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This study determine effectiveness of tomato postharvest processing technologies by
boiling and solar drying for small scale processing based on nutritional and sensory
quality. Tomato sample varieties Asira, Imara and Reogrande were collected from small
scale farmers in Morogoro region for tomato paste and powder development. Nutritional
quality was determined based on moisture, lycopene, ß-carotene and ascorbic acid
contents, titratable acidity and pH. Sensory properties were determined using Quantitative
Descriptive and Affective Analysis by assessing the level of consumer profile and
acceptability of juices and soups prepared from fresh tomato, paste and powder using
9-point hedonic scale. Data were analysed using R-software significantly at p 0.05.
The initial moisture content (MC) in fresh weight basis (FW) for three varieties ranged
from 92.97 0.31 to 95.12 0.12% in fresh tomato, 68.97 0.32 to 71.73 0.48% in
tomato paste and 11.02 0.09 to 11.74 0.41% in tomato powder samples. The lycopene
contents varied from 6.11 0.26 to 7.34 0.02 mg/100g, 8.12 0.25 to 8.81 mg/100g and
10.57 0.01 to 11.30 mg/100gFW in fresh tomato, paste and powder, respectively.
The β-carotene content ranged from 1.46 0.18 to 2.33 0.04 mg/100gFW in fresh
tomato, 2.57 0.17 to 2.91 mg/100gFW in paste and 3.19 0.01 to 3.26 0.03
mg/100gFW in powder. The ascorbic acid content ranged from 10.64 to 12.67 1.76
mg/100g in fresh tomato, 2.03 0.88 to 5.83 0.44 mg/100g in paste and 48.13 2.32 to
51.93 4.19 mg/100g in powder. The titratable acidity (%citric acid) ranged from 0.30
0.07 to 0.38% in fresh tomato, 0.64 to 2.23 0.07% in paste and 6.23 0.30 to 6.48
0.15% in powders. The pH ranged from 4.50 to 4.66 in fresh tomato, 4.56 to 4.68 in paste
and 4.76 to 4.95 in powder. The results indicate significant difference between tomato
products in terms of nutritional content as an effect of processing and individual variety.
Therefore, tunnel solar drying of fresh tomato into powder concentrates nutrients contents
in comparison to boiling into tomato paste. Boiling fresh tomato into paste retains better
nutrients but due to physical removal of skin and seed some of the nutrients were lost
along the process. The Quantitative Descriptive Analysis (QDA) showed that, juice from
fresh samples had significantly higher colour intensity scores 8.50±0.80 (like
very much), paste was aromatic rated 8.10±1.00 (like very much) and powder liked very
much due to acidity, consistency, sweetness, viscosity and clarity rated with 3.20±1.27,
8.30±0.49, 8.10±1.38, 7.70±0.89 and 8.30±0.49, respectively. Overall acceptability of
juice sample from Paste_Asira and Powder_Asira were the most acceptable by consumers
with hedonic scores of 7.00±1.97 and 7.00±2.02 (like moderately).
Furthermore, soup from Fresh_Imara had significantly colour and reddishness intensity
score 8.30±0.65 and 8.20±0.58, respectively. Samples from Paste_Asira had aroma rated
7.60±1.17 while those from Powder_Imara was liked with acidity and consistency score
6.30±0.89 and 8.30±0.62, Powder_Reogrande with saltiness score 5.90±0.67 and
Powder_Asira with viscosity score of 8.50±0.52. Overall acceptability of soup samples
from Paste_Imara, Powder_Imara and Paste_Asira were the most acceptable by
consumers with hedonic scores of 7.40±1.30, 7.40±1.21 and 7.00±1.50, respectively.
Conclusively, juice and soup samples from powder and paste were moderately liked. |
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