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Food Chemistry

Esra Bağda, Mustafa Tüzen
In the present study, a novel and eco-friendly vortex-assisted ionic liquid-based microextraction method was developed for the determination of selenium in food. The microextraction method is based on the liberation of iodine in the presence of selenium; the liberated iodine reacts with I(-) to form I3(-). Anionic I3(-) reacts with cationic crystal violet dye, and the product is extracted into 1-hexyl-3-methylimidazolium hexafluorophosphate phase in the presence of Triton X-114. The proposed method is linear in the range of 2...
October 1, 2017: Food Chemistry
William Tchabo, Yongkun Ma, Emmanuel Kwaw, Haining Zhang, Lulu Xiao, Haroon Elrasheid Tahir
The present study was undertaken to assess accelerating aging effects of high pressure, ultrasound and manosonication on the aromatic profile and sensorial attributes of aged mulberry wines (AMW). A total of 166 volatile compounds were found amongst the AMW. The outcomes of the investigation were presented by means of geometric mean (GM), cluster analysis (CA), principal component analysis (PCA), partial least squares regressions (PLSR) and principal component regression (PCR). GM highlighted 24 organoleptic attributes responsible for the sensorial profile of the AMW...
October 1, 2017: Food Chemistry
Mohamed Ahmed Abbas Mahmoud, Andrea Buettner
Odorous molecules in earthen-ponds rainbow trout aquaculture farming in Germany were investigated with a special focus on musty-earthy off-odorants. To this aim, fish meat and skin were extracted using solvent-assisted flavour evaporation (SAFE) and were mildly concentrated; extracts were subsequently analysed by means of one- and two-dimensional high-resolution gas chromatography coupled with mass spectrometry and olfactometry (GC-MS/O and 2D-HRGC-MS/O). Aroma extract dilution analysis (AEDA) of the solvent extracts revealed the presence of 76 odorants of which 75 were successfully identified...
October 1, 2017: Food Chemistry
D V Peron, S Fraga, F Antelo
The effect of temperature on the degradation of anthocyanins in juçara and "Italia" grape extracts was determined between 50 and 90°C. For both species, thermal degradation followed a first-order kinetic model. The decimal reduction time decreased with increasing temperature, and dependence on the thermodegradable factor was lower at higher temperatures. The anthocyanins from juçara degraded more slowly than those extracted from "Italia" grapes. The activation enthalpy and free energy of inactivation indicated an endothermic reaction, not spontaneous degradation, whereas the activation entropy suggested that the transition state has less structural freedom than that of the reactants...
October 1, 2017: Food Chemistry
Alba Alonso-Rebollo, Sonia Ramos-Gómez, María D Busto, Natividad Ortega
The applicability of qPCR in olive-oil authentication depends on the DNA obtained from the oils and the amplification primers. Therefore, four olive-specific amplification systems based on the trnL gene were designed (A-, B-, C- and D-trnL systems). The qPCR conditions, primer concentration and annealing temperature, were optimized. The systems were tested for efficiency and sensitivity to select the most suitable for olive oil authentication. The selected system (D-trnL) demonstrated specificity toward olive in contrast to other oleaginous species (canola, soybean, sunflower, maize, peanut and coconut) and showed high sensitivity in a broad linear dynamic range (LOD and LOQ: 500ng - 0...
October 1, 2017: Food Chemistry
Netsanet Shiferaw Terefe, Antoine Delon, Cornelis Versteeg
This study for the first time investigated the stability and inactivation kinetics of blueberry peroxidase in model systems (McIlvaine buffer, pH=3.6, the typical pH of blueberry juice) during thermal (40-80°C) and combined high pressure-thermal processing (0.1-690MPa, 30-90°C). At 70-80°C, the thermal inactivation kinetics was best described by a biphasic model with ∼61% labile and ∼39% stable fractions at temperature between 70 and 75°C. High pressure inhibited the inactivation of the enzyme with no inactivation at pressures as high as 690MPa and temperatures less than 50°C...
October 1, 2017: Food Chemistry
Maria Schranz, Katja Lorber, Katharina Klos, Julia Kerschbaumer, Andrea Buettner
Guaiacol and its derivatives are commonly found in nature and are known for their characteristic smoky, clove-like and vanilla-like smells. However, there is no systematic investigation of the smell properties of structurally related guaiacol derivatives. In order to establish a comprehensive database on this olfactorily interesting substance class, odor thresholds in air and odor qualities of guaiacol and its alkylated, alkenylated, and methoxylated derivatives were determined by means of gas chromatography-olfactometry...
