Research Article
Ifeoma Elizabeth Mbaeyi-Nwaoha
Ifeoma Elizabeth Mbaeyi-Nwaoha
Corresponding Author
Department of Food Science and Technology, Faculty of Agriculture, University of Nigeria, Nsukka, Nigeria.
E-mail: ifeoma.mbaeyi-nwaoha@unn.edu.ng; Tel: +234-8037722818
Nnamani Chidera Juliet
Nnamani Chidera Juliet
Department of Food Science and Technology, Faculty of
Agriculture, University of Nigeria, Nsukka, Nigeria.
E-mail: chidejul@gmail.com; Tel: +234-8156790791
Ofoegbu Deborah Chinwendu
Ofoegbu Deborah Chinwendu
Department of Food Science and Technology, Faculty of Agriculture, University of Nigeria, Nsukka, Nigeria.
E-mail: deborahofoegbu4@gmail.com; Tel: +234-8108375742.
Abstract
The Moringa leaf, Roselle calyx and Lemon grass leaf
extracts were added separately at a proportion of 5, 10, 15% into the yoghurt
and refrigerated at 5 ± 1 0C for further analysis. The samples were coded as RCAE1,
RCAE2, RCAE3 for Roselle calyx extract; MLAE1, MLAE2 for Moringa leaf extract
and LGAE1, LGAE2, LGAE3 for Lemon grass leaf extract while YWNE was the control. The
formulated yoghurts were subjected to proximate, micronutrients,
phytochemicals, physicochemical, microbial and sensory evaluation. Data
obtained were subjected to statistical analysis. The results showed that
moisture and carbohydrate increased with an increase in concentration. The ash
content decreased also. There showed no significant difference (p>0.05)
between the control and formulated samples. The micronutrients increased except
for Vitamin A of the Moringa leaf and lemon grass leaf (aqueous extract)
samples decreased as the concentration increased. The phytochemical content of
the samples increased; except tannin of Moringa leaf and Lemongrass which decreased
on addition of aqueous extracts. pH of the formulated yoghurt samples decreased
leading to an increase in titratable acidity. The total viable count for the
yoghurt sample formulated with Roselle and Moringa leaf extract decreased with
increase in the concentration of the extracts. The most acceptable herbal
yoghurt by the panelists in terms of palatability is
RCAE2 while the product best with
respect to the nutritional quality is LGAE3.
Abstract Keywords
Moringa leaf, Roselle calyx, Lemon grass, aqueous extract,
herbal yoghurt.
1. Introduction
With the emergence of fortified foods, there is a worldwide
increase in health awareness and interest in adding herbs as prized food
additives in dairy and food products. Due to
the increased consumer awareness and interest to follow healthy nutrition and
dietary strategy in achieving health benefits from foods beyond their basic
nutrition, the market for value added functional foods has expanded [1]. Herbs have multifarious role such as food
flavorings, preservative and medicinal ingredients and various herbs are
documented for their therapeutic properties such as, anti-oxidative,
anti-hypertensive, anti-inflammatory, anti-diabetic and anti-microbial
properties [2].
Some herbs that have been used in the past are Moringa plant (Moringa oleifera) is used to improve weight in malnourished
children by adding Moringa powder to food. Drinking of Moringa tea relieves
headache, heart burns and gastritis. Yoghurt is one of the most popular fermented
milk products worldwide and has gained widespread consumer acceptance as a
healthy food. It provides an array of nutrients in significant amounts, in
relation to its energy and fat content, making it a nutrient-dense food. In
particular, yoghurt could provide the body with significant amounts of calcium
in a bioavailable form. Furthermore, yoghurt has many health benefits beyond
the basic nutrition it provides, such as improved lactose tolerance, a possible
role in body weight and fat loss, and a variety of health attributes associated
with probiotic bacteria [3]. Yoghurt is an
excellent source of protein, calcium, iodine, phosphorus, riboflavin (vitamin), thiamin (vitamin) and vitamin, and a valuable source of folate,
niacin, magnesium and zinc. Yoghurt provides many of the nutrients needed for
optimal bone health such as calcium, protein, magnesium, zinc and phosphorus.
Hibiscus
sabdariffa commonly named as “red sorrel” or “Roselle” is a member of malvaceae
family. Different extracts from Roselle play a crucial role in treating
different medical problems including many cardiovascular disorders, helmenthic
disease and cancer. The plant also acts as an anti-oxidant and used in obesity
management [4]. Moringa leaves contain seven times the vitamin C of oranges, four
times the vitamin A of carrots, four times the calcium of milk, three times the
potassium of bananas and two times the protein in yoghurt.
