Bioscience Method 2018, Vol.9, No.2, 12-21
15
protein content was calculated according to the equation below.
% Nitrogen= 0.014×VD×N×100×TV
Weight of sample×AD
% Protein=% N×F
Where: VD=Volume of digest; N=Normality of acid; TV=Titre value; AD=Aliquot of digest; F=Conversion factor
for nitrogen to protein (6.25)
1.9 Lipid
Lipid value was obtained by exhaustively extracting 2.0 g of each sample in a Soxhlet apparatus using petroleum
ether (b.p. 40-60°C) as the extractant.
% Lipid=
W3 – W2 x 100 W1
(3)
Where
:
W1=weight of samples; W2=weight of extraction cup (empty (g)); W3=weight of extraction cup +
residue (g)
1.10 Fibre content
One gram of dried sample was digested with 0.128 ml of tetraoxosulphate (VI) acid (H
2
SO
4
) with two drops of
octanol to prevent foaming. The content was boiled for 30 min, and then filtered and washed with hot water to
remove acid. The residue was boiled with 0.22 ml of potassium hydroxide (KOH) for 30 min, and then washed in
boiling water and acetone. The residue was dried and ignited in furnace. The loss of weight represents the crude
fibre (Fawole et al., 2013).
% crude fibre=
dry wt. of residue before ashing – weight of residue after ashing × 100
Weight of sample
1.11 Carbohydrate
Carbohydrate content was calculated based on difference calculation [Carbohydrate=100%-(% moisture+%
ash+% crude protein+% fat)] (Olagunju et al., 2012).
1.12 Mineral concentration
The percentage mineral elemental concentration (macro and micro) including trace elements concentrations were
determined using Atomic Emission Spectrophotometer (AES) and Atomic Absorption Spectrophotometer (AAS)
(Fawole et al., 2007).
1.13 Energy value
The total energy value of the snack was calculated using the method of (Palani et al., 2014). The crude values of
protein, fat and carbohydrate as obtained from the proximate analysis were used as hereunder:
Energy value Kcal/100 g=Px4.00 Protein+Cx4.00 NFE Kcal/100+Fx9.00 Fat Kcal/100 g
1.14 Statistical analysis and data presentation
Data were subjected to one-way analysis of variance (ANOVA) and the means separated using Duncan’s Multiple
Range. Statistical Analysis System (SAS
®
), version 9.1 package was employed for statistical analysis and at 5%
confidence level. Data were presented in mean±, percentile, as well as frequency, pie and bar chats as appropriate.
2 Results
2.1 Nutrient quality
2.1.1 Proximate composition
The proximate composition of snacks produced from
S. galilaeus
and
S
.
galilaeus
fortified with plant crude
extracts is shown in Table 2. The percentage protein content obtained for the snacks ranged from 48.35±0.01% to
60.87±0.01%. The highest protein value was obtained from unfortified
S. galilaeus
snacks and it is significantly
