ABSTRACT
BACKGROUND: The aim of this work was to evaluate the evolution of the quality of extra virgin olive oil obtained from a super-high-density Arbequina orchard, under a drip irrigation system, throughout the ripening process. For this objective, physicochemical, nutritional and sensory parameters were studied. In addition, the oxidative stability, pigment content and colour evolution of olive oil were analysed during the ripening process. RESULTS: Free acidity increased slightly throughout the ripening process, while peroxide value and extinction coefficient decreased. Total phenol content and oxidative stability showed a similar trend, increasing at the beginning of ripening up to a maximum and thereafter decreasing. α-Tocopherol and pigment contents decreased with ripening, leading to changes in colour coordinates. Sensory parameters were correlated with total phenol content, following a similar trend throughout the maturation process. CONCLUSION: By sampling and monitoring the ripeness index weekly, it would be possible to determine an optimal harvesting time for olives according to the industrial yield and the physicochemical, nutritional and sensory properties of the olive oil.
Subject(s)
Agriculture/methods , Food Quality , Fruit/chemistry , Fruit/growth & development , Olea/chemistry , Olea/growth & development , Plant Oils , Agricultural Irrigation , Chemical Phenomena , Fatty Acids/analysis , Fatty Acids/metabolism , Food Storage , Fruit/metabolism , Humans , Hydrogen-Ion Concentration , Nutritive Value , Olea/metabolism , Olive Oil , Oxidation-Reduction , Peroxides/analysis , Phenols/analysis , Phenols/metabolism , Pigments, Biological/analysis , Pigments, Biological/biosynthesis , Sensation , Spain , Taste , alpha-Tocopherol/analysis , alpha-Tocopherol/metabolismABSTRACT
The response to vernalization and the expression of genes associated with responses to vernalization (VRNH1, VRNH2, and VRNH3) and photoperiod (PPDH1 and PPDH2) were analysed in four barley (Hordeum vulgare L.) lines: 'Alexis' (spring), 'Plaisant' (winter), SBCC058, and SBCC106 (Spanish inbred lines), grown under conditions of vernalization and short days (VSD) or no vernalization and long days (NVLD). The four genotypes differ in VRNH1. Their growth habits and responses to vernalization correlated with the level of expression of VRNH1 and the length of intron 1. 'Alexis' and 'Plaisant' behaved as expected. SBCC058 and SBCC106 showed an intermediate growth habit and flowered relatively late in the absence of vernalization. VRNH1 expression was induced by cold for all genotypes. Under VSD, VRNH1 expression was detected in the SBCC genotypes later than in 'Alexis' but earlier than in 'Plaisant'. VRNH2 was repressed under short days while VRNH1 expression increased in parallel. VRNH3 was detected only in 'Alexis' under NVLD, whereas it was not expressed in plants with the active allele of VRNH2 (SBCC058 and 'Plaisant'). Under VSD, PPDH2 was expressed in 'Alexis', SBCC058, and SBCC106, but it was only expressed weakly in 'Alexis' under NVLD. Further analysis of PPDH2 expression in two barley doubled haploid populations revealed that, under long days, HvFT3 and VRNH2 expression levels were related inversely. The timing of VRNH2 expression under a long photoperiod suggests that this gene might be involved in repression of PPDH2 and, indirectly, in the regulation of flowering time through an interaction with the day-length pathway.