Cymbopogon
citratus commonly known as “Lemon grass” or “fever grass” is an aromatic
perennial tall grass with rhizomes and densely tufted fibrous roots.
Nutritionally, lemon grass is a good source of vitamins A and C, folic acid,
magnesium, zinc, copper, iron, potassium, calcium and manganese. Lemon grass
has been used as a food ingredient, in cosmetics and as folk medicines in
several regions of the world. Yoghurt from cow’s milk is lacking in certain
phytochemicals such as carotenoids, flavonoids, anthocyanins, isothiocyanates,
saponins, tannins, lutein and zeaxanthin, that play functional roles in the
body. The lack of these phytochemicals has contributed to certain disease
conditions such as cancer, heart disease, inflammation, ulcers and diabetes. The
main aim of this study was to produce and evaluate yoghurt formulated with
aqueous extracts of Roselle calyx (Hibiscus
sabdariffa), Moringa leaves (Moringa
oleifera) and Lemon grass leaves (Cymbopogon
citratus). Therefore, the addition of herbs would add
phytochemicals to the yoghurt to make a functional yoghurt. These
phytochemicals would improve the nutritional status of the yoghurt and when
taken into the body improves one’s immune system. The use of indigenous
herbs would reduce the cost of production as they are readily available.
2. Materials and methods
2.1 Raw
materials
The raw
materials were whole milk powder, granulated sugar, stabilizer (CMC), yoghurt
culture (Lactobacillus bulgaricus and
Streptococcus thermophilus), dried
Roselle calyx, fresh Moringa leaves and fresh Lemon grass leaves.
2.1.1 Sample
procurement
The whole milk powder, granulated
sugar, stabilizer (CMC) and dried Roselle calyx were procured from Ogige
market, Nsukka, Enugu State. The fresh Moringa leaves and fresh lemon grass
leaves were obtained from farms. These leaves were authenticated by the
Department of Plant Science and Biotechnology, University of Nigeria, Nsukka.
The yoghurt culture was purchased from the International Bakery and
Confectionary market, Ogidi/Ogwunike Onitsha Metropolis, Anambra State.
2.2 Sample
Preparation
2.2.1 Processing
of aqueous Roselle leaf drink (Hibiscus sabdariffa)
Sixty grams
of dried Roselle calyces were cleaned by picking off dirt, foreign matters and
washed with cold water. The calyces were boiled in 300mL of water for 30
minutes to ensure proper extraction of the juice from the calyces. The juice
was filtered using a sieve to remove the Roselle calyces from the aqueous
extract [5]. The production of the Roselle
juice is summarized in Scheme 1.
Scheme 1. Processing of Roselle calyx
extract [5]
2.2.2 Processing
of aqueous Moringa leaf (Moringa
oleifera)
Sixty grams
of fresh Moringa leaves was boiled with 300mL of water for 20 minutes at 80̊ C and cooled for 10 minutes. The extract was
separated from the leaves using a sterile muslin cloth and filtered through a
sterile Whatman filter paper [6]. The
production of Moringa leaf extract is summarized in Scheme 2.
Scheme 2. Processing of
Moringa leaf extract [6]
2.2.3 Processing
of Lemon grass (Cymbopogon citratus) aqueous extract
Sixty grams
of the leaves were washed with clean water, cut into pieces, boiled with 300mL
of water for 30 minutes, cooled for 10 minutes and sieved using a sterile
muslin cloth to obtain the Lemon grass aqueous extract [7].
The production of Lemon grass aqueous extract is summarized in scheme 3.
Scheme 3. Processing of lemon grass aqueous
extract [8]
2.3 Production and formulation of yoghurt
Seventy-five
grams of milk was mixed with 0.6g of stabilizer, 6g of sugar and 215mL of water
as an aqueous medium for mixing. Yoghurt mixes were homogenized to obtain a
uniform product. It was pasteurized at 80 ̊C for 30
minutes to destroy unwanted microorganisms.
The product was cooled to 43 ± 2 ̊C and starter
culture was added and sample was incubated for 4 -6 hours. The leaf extracts
were added separately at a proportion of 5, 10 and 15%. The product was kept
refrigerated at 5 ± 1 ̊C for further
analysis [8]. There were ten samples coded
as RCAE1, RCAE2, RCAE3, MLAE1, MLAE2, MLAE3, LGAE1, LGAE2, LCAE3, YWNE. Sample
YWNE served as the control sample (Table 1). The pictorial representation of
the formulated yoghurt samples (Plate 1-4) is shown in Fig 1.