October 1, 2017: Food Chemistry
Jacek A Koziel, Lam T Nguyen, Thomas D Glanville, Heekwon Ahn, Timothy S Frana, J Hans van Leeuwen
A passive sampling method, using retracted solid-phase microextraction (SPME) - gas chromatography-mass spectrometry and time-weighted averaging, was developed and validated for tracking marker volatile organic compounds (VOCs) emitted during aerobic digestion of biohazardous animal tissue. The retracted SPME configuration protects the fragile fiber from buffeting by the process gas stream, and it requires less equipment and is potentially more biosecure than conventional active sampling methods. VOC concentrations predicted via a model based on Fick's first law of diffusion were within 6...
October 1, 2017: Food Chemistry
Natalia S Podio, María V Baroni, Daniel A Wunderlin
We report the polyphenol profile and antioxidant capacity (AC) of 12 Argentinean wheat varieties from different regions. The polyphenol profile was studied by HPLC-MS. The AC was measured by TEAC and FRAP. Twenty-five polyphenols were identified. ACA 315 and KLEIN GUERRERO varieties showed the highest content of polyphenols, whereas BIOINTA 3004, KLEIN CAPRICORNIO and LE 2330 showed the lowest one. ACA 315 presented the highest AC, while BIOINTA 3004 and KLEIN CAPRICORNIO showed the lowest one. Boosted Regression Trees (BRT) analyses helped finding significant correlations between AC and polyphenol profile, being hydroxybenzoic acid diglucoside, tryptophan, chrysoeriol-6,8-di-C-pentoside and isomers 4, 5, 9 and 12 of diferulic acids key compounds to explain the observed AC...
October 1, 2017: Food Chemistry
Qi Lu, Xingjian Huang, Siyi Lv, Siyi Pan
Understanding the composition and content of carotenoids in red-flesh navel orange "Cara Cara" cultivated in different regions is valuable for its nutrition assessment and fruit processing control. Herein, the carotenoids of "Cara Cara" fruits, harvested from five typical citrus growing regions of China, were identified and quantified by HPLC-DAD coupled with HPLC-DAD-APCI-MS/MS. In saponified extracts, 19 free carotenoids including 8 carotenes and 11 xanthophylls were identified. In unsaponified extracts, 83...
October 1, 2017: Food Chemistry
Yongli Lan, Jin Wu, Xuejiao Wang, Xuchun Sun, Robert M Hackman, Zhixi Li, Xianchao Feng
Antioxidant properties and flavor characteristic profile of pomegranate wine during winemaking were investigated. The total phenol content and radical scavenging activity exhibited a slightly decrease in the end edge. Punicalagins and gallic acid were revealed to be the most abundant phenolic compounds, followed by ellagic acid and vanillic acid. These constituents were mainly responsible for the effective antioxidant capacity of pomegranate wine. The major changes of flavor qualities occurred in the initial stage, particularly 0-4day of fermentation...
October 1, 2017: Food Chemistry
Songsong Wu, Fangfei Zhu, Liming Hu, Jun Xia, Guomao Xu, Daofeng Liu, Qi Guo, Kai Luo, Weihua Lai
Amantadine (AMD) is a prohibitive veterinary medicine in the entire world. In this study, a sensitive colloidal gold immunochromatographic assay (CGICA) was established for the rapid semi-quantitative detection of AMD in chicken muscle. Under optimal conditions, the detection results were obtained in 12min with a limit of detection for 1.80ng/mL. CGICA presented a good linear range from 2.5ng/mL to 25ng/mL, with only 11.5% cross-reactivity with rimantadine. The recovery rates for the fortified samples were ranged from 81% to 120%...
October 1, 2017: Food Chemistry
Yuesheng Qiu, Jie-Hua Chen, Weijun Yu, Pei Wang, Minxian Rong, Hong Deng
The QuEChERS sample preparation method and gas chromatography-tandem mass spectrometry were employed to determine nine volatile N-nitrosamines (VNAs) in Chinese salted fish. This method was validated by considering calibration plot linearity, selectivity, matrix effects, trueness, precision, limits of quantification and specificity. Fifty-four samples of Chinese salted fish obtained from five provinces were analyzed. The results indicated that the concentrations of one VNA, N-nitrosodimethylamine in 57.4% of the samples exceeded the acceptable limit (the China national standard value of 4μgkg(-1)), and total VNA contents in 68...
October 1, 2017: Food Chemistry
Ahmed Behdal Shazly, Zhiyong He, Mahmoud Abd El-Aziz, Maomao Zeng, Shuang Zhang, Fang Qin, Jie Chen
Buffalo and bovine caseins were hydrolysed by alcalase and trypsin to produce novel antioxidant peptides. The casein hydrolysates were purified using ultrafiltration (UF) and further characterized by RP-HPLC. The fractions produced higher antioxidant activities were identified for their peptides using LC MS/MS. All UF-VI (MW<1kDa) fractions showed higher antioxidant activity. Hydrolysate produced by alcalase for buffalo casein (UF-VI with 54.84-fold purification) showed higher antioxidant activity than that obtained by trypsin...
