Biomedical Engineering Reference
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5-5.5%
Dry matter content
a
8-15%
Dry matter content
Plant
Molecular
Biology
94.5-95%
water
85-92%
water
Normal tomato
Transgenic tomato
a
.
- 80% Soluble solids content
20% Insoluble solids content
FIGURE 10.2
Use of biotechnology to increase the dry matter content in tomatoes.
(Adapted from Waterman.
17
)
the dry matter content, both total solids content and soluble solids content. The level
and quality of insoluble solids is directly related to the consistency of tomato
products.
17
The USDA Laboratory in Albany, CA, has already produced tomatoes
with a solids content of 8 to 13%, and one over-achiever registered an astonishing
15% (
Figure 10.2
).
1
6,17
I
MPROVING
F
LAVOR
One criticism of many research programs is that often they focus more on culture,
disease resistance, and uniformity than on flavor. Tomatoes traditionally have been
selected by breeders for yield, fruit size, lack of defects, and resistance to disease.
Unfortunately, this has often resulted in cultivars lacking in flavor.
17
A USDA laboratory in Winter Haven, FL, conducting tomato flavor volatile
research has determined that tomato varieties differ in the level of flavor volatiles;
these volatiles are influenced by ripening, harvest maturity, breeding, and genetics.
Significant differences were found in sugar, including glucose and fructose, and
citric acid content. It was concluded that good flavor may be due not only to higher
volatile levels, but also to the proper balance of individual volatiles, sugar and acid
levels.
17
Poor soil and growing conditions can generate losses of flavor as well as
losses by steam processing and storage. Thus, there are studies focused on the
recovery of aroma compounds from various waste products such as peels, culled
tomatoes, and even the plant itself.
17,29
The Food and Drug Administration has agreed that Calgene's (Davis, CA) Flavr
Savr tomato is safe for consumers and the environment. This tomato is genetically
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