Table 1. Formulation
of herbal yoghurt using different concentrations of Roselle calyx, Moringa
leaves and Lemongrass leaves (aqueous extract).
Sample code |
Roselle calyx (mL) |
Moringa leaves (mL) |
Lemongrass leaves (mL) |
RCAE1 |
5 |
- |
- |
RCAE2 |
10 |
- |
- |
RCAE3 |
15 |
- |
- |
MLAE1 |
- |
5 |
- |
MLAE2 |
- |
10 |
- |
MLAE3 |
- |
15 |
- |
LGAE1 |
- |
- |
5 |
LGAE2 |
- |
- |
10 |
LGAE3 |
- |
- |
15 |
YWNE (Control) |
- |
- |
- |
Key:RCAE1=Herbal yoghurt with 5 mL Roselle calyx (aqueous extract); CAE2=Herbal yoghurt with 10 mL Roselle calyx (aqueous extract); RCAE3=Herbal yoghurt with 15 mL Roselle calyx (aqueous extract); MLAE1= Herbal yoghurt with 5 mL Moringa leaf (aqueous extract); MLAE2= Herbal yoghurt with 10 mL Moringa leaf (aqueous extract); MLAE3=Herbal yoghurt with 15 mL Moringa leaf (aqueous extract); LGAE1=Herbal yoghurt with 5 mL Lemongrass leaf (aqueous extract); LGAE2=Herbal yoghurt with 10 mL Lemongrass leaf (aqueous extract); LGAE3= Herbal yoghurt with 15 mL Lemongrass leaf (aqueous extract); YWNE=Herbal yoghurt with 0 mL of the herbs used as the control. |
Figure
1. Pictorial
representation of the formulated yoghurt samples (Plate 1-4)
2.4 Proximate
analysis of the herbal yoghurt samples
The following
proximate analysis was carried out on the formulated samples of the Roselle,
Moringa and lemon grass flavoured yoghurt and the control.
2.4.1 Determination
of moisture content
The moisture
content of the samples was determined using the hot air oven method described
by Association of Official Analytical Chemists [9].
2.4.2 Determination
of crude fat
The fat
content of the samples was determined using the standard method described by
Association of official Analytical Chemists [9].
2.4.3 Determination
of crude protein
The crude
protein determination was achieved using the standard method (Kjeldahl method)
described by Association of Official Analytical Chemist [9].
2.4.4 Determination
of ash content
The ash
content of each yoghurt sample was determined according to Association of Official
Analytical Chemists [9].
2.4.5 Determination
of carbohydrate
Total
carbohydrate content was calculated by difference as follows:
%
carbohydrate = 100 – (% moisture + % fat + % protein + % ash + % crude fibre).
2.5 Determination
of micronutrient composition
2.5.1 Determination
of vitamin A content
Vitamin A
content was determined according to Association of Official Analytical Chemists
method [9].
2.5.2 Determination
of vitamin C content
Vitamin C
content was determined using the Association of Official Analytical Chemists
method [9].
2.5.3 Determination
of phosphorous content
Phosphorous
content in the sample was determined according to Onwuka by molybdate method
using hydroquinone as a reducing agent [10].
2.5.4 Determination
of calcium content
The calcium
content was determined by the titration method according to Kirk and Sawyer [11].
2.6 Determination
of phytochemicals
2.6.1 Determination
of flavonoids
Total
flavonoids content was determined by a colorimetric assay using the Kapoor’s
method [12].
2.6.2 Determination
of saponins
Total
saponins was determined using Kapoor method [12].
2.6.3 Determination
of tannins
Total tannins
were determined using Kapoor method [12].
2.7 Microbial
analysis
2.7.1 Determination
of lactic acid bacteria (LAB)
The lactic
acid bacteria in the formulated yoghurt was determined using deMan Rogosa
Sharpe (MRS) Agar (CM 361) as described by Oxoid manual. Samples were serially
diluted in duplicates using the surface pour plate method. The plates were
incubated under anaerobic conditions at 37̊ C for 48
hours. After incubation, the number of colonies were counted using the colony
counter and represented as colony forming unit per millilitre (cfu/ml) [13].
