MacaTasteTest_PI_pdf - CSIRO

Creating the tastiest macadamias
Australia is the largest producer of raw macadamias and has an
international reputation for high quality macadamias with excellent
flavour and texture. To maintain this leading position Food Science
Australia and CSIRO have undertaken taste tests to quantify the most
desirable macadamias characteristics.
Valued at over $100 million, Australia’s
macadamia industry can use the results of the
taste tests to develop better roasting methods,
identify other features of macadamias that
could be developed and determine
characteristics of new macadamia tree
varieties.
The tastiest macadamia
Macadamias had to be selected and treated
before the taste test.
Source of nuts
To compare macadamia tree variety and
regional differences nine different
macadamia tree varieties across six
different farms were used in the taste
testing, with the two major growing
regions represented – Bundaberg
and Northern NSW.
A range of macadamias were tested – with fresh, large and
roasted macadamias the favourite.
Size
The macadamia industry currently
uses eight different ‘styles’ to
distinguish the size of macadamias
ranging from large whole kernels
through to mixes of whole and half
kernels and down to just granules.
Three sizes of whole macadamias
were used in the testing: 16-18mm,
18-20mm and 20-22mm diameter.
The taste testers
The research involved two taste testing panels:
a trained expert sensory panel and a consumer
panel.
The experts examined the macadamias to
‘profile’ the sensory characteristics of the
macadamias. A vocabulary of forty sensory
attributes was developed that included a range
of odours, flavours, textures and aftertastes.
Using these measures the trained panel
successfully differentiated between all the
different macadamias and their different
preparations used in the study.
Consumers provided preference ratings for the
macadamias. In terms of preference they did
not notice all the subtleties in character
identified by the expert panel but were very
clear in what they liked best.
Age
Age of macadamias relates directly to how
rancid a macadamia tastes.
Three ages of macadamia were used in the
tests, those kept for 0 weeks and those rapidly
aged for 12 and 14 weeks.
Roast conditions
Roasting is a key contributor to flavour, with
most macadamias roasted and salted prior to
consumption. Raw macadamias were tested
plus nuts roasted using four different conditions.
These roasts also generated a light colour
equivalent to commercial roasted colour and a
medium colour.

And the winner is…
The most popular macadamias identified by the
consumers were fresh (kept for 0 weeks before
consumption), large (18-22mm in diameter),
roasted and slightly darker than an average
retail macadamia.
The good news for growers is that consumers
did not identify any taste difference between
nuts sourced from different macadamia tree
varieties, or macadamias on different farms or
regions.
The trained panel was, however, able to relate
the features the consumers preferred to the
various treatments and sources of nuts. This
information allows growers and producers of
macadamias to get a clearer picture of
consumer likes and dislikes.
Freshness
Consumers easily detected rancid macadamias
even though their rancidity level was within
industry standards. Industry could use this
information to improve rancidity tests to ensure
a more consistent supply of fresh macadamias
to consumers.
Overall, however, the consumers noted that
even the most aged macadamias presented to
them for testing were better than some nuts
they had purchased from retail sources. This
suggests that current shelf stock could also be
improved.
Roasting
Roasting at either 135oC for 18 minutes or
155oC for 8 minutes recorded the same taste
results. Industry could adopt the shorter roast
time to increase production efficiency without
compromising flavour.
Other factors for industry
Consumers were also asked why they chose
macadamias in relation to their mood, health,
convenience, sensory quality and price. The
results suggested that sensory quality and price
are foremost in people’s minds when buying
macadamias.
There is potential to expand the domestic
macadamia market through education and
consumer exposure to a broader spectrum of
macadamia sensory experiences given the
expert panel identified a diversity of macadamia
flavours.
Opportunities to expand the macadamia market
may also exist in the health market, especially if
concerns about fat content raised by female
consumers are addressed and the health
benefits are publicised.
Drawing on CSIRO’s expertise in plant and
human nutrition science, efficient experimental
design and statistical analysis, this project has
delivered a practical outcome for the
macadamia industry.
CSIRO Plant Industry 2008