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Browsing Master Memoires by Author "Ababsa Amira"

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    Valorisation et réutilisation des sous- produits d'olive
    (Université Abbes Laghrour -Khenchela-, 2020) Ababsa Amira; Hafsaoui Nadjette
    This study evaluated the effect of olive wastewater and olive-pomace on the growth of rhizobium and tested its ability to degrade by-products of the olive industry and their use as a carbon substrate. In order to do this, we carried out two tests: a test that showed the inhibitory effect of olive wastewater and olives by determining the MIC for different strains of rhizobium by the diffusion method on disk, the second test consists in studying The biodegradability of these effluents by evaluation the growth of different rhizobium strain on modified YMB media (olive wastewater and olive pomace) as a function of the different incubation times. The results of this study showed that olive wastewater had an inhibitory effect on the growth of rhizobium at concentrations of less than 0.5 mg, while olive pomace had no effect on the growth of rhizobia at the concentrations tested. The biodegradation of these effluents is very slow and difficult to biodegrade and the potential for assimilation of the carbon source in olive wastewater is higher than that of the olive-pomace. The possibility to improve the nutritional value of olive oil by enriching it in phenolic compounds from olive pomace was studied. The Response Surface Methodology (RMS) has being used to investigate the performance of this study. The analysis of the variance showed that the contribution of a quadratic model was significant for the response. The optimal conditions based on combination responses were: temperature of 10°C, ratio of 25% and maceration time of 8 hours. With these conditions, the total polyphenols was passed from 56 ± 4,29mg of Gallic Acid Equivalent/kg of oil to 697 ± 5,35mg of Gallic acid Equivalent/kg of oil which reasonably close to the predicted value (621mg of Gallic Acid Equivalent/ kg of oil). Furthermore, the radical-scavenging activity of the processed oil (DPPH test) confirmed its enrichment in antioxidants. The sensory evaluation of this oil showed a slight increase in the bitterness, but remains acceptable and preferable as well as the virgin olive oil.