Olives

1. Olives Olive Production Manual Louise Ferguson, G. Steven Sibbett, and George C. Martin

2. Classification • Family - Oleaceae • Genera • Fraxinus (ash) • Ligustrum (privet) • Syringa (lilac) • Olea (olive)

3. Olea europaea • Long lived evergreen trees • Wood resists decay • Top dies - stock sprouts • Roots only 3 - 4 ft (1 m) deep • Dense foliage, poor light penetration, cascading multiple branches, heavy fruit on terminals

4. Leaves • Thick, leathery, oppositely arranged • Each leaf grows for 2 yrs • Spring abscission in 2 to 3 years • Stomata on lower surface only • nestled in peltate trichomes

5. Cultivars • Ascolano 9 gm / 18.8% Blk Grn • Manzanillo 5 gm / 20% Fr, Blk, Oil • Sevillano 13.5 gm / 14.4% Blk, Grn, SpGm • Barouni 7.4 gm / 16.5% Fr Blk • Mission 4.1 gm / 21.8% Blk Gr Oil

6. Manzanillo • Most widely planted • Most popular for canning • Low spreading 15 - 30 ft. • Rooted Stem cuttings • Not tolerant to cold • Olive knot - Verticillium wilt

7. Sevillano • Second most popular • Spreading 25 - 35 ft tall • Trained low for easy harvest • Largest fruit in California • Grafting 1 yr rooted cuttings • Somewhat resistant to cold • Bruises easily

8. Ascolana • Rounded shape 20 - 30 ft tall • Bruises easily • Only 3 % of acreage in CA • Canned ripe olives • Fairly resistant to olive knot

9. Mission • From Mexico in 1769, not Italy • Tall upright, 40 - 50 ft • Topped to facilitate harvest • Small, low 6.5 : 1 fruit-to-pit ratio • Rooted cuttings • Trees survive 8oF

10. Mission Harvest • Picked green - Spanish Green Processing because they are late and need to avoid frost. • Red coloration - Ripe olive processin • For oil because of high (21.8% oil) • High monounsaturated fatty acid

11. Barouni • From Tunisia in 1905 • Small tree 15 - 25 ft. spreading • Large fruit, low fruit to pit ratio • Resistant to cold • For fresh use - process quality low • Used for black-ripe table olives

12. Flowering • Summer 2000 - Induction in veg buds • Nov. 2000 - Floral induction • Winter 2000 / 2001 - Chilling • Spring 2001 - Flowers open

13. Chilling is Critical • Optimum Flowering if chilling temps • Maximum 60 to 65oF • Minimum 35 to 40oF • Poor flowering if • Constant 55oF • No flowering if • No temp > 45oF or < 60oF

14. Influence of Leaves • Very little dormancy • Veg. Buds grow at or > 70oF • Inflorescence formation • Requires leaves on fruiting shoots • Thus, prevent defoliation • Hot winds can defoliate

15. Flower Buds • Abnormally cold spring temps • Detrimental to flower buds • Floral differentiation 8 - 10 weeks before May bloom • Irrigate to prevent stress • Start season with moist profile • Playing catch up will not do

16. Stress • Causes predominance • Of male flowers • Why? • Girdling can increase flowering • Danger of Olive Knot • Not a problem in Israel • Root reduction

17. Pollination • Monoecious • Flowers borne axially along shoot in panicles • Self and cross pollination occurs

18. Fruit Set • 500,000 flowers per tree • Need maximum of 10,000 fruit (2%) • 98% abscise in 14 days • Goal is 3 tons per acre yield • Sometimes insufficient perfect flowers to set full crop • Need 10% set if inflorescence limited

19. Fruit Formation • Embryo development • Mature ovule (seed) • Mature ovary (fruit) • Requires rapid pollen growth • Delays caused by cool temperature • Parthenocarpic fruit (shotberries)

20. Sigmoidal Fruit Growth • Endocarp (pit) enlarges to full size and hardens in 6 weeks • Endosperm (liquid to solid) • Embryo development • Embryo maturity (September)

21. Maturation • Gradual growth • Mesocarp (flesh) • Exocarp (skin and peel) • Color change (harvest index) • Green  straw (optimal)  Red (maybe)  Black (unacceptable)

22. Harvesting • Profit or loss depends on accuracy of harvest in October • Delaying harvest = heavier fruit (more valuable) • Delaying too long = black fruit & frost damage • Oil content increases in January

23. Fruit Thinning to Avoid Alternate Bearing • Hand thinning • Both hands - heavy rubber gloves • Strip fruit while leaving leaves • Leave 6 fruit / foot of twig • Complete 3 weeks after full bloom • Effective but not cost effective

24. Thinning by Pruning • Prune more heavily on “on” years • Prune more lightly on “off” years • However, not cost effective

25. Chemical Thinning • NAA effective but must treat prior to knowledge of crop size • Treat 12-18 days after full bloom (FB) • Apply 10 ppm for each day after FB • 15 days after FB = 150 ppm • Dilute spray (300 - 400 gal water per acre

