3.3. Results and Discussion
3.3.2. Mineral content of instant-maize porridge
The carbohydrate content of AOB (81.5%) was observed to be higher than of BEA (64.4%), CIA (61.85 %) and DJE (56.6%) at p < 0.05. Cereals have been reported to contain more carbohydrate and fewer amounts of protein and essential minerals. The carbohydrate content of fortified samples decreased with addition of MO leaves and termite powder (Table 4). Mbata et al. (2009) also reported carbohydrate reduction when plant was added to cereal-based traditional foods. MO leaves are known to be low in carbohydrate (Rajaratnam et al., 2010). The carbohydrate values of sample BEA and CIA in this present study are higher than what was reported by Adepoju & Ajayi (2016), for complementary foods enriched with termite powder (60.5 to 61.7%). The decrease in carbohydrate content of sample DJE in this study could be due to substitution effect. Although the carbohydrate content of the samples in this study decreased from 81.5% to 56.6%, the percentage of carbohydrate content of sample BEA is within the amount recommended (64.0%) by Amankwah et al. (2009) for weaning food. This observation indicates that sample BEA may be a good source of carbohydrate compared to CIA and DJE because of their lower carbohydrate contents. Carbohydrates help in providing energy for all forms of body activity. Deficiency can cause the body to divert proteins and body fat to produce needed energy, thus leading to depletion of body tissues.
although the values reported by Niaba et al. (2013) are lower than in the present study. The increase in Ca in sample BEA, CIA and DJE may be due to the addition of MO, since it has been reported to be high in potassium and Ca (Jideani & Diedericks, 2014). This indicates that sample BEA, CIA and DJE can be appropriate in the formation of teeth and bones of young children if consumed as weaning food.
Table 5. Mineral composition (mg/100g) of instant-maize porridge fortified with Moringa oleifera and termite powders.
Composition (%)
AOB BEA CIA DJE
Calcium 7.08 ± 0.03a 220.95 ± 1.74b 267.77 ± 3.05d 234.69 ± 0.48c Iron 7.73 ± 0.07a 32.30 ± 0.20c 36.85 ± 0.12d 27.87 ± 0.16b Magnesium 31.42 ± 0.14a 97.04 ± 0.36c 92.31 ± 0.39b 91.96 ± 0.26b Zinc 3.40 ± 0.31a 6.54 ± 0.45b 7.12 ± 0.20c 7.57 ± 0.64b Means ± SD. Mean values followed by different letters in the same row are significantly different at p < 0.05. AOB = Control sample (maize), BEA = maize, termites and cooked Moringa oleifera blend, CIA = maize, termites and blanched Moringa oleifera blend and DJE = maize, termites and uncooked Moringa oleifera blend.
Zn content of AOB (3.40 mg/100 g) was observed to be lower than of BEA (6.54 mg/100 g), CIA (7.12 mg/100 g) and DJE (7.57 mg/100 g) at p < 0.05 (Table 5). Upon the addition of MO leaves and termite powder, the Zn content was observed to be higher than what was reported by Ojarotimi & Oluwalana (2013). The application of different fertilizers (Palada et al., 2007; Prasanthi et al., 2017) could also be attributed to an increase in Zn content.
Moreover, the Zn content of FMP in this present study was higher than what was recommended (3. 2 mg/100g) by FAO/WHO (2015) for weaning food. This observation may be attributed to that MO is known to contain substantial amounts of Zn (Edward et al., 2005). Factors such as location, climate and the environment can significantly influence nutritional content of MO tree (Moyo et al., 2011). Moreover, nutritional variability in food can be influenced by factors such as maturity stage, variety/cultivar, post-harvest handling and processing (Prasanthi et al., 2017).
The Fe content of AOB (7.73 mg/100 g) was lower than of BEA (32.30 mg/100 g), CIA (36.85 mg/100 g) and DJE (27.87 mg/100 g) at p < 0.05 (Table 5). Higher Fe values (27.87 – 36.85 mg/100 g) in this present study were observed among fortified samples and this
could be as a result of substitution effect, since fresh uncooked MO leaves are reported to have over three times the amount of Fe than spinach (Edward et al., 2005). Akingbala et al.
