EFFECTS OF DRYING ON THE PHYSICOCHEMICAL PROPERTIES
OF MORINGA OLEIFERA LEAVE
1
Haruna U.S; 1Raliat Abudah
Department of Food Science and Technology Federal polytechnic 0234, Bauchi.
ABSTRACT
Moringa belongs to a monogeric family, cited as one of the world’s most useful plant. It is consumed
throughout African and some Asian countries. Moringa contain large amount of several important
nutrients which are essential to the body. The effects of drying on the nutritional, physical and
chemical properties of moringa oleifera were studied. And different methods of drying (oven, sun and
shade) were applied. Analyses were carried out, including minerals, vitamin, pH value and sensory
evaluation etc. the pH value in both sample indicate that they are slightly acid, from the proximate
analysis results moisture content for oven was 3.8%, sun 4.3% and shade 6.7%. ßcarotene; oven
0.4µg, sun 0.38µg and shade 0.46µg sensory evaluation shows that each sample was accepted
differently by the panellist. It is therefore evident that different method, of drying could have an effect
on the nutritional, physicochemical, and sensory properties of moringa leave and its overall
acceptability by consumers.
INTRODUCTION
Moringa belongs to a monogeneric family: moringaceae cited as one of the world’s most useful
plants; it is widely cultivated fast growing tree and has become naturalized in many locations in the
tropics (Fahey, 2005; palada and chang, 2003). Moringa leaves are edible and are of high nutritive
value. It is consumed throughout West Africa as well as some Asian Countries (Fuglie, 2001).
Moringa leaves has been reported to contain more vitamin A than Carrots, more calcium than milk,
more iron than spinach, more vitamin C than orange and more potassium than bananas, noting that the
protein quality of moringa leaves are more than that of milk and eggs, its total protein digestibility is
(85%) and its amino acid composition corroborates with the FAO references on protein from
antinutritive factors such as phenols, tannins and saponins (Fuglie, 2001).
Moringa leaves also contain Calcium which builds strong bones and teeth it helps to prevent
osteoporosis. Potassium which is essential for the functioning of the brain and nerves and proteins for
building blocks of all our body cell. The amino acid of moringa leaves act as a building blocks of
proteins. Drying is a process of preservation whereby moisture is reduced to 2-3% depending in the
quantity of the food material (Sauveur, 2008). Moringa leaves can be dried by three processes, this
includes: sun drying, shade drying and oven drying (www.Kvafa.com). Drying is very important it
lowers the weights and volume of the leaves hence lowers the cost of transportation and storage,
drying also reduce deterioration and action of enzymes on the nutritional quality of moringa leave,
hence drying is its method of preservation. The objectives of this research are:
To determine the suitable method for drying fresh leaves of the moringa.
To determine the effect of drying on the physicochemical properties of moringa,
MATERIAL AND METHODS
The moringa oleifera leaves were obtained from Yelwa Tudu Bauchi. Leaves were sorted and
graded; Fresh, green, undamaged leaves were selected for the experiment.
DRYING METHODS
The drying methods of Delongs (2003), were followed in drying the fresh moringa leaves
Oven Drying; The leaves were loaded on the trays forming one single layer on the dryer. The oven
was preheated to 600C and the loaded tray was introduced into the oven. until all the leaves were
done. The temperature was maintained at 60oc and the leaves were left for 3 to 4 hours for complete
drying, to become crispy and brittle to touch.
Sun Drying; The leaves were placed on curtain cloth and kept on a table to keep off animal and
insect, to ensure even drying the leaves were brought indoor at night as soon as the temperature
during the day fade down. The leaves were dried for four days this depends on the temperature of the
day.
Shade Drying; The leaves were spread on a clean curtain cloth and kept in the room only. The room
selected for shade drying is well ventilated; natural current of air is used for shade drying. The leaves
took about six to seven days to dry completely and become crispy and brittle to touch.
Sensory Analysis
All the dried samples were milled into flour and subjected to panellist for sensory evaluation. The
mean values were analysed using ANOVA.
Chemical Analysis
Chemical analyses (moisture, crude protein, fat, total ash, carbohydrate, fibre, pH, and vitamin c)
were carried out based on Kirk and sawyer (2007) and the official method of analysis (AOAC, 2004).
All results are average of their triplicate values.
RESULTS AND DISCUSSION
Table 1: physical/sensory characteristics.
