Firibu K. Saalia

Polycyclic aromatic compounds (PAHs and oxygenated PAHs) and trace metals in fish species from Ghana (West Africa): Bioaccumulation and health risk assessment

We report the concentrations of 28 PAHs, 15 oxygenated PAHs (OPAHs) and 11 trace metals/metalloids (As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Se, and Zn) in muscle and gut+gill tissues of demersal fishes (Drapane africana, Cynoglossus senegalensis and Pomadasys peroteti) from three locations along the coast of the Gulf of Guinea (Ghana). The concentrations of ∑28PAHs in muscle tissues averaged 192ngg(-1) dw (range: 71-481ngg(-1) dw) and were not statistically different between locations. The concentrations of ∑28 PAHs were higher in guts+gills than in muscles. The PAH composition pattern was dominated by low molecular weight compounds (naphthalene, alkyl-naphthalenes and phenanthrene). All fish tissues had benzo[a]pyrene concentrations lower than the EU limit for food safety. Excess cancer risk from consumption of some fish was higher than the guideline value of 1×10(-6). The concentrations of ∑15 OPAHs in fish muscles averaged 422ngg(-1) dw (range: 28-1715ngg(-1)dw). The ∑15 OPAHs/∑16 US-EPA PAHs concentration ratio was >1 in 68% of the fish muscles and 100% of guts+gills. The log-transformed concentrations of PAHs and OPAHs in muscles, guts+gills were significantly (p<0.05) correlated with their octanol-water partitioning coefficients, strongly suggesting that equilibrium partitioning from water/sediment into fish tissue was the main mechanism of bioaccumulation. The trace metal concentrations in the fish tissues were in the medium range when compared to fish from other parts of the world. The concentrations of some trace metals (Cd, Cu, Fe, Mn, Zn) were higher in guts+gills than in muscle tissues. The target hazard quotients for metals were<1 and did not indicate a danger to the local population. We conclude that the health risk arising from the consumption of the studied fish (due to their PAHs and trace metals content) is minimal.

Effect of pulp preconditioning on acidification, proteolysis, sugars and free fatty acids concentration during fermentation of cocoa (Theobroma cacao) beans.

Changes in acidification, proteolysis, sugars and free fatty acids (FFAs) concentrations of Ghanaian cocoa beans as affected by pulp preconditioning (pod storage or PS) and fermentation were investigated. Non-volatile acidity, pH, proteolysis, sugars (total, reducing and non-reducing) and FFAs concentrations were analysed using standard methods. Increasing PS consistently decreased the non-volatile acidity with concomitant increase in pH during fermentation of the beans. Fermentation decreased the pH of the unstored beans from 6.7 to 4.9 within the first 4 days and then increased slightly again to 5.3 by the sixth day. Protein, total sugars and non-reducing sugars decreased significantly (p < 0.05) during fermentation, whereas reducing sugars and FFA increased. PS increased the FFA levels, reduced the protein content but did not have any effect on the sugars. The rate of total and non-reducing sugars degeneration with concomitant generation of reducing sugars in the cocoa beans was largely affected by fermentation than by PS.

Extrusion of Maize–Cowpea Blends in a Modified Oil Expeller

A laboratory oil expeller was modified by using a press cylinder without openings for expelling the oil. Central composite rotatable design for k = 3 was used to study the effects of process variables, cowpea level (0-25%), feed moisture (10-25%) and barrel temperature (130-200°C) on product indices (moisture, expansion index, bulk density, water absorption, extractable solids, swell volume and the degree of gelatinisation of flour from the extrudate). Regression models developed to predict product indices were significant and showed no significant lack of fit. The model for moisture content of the extrudate had an R 2 of 0.98. Product moisture was influenced by the amount of cowpea in the feed, the temperature of extrusion and feed moisture. Furthermore, the product moisture measured at each cowpea level was dependent on the temperature of extrusion. The model for product expansion index showed that this index decreased with feed moisture and the cowpea level. Regression models for bulk density, water absorption, extractable solids and the maximum swell volume of flour from the extrudate were influenced by the process variables. The degree of gelatinisation decreased with cowpea level and increased with extrusion temperature.