No of
colonies (cfu/ml) = average count × dilution factor (D.F)
2.7.2 Determination
of total viable count (TVC)
The total
viable count test was carried out using the method described by Prescott [14]. Using sample and sterilized quarter strength
ringer solution as diluents, one millilitre (1 mL) of the water sample was
pipetted into a sterile test tube and 9 ml ringer solution pipetted into it and
other test tubes arranged for serial dilutions (10-3). The diluted
sample was pipetted into a marked petri dish and sterile nutrient agar of 20 mL
was poured into the same petri dish and swirled to mix and incubated (under
conditions that permit microbial reproduction so that colonies develop could be
seen without the aid of a microscope at a temperature of 37 °C for
24 hours. After incubation, the number of colonies were counted and represented
as colony forming unit per millilitre (cfu/ mL).
No of
colonies (cfu/mL) = average count × dilution factor (D.F)
2.7.3 Determination
of mould count
The mould
count test was carried out using the method described by Prescott [14] and Sabouraud dextrose agar (SDA) was used as
the media. Fifteen milliliters of the media was added to one gram of sample in
the Petri dish and mixed. The media was allowed to settle before incubating at
37 0C for 48 hours. After incubation, the number of colonies were
counted and represented as colony forming unit per millilitre (cfu/mL).
No of
colonies (cfu/mL) = average count × dilution factor (D.F)
2.8 Titratable
Acidity (TTA)
The
titratable acidity was determined according to Association of Official
Analytical Chemist Method [9].
2.9 pH
The pH of the
samples was measured in a 10% (w/v) dispersion of the samples in distilled
water. Each suspension was mixed thoroughly and a standard pH meter (Hanna
meter model H196107) was used for pH determination. The pH electrode was dipped
into mixture and reading taken [9].
2.10 Sensory
evaluation
The sensory
properties of samples were evaluated by a semi-trained panel consisting of 20 panelists
(including students and staff in the Department of Food Science and Technology,
University of Nigeria, Nsukka). A 9-point Hedonic scale was used to assess the
formulated herbal yoghurt, 0 = like extremely and 1 = dislike extremely. The
samples were served in plastic cups and randomly presented. A questionnaire
comprising of the five sensory attributes namely, color, taste, aftertaste,
flavor, texture, consistency and overall acceptability was given to each
panelist [15].
2.11 Experimental
design and data analysis
The
experiment was laid on
Completely Randomized Design (CRD). Data obtained was subjected to statistical
analysis. The analysis of variance (ANOVA) tests were carried out by
using the general linear model procedure of the SPSS (Version 23.0). Means were separated by Duncan’s new
multiple range test (DNMRT). Significance was accepted at p<0.05 [26].
3. Results and discussion
3.1 Proximate composition of the yoghurt samples
formulated with Roselle calyx, Moringa leaf and Lemon grass (aqueous extract)
3.1.1 Moisture content
The moisture
content of the flavored yoghurt samples ranged from 70.80 % for MLAE1 to 76.92
% for LGAE3. There showed a significant difference (p<0.05) between the
flavored yoghurt samples and the sample YWNE which was plain and served as
control sample. The difference in moisture increased as the concentration of
the extracts increased. The increase in moisture could be attributed to the
increasing water content of the aqueous extracts [16]
3.1.2 Ash
content
The ash
content of the samples ranged from 0.20 % for LGAE3 to 0.85 % to RCAE1. There
showed a significant difference (p<0.05) between the flavoured samples and
the control sample. The ash content of the flavoured yoghurts decreased as the
concentration of the extract increased. This implies that increase in the
concentration of the extracts did not contribute to the increase in the solid
residues in the yoghurt samples. The ash content was similar to the report by
Salisu [17].
3.1.3 Crude
fat
The fat
content ranged from 12.97 % for RCAE3 to 15.83 % for MLAE2. There showed no
significant difference (p>0.05) between the flavoured yoghurt samples and
sample YWNE. This could be attributed to the low fat content of Roselle calyx,
Moringa and Lemon grass fresh leaves as with the report of Lakshmipriya [18].
3.1.4 Protein
content
The protein
content ranged from 5.11 % for YWNE to 5.59 % for MLAE2. There was no
significant difference (p>0.05) between the flavoured yoghurt samples and
sample YWNE. This could be attributed to the low protein content of Roselle calyx,
Moringa and Lemon grass fresh leaves as to the report of Lakshmipriya [18].
3.1.5 Carbohydrate
content
The carbohydrate content ranged
from 3.84 % for LGAE2 to 7.51 % for MLAE1. There was no significant difference
(p>0.05) between the flavoured yoghurt samples and sample YWNE. This could
be due to the small amount (5, 10 and 15 ml) of Roselle calyx, Moringa and
Lemon grass aqueous extracts added [16]. The
proximate compositions are shown in Fig. 2.
