Quantification of lycopene in tomato products: comparing the performances of a newly proposed direct photothermal method and high‐performance liquid chromatography

A new photothermal method suitable for direct, accurate and highly reproducible quantitative measurements of lycopene in tomato products has been introduced. The intrinsic precision of the method is typically better than 0.2%; the repeatability of determination is comparable to that of high‐performance liquid chromatography, with 0.86% least overall error. Copyright © 2005 Society of Chemical Industry     

Photoacoustic spectroscopy and optothermal window as analytical tools to quantitate carotenes in margarines

Photoacoustic spectroscopy (PAS) and optothermal window (OW) with a cw Ar ion laser used as a radiation source at 476.5, 488 and 496 nm were applied to quantify total carotenes (TC) in margarines. Both techniques, being rapid and extremely simple, allow for direct measurement without any pretreatment of the sample. The PAS has proven precise and sensitive enough to allow quantitation of TC in margarines containing 1–9 mg TC/kg, in applications such as the quality control of intermediate and final products. The sensitivity of OW is lower than that of PAS but the approach can still be used for quantitation of TC in margarine matrices at much higher concentrations.     

Indolylfuran,a potent aryl hydrocarbon receptor agonist from sauerkraut,interacts with the oestrogen pathway

Numerous ligands of the aryl hydrocarbon receptor (AhR) have been found in plants, especially edible plants, such as cruciferous vegetables, which exert beneficent health effects. A potent activator of the AhR was found in sauerkraut juice. The isolated active ingredient was identified as the novel AhR ligand, (1-(2-furanyl)2-(3-indolyl)ethanone, common name indolylfuran. The isolated and the synthesised compound exerted similar potencies; their EC₅₀-values in an AhR transactivation assay were 160 and 123 nM, respectively. Our in vivo studies confirm and enlighten basic interactions between the AhR and oestrogen receptors (ERs). Further anti-oestrogenic effects of sauerkraut extract were shown. Indolylfuran regulates ER α and β expression, most likely via the AhR pathway, since indolylfuran had no effect on uterus weight and did not agonise ERα. Sauerkraut and indolylfuran may have potential for the prevention or treatment of diseases through modulation of AhR regulation and, indirectly, the ER pathway.     

Fast quality screening of vegetable oils by HPLC-thermal lens spectrometric detection

Isocratic reversed-phase HPLC with thermal lens spectrometric (TLS) detection enabled identification of linseed, olive, sesame, and wheat germ vegetable oils to control the authenticity of the oils based on characteristic carotenoid/carotene profiles. Four characteristic regions of carotenoids (i.e., lutein, xanthophyll, carotene, and lycopene) have been identified in each type of oil. The concentrations of total β-carotene (BC) and α-carotene (AC), together with trans-to cis-isomers of β-carotene (TBC/CBC) and BC/AC ratios were shown to be reliable and useful indices for fast screening of oils for nutritional quality. The oil TBC/CBC ratio and the BC concentration (in μg/mL) should meet the following numerical criteria: linseed (≽2∶1, ≽1.7), olive (≽3∶1, ≽0.4), sesame (≽1∶1, ≽0.1), and wheat germ oil (≽1∶1, ≽1.7). Based on the above criteria, unsatisfactory olive oils differed significantly from the consumable ones. Likewise, the concentration of AC in consumable wheat germ and sesame oil should not be lower than 0.6 and 0.02 μg/mL, respectively. The AC level in safflower oil should not be higher than 0.04 μg/mL. The BC/AC ratios exceeding 3∶1, 6∶1, and 8∶1 should be used as an additional quality requirement for consumable wheat germ, sesame, and safflower oil, respectively.     

Evaluation of serious game for changing students' behaviour in bullying situation

The aim of the study was to test the effectiveness of a serious game in improving the helping behaviours of bystanders in bullying situations by using a multimethod approach. Students (N=345, aged 12 to 14) participated in an experimental study with one experimental and two control groups. Before and after playing the game, all students completed an online questionnaire about their knowledge, experiences and behaviours related to bullying, and their behaviours in everyday social situations. For the experimental group, players' reactions during game-play were recorded. Results showed that students' social behaviour displayed before gaming experience determined their playing activities. Besides, most of the students who declared in pre-test that they do not help the victim, although they think they should, chose helping behaviour in all bullying situations in by stander role in the game. Results indicate weak positive effect of the game on students' behavioural choices.     

Bioactive and Sensory Properties of Herbal Spirit Enriched with Cocoa (Theobroma cacao L.) Polyphenolics

In the Southeast European and Mediterranean regions, consumption of various alcoholic beverages in the form of plain and aromatized spirits and liqueurs is an important part of traditional local gastronomy. Especially herbal spirits and liquors are widely spread and consumed. The objective of this study was to evaluate the potential of using cocoa raw materials (cocoa beans, cocoa nibs or cocoa liquor) in order to enhance the bioactive profile of traditional herbal liqueur, and to produce an appealing cocoa-flavoured alcoholic beverage. Therefore, the polyphenolic profile, antioxidative and sensory properties of herbal liquors containing the macerated cocoa raw materials were monitored during 6 months, in order to evaluate the kinetics of cocoa polyphenols release and optimise the maceration procedure for obtaining the best cocoa-enriched herbal spirit. Compared to plain herbal liquor without the additions, the obtained herbal liqueurs exhibited significantly higher content of polyphenolic antioxidants. Among the used cocoa raw materials for the maceration, cocoa nibs were evaluated as the best source of polyphenolic compounds (herbal liqueur containing cocoa nibs, 3,081.82 mg GAE/L), followed by cocoa liquor (1,897.73 mg GAE/L) and cocoa beans (1,358.64 mg GAE/L). Prolonged maceration time (up to 6 months) resulted with an increase in the content of polyphenolic compounds and the antioxidant capacity of herbal liqueurs. Herbal liqueurs containing the cocoa raw materials of bigger particle size (cocoa beans and cocoa nibs) exhibited better sensory properties (overall acceptability and chocolate-like flavour) than herbal liqueur containing cocoa liquor.     

