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Teniendo en cuenta la importancia de la temática se busca que el mercado laboral del caribe colombiano confíe en los Millennials, e intente satisfacer necesidades propias de quienes son su fuerza laboral, por lo que es relevante para el sector estudiar lo que motiva laboralmente a esta generación. Incluye referencias bibliográficas (páginas 48- 52)

In this work, a total flow analysis system based on a novel solid-liquid extraction chamber is presented. This strategy enables all the main experimental procedures for the analysis of a solid sample to be performed automatically: enrichment of the liquid extract, sample treatment, filtration of the liquid extract from the solid sample, directing the extract towards detection, and finally cleansing of the chamber for the following solid sample to be analyzed. The chamber designed to be incorporated in the flow manifold presents two main features: it accommodates stirring bars for enhancing the extraction process, and it presents replaceable solid sample containers (a spare part of the solid-liquid extraction chamber) to easily replace the solid sample and therefore enhance sample analysis throughput. The chamber performance was assessed using two different solid samples, an ion exchanger resin and vegetable samples, focussing on proton and nitrate ion extraction, respectively. The main figures of merit achieved were relative standard deviation (RSD) and relative error values below 7 % for all determinations. The determination rate for vegetable samples was ca. 12 samples h-1. The proposed strategy may be exploited to perform automatically the analysis of solid samples as it embodies a simple automatic strategy of a very important but time-consuming and laborious analytical operation. Graphical abstract TAS for solid liquid extraction and nitrate potentiometric determination of vegetable samples.

A standard addition method was implemented by using a flow manifold able to perform automatically multiple standard additions and in-line sample treatment. This analytical strategy was based on the in-line mixing of sample and standard addition solutions, using a merging zone approach. The flow system aimed to exploit the standard addition method to quantify the target analyte particularly in cases where the analyte concentration in the matrix is below the lower limit of linear response of the detector. The feasibility of the proposed flow configuration was assessed through the potentiometric determination of fluoride in sea salts of different origins and different types of coffee infusions. The limit of quantification of the proposed manifold was 5×10(-6) mol L(-1), 10-fold lower than the lower limit of linear response of the potentiometric detector used. A determination rate of 8 samples h(-1) was achieved considering an experimental procedure based on three standard additions per sample. The main advantage of the proposed strategy is the simple approach to perform multiple standard additions, which can be implemented with other ion selective electrodes, especially in cases when the primary ion is below the lower limit of linear response of the detector.

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Two analytical methods were proposed for the determination of sodium chloride. A flow injection turbidimetric determination, based on the precipitation of silver chloride, was found to be a simple methodology to be implemented for routine analysis with a high sampling frequency, low reagent consumption and waste production in comparison with the reference methodology. On the other hand, the infrared methodology allowed NaCl determination with no reagent consumption. Both methodologies can be implemented for routine chemical analysis determinations in the food industry.

9 pages, 8 tables, 1 figure., The main phenolic compounds in six pear cultivars were identified and quantified using high-performance liquid chromatography/diode array detection (HPLC/DAD) and HPLC/electrospray ionisation mass spectrometry (HPLC/ESIMS). Major quantitative differences were found in the phenolic profiles. The peel contained higher concentrations of chlorogenic acid, flavonols and arbutin than the flesh, where only chlorogenic acid was detected. Total phenolics ranged from 1235 to 2005 mg kg-1 in the peel and from 28 to 81 mg k g-1 in the flesh. Ascorbic acid and dehydroascorbic acid were detected in the peel, whereas only dehydroascorbic acid was present in the flesh. The ranges of vitamin C content were from 116 to 228 mg kg-1 in the peel and from 28 to 53 mg kg-1 in the flesh. The antioxidant capacity was correlated with the content of chlorogenic acid (r = 0.46), while ascorbic acid made only a small contribution to the total antioxidant capacity of the fruit., ACGS acknowledges the Fundaçäao para a Ciência e Tecnologia (FCT), Portugal for a grant (PRAXIS XXI BD/18392/98). AGI is grateful to the Spanish MEC for a predoctoral grant.

The main phenolic compounds in six pear cultivars were identified and quantified using high-performance liquid chromatography/diode array detection (HPLC/DAD) and HPLC/electrospray ionisation mass spectrometry (HPLC/ESIMS). Major quantitative differences were found in the phenolic profiles. The peel contained higher concentrations of chlorogenic acid, flavonols and arbutin than the flesh, where only chlorogenic acid was detected. Total phenolics ranged from 1235 to 2005mgkg−1 in the peel and from 28 to 81mg k g−1 in the flesh. Ascorbic acid and dehydroascorbic acid were detected in the peel, whereas only dehydroascorbic acid was present in the flesh. The ranges of vitamin C content were from 116 to 228mg kg−1 in the peel and from 28 to 53mg kg−1 in the flesh. The antioxidant capacity was correlated with the content of chlorogenic acid (r = 0.46), while ascorbic acid made only a small contribution to the total antioxidant capacity of the fruit.

Firmness and pectinmethylesterase (PME) activity were evaluated in pears (cv Rocha) after 9 months of storage in controlled atmosphere (CA) followed by various periods of exposure to air at room temperature. The free calcium content was also evaluated in tissues. Fruit firmness decreased with increasing time of air exposure for all four different CA storage conditions tested. After 9 days of air exposure, fruits stored in 2% O2 + 1.5% CO2 were less firm than control fruits (stored in air) and showed higher PME activity. In spite of normal textural changes being observed with increasing time of exposure to air at room temperature, the underlying metabolism might have been affected by CA storage.