Figure 2. Graphical
representation of the proximate composition of the formulated yoghurt samples. (Values
are means ± standard deviation of triplicate determinations. Means with
different superscripts in the same column are significantly different at p˂ 0.05).
3.2 Selected
micronutrient composition of the yoghurt samples formulated with Roselle calyx,
Moringa leaf and Lemon grass (aqueous extract)
3.2.1 Vitamin
C content
The vitamin C
content of the yoghurt samples ranged from 1.06 mg/100g for YWNE to 3.60 mg/100g
for LGAE3. There was a significant difference (p>0.05) between the control
sample (YWNE) and the flavoured yoghurt samples. The increase in vitamin C
content follows a simultaneous increase in the concentration of the aqueous
extracts. This is due to Roselle calyx, Moringa and Lemon grass leaves already
containing a high vitamin C content as reported by Martha [19].
3.2.2 Vitamin
A content
The vitamin A
content ranged from 0.19 mg/100g for MLAE2 to 0.26 mg/100g for RCAE3. There was
no significant difference (p>0.05) between the control sample (YWNE) and the
flavoured samples except for sample RCAE3 which increased the vitamin A content
of the yoghurt at Roselle calyx extract concentration of 15 ml. This could be
due to increase in the extract at 15 ml contributing to the increase in the
vitamin A content of the yoghurt as reported by Fasoyiro [20].
3.2.3 Phosphorous
content
The
phosphorous content of the yoghurt samples ranged from 174.59 mg/100g for YWNE
to 588.41 mg/100g. There was a significant difference (p<0.05) between the
control sample and the flavoured yoghurts. The increase in the concentration of
the aqueous extracts led to the increase in the phosphorous content of the
flavoured yoghurt samples and this is due to the high phosphorus content of
Roselle calyx, Moringa and Lemon grass leaves [18, 20].
3.2.4 Calcium
content
The calcium
content of the yoghurt samples ranged from 81.32 mg/100g for LGAE1 to 104.26
mg/100g for RCAE3. There was a significant difference (p<0.05) between the
control sample and the flavoured yoghurts. The result shows that addition of
aqueous extract with increasing concentration led to increase in the calcium
content of the yoghurt samples. The values of the calcium content obtained
agreed with the report of Tajidin [21]. The
micronutrient composition of the yoghurt samples is shown in Fig. 3.
Figure 3. Graphical
representation of the micronutrient of the formulated yoghurts. Values are
means ± standard deviation of triplicate determinations. Means with different
superscripts in the same column are significantly different at p ˂ 0.05)
3.3 Physicochemical
composition of the yoghurt samples formulated with Roselle calyx, Moringa leaf
and Lemon grass (aqueous extract)
3.3.1 Titratable
acidity
The
titratable acidity of the yoghurt samples ranged from 0.90 % for YWNE to 1.09 %
for RCAE3. There was a significant difference (p<0.05) between the control
sample and the flavoured yoghurt samples. The titratable acidity of the yoghurt
samples was increasing with increase in the concentration of the aqueous
extract [20].
3.3.2 pH
The pH of the
yoghurt samples ranged from 3.75 for LGAE3 to 4.57 for YWNE. There was a
significant difference (p<0.05) between the control sample and the flavoured
yoghurt samples. The pH of the flavoured yoghurt samples decreased with
increase in the concentration of the aqueous extract [19,
20]. The physicochemical composition of the yoghurt samples is shown in Fig.
4.
Figure 4. Graphical
representation of the physicochemical composition of the formulated yoghurts.
Values are means ± standard deviation of triplicate determinations. Means with
different superscripts in the same column are significantly different at (p ˂ 0.05).
3.4 Physiochemical composition of the Roselle calyx,
Moringa leaf and Lemon grass (aqueous extract)
3.4.1 Titratable acidity
The
titratable acidity (Table 2) of Roselle calyx aqueous extract is 1.22 % showing
the acidic level of the Roselle calyx, Moringa leaf is 0.64 % due to its
alkaline nature and lemon grass is 0.41 % [17,19,20].
3.4.2 pH
The pH (Table
2) of Roselle
calyx aqueous extract is 3.88 due to the acidic level of Roselle calyx [20], Moringa leaf is 6.89 due to its alkaline
nature and lemon grass is 5.92 [17, 19].
