DEODORIZATION OF FERMENTED FOOD CONDIMENT FROM PROSOPIS AFRICANA (AFRICAN MESQUITE) SEEDS AND ITS EFFECT ON NUTRIENTS AND ANTINUTRIENTS COMPOSITION

Prosopis Africana seeds were processed to produce local fermented food condiment. The aim of this study was to deodorize laboratory prepared fermented food condiment from Prosopis Africana seeds with potential chemical deodorant; cyclodextrin (CD), and powdered activated carbon (PAC) and determine its nutrients and antinutrients composition. Heterotrophic bacterial counts were determined using pour plate method and the growth increased exponentially from days 1- 6, with peak counts at day 7 (2.24 x 10⁶, 1.54 x 10⁷, 1.16 x10⁸ and 0.77 x10⁹) cfu/g and day 8 (2.25 x 10⁶, 1.56 x 10⁷, 1.18x10⁸ and 0.78 x10⁹) cfu/g respectively with steady growth, offensive odor and dark mash sticky cotyledon at days 7 - 9. Cyclodextrin treated sample 2.5g/100g and PAC treated sample 2.5g/100g had the least odor (Barely perceived odor) 73.4% and 86.6% respectively. In all, there were 27 volatile constituents in control sample using GC- MS, 19 in CD and 10 in PAC based on their retention time. The GC-MS of the control sample had 27 volatile constituents while the sample treated with PAC (2.5g/100g) which achieved 86.6% deodorization had only 10 volatile constituents suggesting that the 17 constituents which had been removed are largely responsible for the offensive odor. Treatment with deodorants reduced antinutritional constituents like alkaloids from control 7.21mg/100g to 4.10mg/100g and 4.95mg/100g respectively for CD and PAC treated samples as well as saponins from 47.45mg/100g to 34.55mg/100g and 35.86mg/100g for CD and PAC treated samples respectively. In conclusion, the present study depicted the potentiality of CD, and PAC as good chemical deodorants for the deodorization of fermented food condiment from Prosopis Africana seed with PAC having the highest deodorization potential.

 

4.1 Heterotrophic Bacterial Count of Laboratory Fermented Prosopis Africana Seeds 69

4.2 Changes in   Physical   Sensory   Parameters   of   Laboratory   Fermented   Prosopis   Africana seeds………68

4.3 Odor   Evaluation    of    Deodorized    Fermented    Condiment    from    Prosopis    Africana seeds 71

4.4 Volatile Constituents of Deodorized   Fermented   Condiment from   Prosopis   Africana seeds… 74

4.5 Effects of Deodorizing Agents on Proximate Compositions of Deodorized Fermented Condiment from Prosopis Africana Seeds 77

4.6 Effects of Deodorizing Agents on Vitamins Composition of Deodorized Fermented Condiment from prosopis Africana Seeds… 78

4.7 Effect of Deodorizing Agents on Mineral Elements Compositions of Deodorized Fermented Condiment from Prosopis Africana seeds… 82

4.8 Effects of deodorizing agents on antinutrients composition of deodorized fermented condiment from Prosopis Africana seeds 84

4.8 Effect of Deodorizing Agents on Antinutrients Composition of Deodorized Fermented Condiment from Prosopis Africana Seeds 84

 

Table 4.1; Changes in physical sensory parameters of laboratory fermented Prosopis Africana seeds… 70

Table 4.2; Volatile constituents of  deodorized fermented condiment from Prosopis Africana seeds 76

Table 4.3; Effect of deodorizing agents on proximate compositions of deodorized fermented condiment from Prosopis Africana seeds 79

Table 4.4; effect of deodorizing agents on vitamins compositions of deodorized fermented condiment from Prosopis Africana seeds… 81

Table 4.5; Effect of deodorizing agents on mineral compositions of deodorized fermented condiment from Prosopis Africana seeds 83

Table 4.6; Effect of deodorizing agents on antinutrients composition of deodorized fermented condiment from Prosopis Africana seeds 86

 

Table 4.7; Physicochemical characteristics of deodorized fermented condiment from Prosopis Africana seeds 87

Figure 3.1; Flow chart of laboratory preparation and deodorization of fermented condiment from Prosopis Africana  seeds (okpehe)… 45

Figure 4.1; Heterotrophic bacterial count of laboratory fermented Prosopis Africana seeds (cfu/g)……69

Figure 4.2; Odor evaluation of deodorized fermented condiment from Prosopis Africana seeds treated with Cyclodextrin (CD) 72

Figure 4.3; Odor evaluation of deodorized fermented condiment from Prosopis Africana seed treated with Powdered Activated Carbon (PAC)… 73

Plate 1: Prosopis Africana's leaves and fruit… 25

Plate 2: (a); Prosopis Africana pods and (b); Prosopis Africana seeds 26

 

Prosopis trees are woody unceasing belonging to the family Leguminosae. The Prosopis genus comprises about 44 species of trees and shrubs; the number could be as high as more than 70 (Balogun and Oyeyiola, 2012). The species have been distributed in North America, Central/South America, Africa, and Asia (Ogunshe et al., 2007). It occurs naturally in arid and semi-arid areas where it has been used by local populations as a good source of timber, fuel, fodder, food, gum, tannin or dyestuff. In Nigeria, it is predominant in North Central geopolitical zone around Kogi, Benue, Nasarawa, Kaduna, Niger and Plateau states (Ogunshe et al., 2007). It is also sparsely growing in the South East geopolitical zones. The pod of Prosopis spp. consists of three separable components: exo and mesocarp (pulp), endocarp and the seed (Balogun and Oyeyiola, 2012). The pods are used as food for cattle and as fish poison by fishermen. Interestingly, these pods also contain seeds which can be processed to produce local fermented food condiment called ―okpehe‖ by Idoma, Igala and other middle belts tribes. It is also called Daddawa, Iru, Ogiri in Hausa, Yoruba and Igbo respectively (Balogun and Oyeyiola, 2012).

