Food Science

The major (K, Mg, Cl, Ca and Na) and minor (Mn, Fe, Cr, Co, Cu and Br) elemental concentrations in different parts of Graviola (Annona Muricata) fruit including the fruit fibres, fruit cover, seed, fruit juice and seed cover were determined using instrumental neutron activation analysis. Their concentrations were found to vary in the various fruit parts. The elements Br, Ca, Cl, K, Mg, Mn and Na were recorded in all the various fruit parts. The highest concentrations recorded were K in the fruit cover (1.43±0.03%), fruit fibre (1.46±0.09%), fruit juice (2.28±0.15%) and seed (0.55±0.06%). In the seed cover however, Ca recorded the highest concentration of 0.25±0.02%. Chromium was below the detection limits of INAA in the fruit cover, fruit fibre and fruit juice. Copper and Fe were below detection limits in the fruit juice and seed cover respectively. The presence of Ca, Mg, Na, K, Co, Cr, Cu, Fe, Br, Cl and Mn reflects the function of the Graviola fruit as a source of essential nutrient elements. Therefore, the Graviola fruit becomes important in view of the fact that their regular consumption might help the body to attain the required levels of these essential nutrient elements.

Toxic heavy metal monitoring in the environment and food is a key requirement for protection against the hazards of metal toxicity. The concentrations of heavy metals (Mercury, Copper and Cadmium) and other elements (Vanadium, Magnesium, Manganese, Calcium and Chloride) in cocoa beans from 73 district representing six of the seven cocoa regions for the 2011/2012 light crop year were analyzed using Neutron Activation procedures to look at the distribution of metals, especially heavy metals in the beans meant for export. Certain basic quality parameters such as pH, moisture and percentage fat content were also measured. Analysis of cocoa beans yielded the following results; Calcium (Ca; 2155 -5863, average 3443.20 mg kg?¹) showed the highest concentration, followed by Magnesium (Mg; 2147 to 4601 mg kg?¹, average 3227.02 mg kg?¹) and Aluminium (Al; 32.86 -147.40, average 54.32 mg kg?¹). Manganese (Mn) was also found to range between 19.66 -50.01; average 35.40 mg kg?¹. Vanadium and chloride were on the average 0.20 and 82.37 mg kg?¹ respectively. Amongst the heavy metals analysed, Cadmium (Cd) was in the range of <0.01 and 48.30 µg kg?¹, well below the proposed MRL of 0.6 mg Kg?¹ whereas mercury was below 0.01µg kg?¹, the detection limit of the NAA method used. Copper (Cu) was in the range of 10.04–26.76 mg kg?¹ in the beans analysed. Fat content of the beans were higher than 52.63% with a pH range of 4.52-5.58, typical of Ghana’s cocoa. The results showed that heavy metal concentrations in the beans are generally low with accompanying high quality indicators. Although levels of these heavy metals are very low, a potential danger may emerge in the future depending on the management of soil pollution since soil-to-plant transfer of heavy metals is a major pathway to product pollution.

The food safety processing and evaluation of powdered pap from maize and malted maize with carrot were carried out. The standard operating procedures in flow chart for the processing of fermented maize flour (plain pap), malted maize flour and carrot powder were used. Recipe for the variables and mixing ratios was formulated. 100% fermented maize flour (plain akamu/ pap) was used as control against other variables (fermented maize flour - FMF, carrot powder - CP and malted maize flour -MMF). The variable with the ratio of 85:5:10 (FMF:CP:MMF) tagged “BOB” was found to be the most acceptable. Result showed that sample BOB pulled the following values to emerge the best in ratio composition: consistency (7.9±0.08), colour (8.3±0.41), taste (8.0±0.04), mouthfeel (7.8±0.11), aroma (7.6±0.02) and overall acceptability (8.0±0.06). Microbial assessment showed that counts were high above thresholds for coliforms (1.9 x101 ±0.14 to 2.0 x102 ±0.39 CFU/g), and moderate for aerobic bacteria (4.1 x103 ±0.37 to 3.7 x104 ±0.14 CFU/g) and fungi (1.3 x102 ±0.12 to 3.2 x103 ±0.10 CFU/g). Five (5) bacterial and three fungal isolates were identified to include Lactobacillus species, Bacillus species, Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, and Saccharomyces cerevisiae, Penicillium species and Aspergillus species respectively. From the results obtained, it could be deduced that the problems of sour taste among infants consuming plain pap and malnutrition have been eliminated by blending with malted maize flour and carrot powder. These were achieved through the process of malting and enrichment with carrot powder which is a good source of beta carotene, a precursor of pro-vitamin A.