Table 2. Selected physiochemical composition of the Roselle calyx, Moringa leaf
and Lemongrass leaf (aqueous extract).
Sample |
TTA
(% lactic acid) |
pH |
RCAE |
1.22g ± 0.06 |
3.88cd ± 0.01 |
MLAE |
0.64b ± 0.01 |
6.89f ± 0.01 |
LGAE |
0.41a ± 0.00 |
5.92e ± 0.01 |
Values are means ± standard deviation of
triplicate determinations. Means with different superscripts in the same
column are significantly different at (p˂ 0.05). Values are means±standard deviation of duplicate
determinations. Values in the same columns with the different superscript are
significantly (p<0.05) different. RCAE=Yoghurt with Roselle calyx extract;
MLAE=Yoghurt with Moringa leaf extract; LGAE=Yoghurt with Lemon grass leaf
extract. |
3.5 Phytochemical
composition of the yoghurt samples formulated with Roselle calyx, Moringa leaf
and Lemon grass (aqueous extract)
3.5.1 Flavonoid
content
The flavonoid
content ranged from 0.17 mgQE/100g for YWNE to 8.76 mgQE/100g for RCAE3. There
was no significant difference (p<0.05) between the control sample and
flavoured yoghurt samples. This could be due to the amount (5, 10 and 15 ml) of
Roselle calyx, Moringa and Lemon grass aqueous extracts added not been enough to
cause a significant increase in the flavonoid content of the yoghurt samples [16].
3.5.2 Tannin content
The tannin
content ranged from 0.02 mgTA/100g for YWNE to 0.97 mgTA/100g for RCAE3. There
was a significant difference (p<0.05) between the control sample and the
flavoured yoghurt samples. The tannin content of the yoghurt formulated with
Roselle calyx extract increased with increase in concentration of extract and
this could be related to Roselle calyx containing non-hydrolyzable tannin,
namely catechin [17]. Also, the tannin
content of the yoghurt formulated with Moringa leaf and Lemon grass leaf
aqueous extract was decreasing with increase in the concentration of the
extracts and this could be due to Moringa and Lemon grass leaf containing
hydrolysable tannin, namely tannic acid, which gets easily hydrolysed in water [17].
3.5.3 Saponin
content
The saponin content ranged from
0.05 mg/g for YWNE to 4.83 mg/g for MLAE3. There was a significant difference
(p<0.05) between the control sample and the flavoured yoghurt samples. The
saponin content of the yoghurt samples was increasing with increase in
concentration of the extracts and this is due to the saponin content of Roselle
calyx, Moringa leaf and Lemon grass leaf [18]. The phytochemical composition of the yoghurt
samples is shown in Fig. 5.
This work is licensed under the
Creative Commons Attribution
4.0
License (CC BY-NC 4.0).
Abstract
The Moringa leaf, Roselle calyx and Lemon grass leaf
extracts were added separately at a proportion of 5, 10, 15% into the yoghurt
and refrigerated at 5 ± 1 0C for further analysis. The samples were coded as RCAE1,
RCAE2, RCAE3 for Roselle calyx extract; MLAE1, MLAE2 for Moringa leaf extract
and LGAE1, LGAE2, LGAE3 for Lemon grass leaf extract while YWNE was the control. The
formulated yoghurts were subjected to proximate, micronutrients,
phytochemicals, physicochemical, microbial and sensory evaluation. Data
obtained were subjected to statistical analysis. The results showed that
moisture and carbohydrate increased with an increase in concentration. The ash
content decreased also. There showed no significant difference (p>0.05)
between the control and formulated samples. The micronutrients increased except
for Vitamin A of the Moringa leaf and lemon grass leaf (aqueous extract)
samples decreased as the concentration increased. The phytochemical content of
the samples increased; except tannin of Moringa leaf and Lemongrass which decreased
on addition of aqueous extracts. pH of the formulated yoghurt samples decreased
leading to an increase in titratable acidity. The total viable count for the
yoghurt sample formulated with Roselle and Moringa leaf extract decreased with
increase in the concentration of the extracts. The most acceptable herbal
yoghurt by the panelists in terms of palatability is
RCAE2 while the product best with
respect to the nutritional quality is LGAE3.
Abstract Keywords
Moringa leaf, Roselle calyx, Lemon grass, aqueous extract,
herbal yoghurt.
This work is licensed under the
Creative Commons Attribution
4.0
License (CC BY-NC 4.0).
This work is licensed under the
Creative Commons Attribution 4.0
License.(CC BY-NC 4.0).