University of Lleida

About: University of Lleida is a education organization based out in Lleida, Spain. It is known for research contribution in the topics: Population & Pregnancy. The organization has 2939 authors who have published 5853 publications receiving 148417 citations. The organization is also known as: Escola Superior Politècnica & Universitat de Lleida.

Microbiological and biochemical stability of fresh-cut apples preserved by modified atmosphere packaging

Abstract: The microbial shelf life of fresh-cut Golden Delicious apples was assessed throughout storage under different modified atmosphere packaging conditions. Microbial viability rose rapidly during the first weeks of storage for all the studied conditions mostly due to the increase in mesophilic aerobic bacterial populations. Apple cubes preserved in plastic bags of 15 cm 3 O 2 m −2 bar −1 24 h −1 and flushed with 100% N 2 had the longest stability with microbial counts below 5 log[CFU g −1 ] during the first month of refrigerated storage. These conditions also resulted in non-significant changes in the product acidity and in the sugars content throughout the studied period. Ascorbic acid contents decreased showing considerable influence of the O 2 availability. It was also demonstrated that a modification of the Gompertz equation was suitable for describing the evolution of microbial populations, thus being useful for predicting the shelf life of such commodity as influenced by processing and packaging conditions.

No effects of Bacillus thuringiensis maize on nontarget organisms in the field in southern Europe: a meta-analysis of 26 arthropod taxa

Abstract: Maize with the insecticidal properties of the entomopathogenic bacterium Bacillus thuringiensis Berliner, known as Bt maize, has been sown in Europe since 1998. For several years, EU and Spanish regulations have required laboratory and field trials to assess risks of genetically modified crops for nontarget organisms prior to their authorization. Thirteen field trials were conducted in Spain to measure the effects of Bt maize on a broad range of arthropod taxa; no effects were found in accordance with most literature records. However, statistical analyses of single trials rarely have the statistical power to detect low effect sizes if they do not have a sufficient sample size. When sample size is low, meta-analysis may improve statistical power by combining several trials and assuming a common measure of effect size. Here we perform a meta-analysis of the results of 13 independent field trials conducted in Spain in which effects of single or stacked Bt traits on several arthropod taxa were measured with no significant results. Since the taxa included in each single trial were not the same for all trials, for the meta-analysis we selected only those taxa recorded in a minimum of six trials, resulting finally in 7, 7, and 12 taxa analyzed in visual counts, pitfall traps and yellow sticky traps, respectively. In comparison with single trial analysis, meta-analysis dramatically increased the detectability of treatment effects for most of the taxa regardless of the sampling technique; of the 26 taxa analyzed, only three showed poorer detectability in the meta-analysis than the best recorded in the 13 single trials. This finding reinforces the conclusion that Bt maize has no effect on the most common herbivore, predatory and parasitoid arthropods found in the maize ecosystems of southern Europe.