In many countries in Africa including Nigeria, protein malnutrition is a major problem. The food diet of Nigerians is mostly from roots, tubers and cereals. The low protein content in the Nigerian diet contributes to the low nutrition security of the people (Ogunshe et al., 2007). The high cost of animal protein has also directed interest towards several leguminous seed proteins as potential sources of vegetable protein for human food (Giri et al., 2010). Most of the fermented vegetable proteins reported are from leguminous seeds (Balogun et al., 2017). Quite often, seeds that are used for fermentation are inedible in their raw unfermented or cooked state (Akande and Fabiyi, 2010). The seeds of legumes may account for up to 80% dietary protein and be the only source of protein for some groups of people (Adeniyi et al., 2009). Although fermented food condiments have constituted a significant proportion of the diet of many people, Nigerians exhibit an ambivalent attitude in terms of consumer tastes and preferences for such foods (Balogun et al., 2017). Prosopis africana seed commonly known as African mesquite but also known by different native Nigerian names such as Kirya (Hausa), Kohi (Fulani), Sam chi lati (Nupe), Ayan (Yoruba), Kpaye (Tiv), Ubwa (Ibo) and okpehe (Idoma) is one of the lesser known legume seed crops which can be fermented and used as a food condiment known as okpehe (Ogunshe et al., 2007). Okpehe is used as a food condiment in Nigeria by the Idoma and Igala people of the middle belt region and some parts of the Eastern and Southern Nigeria. It adds variety and pleasure to the otherwise monotonous traditional diet. It serves not only as a seasoning agent but also as a low-cost source of protein in the diet (Ogunshe et al., 2007). Okpehe can serve as a substitute for meat for lowincome earners and can reduce protein-calorie malnutrition and essential fatty acid deficiencies (Akande and Fabiyi, 2010).

 

Prosopis Africana (reaches 4-20 m in height); has an open crown and slightly rounded buttresses; bark is very dark, scaly, slash orange to red brown with white streaks (Apata and Olaghobo, 1994). Foliage drooping; leaves alternate, bipinnate; rachis 10-15 cm long with 3-6 pairs of opposite pinnae (5-8 cm long); 9-16 pairs of leaflets, oblonglanceolate, 12-30 mm, pubescent; a typical gland between pairs of pinnae and leaflets. Flowers greenish-white to yellow, fragrant, in dense 6-10 cm long axillary spikes; calyx pubescent but petals glabrous; 10 free-standing stamens; anthers with a small apical gland. Pods dark brown, cylindrical, thick and hard, shiny, up to 15 x 3 cm, with woody walls, compartmented; about 10 loose, rattling seeds per pod with a thin, inter-marginal line around (Borchers and Ackerson, 2015).

Fermented food condiments remain of interest since they do not require refrigeration during distribution and storage. The traditional fermented condiments have not attained commercial status due to the objectionable packaging materials, stickiness and the characteristic putrid and unpleasant odor (Culleré et al., 2010). Fermented condiments often have a stigma attached to them despite serving not only as a nutritious non-meat protein, they are often considered as food for the poor due to the off odor associated (Difo et al., 2015).

Malnutrition is considered to be of public health concern in Nigeria. Global nutrition survey indicates that deficiency in Macro and Micronutrients are most prevalent, because the sources of essential nutrients are expensive and beyond the reach of majority of the population (Difo et al., 2015). Consumptions of monosodium glutamate and salts that are rich in sodium as flavour enhancers has been associated with health related cardiovascular disorders, thus there is need to substitute them with natural fermented condiments (Culleré et al., 2010).

 

There is paucity of data on deodorization potential of cyclodextrin (CD) and powdered activated carbon (PAC) on fermented food condiments from Prosopis Africana seeds. Fermented food condiments remain of interest since they are cheap, easily accessible and affordable by low income earners. However, acceptability of such condiments by the consumers is of serious challenge due to the offensive odor associated with them (Balogun et al., 2017). Therefore, removing or reducing the odor may increase its acceptability and market range to people thus provide a cheap and healthier alternative to monosodium glutamate.

The aim of this research study was to deodorize the fermented food condiments (Okpehe) from prosopis Africana seeds and determine its nutritional composition.

The specific objectives of this research are to;

i. Prepare and deodorize the laboratory prepared fermented food condiment from Prosopis Africana seeds with potential chemical deodorants; β-Cyclodextrin, and powdered activated carbon.

 

There is no significant effect of potential chemical deodorants; cyclodextrin, and powdered activated carbon on the off-odor, nutrients and antinutrients of fermented food condiment from Prosopis Africana seeds.