Olive oil composition as a function of nitrogen, phosphorus and potassium plant nutrition

BACKGROUND: Macronutrients play fundamental roles in processes affecting olive oil productivity and are expected to influence oil composition. A necessary step in optimal nutrient application management for olives is an understanding of the relationship between olive tree nutritional status and oil quality parameters. We studied the independent effects of N, P and K concentrations in irrigation solution on the oil quality of ‘Barnea’ olives by applying a wide range of macronutrient concentrations under highly controlled conditions.

Transcript

1. Olive Oil Composition as a Function Of Nitrogen, Phosphorus and Potassium Plant Nutrition Eric Ben-David, Ran Erel, Arnon Dag, Zohar Kerem, Alon Ben-Gal, Loai Basheer and Uri Yermiyahu
2. Recent modernization of olive cultivation – densely planted irrigated orchards. Introduction
3. Recent modernization of olive cultivation. Levels of nutrients influence plant growth, fruit production and oil yield. Introduction
4. Introduction Recent modernization of olive cultivation. Levels of nutrients influence plant growth, fruit production and oil yield. Agro-technologies, cultivars and milling technologies influence health promoting compounds and sensorial properties of olive oil. Gutierrez, F., Jimenez, B., Ruiz, A. and Albi, M.A. 1999. Effect of olive ripeness on the oxidative stability of virgin olive oil extracted from varieties Picual and Hojiblanca and on the different components involved. J Agric Food Chem 47, 121-127. Beltran, G., del Rio, C., Sanchez, S. and Martinez, L. 2004. Influence of harvest date and crop yield on the fatty acid composition of virgin olive oils from cv. Picual. J Agric Food Chem 52, 3434-3440 . Tura, D., Gigliotti, C., Pedo, S., Failla, O., Bassi, D. and Serraiocco, A. 2007. Influence of cultivar and site of cultivation on the levels of lipophilic and hydrophilic antioxidants in virgin olive oils (Olea europea L) and correlation with oxidative stability. Scientia Hort 112, 108-119.
5. Recent modernization of olive cultivation. Levels of nutrients influence plant growth, fruit production and oil yield. Agro-technologies influence olive oil composition. Sparse knowledge about the relations between nutrients & oil quality particularly under irrigation conditions. Fern´andez-Escobar R, Beltr´an G, S´anchez-Zamora MA, Garci´a-Novelo J, Aguilera MP and Uceda M, Olive oil quality decreases with nitrogen over-fertilization. HortScience 41:215–219 (2006). Morales-Sillero A, Jim´enez R, Fern´andez JE, Troncoso A and Beltr´an G, Influence of fertigation in ‘Manzanilla de Sevilla’ olive oil quality. HortScience 42:1157–1162 (2007). Introduction
6. 6 9 6 5 4 3 Perica, 2001 Dimassi et al., 1999 Fernandez-Escobar et al,. 1999 Sibbett and Ferguson, 2002 Sharma et al., 2005 ., Jordao et al, 1994 Cimato et al., 1990 Tattini et al., 1990 Fernandez-Escobar et al,. 2008 Hartmann and Brown, 1953 Fernandez-Escobar et al,. 2004 Klein an Weinbaum, 1984 Fernandez-Escobar et al,. 2000 Therios, 1988 Inglese et al., 2002 Tabatabai, 2006 Hartmann, 1958 Fernandez-Escobar et al., 2004 Jastrotia et al., 1999 Klein and Lavee, 1977 Martin and Fernandez-Escobar, 1997 Restrepo-Diaz et al., 2008 Restrepo-Diaz et al., 2008 Perica, 2001 Arquero et al., 2006 Ben Mimoun et al., 2004 Hartmann and Brown, 1953 Jastrotia et al., 1999 Klein and Lavee, 1977 Hartmann and Brown, 1953 1 Simoes et al., 2002 Fernandez-Escobar et al., 2006 Fernandez-Escobar et al., 2002 Inglese et al., 2002 23 2 8 32 15 9 5 Morales et al., 2007 Perica et al., 1994 Perica et al., 1994 6 Non-irrigated Irrigated Seedlings NPK in leaves N Fertilization K Fertiliza- tion P-Fer. Fertilization & oil Total
7. Oil Quality Quality indices: 1. Acidity. 2. Peroxide value. 3. Polyphenols content. 4. Fatty acid composition.
8. Acidity (FFA): % free fatty acids (oleic acid). <0.8% for extra virgin. Introduction
9. Introduction Acidity (FFA): % free fatty acids (oleic acid). <0.8% for extra virgin. Peroxide Value: a measure of the active oxygen and the potential to go rancid. Primary products of oxidation. ≤ 20 mEQ O2 /kg oil.
