Food & Nutrition

Arab Journal of Food & Nutrition
30. A Study of the Possibility of Producing New Products from Tomato Fruits
(1998)
Nasr Ahmad Ibrahim Hasanain
Supervisor: Dr. Mohammed Ali Humeid
Tomatoes have a nutritional value similar to that of many fruits, but differ mainly
from typica1 fruits in their low sugar content, rendering tomatoes low in the total solid
content.
This study aimed at investigating the possibility of producing jams, jellies and
“fruity” drinks from tomatoes.
The results of the study revealed the feasibility of producing jam from tomatoes
by cooking a mixture of 60 parts cut tomato fruits, with 40 parts sugar and 4g citric
acid/kg added sugar to reach 70 brix. Fruits from the green mature stage must be
excluded because they produce unfavorable color and fruits from red mature stage
should not be used alone because this will result in unfavorable flavor.
The results of sensory evaluations showed that the acceptability of jam increased
when jam was produced from skinned and deseeded tomatoes. Making jam from
tomatoes with quince as well as flavoring the jam with natural fruit concentrate of
strawberry, apricots or pineapple increased the acceptability of jams. Whereas jams
made of a mixture of tomato and apple or flavored with natural cherry concentrates
decreased acceptability.
Acceptable jelly could be cooked from clarified juice produced by boiling the
turbid juice for 15 seconds, then cooling and straining in fine mesh cloth. The Jelly
was prepared from 60 parts juice, 40 parts sugar, 4g citric acid/kg added sugar and 22
g pectin/kg juice. The flavor of the jelly was fruity and the texture was good thus no
other treatments were needed to increase acceptability.
Primary experiments to produce a “fruity” drink from clarified juice by adding
sugar, acid and natural juices or natural flavors powders failed to give acceptable
products since the flavor of tomato was objectionable in all of treatments. Boiling a
mixture of one part of juice with 0.5 part of water in a pressure cooker (0.5 bar
pressure) for 30 minutes was efficient in eliminating the tomato flavor. On the other
hand, heating the juice in closed bottles in an autoclave (121°C , 1bar) for 25 min, or
boiling in an open pan for 30 minutes as well as passing the juice through activated
charcoal bed failed in eliminating the flavor.
Acceptable “fruity” beverage was prepared by mixing deflavored tomato juice
with more than 50 parts orange juice or 20 parts lemon juice. Concentrated “fruity”
drink could be prepared by adding sugar to deflavored tomato juice to reach 65 brix,
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