Evaluate Mechanically Harvested Olives

An Olive Tasting - 2008

Soh Min Lee at the tasting

A tasting panel was convened on the UC Davis campus on June 23, 2008, to evaluate processed olives from the experimental harvests of Fall 2007. Treatments included: olives from hand-harvested and mechanically harvested lots, and olives harvested from a traditional and a hedgerow orchard.

The tasting was conducted by Soh Min Lee, a graduate student in Food Sciences and Technology, working with Dr. Jean-Xavier Guinard. Panel members extensive training in the process of evaluation, involving discernment of aroma, texture and firmness, as well as taste. Dr. Ferguson participated in this event, as an unofficial taster.

The findings of the panel indicated that the difference in processing methods produced more differences among the samples than differences in harvest method.
Ms. Lee's detailed evaluation: Descriptive analysis of Table Olives with Different Methods of Harvest (pdf)

Panel receives instructions

Sampling aroma

Sampling for taste

An Olive Tasting - 2007

Tasting Panel 2007

How mechanical harvesting affects processed fruit quality is the limiting factor in determining if mechanical harvesting is feasible for black ripe processed table olives. In October, 2006 'Manzanillo' olives at the UC Lindcove Field Station were:

Mechanically harvested, using the 2006 model of the DSE harvester
Hand-harvested, using traditional methods
Hand-harvested from the ground after the DSE harvester passed through the tree (either dropped from the harvester or dropped straight from the tree to the ground)

Olives of each pruning treatment were processed in small lots and canned by Musco Family Olives and Bell Carter Company. On the olive tasting day, March 28th, the olives were judged as acceptable or unacceptable in a blind rating, by growers and processors. The results are as follows.

% Fruit Quality Acceptability Score by Harvest Method

Mechanically harvested	64.5% a*
Hand harvested	66.4% a
Gleaned from ground after mechanical harvest	61.6% a

*Values in the column followed by the same letter are not significantly different

The three values above, all within a few percentage points of one another, indicated hand harvested olives were indistinguishable from machine harvested olives after processing. These were small sample lots. To ensure these results are accurate commercial size lots, 5-10 tons, of the 2007 harvest were delivered to both processors in October, 2007. These lots were carefully evaluated upon delivery by Dr. Jane Yegge of Bell Carter and Abdul Sigal MS of Musco Family Olives, and will be canned in January 2008.