Sample
Oven dried
Sun dried
Shade dried
Colour
8.1 a
8.2 a
7.3b
Characteristics 1,
flavour
mouth feel
a
7.3
6.5a
6.9 a
6.8a
a
7.4
7.1b
overall acceptability
7.8a
7.9a
7.4a
1
Means with different superscripts within the same column differ significantly (p>0.05)
Duncan multiple range test.
Table 2 proximate chemical composition.
Nutrient
Oven Dried
Sun dried
Shade dried
Carbohydrate %
Protein %
Fat %
Ash%
Moisture%
Crude fibre%
62.02
26.3
3.68
4.5
3.5
12.5
60.5
26.68
3.71
4.75
4.3
14
57.36
27.14
3.9
4.9
6.7
14.2
pH
5.5
5.5
5.6
ß carotene(mg/100g) 0.40
0.38
0.46
Vitamin C mg/100g 3.12
2.92
3.24
using
DISCUSSION
Sensory Evaluation
Oven dried sample and shade dried samples recorded insignificant difference in colour by panellists
while there was significant difference between the two and shade dried samples . Oven dried and
shade dried recorded closer but statiscally indicated no significant difference between the three
samples interms of flavour. Relatively there was an indication that sundried samples were more
acceptable by the panellist based on the overall acceptability values.
Proximate Chemical Analysis
The Result from table 2 showed that drying reduced moisture content markedly with oven dried
sample having the lowest mean moisture of 3.5% , sun drying 4.5% and shade drying 6.7%.
Ash content for oven dried sample was 4.5%, sun drying was 4.75% and shade having the higher
value of 4.9% respectively. This could be attributed to the reduction in moisture content during drying
that result in corresponding increase in dry matter content due to concentration of soluble solids.
Fat content of oven dried leaves was 3.68% sun dried leaves 3.71% and shade dread leaves 3.9%.
This show that shade dried leaves 3.9%, this show that shade dried have the highest value, then sun
dried and oven dried.
Crude fibre oven dried sample was 12.5%, sun dried 14% and shade 14.2. Fibre content in dried
moringa leave is indicative that they are substantial and will provide bulk for peristaltic action, which
will enhance movement of food potential to through the alimentary canal with the potential to prevent
colon cancer (Waldron et al. 2003).
Protein content in oven dried was 26.3% sun dried 26.68% and shade 27.14% their values are in
agreement with protein content (27.1%) Fuglie (2001) reported for moringa .
The carbohydrate content of the oven dried sample was 62.02%, sun dried sample 60.5% and shade
57.36% oven dried sample have the highest carbohydrate content.
The ß carotene content for oven dried sample was 0.40Mg, sun dried sample 0.38mg and shade dried
sample 0.46mg. Which have the higher ß carotenes? The ß carotene in moringa leave (per 100g of
edible portions) which exceed the recommended daily allowance for children is 1.5mg/100g and for
woman and lactating mother (8.7mg/100g (fuglie, 2001) ß carotene particularly has strong antioxidant
effect in vitro, eliminating free radicals, it has seen demonstrated to help prevent aging and cancer,
(www.moringatree.org 2006).
Vitamin C (Ascorbic acid). The result from table 3 shows that vitamin which can be easily destroyed
by drying was still present in the sample even though it was little. The vitamin C content for oven
dried leaves was 3.12mg/100g, sun dried leaves 2.92mg/100g and shade dried sample 3.24mg/100g.
pH value for oven dried leaves was 5.5, sun dried 5.5 and shade dried 5.6. These values were
indication that the samples are slightly acidic.
CONCLUSIONS AND RECOMMENDATION
Moringa oleifera leaves used in this study had relatively high levels of crude protein, crude fibre, fat,
minerals like iron, zinc, phosphate and sulphate as well as vitamin C and B carotene. Sensory analysis
was carried out on the sample with the different method of drying such as oven, sun and shade
method. Among the three method of drying oven drying at 600C for 6 hours had the best nutritional
and physico chemical properties of the dried leave. Sun dried also give the leave a pleasant colour ,
while shade dried retained most of the vitamin like vitamin C which can be easily be destroy during .
It is therefore evident that different methods of drying could have an effect on the nutritional,
physicochemical and sensorial properties of moringa leaves and the overall acceptability by
consumers.
1.
Processors and consumer need to be educated about the best processing method of drying that
is suitable for moringa leave in order to prevent alteration of nutrient content (especially
minerals and vitamins).
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