Improving complementary feeding in Ghana: reaching the vulnerable through innovative business--the case of KOKO Plus.

Reaching vulnerable populations in low‐resource settings with effective business solutions is critical, given the global nature of food and nutrition security. Over a third of deaths of children under 5 years of age are directly or indirectly caused by undernutrition. The Lancet series on malnutrition (2013) estimates that over 220,000 lives of children under 5 years of age can be saved through the implementation of an infant and young child feeding and care package. A unique project being undertaken in Ghana aims to bring in two elements of innovation in infant and young child feeding. The first involves a public–private partnership (PPP) to develop and test the efficacy and effectiveness of the delivery of a low‐cost complementary food supplement in Ghana called KOKO Plus™. The second involves the testing of the concepts of social entrepreneurship and social business models in the distribution and delivery of the product. This paper shares information on the ongoing activities in the testing of concepts of PPPs, social business, social marketing, and demand creation using different delivery platforms to achieve optimal nutrition in Ghanaian infants and young children in the first 2 years of life. It also focuses on outlining the concept of using PPP and base‐of‐the‐pyramid approaches toward achieving nutrition objectives.

The Effect of Thermal and Ultrasonic Treatment on Amino Acid Composition, Radical Scavenging and Reducing Potential of Hydrolysates Obtained from Simulated Gastrointestinal Digestion of Cowpea Proteins

The effect of thermal and ultrasonic treatment of cowpea proteins (CP) on amino acid composition, radical scavenging and reducing potential of hydrolysates (CPH) obtained from in vitro simulated gastrointestinal digestion of CP was evaluated. Hydrolysis of native and treated CP with gastrointestinal pepsin and pancreatin yielded CPH that displayed antioxidant activities based on oxygen radical scavenging capacity (ORAC), ferric reducing antioxidant power (FRAP) and superoxide radical scavenging activity (SRSA). CPH derived from the treated CP yielded higher ORAC values than CPH from untreated proteins. However, lower significant FRAP and SRSA values were observed for these samples compared to untreated CPH (p < 0.05). Amino acid analysis indicated that CP processing decreased total sulphur-containing amino acids in the hydrolysates, particularly cysteine. The amount of cysteine appeared to be positively related to FRAP and SRSA values of CPH samples, but not ORAC. The results indicated that thermal and ultrasonic processing of CP can reduce the radical scavenging and reducing potential of the enzymatic hydrolysates possibly due to the decreased amounts of cysteine. Since the hydrolysates were generated with gastrointestinal enzymes, it is possible that the resulting compounds are produced to exert some health functions during normal consumption of cowpea.

Optimisation of chocolate formulation using dehydrated peanut-cowpea milk to replace dairy milk.

BACKGROUND The rheological properties of chocolate, based upon its acceptability by consumers, are determined largely by the ingredients and their proportions used in the formulations. Milk chocolates are very popular because milk provides flavour and smooth texture to the product. This study aimed to determine the optimal ingredient formulation for vegetable milk chocolate using peanut-cowpea milk as a substitute for dairy milk. The study followed a four-component constrained mixture design, with cocoa liquor, vegetable milk, cocoa butter and sugar as the components. Lecithin and vanillin were added at a constant amount to all formulations. Critical attributes of the chocolates were evaluated using descriptive sensory tests and instrumental techniques. RESULTS Regression models were fitted to the data, and the optimum ingredient formulation for acceptable vegetable milk chocolate was determined. The vegetable milk had significant (P = 0.05) influence on flavour, mouth feel, hardness and after taste of chocolates. CONCLUSIONS The optimum ingredient formulation for acceptable vegetable milk chocolates was determined to be cocoa liquor (18.00%), sugar (30.75%), peanut-cowpea milk (28.93%), and cocoa butter (22.32%). The results demonstrate that it is feasible to use vegetable source milk for chocolate. The findings also provide clues for scale-up criteria for large-scale production of vegetable milk chocolate.

