Olive Leaves as Source Material for Novel Products to Boost Economic Sustainability of Olive Growers

Commodities

• Fruits: olives
• Additional Plants: other

Practices

• Crop Production: food processing, season extension
• Sustainable Communities: new business opportunities

Olive trees are one of the most agronomically and ecologically sustainable crop trees in the Western U.S.: low pest pressure and low nutrient needs mean low inputs; low to no water needs; excellent year-round carbon sequestration. They are a viable permanent crop on small/family farms, particularly in multi-cropping systems or in conjunction with pasturing. 

Olive growers in the Western U.S. produce mainly olive oil. The problem they face is intense pricing competition from very large producers of olive oil from Mediterranean countries. Western U.S. growers are at a significant disadvantage. They need help to make olive growing more economically sustainable. 

PI Caceu (olive grower) and TA Traber (Linus Pauling Institute) will research the most sustainable, simple, energy-efficient, cost-effective method to prepare an olive leaf powder that is high in polyphenols (molecules with antioxidant and anti-inflammatory properties). Working with olive leaves offers the advantage of up-cycling a by-product of the pruning of olive trees, and extends the season from a brief fall harvest (of olives for olive oil) to a year-round harvest of olive leaves for olive leaf powder. 

The olive leaf powder represents a new business opportunity for olive growers. The powder could be marketed as a standalone food product (replacement for green tea) or as an ingredient to impart polyphenols into food products. Produced in addition to olive oil, the olive leaf powder expands and diversifies olive growers’ product lineup.

The final project report, the article submitted for publication in Antioxidants (or a similar open-source, peer-reviewed journal) and the educational webinar organized by the Linus Pauling Institute with support from AOOPA, the trade organization that represents 80% of olive growers in the U.S., will provide olive growers with information about a novel product they can produce to expand and diversify their product lineup and thereby fortify their economic sustainability.

The project's research objective is multilayered:

(1) Crop processing sustainability. The project seeks to identify a process that is simple, energy efficient (low temperature oven drying) or energy free (air drying), cost effective (little to no inputs), and therefore highly sustainable, to prepare an olive leaf powder.

(2) Nutritional value of the olive leaf powder. With support from TA Traber and thanks to the Linus Pauling Institute's ability to conduct highly accurate assays, the project seeks to identify a process that is not only simple and sustainable but also one that captures the highest levels of polyphenols from olive leaves. Polyphenols (or phenolic compounds) are molecules with strong antioxidant and anti-inflammatory activity that have been linked to health maintenance in humans.  

(3) Agronomic sustainability, increased by the up-cycling of a by-product for a farm practice. The project's focus is on olive leaves, not on olives (the fruit) or olive oil. That is because scientific literature shows that olive leaves have similar and sometimes higher polyphenols (depending on olive varietal, time of harvest, etc.) than olives or olive oil. Entire olive branches are pruned each year in order to maintain the 'open vase' shape of the trees that is best for the health of the olive tree (air flow) and best for production of olives (thanks to light penetration inside the olive tree's canopy). The project's research elevates the by-product of yearly pruning into a product that can be marketed. 

(4) Agronomic and economic sustainability, increased by season extension. Olive growers in the U.S. primarily produce olive oil. The olives are harvested and milled in the fall, during a very brief season. Working with olive leaf, on the other hand, could happen at any time of the year because olive trees are evergreen and olive leaves are always available to be harvested and processed. This would extend the season to one that is year-round. 

(5) Economic sustainability, increased by product diversification. The olive leaf powder is a novel product. It represents a new business opportunity for olive growers. The powder could be marketed as a standalone food product (e.g., as a replacement for green tea that has equal or higher amounts of antioxidants but is naturally caffeine free and has a much lower carbon footprint than a green tea shipped from abroad), or it could be marketed as a functional ingredient to be used in other food and beverage products to impart polyphenols. Produced in addition to olive oil, the olive leaf powder expands and diversifies the product lineup, which can only be beneficial for the economic sustainability of a grower.  

The project's educational objective is to submit the project's findings for publication in an open access, peer reviewed journal such as Antioxidants, and to present the project's findings at an educational webinar organized by the Linus Pauling Institute. The Institute’s webinars routinely attract an average of 1,000 participants. The webinar will be further amplified by stakeholders such as Oregon State University and by AOOPA, the leading trade group for olive growers and producers of olive oil in the U.S.