray ionization tandem mass spectrometry (LC–ESI–MS/MS). The recoveries were as follows: MG (74.8–83.8%), LMG (80.0–88.4%), CV (68.6–73.9%), and LCV (85.5–90.0%). The method modified in this study has been evaluated by application in-house to a survey of 253 processed fish products. As a result of monitoring, MG and CV were positive in one shrimp and one eel sample, respectively. Our results showed that regular monitoring of these antibiotic residues is recommended for protection of public health.     

Assessment of phenolic profile of Turkish honeys

In this study, phenolic profile and antioxidant activity of 60 Turkish honey samples of nineteen different floral origins were evaluated by ultra-performance liquid chromatography with electrospray ionization coupled to tandem mass spectrometry, providing the identification of 32 phenolic compounds. Thyme (1051.58 mg/kg), pine (994.18 mg/kg), carob (935.03 mg/kg), eucalyptus (814.46 mg/kg), rhododendron (680.71 mg/kg), heather (562.59 mg/kg), cedar (561.83 mg/kg), and euphorbia (501.64 mg/kg) present significantly high phenolic content. Moreover ferulic, homogentisic, gentisic, syringic, 3,4-dihydroxybenzoic, caffeic, vanillic, p-coumaric, 4-hydroxy benzoic, and trans-2-hydroxy cinnamic acids were the most abundant of the determined compounds. The antioxidant activities of the honeys were evaluated by β-carotene-linoleic acid inhibition, DPPH free radical scavenging activity and ABTS⁺ cation radical scavenging activity which were measured as IC₅₀: 10.87 – 48.23 µg/mL, SC₅₀: 54.33 – 99.40 µg/mL and SC₅₀: 10.33 – 41.20 µg/mL, respectively. Phenolic compounds are considered antioxidant constituents, and they could be stated as components that account for antioxidant activity in Turkish honeys.     

Influence of aflatoxin in Nuruk on the safety of starch-based alcoholic beverage

Nuruk is a fermentation agent used to manufacture alcoholic beverages, which contains a variety of microorganisms. Most microorganisms in Nuruk are useful for the production of alcoholic beverages; however, Nuruk can be infected with Aspergillus flavus, which produces aflatoxin (AF). Therefore, this study analyzed total AF concentrations in Nuruk, the transfer of AF from Nuruk to alcoholic beverages, and AF-producing microorganisms to determine the safety of alcoholic beverages with respect to this toxin. ELISA showed that total AF levels in 14 of 61 Nuruk samples exceeded 15 ppb, the Korean permissible level in cereal products. In alcoholic beverages produced with Nuruk containing AF levels >15 ppb, only AF G₁ was detected, at a level of 0.3 ppb, and the transfer ratio of AF G₁ was approximately 1.2% to 1.3%. The dominant genera in Nuruk were Aspergillus and Rhizopus. Among 30 strains belonging to Aspergillus, 10 produced only AF B₁ at levels of 0.1 to 2.4 ppb after incubation at 25 °C for 8 days on potato dextrose agar plates. Although AF in Nuruk was rarely transferred to alcoholic beverages and the aflatoxigenic strains were found to possess poor AF-producing capacity, further efforts to reduce AF in Nuruk are needed to ensure the safety of alcoholic beverages.     

Improved method for the determination of 12 non-nutritive sweeteners and monitoring in various foods using liquid chromatography–tandem mass spectrometry

An improved and highly sensitive method was developed and validated for the determination of 12 (7 permitted and 5 non-permitted in Korea) non-nutritive sweeteners in various foods using liquid chromatography-electrospray ionisation-tandem mass spectrometry. The chromatographic separation was performed on an Xbridge BEH C18 column (3 mm × 100 mm, 2.5 μm) with gradient elution using 10 mM ammonium acetate in water and 10 mM ammonium acetate in methanol. Sample preparation consisted of simple dilution, homogenisation, centrifugation and purification with a C18 cartridge prior to analysis. The relative matrix effect (%ME) was within ±20% for all sweeteners. The method also showed good linearity (R² > 0.99). The limit of detection and limit of quantification values in sample were in the range of 0.02–2.66 and 0.06–8.05 mg kg^?1, respectively. The recoveries at three concentration levels ranged between 80% and 119%, with relative standard deviation values below 10%. In addition, the expanded uncertainties determined for 12 sweeteners in 5 different food matrices were confirmed to be <14%. Finally, the method was successfully applied to the analysis of sweeteners in 681 food samples purchased in Korea, Australia and Turkey. These results demonstrate that the method is suitable for the simultaneous determination of multiple-sweeteners in a variety of foods.     