Aeromonas spp. simultaneously harbouring blaCTX-M-15, blaSHV-12, blaPER-1 and blaFOX-2, in wild-growing Mediterranean mussel (Mytilus galloprovincialis) from Adriatic Sea,Croatia

Aeromonas species are becoming renowned as emerging pathogens by increasingly giving rise to a wide spectrum of food and waterborne infections in humans. Another worrisome feature of aeromonads is the growing frequency of antibiotic resistance as a consequence of their prominent diversity in terms of resistance determinants. This study aimed at determining the antimicrobial resistance pattern, prevalence and characterization of acquired β-lactamases, including extended-spectrum-β-lactamases (ESBLs) and AmpC cephalosporinases, as well as the presence of class 1 and 2 integrons, in Aeromonas isolates from wild-growing Mediterranean mussel (Mytilus galloprovincialis) of the eastern coast of Adriatic Sea, Croatia. Isolates were tested for susceptibility to 16 antibiotics and β-lactam/β-lactamase inhibitor combinations. Cephalosporin-resistant isolates were further screened by PCR for genes encoding AmpC (bla_FOX, bla_CMY, bla_MOX, bla_LAT, bla_BIL, bla_DHA, bla_ACC, bla_MIR, bla_ACT), ESBLs (bla_TEM, bla_SHV, bla_CTX-M, bla_PER, bla_VEB, bla_GES/IBC, bla_OXA) and integrases (intI1, intI2, intI3). Location of bla genes was characterized by plasmid DNA fingerprinting and Southern blot hybridization. Plasmids carrying ESBL genes were investigated for transferability by conjugation and PCR-based replicon typed. Out of 147 Aeromonas isolates recovered, 30 (20%) demonstrated multiple resistance profile, with co-resistance most frequently detected against penicillins, piperacillin/sulbactam and tetracycline. ESBL-encoding genes were detected in 21 (13 Aeromonas caviae and 8 Aeromonas hydrophila) isolates, with bla_CTX-M-15 gene identified in 19 and bla_SHV-12 in 12 isolates. Among them, 10 isolates simultaneously harboured bla_CTX-M-15 and bla_SHV-12, while 3 isolates additionally carried an AmpC β-lactamase bla_FOX-2 gene. bla_PER-1 gene was identified in a single isolate also harbouring the bla_CTX-M-15 gene. While bla_SHV-12 was chromosomally encoded, bla_CTX-M-15 was located on conjugative IncFIB-type plasmids of ~ 40 kb in A. caviae isolates. IntI1 and intI2 genes were detected in 57.1% and 33.3% of ESBL-producing isolates.     

Rheological Properties of Milk Chocolates as Influenced by Milk Powder Type,Emulsifier, and Cocoa Butter Equivalent Additions

The research examines the influences of different emulsifiers (lecithin, CITREM LR10—both individually and combined with polyglycerol polyricinoleate, and CITREM 2in1) and cocoa butter equivalent additions on the rheological properties of milk chocolates produced using spray or roller-dried milk. The substitution of lecithin with other emulsifiers caused an increase in the Casson plastic viscosity (μ_CA), as well as a decrease in the Casson yield stress (τ_CA) in milk chocolates containing roller-dried milk powder, whereby the lecithin-polyglycerol polyricinoleate blend had the most pronounced influence. Cocoa butter equivalent addition resulted in the highest μ_CA when CITREM LR10 was used, and the lowest τ_CA with lecithin-polyglycerol polyricinoleate blend. When spray-dried milk was used, the highest μ_CA was determined in the sample containing CITREM LR10 and the lowest τ_CA in the sample containing the lecithin-polyglycerol polyricinoleate blend. Cocoa butter equivalent addition resulted in an increase in the τ_CA---except when CITREM LR10-polyglycerol polyricinoleate blend was used as emulsifier.     

Honey‐bee products in prevention and/or therapy of murine transplantable tumours

We investigated the effects of water‐soluble derivative of propolis (WSDP), caffeic acid, honey, royal jelly and bee venom on tumour development and metastasis in murine tumour models. Transplantable murine tumours were used: a spontaneous mammary carcinoma (MCa) and a methylcholanthrene–induced fibrosarcoma (FS) of CBA mouse. Metastases in the lung were generated by injecting 10⁵ or 2 × 10⁵ viable tumour cells intravenously. Tumours in the hind leg were generated by subcutaneous injection of 10⁴ or 10⁵ mammary carcinoma cells. Oral application of WSDP or caffeic acid significantly reduced subcutaneous tumour growth and prolonged survival of mice. Honey also exerted a pronounced antimetastatic effect (p < 0.01 or p < 0.001) when applied before tumour cell inoculation (2 g kg^?1 orally once a day for 10 consecutive days). Royal jelly did not affect the formation of metastases when given intraperitoneally or subcutaneously. However, synchronous application of tumour cells and royal jelly intravenously significantly (p < 0.001) inhibited the formation of metastases. When bee venom was injected intratumourally, tumours decreased in size. These findings demonstrated that honey‐bee products given orally or systemically may have an important role controlling tumour growth and metastasis. Copyright © 2004 Society of Chemical Industry