Effect of Selected Environmental Parameters on Quality of Syzygium Cuminii Fruits in Kenya
Abstract
Syzygium cuminii tree species belongs to the Myrtaceae family. The problem of underutilization
of indigenous and traditional food resources can be addressed by promoting the utilization of these
fruits to strengthen the food availability and adequacy systems in Kenya. This research
investigated the effect of selected environmental parameters namely; temperature, rainfall,
sunshine, relative humidity and soil types on the quality of the Syzygium fruits. The parameters
studied include fruit size, moisture content, color, pH, Total Soluble Solids, Titratable acidity,
minerals, vitamin C, crude proteins, crude fat and fibre, carbohydrates and energy. Analysis was
done using standard methodologies including use of an Inductively Coupled Plasma – Optical
emission Spectrometer for elemental analysis and High Pressure Liquid Chromatography for the
determination of Vitamin C that ranged between 76.55 ± 0.02 and 965.24 ± 0.21 mg/100 g. There
was a significant difference at P = .05 in ash content with Kwale recording a mean value of 2.74±
0.01 Vis avis 1.61 ±0.02 percent from Bungoma. There was a positive correlation between TSS
with fruit Maturity. Soil pH, Na, Mn, and Zn were significantly different between the two counties,
P = 0.05. Soil porosity highly influenced soil pH, while particle density caused an increase in bulk
density, which in turn increased fruit weight, fruit pH, and ash content. Five out of 12 models with
P = 0.05 were used to predict the dependent variables; Model 3 can predict ascorbic acid with the
highest accuracy at R2 = 0 .93, 5, crude protein, R2 = 0.87, 6, Zinc, R2 = 0.98, 9, ascorbic acid, R2
=0.99 and 12, Zinc, R2 = 0.99. The quality of fruits was affected by the tree canopy orientation
with fruits oriented towards the east developed higher TSS, Vitamin C content and intense color.
Higher annual rainfall of 1700 mm in Bungoma compared to 1032 mm in Kwale resulted in low
Total Soluble Solids of 14.27 ± 0.01 to 15.05 ± 0.18 and high Titratable acidity, 0.74 ± 0.01 – 0.78
± 0.02 for over 51 percent of the fruits that were analyzed. Fruits obtained from Kwale at low
altitude, 162 ± 7 m had better quality than those from Bungoma at higher altitude, 1612 ± 18 m.
Although the brix content and pH of fresh fruit varied with the prepared juice, no significant
difference relating to abiotic factors was observed. The results of this revealed that Syzygium
cuminii fruit is rich in most of the dietary macro and micro elements such as Vitamin C, needed
for health, and the fruits can be used for establishing small and medium enterprises. Hence, there
should be increase in efforts to provide the much needed resource base for product development,
value addition and development of organic fruit juices.
Publisher
University of Nairobi
Rights
Attribution-NonCommercial-NoDerivs 3.0 United StatesUsage Rights
http://creativecommons.org/licenses/by-nc-nd/3.0/us/Collections
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