scholarly journals Olive oil quality influenced by biostimulant foliar fertilizers

2020 ◽  
Vol 7 (15) ◽  
pp. 3-18
Author(s):  
Imen Zouari ◽  
Beligh Mechri ◽  
Meriem Tekaya ◽  
Olfa Dabbaghi ◽  
Imed Cheraief ◽  
...  

Foliar fertilization has been used as an important tool to meet the tree nutrient demand and to be an environmental beneficial with the use of little quantities. Actually modern fruit trees physiology is focused on the stimulation of plant cell development and fruit production using biostimulants. In olive trees, few products have been used for improving oil quality. For this purpose, two biostimulants products have been tested and used simple or combined with a third product rich in nitrogen. The treatments were classified to: T1 (rich in nitrogen) and biostimulants treatments as following T2 (combination of boron, magnesium, sulfur and manganese associated with seaweed) TNi (biostimulant combining a protein extract with a calcium base), T12 (combined application of T1 and T2) and finally T12Ni (combined application of T1, T2 and TNi) with a control treatment CON (without foliar fertilization). All these foliar nutrients were sprayed during two successive years on trees issued of Chemlali cultivar cultivated in rain-fed conditions of central Tunisia. Biochemical parameters of the olive oil, like physiochemical characteristics, fatty acid profile total polyphenols, ortho-diphenols, chlorophyllic and carotenoids pigments were analyzed annually after the application of these foliar compounds. All the olive oils issued from the treatments were classified as extra virgin and the physiochemical parameters were sensitive to foliar fertilization except for some parameters. Quantitative changes were observed in the pool of the fatty acids composition and the treatment TNi (rich in calcium) increased significantly the percentage of the monounsaturated fatty acid (MUFA) C18:1 as well as the ratios C18:1/C18:2 and MUFA/polyunsaturated fatty acids (PUFA) during the first year of experimentation. This treatment induced also an increase in the total polyphenols concentration. An annual variation between treatments has been observed according the polyphenols concentration and othodiphenols which can be influenced by climatic conditions principally in rain-fed conditions. This study highlighted the effect of the nutrient availability cumulated after two years of foliar application on the olive oil quality.

2018 ◽  
Vol 28 (5) ◽  
pp. 607-614 ◽  
Author(s):  
Josep Rufat ◽  
Agustí J. Romero-Aroca ◽  
Amadeu Arbonés ◽  
Josep M. Villar ◽  
Juan F. Hermoso ◽  
...  

This study describes the effects of mechanical harvesting and irrigation on quality in ‘Arbequina’ olive oil (Olea europaea L.). Irrigation treatments included a control, deficit irrigation (DI) during pit hardening, and subsurface deficit irrigation (SDI). Results showed that mechanical harvesting damaged the olives and reduced olive oil quality by increasing free fatty acids (FFAs) and peroxide value, and by decreasing fruitiness, stability, bitterness, and pungency. DI resulted in increased fruit dry weight and oil content, which could be explained by their reduced crop load (9.3% of crop reduction for DI and 23.9% for SDI). DI did not affect olive oil characteristics, whereas SDI increased stability, fruitiness, and bitterness, and decreased polyunsaturated fatty acid (PUFAs). In conclusion, mechanical harvesting tended to damage the fruit, resulting in lower quality olive oil, the DI strategy neither affected fruit nor olive oil characteristics, whereas the SDI strategy positively affected oil quality when greater water restrictions were applied.