10. Acidity (FFA): % free fatty acids (oleic acid). <0.8% for extra virgin. Peroxide Value: a measure of the active oxygen and potential to go rancid. primary products of oxidation. Polyphenols (P”P): strong antioxidants; important for stability and flavor characteristics (bitterness and pungency). Introduction
11. Introduction Acidity (FFA): % free fatty acids (oleic acid). <0.8% for extra virgin. Peroxide Value: a measure of the active oxygen and potential to go rancid. primary products of oxidation. Polyphenols (P”P): strong antioxidants; important for stability and flavor characteristics. Fatty Acid Profile (FAP): % individual fatty acids in the oil. Influence stability and nutritional value. Authenticity assurance. Oleic = desirable nutritionally ; linoleic and linolenic = undesirable for stability .
12. Oleic acid C 18:1 Linoleic acid C 18:2 Linolenic acid C 18:3 PUFA MUFA Introduction Purity Standards for Olive Oil (2002 EU) (1996 IOC) 55.0 - 83.0 3.5 - 21.0 1.0 Max. (EU – 0.9) Oleic acid C 18:1 Linoleic acid C 18:2 Linolenic acid C 18:3 Fatty acid composition (methyl esters %)
13. To study the independent effects of N, P and K levels in the irrigation solution on the composition of olive oil (var. ‘Barnea’) using wide concentrations range under highly controlled conditions. Objective N P K
14. Fruits picked by hand upon reaching an appropriate ripeness index. Methods
15. Fruits picked by hand upon reaching an appropriate ripeness index. Oil was extracted using an ‘Abencor’ system. Methods
16. Fruits picked by hand upon reaching an appropriate ripeness index. Oil was extracted using an ‘Abencor’ system. Oil quality indices analyzed according to ISO & IOC. Methods
17. Leaf (□) and fruit flesh (◦) concentrations of N, P and K Symbols are means (n = 6) and lines are best-fit regression using all data (p<0.0001). N Strong associations: irrigation solution vs. tissue levels & leaf vs. flesh conc. Saturation curves for N & P; N levels higher in leaf; opposite for P & K. Wide range of mineral conc. in tissue. Enable study of oil quality as a function of mineral conc. in tissue. Flesh importance - synthesis and accumulation of oil occur in the flesh. Leaf Flesh P K Results - Mineral Accumulation in Tissue
18. N
19. Acidity (FFA) Trend repeated for 2 consecutive years. FFA was negatively influenced by N conc. FFA more than doubled between the two extreme treatments. y = 0.36x - 0.16 R2 = 0.77 y = 0.37x - 0.35 R2 = 0.83 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.0 1.0 2.0 3.0 Flesh N concentration (% DW) FFA conc. (%) 2008 2007 N
20. Polyphenols (P”P) Highest P”P content at deficiency level for N (lowest N treatment). 0 150 300 450 600 750 0.0 0.5 1.0 1.5 2.0 Flesh N concentration (% DW) P"P conc. (ppm) 2008 2007 y = 0.36x - 0.16 R2 = 0.77 y = 0.37x - 0.35 R2 = 0.83 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.0 1.0 2.0 3.0 Flesh N concentration (% DW) FFA conc. (%) 2008 2007 N Acidity (FFA) Trend repeated for 2 consecutive years. FFA was negatively influenced by N conc. FFA more than doubled between the two extreme treatments.
