[Show abstract][Hide abstract] ABSTRACT: In this study, chemical composition and growth responses of chia plants (Salvia hispanica L.) to inoculation with an arbuscular mycorrhiza (AM, Glomus mosseae, Nicol. & Gerd.) fungal inoculum (namely MC10) under the influence of soil pH were investigated. The experiment project included six treatments, i.e., control-non-arbuscular mycorrhiza fungi (NAMF, pH 7.1), control-arbuscular mycorrhiza fungi (AMF, pH 7.1), acid-NAMF (pH 5.1), acid-AMF (pH 5.1), alkaline-NAMF (pH 8.2), and alkaline-AMF (pH 8.2). Stunted growth and leaf chlorosis were noticed mainly in plants grown in soil with acidic pH. An increase in fresh biomass was attained in plants amended with AM fungi in alkaline soil pH. Alkaline sandy soil with low levels of available P stimulated AMF colonization of chia roots, which subsequently enhanced P uptake and translocation in plant tissues. Total proteins, carbohydrates, and total fat content in leaves increased in AMF-inoculated plants in neutral and alkaline soil pH, while only fat content enhanced under acidic soil pH. MC10 inoculum resulted in reduced levels of total phenolics under alkaline conditions, whereas under acidic soil resulted in increased levels compared to the non-inoculated plants. The predominant fatty acids of chia leaves were palmitic (18.3 %), a-linolenic (17.1 %), pentadecenoic (11.0 %), linoleic (7.5 %), oleic (7.5 %), and stearic (6.3 %). Higher concentration of stearic, oleic, linoleic, and a-linolenic acids was observed in the leaves of chia plants grown on control (neutral pH) and alkaline soil in the presence of the MC10 inoculum. Alkaline soil combined with AM inoculation enhanced the nutritional value of chia leaves.
[Show abstract][Hide abstract] ABSTRACT: Four different chemical treatments, GA3, 1‐MCP, essential oils and nano‐Cu, were applied immediately after harvest to Petroselinum crispum (Mill) plants. The efficacy of the above chemicals on shelf life extension of parsley stored at 5 °C and 20 °C was determined by analysing physiological and biochemical factors that determine quality standards of storage fresh parsley. Nonsprayed parsley revealed the highest loss of weight, ascorbic acid, pigments and an enhancement of CO2 production and lipid peroxidation at 5 °C and 20 °C of storage. Nano‐Cu was more effective for delaying weight loss and revealed a better storage capacity. GA3, 1‐MCP and essential oils sprays were more effective in ascorbic acid retention at 20 °C than at 5 °C, whereas all substances protect samples from lipid peroxidation. Essential oils were more clearly inhibitory towards both total viable counts and yeast infection. Our results suggest that GA3, 1‐MCP, essential oils and Nano‐Cu exert their function through different mechanisms during ripening and could provide an effective and complementary means for maintaining high‐quality parsley leaves after harvest.
International Journal of Food Science & Technology 08/2013; 48(8). DOI:10.1111/ijfs.12131 · 1.38 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Olive mill wastewater (OMW) generated during the oil extraction from Olea europea L. var. koroneiki olives was sampled at the beginning, the middle and the end of the harvesting season for three successive crop production years, and from four olive mills. OMW samples were examined in respect to their physicochemical characteristics, fatty acid composition of the lipid fraction, and adverse effects on biomass production of nine white-rot fungi of the basidiomycetous genus Pleurotus. Total N, nitrogen species, potassium and phosphate concentrations as well as total phenolics content of OMW samples were influenced by the crop year but not from the harvest period (albeit higher values for nitrate, nitrite, phosphate and potassium as well as total phenolics contents were obtained during ripening of olives), whereas protein concentration, total organic carbon and total solids were not significantly affected by the crop year or the harvest period. In addition, fatty acids composition, i.e. nC14:0, nC16:1Δ9cis, nC17:1Δ10cis, nC18:0, nC18:1Δ9cis, nC22:0 and nC24:0 varied significantly during different crop years and harvest periods. Olive fruits maturity and biannual alternate-bearing appear to play key-roles in the fatty acid variation detected in OMW samples. OMW toxicity as evaluated by the mycelium growth of Pleurotus strains was influenced significantly by the phenolic content of OMW samples obtained during three successive crop years; in contrast, the olives harvest period did not affect Pleurotus biomass production. Hence, experimental data indicated that selected Pleurotus strains could serve as bioindicators of OMW toxicity. Development of viable OMW detoxification processes as well as the exploitation of the effluent's fertilizing value are discussed in the light of the above findings.