2013 ◽  
Vol 44 (2s) ◽  
Author(s):  
Francesco Genovese ◽  
Giovanni Carlo Di Renzo ◽  
Giuseppe Altieri ◽  
Antonella Tauriello

The entire process of olive oil extraction involves the breakage of olive fruits to obtain a paste, the kneading of the paste, a centrifugation, and a further cleaning, performed by a disc stack centrifuge, to separate the residual water. In this research, in order to evaluate the effect of final centrifugal separation on olive oil quality and to both define and design the settings of a innovative separation system, olive oil was separated off from water using an accelerated separation process, tested in comparison with a disc centrifuge. The laboratory plant used for the trials was constituted by a twin cylindrical separator equipped with 4 variable frequency inverters, in order to regulate the fluid flow rates in the plant. Oil samples were collected during the trials to evaluate the influence of the proposed innovative process on oil quality; measuring some parameters as free acidity, peroxides (PV), specific extinction coefficients K232 and K270, chlorophylls , carotenoids, total polyphenols (POL) and turbidity. Results showed statistically significant differences (p-values<0.05) in some parameters as POL, PV, and ultraviolet absorption K232 and K270.


2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Dariusz Nowak ◽  
Michał Gośliński ◽  
Cezary Popławski

Olive oil is considered a valuable ingredient of human diet. It is a good source of mono- and polyunsaturated fatty acids, as well as other bioactive compounds, especially polyphenols. The composition of olive oil depends mainly on the variety of plant, cultivation practices, and manufacturing conditions. Traditional processing methods may ensure better quality and health benefits. Therefore, the aim of the study was the evaluation of antioxidant properties and fatty acid profile of Cretan extra virgin bioolive oils. These ones were compared with commercial Spanish, Italian, and Greek extra virgin olive oils. Obtained results showed that sample Cretan 1 had about 15% higher antioxidant capacity and about 60% higher total polyphenol content than commercial counterparts. This one had also a favorable profile of fatty acids, especially 20% more linoleic acid. We concluded that traditional production methods, using millstones, cold pressing, and without centrifugation and filtration ensure better olive oil quality and related health benefits.


HortScience ◽  
2006 ◽  
Vol 41 (1) ◽  
pp. 215-219 ◽  
Author(s):  
R. Fernández-Escobar ◽  
G. Beltrán ◽  
M.A. Sánchez-Zamora ◽  
J. García-Novelo ◽  
M.P. Aguilera ◽  
...  

Mature `Picual' olive (Olea europaea L.) trees growing in two different localities of Córdoba and Jaén provinces, southern Spain, were subjected to annual applications of 0, 0.12, 0.25, 0.50, or 1.0 kg N/tree in the Cordoba's experiment, and to 0 or 1.5 kg N/tree in the Jaén's experiment. Nitrogen was applied 50% to the soil and 50% through foliar application in Córdoba, and 100% to the soil in Jaén. Three years after the initiation of treatments, when the trees showed differences among them in nitrogen content, fruit were sampled at maturity from each experimental tree during six consecutive seasons to determine the effect of nitrogen fertilization on olive oil quality. Tree nitrogen status was always above the threshold limit for deficiency even in control trees, indicating that most treatments caused nitrogen over fertilization. Nitrogen in excess was accumulated in fruit and, consequently, polyphenol content, the main natural antioxidants, significantly decreased in olive oil as nitrogen increased in fruit. The decrease in polyphenols induced a significant decrease in the oxidative stability of the oil and its bitterness. Tocopherol content, on the contrary, increased with nitrogen application, mainly by an increase in α-tocopherol, the main component in the olive oil. No effect was found on pigment content, particularly carotenoid and chlorophyllic pigments, neither on fatty acid composition.


2018 ◽  
Vol 69 (1) ◽  
pp. 239 ◽  
Author(s):  
Ö. Kula ◽  
A. Yıldırım ◽  
A. Yorulmaz ◽  
M. Duran ◽  
İ. Mutlu ◽  
...  

The objective of the current study was to assess the influence of a modified crushing process and kneading operation on the quality parameters, volatile compounds, and the fatty acid and sterol profiles of virgin olive oil from the Edremit yaglik variety. In the study, olive oil samples were produced in two different processes. The first one was produced without malaxation and the second one was produced with the malaxing process. During crushing, the effect of different temperatures was tested. The results demonstrate that different crushing temperatures generally did not affect the amount of free fatty acids, or peroxide value. Total phenol contents were positively affected by the additional malaxation process. Fatty acids and sterol composition were not significantly altered at different crushing temperatures or during the subsequent malaxation application. PCA enabled a clear classification of the oils obtained from different processing techniques.