Acceptability of locally produced ready-to-use therapeutic foods in Ethiopia, Ghana, Pakistan and India

Abstract Successful treatment of severe acute malnutrition has been achieved with ready‐to‐use therapeutic food (RUTF), but only 15% of children with severe acute malnutrition receive RUTF. The objective of this study was to determine whether new formulations of RUTF produced using locally available ingredients were acceptable to young children in Ethiopia, Ghana, Pakistan and India. The local RUTFs were formulated using a linear programming tool that allows for inclusion of only local ingredients and minimizes cost. The study consisted of 4 two‐arm, crossover, site‐randomized food acceptability trials to test the acceptability of an alternative RUTF formula compared with the standard peanut‐based RUTF containing powdered milk. Fifty children with moderate wasting in each country were enrolled in the 2‐week study. Acceptability was measured by overall consumption, likeability and adverse effects reported by caregivers. Two of the four RUTFs did not include peanut, and all four used alternative dairy proteins rather than milk. The ingredient cost of all of the RUTFs was about 60% of standard RUTF. In Ethiopia, Ghana and India, the local RUTF was tolerated well without increased reports of rash, diarrhoea or vomiting. Children consumed similar amounts of local RUTF and standard RUTF and preferred them similarly as well. In Pakistan, local RUTF was consumed in similar quantities, but mothers perceived that children did not enjoy it as much as standard RUTF. Our results support the further investigation of these local RUTFs in Ethiopia, Ghana and India in equivalency trials and suggest that local RUTFs may be of lower cost.

Spatial distribution of total phenolic content, enzymatic activities and browning in white yam (Dioscorea rotundata) tubers

Browning in raw and processed yams resulting from enzymes, polyphenol oxidase (PPO) and peroxidase (POD), activities is a major limitation to the industrial utilization of Dioscorea varieties of yams. Two elite cultivars of D. rotundata species were selected to study the spatial distribution of total phenols and enzymes (PPO and POD) activities. The intensities of tissue darkening in fresh yam chips prepared from the tuber sections of cultivars during frozen storage were also studied. Total phenolic content was observed to be highest in the head and mid sections of the cultivars than at the tail end. PPO activity did not have any specific distribution pattern whereas POD activity was found to be more concentrated in the head than in the middle and tail regions. Browning was found to be most intense in the head regions of the two cultivars studied; and was observed to correlate with total phenol and dry matter contents of tubers. Between the two enzymes, POD activity appeared to be more related to browning than PPO.

Formulation of a drinkable peanut-based therapeutic food for malnourished children using plant sources

High ingredient costs continue to hamper local production of therapeutic foods (TFs). Development of formulations without milk, the most expensive ingredient, is one way of reducing cost. This study formulated a ready-to-drink peanut-based TF that matched the nutrient composition of F100 using plant sources. Three least cost formulations namely, A, B and C were designed using computer formulation software with peanuts, beans, sesame, cowpeas and grain amaranth as ingredients. A 100 g portion of the TF provided 101–111 kcal, 5 g protein and 5.3–6.5 g fat. Consumer acceptability hedonic tests showed that the products were liked (extremely and moderately) by 62–65% of mothers. These results suggest that nutrient dense TFs formulated from only plant sources have the potential to be used in the rehabilitation phase of the management of malnourished children after clinical testing.

Soybean-Enriched Snacks Based on African Rice

Snacks were produced by extruding blends of partially-defatted soybean flour with flours from milled or parboiled African-grown rice. The interplay between composition and processing in producing snacks with a satisfactory sensory profile was addressed by e-sensing, and by molecular and rheological approaches. Soybean proteins play a main role in defining the properties of the protein network in the products. At the same content in soybean flour, use of parboiled rice flour increases the snack’s hardness. Electronic nose and electronic tongue discriminated samples containing a higher amount of soybean flour from those with a lower soybean flour content.