21. y = 9.0728x-0.9147 R2 = 0.6312 y = 44.403x-0.4698 R2 = 0.765 0 50 100 150 200 250 0.00 0.05 0.10 0.15 0.20 0.25 P conc. (% DW) P"P conc. (ppm) 2008 2007 Polyphenols (P”P) Three lowest P treatments produced the highest P”P content. Low initial P”P due to irrigation/N fertilization. y = 0.54x + 0.12 R2 = 0.89 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.00 0.05 0.10 0.15 0.20 0.25 Flesh P conc. (% DW) FFA conc. (%) 2008 2007 Acidity (FFA) P conc. influenced acidity negatively in 2008 but not in 2007 and not as strongly as N. Acidity increased from 0.14% to 0.23% between the two extreme P treatments. P
22. K 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.00 1.00 2.00 3.00 4.00 Flesh K conc. (% DW) FFA conc. (%) 2008 2007 0 20 40 60 80 100 120 0.00 1.00 2.00 3.00 4.00 Flesh K conc. (% DW) P"P conc. (ppm) 2008 2007 FFA and P”P were not influenced despite the wide concentrations range and high levels of K. FFA P”P
23. Fatty Acid Profile (FAP) y = -4.5x + 63.5 R2 = 0.80 y = -8.0x + 68.8 R2 = 0.60 51 54 57 60 63 66 0.0 1.0 2.0 3.0 Flesh N conc. (%) C18:1 conc. (%) y = 28.7x + 16.3 R2 = 0.64 y = 11.8x + 20.3 R2 = 0.46 12 14 16 18 20 22 24 26 0.0 0.1 0.2 0.3 y = 2.07x + 0.72 R2 = 0.93 y = 2.14x + 0.73 R2 = 0.95 0.4 0.6 0.8 1.0 1.2 1.4 1.6 0.0 0.1 0.2 0.3 2008 2007 y = -26.4x + 62.1 R2 = 0.51 y = -11.9x + 57.9 R2 = 0.44 51 54 57 60 63 66 0.00 0.10 0.20 0.30 Flesh P conc. (%) MUFA y = 0.40x + 0.59 R² = 0.85 y = 0.38x + 0.58 R2 = 0.69 0.4 0.6 0.8 1.0 1.2 1.4 1.6 0.0 1.0 2.0 3.0 C18:3 conc. (%) 2008 2007 y = 4.6x + 15.1 R2 = 0.75 y = 7.96x + 9.19 R2 = 0.66 12 14 16 18 20 22 24 26 0.0 1.0 2.0 3.0 C18:2 conc. (%) PUFA Higher flesh’ N levels led to sharply lower MUFA & higher PUFA. C18:3 & flesh’ N levels correlated particularly well. Higher flesh’ N levels in 2007 correlated with lower MUFA & higher PUFA compared with 2008. P displayed similar trends albeit weaker. K had no effect on FAP. C18:1 C18:3 C18:2 N P K
24. ‘Barnea’ oil composition was significantly influenced by N & P levels; K had a minor effect. Conclusions
25. ‘Barnea’ oil composition was significantly influenced by N & P levels; K had a minor effect. Decreased MUFA and P”P content coupled with increased PUFA suggest decreased oil stability. Conclusions PUFA MUFA P”P FFA C18:3 C18:2 C18:1 ↑ ↑ ↓ ↓ ↑ ↑ N ↑ ↑ ↓ ↓ ↑ ↑ P -------- -------- -------- ----- ------ ↑ K
26. ‘Barnea’ oil composition was significantly influenced by N & P levels; K had a minor effect. Decreased MUFA and P”P content coupled with increased PUFA suggest decreased oil stability. Peroxide value was not influenced by the mineral’s concentrations. Conclusions
27. Conclusions ‘Barnea’ oil composition was significantly influenced by N & P levels; K had a minor effect. Decreased MUFA and P”P content coupled with increased PUFA suggest decreased oil stability. Peroxide value was not influenced by the mineral’s concentrations. The study highlights the potential hazard of over- fertilization with N & P.
28. Conclusions ‘Barnea’ oil composition was significantly influenced by N & P levels; K had a minor effect. Decreased MUFA and P”P content coupled with increased PUFA suggest decreased oil stability. Peroxide value was not influenced by the mineral’s concentrations. The study highlights the potential hazard of over- fertilization with N & P. Validating the results under field conditions is necessary.