2014 ◽  
Vol 4 (1) ◽  
pp. 31-39
Author(s):  
Siwitri Kadarsih

The objective was to get beef that contain unsaturated fatty acids (especially omega 3 and 6), so as to improve intelligence, physical health for those who consume. The study design using CRD with 3 treatments, each treatment used 4 Bali cattle aged approximately 1.5 years. Observations were made 8 weeks. Pasta mixed with ginger provided konsentrat. P1 (control); P2 (6% saponification lemuru fish oil, olive oil 1%; rice bran: 37.30%; corn: 62.70%; KLK: 7%, ginger paste: 100 g); P3 (lemuru fish oil saponification 8%, 2% olive oil; rice bran; 37.30; corn: 62.70%; KLK: 7%, ginger paste: 200 g). Konsentrat given in the morning as much as 1% of the weight of the cattle based on dry matter, while the grass given a minimum of 10% of the weight of livestock observation variables include: fatty acid composition of meat. Data the analyzies qualitative. The results of the study showed that the composition of saturated fatty acids in meat decreased and an increase in unsaturated fatty acids, namely linoleic acid (omega 6) and linolenic acid (omega 3), and deikosapenta deikosaheksa acid.Keywords : 


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 682-682 ◽  
Author(s):  
Kayla Dillard ◽  
Morgan Coffin ◽  
Gabriella Hernandez ◽  
Victoria Smith ◽  
Catherine Johnson ◽  
...  

Abstract Objectives Non-alcoholic fatty liver disease (NAFLD) represents the major cause of pediatric chronic liver pathology in the United States. The objective of this study was to compare the relative effect of inclusion of isocaloric amounts of saturated medium-chain fatty acids (hydrogenated coconut oil), saturated long-chain fatty acids (lard) and unsaturated long-chain fatty acids (olive oil) on endpoints of NAFLD and insulin resistance. Methods Thirty-eight 15-d-old Iberian pigs were fed 1 of 4 diets containing (g/kg body weight × d) 1) control (CON; n = 8): 0 g fructose, 10.5 g fat, and 187 kcal metabolizable energy (ME), 2) lard (LAR; n = 10): 21.6 g fructose, 17.1 g fat (100% lard) and 299 kcal ME, 3) hydrogenated coconut oil (COCO; n = 10): 21.6 g fructose, 16.9 g fat (42.5% lard and 57.5% coconut oil) and 299 kcal ME, and 4) olive oil (OLV, n = 10): 21.6 g fructose, 17.1 g fat (43.5% lard and 56.5% olive oil) and 299 kcal ME, for 9 consecutive weeks. Body weight was recorded every 3 d. Serum markers of liver injury and dyslipidemia were measured on d 60 at 2 h post feeding, with all other serum measures assessed on d 70. Liver tissue was collected on d 70 for histology, triacylglyceride (TG) quantification, and metabolomics analysis. Results Tissue histology indicated the presence of steatosis in LAR, COCO and OLV compared with CON (P ≤ 0.001), with a further increase in in non-alcoholic steatohepatitis (NASH) in OLV and COCO compared with LAR (P ≤ 0.01). Alanine and aspartate aminotransferases were higher in COCO and OLV (P ≤ 0.01) than CON. All treatment groups had lower liver concentrations of methyl donor's choline and betaine versus CON, while bile acids were differentially changed (P ≤ 0.05). COCO had higher levels of TGs with less carbons (Total carbons < 52) than all other groups (P ≤ 0.05). Several long-chain acylcarnitines involved in fat oxidation were higher in OLV versus all other groups (P ≤ 0.05). Conclusions Inclusion of fats enriched in medium-chain saturated and long-chain unsaturated fatty acids in a high-fructose high-fat diet increased liver injury, compared with fats with a long-chain saturated fatty acid profile. Further research is required to investigate the mechanisms causing this difference in physiological response to these dietary fat sources. Funding Sources ARI, AcornSeekers.


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