October 1, 2017: Food Chemistry
Marija Perusko, Ayah Al-Hanish, Jelena Mihailovic, Simeon Minic, Sara Trifunovic, Ivana Prodic, Tanja Cirkovic Velickovic
Major green tea catechin, epigallocatechin-3-gallate (EGCG), binds non-covalently to numerous dietary proteins, including beta-lactoglobulin of cow's milk. The effects of glycation of proteins via Maillard reaction on the binding capacity for polyphenols and the antiradical properties of the formed complexes have not been studied previously. Binding constant of BLG glycated by milk sugar lactose to EGCG was measured by the method of fluorophore quenching. Binding of EGCG was confirmed by CD and FTIR. The antioxidative properties of the complexes were examined by measuring ABTS radical scavenging capacity, superoxide anion scavenging capacity and total reducing power assay...
October 1, 2017: Food Chemistry
Bárbara Nieva-Echevarría, Encarnación Goicoechea, María D Guillén
The extent of cod liver oil hydrolysis and oxidation during in vitro gastrointestinal digestion was investigated by Proton Nuclear Magnetic Resonance ((1)H NMR) and Solid Phase Microextraction-Gas Chromatography/Mass Spectrometry (SPME-GC/MS). These techniques evidenced the degradation of polyunsaturated ω-3 and ω-6 lipids and, for the first time, that of vitamin A, naturally present in cod liver oil. Cis,trans-conjugated dienes associated with hydroperoxides, as well as monoepoxides, cis,trans-2,4-alkadienals, 4-hydroperoxy- and 4-hydroxy-2-alkenals, and several vitamin A derived metabolites were generated...
October 1, 2017: Food Chemistry
Liurong Huang, Xiaona Ding, Chunhua Dai, Haile Ma
Structure and dissociation properties of soybean protein isolate (SPI) induced by ultrasound and acid were investigated. Results of solubility showed that ultrasound-assisted acid had no effect on the content of soluble aggregates in SPI. Increase of fluorescence intensity and red-shift of maximum emission wavelength indicated that acid induced molecular unfolding of SPI and exposure of hydrophobic groups. Circular dichroism spectra showed that ultrasound-assisted acid pretreatment resulted in increases in the α-helix content by 29...
October 1, 2017: Food Chemistry
Mahmoud Koushesh Saba, Rasoul Amini
Minimally processed pomegranate rapidly loses its overall quality because of high water loss and microbial contamination. Nano-ZnO in combination with carboxymethyl cellulose (CMC) coating was used on pomegranate arils. Arils were dipped for 4min in distilled water (control), 0.1 or 0.2% (w/v) nano-ZnO suspension and then ZnO treated arils were coated with 0.5% (w/v) CMC and stored for 12days at 4°C. Coatings decreased total yeast+mold during 12days of storage while total mesophilic bacteria was decreased during 6days of storage...
October 1, 2017: Food Chemistry
Hui He, Xingfei Li, Xiangzhen Kong, Yufei Hua, Yeming Chen
Due to the complications of the soymilk system, the heat-induced Bowman-Birk inhibitor (BBI) inactivation mechanism is not well known. In this study, two BBI samples with low and high purities were prepared from soymilk. It was confirmed that three groups (A, C, and D) of BBI, which are contained in soybean seeds, were transferred into soymilk during processing. On heating, it was found that 1) the two subdomains of BBI were not equally heat stable, 2) the conformation of BBI gradually changed, 3) some amino acid residues (namely, cystine, serine and lysine) in BBI were degraded, 4) BBI did not tend to form intermolecular cross-links with another BBI, but did slightly with non-BBI proteins...
October 1, 2017: Food Chemistry
Shaimaa Awadain Elsharif, Andrea Buettner
β-Citronellol, 1, and citronellyl acetate, 2, are renowned fragrant constituents in perfumes and flavoring agents in foods and beverages. Both substances smell citrussy, fresh and floral. To elucidate the structural features required for these sensory effects, six C-8 oxygenated derivatives of 1 and 2 were synthesized and analytically characterized. All compounds were tested for their odor qualities and odor thresholds in air, revealing that there were no significant differences in odor impressions from the parent monoterpenes and their derivatives in most cases; however, substantial differences in their odor threshold values were observed, with β-citronellol as the most potent (10ng/Lair) and 8-hydroxycitronellyl acetate as the least potent odorant (1261ng/Lair)...
October 1, 2017: Food Chemistry
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