[Show abstract][Hide abstract] ABSTRACT: The application of gibberellic acid (GA(3)), ascorbic acid (ASA) and olive mill wastewater (OMW) as spray was used as possible techniques for storage life prolongation and quality maintenance of bean (Phaseolus vulgaris L.) fruits at 20 and 5 degrees C. Control and OMW-treated beans displayed greater rates of O-2 depletion and CO2 production. GA(3) sprayed beans respired slower and revealed the lowest weight losses. Changes in glucose and fructose contents were less inhibited, while higher decrease under OMW treatment was recorded at both temperatures; total protein content profile did not change upon treatments. GA(3) and ASA seem to be particularly effective in inhibiting enzymatic browning of beans. GA(3) and ASA reduced the metabolic activity of moulds, while inducing the growth of yeasts as compared to the control. OMW-treated beans showed enhanced development of moulds and yeasts. The beneficial effect of GA(3) on bean shelf-life prolongation was shown; while the protective effect of ASA was only partial.
[Show abstract][Hide abstract] ABSTRACT: Olive-mill wastewater (OMW) constitutes a major agricultural waste stream for which disposal is associated with significant environmental repercussions. No data are available on the effects of biotreated OMW and of the protective role of exogenously provided proline on plant physiology. In the present study, OMW was administered, either raw or previously treated by the white-rot fungus Pleurotus ostreatus, with or without proline amendment, to lettuce plants growing in sterilized sand. Biotreated OMW and proline addition resulted in significant moderation of OMW adverse effects on plant biomass production and ascorbic acid content, while their synergistic action alleviated the severe negative impact on net photosynthetic rate, water use efficiency and photosynthetic activity (Fv/Fo) invoked by the effluent. Moreover, biotreated OMW supplemented with proline, moderated the decrease in chlorophylls exerted by raw OMW, but it did not contribute at restoring carotenoids content. Restoration of plant transpiration was complete when biotreated OMW was used (with or without proline); proline alone mitigated the negative impact of OMW on photosynthetic efficiency (Fv/Fm and Fv'/Fm'). It seems that key photosynthetic parameters could be exploited as suitable evaluators of wastewater-induced plant toxicity, while plant fertigation with biotreated and/or supplemented OMW could be an interesting prospect in valorizing this effluent.
Journal of Environmental Science and Health Part B Pesticides Food Contaminants and Agricultural Wastes 08/2012; 47(7):728-35. DOI:10.1080/03601234.2012.669326 · 1.20 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study is exploring the effects of nano-copper postharvest spraying on parsley, stored at the market temperature of 20°oC for 10 days and at the storage temperature of 5oC for 23 days, aiming at its shelf life extension. Nano-Cu- treated plants showed significantly lower CO2 production than control at both storage temperatures. Spraying with Nano-Cu, parsley displayed the lowest weight losses at high and low temperature. Parsley leaves revealed high respiration rates with high moisture loss, which was inhibited by the application of Nano-Cu. Nano-Cu was also able to protect samples from lipid peroxidation after 23 days, since they were found to contain lower levels of MDA than control samples, while Nano-Cu treated parsley retained significantly higher ascorbic acid concentrations than the control. Nano-Cu application induced a prevention of the disturbances in the photosynthetic electron transport and the damages to the thylakoid structure occurring during storage. In addition, an inhibitory effect of Nano-Cu on yeast growth and TVC was observed. Spraying of harvested parsley with Nano-Cu seems like a promising shelf life extension technique, although attention should be given on the possible ecotoxicity of its widespread use.
[Show abstract][Hide abstract] ABSTRACT: We have studied the changes in the physiology and nutritional quality of Lycopersicon esculentum exposed to olive mill wastewater (OMW) with regard to cultivation in sand and soil. Tomato plant performance decreased with increasing concentration of OMW to both substrates. Root was more sensitive to OMW than the upper parts of the plants, grown either in sand or in soil for 10 days and 3 months, respectively, probably due to the direct OMW toxicity on roots as compared to other parts. Significant restriction on uptake and translocation of nutrients (K, Na, Fe, Ca and Mg) under OMW application was found. The decrease in the photochemical efficiency of PSII photochemistry in the light adapted state and the big decrease in photochemical quenching, indicate that OMW resulted in diminished reoxidation of Q(A)(-) and started to inactivate the reaction centers of PSII. The OMW supply on soil and sand, resulted in leaf water stress and lesser water use efficiency. Plants treated with high OMW concentration, produced fewer but bigger tomatoes as compared to plants treated with lower OMW concentration. Generally, fruit yield and nutritional value was inhibited under OMW application.