María J. Sainz

1H-Nuclear Magnetic Resonance Analysis of the Triacylglyceride Composition of Cold-Pressed Oil from Camellia japonica

Camellia japonica (CJ) has oil-rich seeds, but the study of these oils has received little attention and has mainly focused only on their health properties. In the present work the relative composition of the fatty acid (FA) components of the triglycerides in cold-pressed oil from CJ is studied by 1H-NMR. The results obtained were: 75.75%, 6.0%, 0.17% and 18.67%, for oleic, linoleic, linolenic and saturated FA respectively. Levels of C18 unsaturated FA found in CJ oil were similar to those reported for olive oils. We also checked the possibility of using 13C-NMR spectroscopy; however, the results confirmed the drawback of 13C over 1H-NMR for the study of FA components of CJ triglycerides due to its low gyromagnetic ratio and its very low natural abundance.

Triacylglyceride, Antioxidant and Antimicrobial Features of Virgin Camellia oleifera, C. reticulata and C. sasanqua Oils

Virgin oils obtained from seeds of Camellia oleifera (CO), Camellia reticulata (CR) and Camellia sasanqua (CS) were studied for their triacylglyceride composition, antioxidant and antimicrobial activities. Levels of fatty acids determined by 1H-nuclear magnetic resonance analysis were similar to those reported for olive oils (82.30%–84.47%; 5.69%–7.78%; 0.26%–0.41% and 8.04%–11.2%, for oleic, linoleic, linolenic and saturated acids, respectively). The CR oil showed the best antioxidant potential in the three in vitro models tested. With regard to EC50 values (µg/mL), the order in DPPH radical-scavenging was CR (33.48) < CO (35.20) < CS (54.87). Effectiveness in reducing power was CR (2.81) < CO (3.09) < CS (5.32). IC50 for LPO inhibition were 0.37, 0.52 and 0.75 µg/mL for CR, CO and CS, respectively. All the oils showed antimicrobial activity, and exhibited different selectivity and MICs for each microorganism tested (E. coli, B. cereus and C. albicans). B. cereus was the less sensitive species (MIC: 52.083 ± 18.042 for CO; 41.667 ± 18.042 for CR; 104.167 ± 36.084 for CS mg/mL) and the E. coli was the most sensitive to camellia oil’s effect. The standard gentamicin presented higher MIC for E. coli (4.2) than the CR (MIC= 2.6) and CO (MIC = 3.9) oils.

A fast method for production of Armillaria inoculum

AbstractA new method is described for the production of inoculum of Armillaria species. An Armillaria mellea isolate was obtained from an infected grapevine plant. Inocula were then obtained by the...

Detection of new emerging type-A trichothecenes by untargeted mass spectrometry

Mycotoxins occur naturally as agricultural contaminants all over the world. The toxic effects of some of their metabolites are known and their presence regulated in food and feed. This paper describes two methods for the detection of toxins of type-A trichothecenes group, and their modified forms, using mass spectrometry. Ultra-performance liquid chromatography coupled to mass spectrometry-ion trap-time of flight (UPLC-MS-IT-TOF) was employed to characterize the fragmentation pathways of 10 type-A trichothecenes, and characteristic ions were tentatively identified in scan mode through their accurate masses. Unknown signals were detected in a F. sporotrichioides extract, which afterwards were identified as seven modified forms of neosolaniol (NEO) and T-2 toxin. Then, UPLC coupled to tandem mass spectrometry (MS/MS) was employed to develop a precursor ion scanning method that can be used as a screening tool to detect any modified type-A trichothecenes.

Analysis of natural toxins by liquid chromatography

Abstract This chapter focuses on the analysis of the main natural toxins associated with food safety. Mycotoxins are produced primarily by fungi of the genera Fusarium, Aspergillus, Penicillium, Claviceps, and Alternaria. The main representatives are aflatoxins, ochratoxin A, patulin, trichothecenes, zearalenone, fumonisins, and ergot alkaloid. Marine toxins are produced primarily by dinoflagellates of several genera. The main toxins are classified on the basis of the main toxin content: okadaic acid and dinophysistoxins, azaspiracids, yessotoxins, pectenotoxins, domoic acid, and saxitoxin and gonyautoxins. Cyanotoxins are produced by blue-green microalgae classified according to their effect: hepatotoxins (microcystins (MCs), nodularins and cylindrospermopsins), neurotoxins (anatoxin-a and analogs, saxitoxins, and s-N-methylamino- l -alanine), and dermatotoxins (aplysiatoxins and lyngbyatoxins). Finally, tetrodotoxin is produced by bacteria and it is a concern in fish and shellfish. All these toxins are analyzed mostly by LC-MS, and the specific features of the analysis is discussed in the chapter.

