properties (density, melting point, etc.), differences in the batter are expected: batter
viscosity, surface tension and the size of the air bubbles inside the cake are modified,
resulting in lower density and higher volume. Regarding volatile composition, some
important changes were observed. Certain alcohols, such as (Z)-2-pentenol, (Z)-3hexenol, (E)-2-hexenol, (Z)-2-hexenol, phenylethanol and nerolidol; hydrocarbons
such as 3-ethyl-1,5-octadiene isomers, a-copaene and a-farnesene; the esters (Z)-3hexenyl acetate and hexyl acetate; as well as the aldehydes (E)-2-hexenal and (E)-2decenal were identified only in the extra virgin olive oil-containing samples. The
cake prepared with an extra virgin olive oil/margarine mixture was the most highly
preferred by the panellists, whereas the sole use of virgin olive oil could decrease the
panellist preference (Matsakidou et al. 2010).
Caponio et al. (2013) studied the type of fat used in taralli, a typical Italian bakery
product. They made taralli using EVOO or olive oil, olive-pomace oil and palm oil.
EVOO gave the lowest values of oxidation indices (except the peroxide value) and
gave lower trans isomers. In addition, using EVOO instead of other fats added
phenolic compounds to taralli, as well as characteristic sensory properties, with
better visual appearance and odour.
It is worth mentioning that the use of EVOO to replace refined vegetable oils
commonly used in bakery products led to a significant reduction of oxidative
polymerisation, such as triacylglycerol oligopolymers and level of geometrical isomers which are nutritionally undesirable (Caponio et al. 2013).
9.8 Other Olive Products
Olive fruit has multiple uses. The present chapter has focused on olive oil, but
exploitation of many other products obtained from the olive tree is possible. For
example, the production of table olives, which have a quite big market worldwide, is
carried out in a wide range of styles, giving different final products. Cultivars,
processing of fruits for the preparation of the main commercial types and their
bioactive constituents have been recently discussed by Boskou et al. (2015).
When olive oil is produced, and the fat has been extracted from the fruit, the solid
parts of the olives can be dried and used for composting (pulp residues) or as a fuel
(olive solid particles). Research is ongoing to recover phenolic compounds, especially from the olive mill wastewater (OMW) for a possible use in the cosmetic,
pharmaceutical or food industries.
Caporaso et al. (2016a, b) used OMW phenolic extracts obtained by spray-drying
of a concentrate recovered by subsequent membrane filtration. The extracts were
coated using maltodextrins and added as an ingredient in olive oil-in-water (O/W)
emulsions, where xanthan gum was used as a stabiliser, in combination with whey
protein isolate (WPI). The authors showed that weak interactions between OMW
phenolic extracts and WPI can be observed. OMW phenolics had a small effect in
retarding lipid oxidation in emulsion. This is probably due to the coating material,
which protects the phenolics from the external environment. During consumption,
244
N. Caporaso and D. Boskou
viscosity, surface tension and the size of the air bubbles inside the cake are modified,
resulting in lower density and higher volume. Regarding volatile composition, some
important changes were observed. Certain alcohols, such as (Z)-2-pentenol, (Z)-3hexenol, (E)-2-hexenol, (Z)-2-hexenol, phenylethanol and nerolidol; hydrocarbons
such as 3-ethyl-1,5-octadiene isomers, a-copaene and a-farnesene; the esters (Z)-3hexenyl acetate and hexyl acetate; as well as the aldehydes (E)-2-hexenal and (E)-2decenal were identified only in the extra virgin olive oil-containing samples. The
cake prepared with an extra virgin olive oil/margarine mixture was the most highly
preferred by the panellists, whereas the sole use of virgin olive oil could decrease the
panellist preference (Matsakidou et al. 2010).
Caponio et al. (2013) studied the type of fat used in taralli, a typical Italian bakery
product. They made taralli using EVOO or olive oil, olive-pomace oil and palm oil.
EVOO gave the lowest values of oxidation indices (except the peroxide value) and
gave lower trans isomers. In addition, using EVOO instead of other fats added
phenolic compounds to taralli, as well as characteristic sensory properties, with
better visual appearance and odour.
It is worth mentioning that the use of EVOO to replace refined vegetable oils
commonly used in bakery products led to a significant reduction of oxidative
polymerisation, such as triacylglycerol oligopolymers and level of geometrical isomers which are nutritionally undesirable (Caponio et al. 2013).
9.8 Other Olive Products
Olive fruit has multiple uses. The present chapter has focused on olive oil, but
exploitation of many other products obtained from the olive tree is possible. For
example, the production of table olives, which have a quite big market worldwide, is
carried out in a wide range of styles, giving different final products. Cultivars,
processing of fruits for the preparation of the main commercial types and their
bioactive constituents have been recently discussed by Boskou et al. (2015).
When olive oil is produced, and the fat has been extracted from the fruit, the solid
parts of the olives can be dried and used for composting (pulp residues) or as a fuel
(olive solid particles). Research is ongoing to recover phenolic compounds, especially from the olive mill wastewater (OMW) for a possible use in the cosmetic,
pharmaceutical or food industries.
Caporaso et al. (2016a, b) used OMW phenolic extracts obtained by spray-drying
of a concentrate recovered by subsequent membrane filtration. The extracts were
coated using maltodextrins and added as an ingredient in olive oil-in-water (O/W)
emulsions, where xanthan gum was used as a stabiliser, in combination with whey
protein isolate (WPI). The authors showed that weak interactions between OMW
phenolic extracts and WPI can be observed. OMW phenolics had a small effect in
retarding lipid oxidation in emulsion. This is probably due to the coating material,
which protects the phenolics from the external environment. During consumption,
244
N. Caporaso and D. Boskou