Isolation and identification of low molecular weight antioxidant compounds from fermented "chorizo" sausages

This work is focused on the determination of low molecular weight compounds extracted from samples of fermented sausages. The antioxidant activity of fractions isolated from chorizo extracts was tested by their ability to quench free radicals by the DPPH-radical scavenging assay. Natural dipeptides and metabolites characteristic of meat were abundant in the fractions isolated by RP-HPLC from chorizo extracts. Due to extensive degradation during the ripening of chorizo, the extracts did not contain many peptides in a concentration that allowed identification. However, many free amino acids were identified by LC-MS/MS and HILIC-MS/MS. The fractions with the most hydrophilic compounds showed the highest antioxidant activity.     

瓜馥木挥发油GC—MS分析

利用GC–MS方法鉴定分析瓜馥木挥发油,结果表明,已鉴定成分占总脂溶性成分72.137%,共50种化合物,主要包含饱和烃、烯烃、脂肪烃衍生物、生物碱、黄酮和芳香族化合物。总挥发油以生物碱(22.349%)、黄酮类(22.192%)和脂肪烃衍生物(12.237%)为主,其中相对含量最高单体化合物是4',5,6,7–四甲氧基黄酮(22.192%),其次是1–(9–硼双环[3.3.1]壬基)–4–乙基–3,5–二叔丁基吡唑(21.063%),再次是油酸甲酯(5.917%)。     

Degradation Kinetics of Jujuboside a by Rat Intestinal Flora and Identification of the Metabolites by HPLC-Ms/Ms

Jujuboside A (JuA) is a representative saponin with significant sedative and hypnotic effects. Up to now, there were many arguments on its metabolic mechanism. In this study, a high performance liquid chromatography-tandem mass spectrometry (MS/MS) method was developed for investigating the degradation characteristics of JuA incubated with rat feces. With the method, the degradation kinetics of JuA was studied. The results showed JuA decomposed rapidly. It could decompose nearly 100% in only 4–6 h. The degradation regularity was consistent with the first dynamic process. In addition, seven metabolites were determined and identified to be the serial hydrolysis products of JuA. The results revealed that gastrointestinal microbiota played an indispensable role in the metabolic process of JuA. JuA may be a supplier of sugars under the hydrolysis effect induced by the bacterial enzymes. At the same time, its aglycone was produced as a by-product, which could be easier to be absorbed into the body to perform its specific bioactivities.     

Survey on acrylamide in roasted coffee and barley and in potato crisps sold in Italy by a LC–MS/MS method

ABSTRACT

A survey on the occurrence of acrylamide (AA) in roasted coffee, barley, and potato crisps was carried out using an intra-lab validated liquid chromatography (LC)–MS (mass spectrometry)/MS method. Over the years 2015–2016, 66 samples of coffee, 22 of roasted barley, and 22 of potato crisps were collected from retail outlets in Italy. AA was detected in almost all samples. In roasted coffee, the level exceeded 450 µg kg^?1, the limit recommended by the European Commission (EC), in 36.4% of the samples. In roasted barley, mean contamination was slightly lower than in coffee and no sample exceeded the EC limit of 2000 µg kg^?1. The AA contamination in potato crisps was remarkable. A percentage of 36.4 (n = 8) showed a value higher than the EC limit of 1000 µg kg^?1. Considering the average consumption of coffee and potato crisps by Italian people, AA exposure is significant and should be decreased.     

Determination of acrylamide in food using a UPLC–MS/MS method: results of the official control and dietary exposure assessment in Cyprus

ABSTRACT

The determination of acrylamide in potato products, bakery products and coffee, and the human dietary exposure is reported. The method reported is based on a single extraction step with water, followed by the clean-up of the extract using solid phase extraction columns and finally, the determination of acrylamide using UPLC–MS/MS. The MS/MS detection was carried out using an ESI interface in positive ion mode. Internal calibration was used for the quantification of acrylamide, because of the suppression/enhancement matrix effects due to the complex nature of the samples. The method performance characteristics were determined after spiking blank samples. The mean recoveries in spiked coffee samples, potato chips, breakfast cereals and crispbread ranged from 93% to 99%, with RSDs lower than 5% for both repeatability and reproducibility conditions. The estimated limits of detection and quantification of the method were 10 and 32 μg kg^?1, respectively. The method was used for monitoring acrylamide in 406 samples. Acrylamide amounts ranged from <32 to 2450 μg kg^?1. A total of 360 samples (89%) were contaminated with acrylamide, but only 14% of the samples exceeded the benchmark levels of the EU legislation. Foods with the highest mean acrylamide amounts were potato crisps (642 μg kg^?1), French fries (383 μg kg^?1) and biscuits (353 μg kg^?1). The mean and 95th percentile acrylamide exposures of adolescents in Cyprus were 0.8 and 1.8 μg kg^?1 body weight per day, respectively. The estimated levels of dietary exposure to acrylamide are not of concern with respect to neurotoxicity. However, the margins of exposure (MOEs) indicate a concern for carcinogenicity. Potato fried products (45%), fine bakery ware (21%) and potato chips (14%) contributed the most to overall acrylamide exposure.