UPLC–MS–IT–TOF Identification of Circumdatins Produced by Aspergillus ochraceus

A method based on the combined use of ultraperformance liquid chromatography coupled to mass spectrometry-ion trap-time-of-flight (UPLC-MS-IT-TOF) detection was employed to identify the metabolite production of Aspergillus ochraceus, which is the major cause of food and feed contamination due to ochratoxin A. Under the proposed chromatographic conditions, seven metabolites belonging to the family of circumdatins were separated and identified. Their initial identification was performed through the exact molecular formula, as a function of their accurate mass. Collision-induced dissociation was applied to predict precursor and product ions, and the elemental composition of each compound was obtained. The elimination of nitrogenous groups followed by successive losses of carbonyl groups is the common fragmentation pathway of circumdatins. With the fragmentation data obtained, an UPLC-MS/MS method was created and optimized to detect circumdatins in corn samples.

A QuEChERS based extraction procedure coupled to UPLC-MS/MS detection for mycotoxins analysis in beer

A new method based on a QuEChERS extraction followed by the ultra-high liquid chromatography tandem mass spectrometry (UPLC-MS/MS) detection has been developed for the analysis of mycotoxin in beer. The method allows the identification and quantification of 23 mycotoxins with different chemical characteristic including regulated, emerging and masked compounds. A sample treatment procedure involving a QuEChERS extraction and dispersive solid-phase clean-up steps was applied. This protocol involves a new approach based on a sample concentration before the extraction. The method was in-house validated in terms of limits of detection (LODs), limits of quantification (LOQs), linearity, repeatability and recoveries. For most compounds, recoveries ranged from 70% to 110% with LOQs (from 0.038 to 30.43 µg/L) lower than the maximum residue levels established in European regulations. In general, acceptable performance characteristics were obtained fulfilling the current legislation. Therefore, the proposed method is appropriate for routine analysis of beer.

Salt effect of dehydrated broiler litter on organic lettuce

Abstract This paper examined salinity changes in soil in a greenhouse over four cropping cycles of lettuce (two autumn-winter cycles followed by two spring-summer cycles), testing the effect of applying an organic fertiliser consisting of dehydrated broiler litter at variable rates from 267 to 1596 g m−2 and comparing this with two mineral fertilisers; ammonium nitrate applied at 58.5 g m−2 and Nitrofoska Stábil® applied at 100 g m−2. The electrical conductivity of the soil (ECe) increased with increased rates of the organic fertiliser. Also, the increased temperatures and evaporation in the spring-summer cropping cycles resulted in increased concentrations of the fertiliser components salts in the soil. However, ECe remained below 4 dS m−1 and, although the highest fertilisation rates led to ECe levels near the acceptable threshold for lettuce (1.3 dS m−1), the weights of the lettuce increased. This result suggested that the favourable effects of the organic fertiliser on soil properties offset its adverse effects on salinity. Long-term risks of salinization can be avoided by using dehydrated manure rates not exceeding 600 g m−2 in autumn and 1200 g m−2 in spring or 532 g m−2 at any time of the year where repeated applications are made.

Pilidium lythri Is Associated with Bunch Rot of Grapevine (Vitis vinifera)

Bunch rot of Vitis vinifera is frequently caused by a complex of filamentous fungi. In a study on non-Botrytis fungi associated with bunch rot at harvest in northwestern Spain, rotting berries showing pink masses were observed in bunches of V. vinifera Albariño in one vineyard that experienced prolonged warm, moist conditions before harvest. The aim of this work was to identify the fungal species and determine its pathogenicity on grapes. Fungal isolates not corresponding morphologically to any known genus associated with bunch rot were obtained from the pink masses. Morphological and molecular phylogenetic analyses revealed that the isolates belonged to Pilidium lythri, an opportunistic pathogen causing tan-brown rot on strawberry. Most frequent non-Botrytis grape-rotting fungi at the vineyard were Penicillium brevicompactum, Penicillium expansum, and Talaromyces purpurogenus, while P. lythri had a low isolation frequency. Pathogenicity tests showed that P. lythri caused tan-brown rot in berries of the V. vinifera table grape varieties Regal Seedless and Red Globe. That P. lythri can directly infect healthy grape berries suggests that it may be a true pathogen associated with bunch rot on grapevine. Its presence on berries may contribute to postharvest decay of table and wine grapes.