26. Thinning Ornamental Olives • Olives in landscape are more desirable if all the fruit are removed • Use 200 ppm 2-3 days before FB • Use second spray 1 week later • Large trees require power sprayer • 10 - 15 gal per tree • Detrimental if temperature > 100oF

27. Processing Olives • Types • Black-ripe (BR) - 99% in CA • California-style green • Spanish-style green (<1%) • Pickling - process of adding lactic or acetic acid

28. Chemical Composition of Ripe Mission Olives (%) • Water 55.0 • Brix 13.1 • Oil 21.4 • Sugars 4.6 • Protein 1.7 • Mannitol 4.4

29. Oleuropein • A glucoside (bitter factor in fresh olives) • Destroyed by dilute alkali at room temperature • Remove alkali (1 - 2% lye) and bitterness does not return

30. Pigments • Anthocyanins are major pigment • Increases until fruit is ripe • Decreases in overripened fruit • Light increases formation • 10 times more anthocyanin in fruit ripened in light vs dark

31. Salt Free Storage • Acidulant solution • 0.67% lactic acid • 1.00% acetic acid • 0.30% sodium benzolate • 0.30% potassium sorbate

32. Traditional Brine System • Concrete or wooden tanks • Capacity - 20 tons • 5.0 - 7.5% NaCl • 20 - 30o Salometer • Saturated solution - 26.5% salt = 100o on Salometer

33. Storage Containers • Open-top redwood tanks 5x6 ft • Holds 2.5 tons of olives • Polyethylene 6 mil plastic prevents contact between olives and inside of tank • No fermentation in this system • Flavor better than in brine

34. California Style Black Olives • Paraffin or plastic lined 20 T tank • Four overhead pipes • Water • Dilute dye • Dilute brine • Compressed air

35. Lye (NaOH) Treatment • 3 - 5 applications of 0.5 - 1.5% • Better color by • Reducing lye concentration • Increasing treatment numbers • Reducing duration

36. Color Formation • Lye helps • Natural phenolic compounds to oxidize and polymerize • Causing formation of black pigment • Provided aeration is present

37. Calcium Helps Fix Color • Color formation most rapid at 8.0 to 9.5 pH • Retention better in hard water • Ca(Cl)2 (0.1 - 0.5%) improves color retention

38. Lye Removal • Lye removed by changing water in tanks at least twice daily • Solution stirred frequently with paddles of compressed air • Lye removed in 3 - 4 days

39. Canning • 7.0 - 7.5 pH at time of canning retains color • Packed in C-enamel lined cans • Filled with 2 - 2.5 % salt brine • Cans exhausted at 199 to 205oF for 5 min to reach 170oF or higher

40. Finish Canning • Rebrined and sealed at 170oF in a double seamer • Olives in glass containers processed in retort for 70 min. at 240oF

41. Spanish-Style Pickled Green Olives • Fruit reaches full size but harvested before color changes • Promptly placed in shallow paraffin - or plastic-coated concrete pickling vats

42. Lye Treatment • Dilute lye (1.25 - 1.75%) at 54 - 70oF penetrates 3/4 way to pit in 8 - 12 hrs. • Small amt of untreated bitter flesh characteristic of green olives • 1 drop of phenolphthalein to cut surface shows depth of lye penetration

43. Post Lye Treatment • Olives washed in cold H2O 24-36 hrs • Water changed every 4 - 6 hrs • Then response to indicator very faint

44. Fermentation • Washed, lye-treated olives transferred to 50 gal oak barrels • Head replaced and hoops driven • 11% brine added through side bung • Lactic acid content 0.8 - 1.2% • 3.8 pH or less • Fermentation at 75 - 80oF for 1-12 mo

45. Producing Olive Oil • Spain, Italy, and Greece (in that order) produce 80% of world’s oil • They consume 75% • USA < 1% of world’s olive oil • International Olive Oil Agreement • Administered by International Olive Oil Council in Madrid, Spain

46. Fatty Acid Profile • Oil Saturated Unsaturated • Mono Poly • Olive 1st CP 3 88 9 • Olive 2nd CP 11 83 5 • Pecan C P 9 73 18 • Cardin Pecan 5 85 10 • Walnut EP 9 18 73 • CP = Cold Pressed, EP= Expeller Pr

47. Definition of Olive Oil • Olive oil - obtained solely from olives • Excludes oil extracted by solvents or reesterification processes, or any mixtures with other oils • Pure olive oil cannot be any olive residue oils

48. Virgin Oil • Mechanically pressed from olive fruit without using heat - cold pressing • Only washed, decantation, and centrifugation (natural product) • May have vintage years on label

49. Grades of Virgin Oil • Virgin Olive Oil Extra • Extra Vergine (Italian) • Vierge Extra (French) • Pure unadulterated oil from top quality olives • Perfect taste and odor • Max of 1% acid and strong odors

50. Other Olive Oils • Virgin Olive Oil Fine or Fino • Almost perfect taste but 1.5% acid • Semi-fine or Ordinary Olive Oil • Good taste maximum acidity 3.3% • Virgin Olive Oil Lampante > 3.3% • Not for human consumption