(2005); Aminigo & Akingbala (2004); Otunola et al. (2007) recorded Fe values of 7.50 to 18.00 mg/100 g in the substitution of ogi with okra seed flour. Upon the addition of MO leaves and termite powder, the iron content was observed to be higher than what was reported by Ojarotimi & Oluwalana (2013), where the Fe content of fermented popcorn- moringa leaves was 4.12 g/100 g. This may be attributed to the fact that MO leaves and termites contain substantial amounts of Fe. Moreover, the Fe values in this present study are lower than what was reported by Adepoju & Ajayi (2016), where the Fe content of complementary foods enriched with termite powder was 4.13 mg/100 g. The nutritional composition also varies due to various factors such as the genetics, processing effects and various links in the food chain (Fubara 2008). Although, processing has beneficial effects such as destruction of trypsin inhibitors and the liberation of bound niacin in cereals, loss of nutrients and reduction in the nutritional composition is profound in processed foods than in the raw food material. Nutrient loss may occur during harvesting, handling and transportation, processing, storage and distribution (Selinger, 2016).
The Mg content of AOB (31.42 mg/100 g) was lower than of BEA (97.04 mg/100 g), CIA (92.31 mg/100 g) and DJE (91.96 mg/100 g) at p < 0.05 (Table 5). This observation could be as a result of substitution effect, since MO leaves and termites has been reported to contain four times the amount of Mg. Upon the addition of MO leaves and termite powder, the Mg content was observed to be lower than what was reported by Ojarotimi & Oluwalana (2013), for fermented popcorn-moringa leaves (284.40 - 285.71 mg/100 g). The type of soil can contribute to the nutrient content and strength of the plant. Dania et al. (2014) reported that the type of fertilizers used to nurture plants also plays a major role in nutritional value of a product. In addition, the Mg content of FMP was found to be more compared to the commendation made by FAO/WHO (2015) for weaning food (76 mg/100 g).
The increase in Ca, Fe, Zn and Mg contents of sample BEA, CIA and DJE may be attributed to the addition of MO and termites which contain substantial amounts of Fe, Zn and Mg (Defoliart, 2002). This indicates that sample BEA, CIA and DJE could help improve Fe and Zn status and help prevent anaemia and Zn deficiency of the pre-school children in the Vhembe district who were reported to be Fe and Zn deficient in 2015 (Motadi et al., 2015). Food fortification has been recommended by many researchers to enhance essential nutrients lost during the processing of food (Rosalind et al., 2000; Lutter & Dewey, 2003).
Conclusion
The nutritional properties of an instant-maize porridge fortified with MO and termite powders were determined. It was observed that the addition of MO leaves and termite powders to maize increased the nutritional content of fortified instant-maize porridge. The findings also showed that the fortified samples, particularly samples DJE (maize, uncooked MO leaves and termite powders blend), CIA (maize, blanched MO leaves and termite powders blend), and BEA (maize, cooked MO leaves and termite powders blend) were higher in terms of protein and mineral contents than the control sample (maize-AOB).
Hence, these formulations could be used as food for pregnant women, lactating mothers and infants, particularly underprivileged families, which are unable to afford nutritious and healthy weaning food. In addition the nutrient composition of instant-maize porridge fortified with MO leaves and termites based weaning food may be proper to be used as supplement for weaning food, which contains low amount of essential nutrients.
Chapter Four: The effect of Moringa oleifera leaves and termite powders on the physical, pasting and sensory properties of an instant-maize porridge.
Abstract
Moringa oleifera (MO) and termite are known to contain a substantial amount of protein.
The aim of this study was to determine the effect of MO leaves and termite powders on the physical, pasting and sensory properties of instant-maize porridge. Inclusion of MO leaves and termite powders in instant-maize porridge, at different treatments were considered using a completely randomised design. Factor levels were: AOB-control (maize flour); BEA (maize, cooked dried MO and termite powders); CIA (maize, blanched dried MO and termite powders) and DJE (maize, uncooked dried MO and termite powders). Data from three replications were analysed using SPSS version 23. The viscosity of sample AOB, BEA, CIA and DJE of the uncooked paste was significantly different at p < 0.05. The least gelation concentration increased as MO and termite powder was added to maize. The colour values of the raw and cooked FMP were significantly different at p < 0.05. The L*, a*, b*, c* and h˚ values of the instant-maize flour were higher values as compared to the instant-maize porridge. Sensory results showed that among fortified porridges, CIA was rated high for colour and texture, BEA higher in taste and DJE higher for aroma. AOB had higher acceptance than fortified porridges for taste. Generally sample BEA was highly accepted by consumers among the fortified samples (CIA and DJE).
Keywords: Instant-maize porridge, Moringa, termites, gelatinisation, viscosity, acceptability.