Thryonomys swinderianus is one of two species of cane rats. This study concerned the evaluation of the lipid profiles of T. swinderianus skin, muscle and liver. SFA (% total fatty acid) was 39.5 (muscle), 41.5 (liver) and 42.4 (skin). MUFA ranged as follows (%): 10.5 (muscle), 14.0 (liver) and 21.0 (skin). The n-6 + n-3 (PUFA) (%) of 49.9 (muscle), 44.4 (liver) and 36.5 (skin) were recorded. MUFA +PUFA predominated in all the samples having (% total fatty acid) 60.4 (muscle), 58.4 (liver) and 57.5 (skin) with respective PUFA/SFA values of 1.26, 1.07 and 0.86. The n-6: n-3 range of 50.0:1 (muscle), 83.2:1 (liver) and 15.1:1 (skin) are in unhealthy ratios. The samples would supply the following values as food source (g/kg): highest in SFA (C18:0) 0.0383 (muscle), 8.43 (skin) but C16:0 in liver (7.84) whilst highest in PUFA (C18:2n-6, trans) 5.41 (skin), 5.29 (skin) but C22:6n-3, cis in muscle (0.0185). The cholesterol level in (g/kg): skin (10.5) and liver (10.5). The highest phospholipid in the samples was phosphatidylcholine. Significant differences existed in skin/muscle, muscle/liver and skin/liver in their fatty acids as well as skin /liver in phospholipids and sterols at r = 0.05.

Nutrient evaluation and acceptability of cookies produced from wheat flour, tiger nut milk and fermented jack fruit seeds (Artocarpus heterophyllus). Jack fruit seeds were removed, sliced and boiled for about 60 minutes. The fermented seed was obtained by adding 3:1 ratio of water to 500g boiled jackfruit seed and were allowed to ferment naturally at room temperate for 48 hours, oven dried at 60? for 1hour, milled and sieved. Date palm fruit was washed and de-seeded. The date palm (with the pericarp) was oven dried at 45? for 8hours, milled and sieved. Tiger nut tubers was cleaned, sorted, washed and soaked overnight and milled. Tiger nut milk was centrifuged for 15mintues and pasteurized at 72? for 15minutes. Four samples were formulated FJWC1 to FJWC4.  Proximate composition of the cookies shows that cookies were higher in moisture, protein, ash (19.70%, 18.97% and 2.99%) for sample FJWC4, crude fibre (2.00%) and carbohydrate (58.82%) in FJWC1 while crude fat (13.44) in FJWC3. Micronutrient composition shows that sample FJWC4 was higher in calcium (48mg/100g), manganese (7250mg/100), iron (54250mg/100g), zinc (32720mg/100g), vitamin A (1180mg/100g) and vitamin C (1840mg/100g) while sample FJWC3 was higher in manganese (60mg/100g) and copper (2520mg/100g). Sample FJWC4 had the best score in all the sensory parameters for the formulated cookies except sample FJWC1 (100% wheat flour). 

Heavy metal (Cd, Sn, Hg and Pb) concentrations of canned fish sold on markets in Accra were determined using Atomic Absorption Spectroscopic (AAS) procedures. Levels of cadmium (Cd), tin (Sn) and lead (Pb) were determined by graphite furnace atomic absorption spectrometry (GF-AAS). Mercury (Hg) content was analysed by the cold vapour atomic absorption spectroscopic technique after Hg ions reduction with SnCl₂ (CV-AAS). The accuracy of the method was determined by use of a certified reference material (DORM-2 (Dogfish muscle).The average contents of heavy metals in canned fish brands were found as 10.03 mg/kg for tin, 0.11 mg/ kg for cadmium, 0.203 mg/kg for lead, and 0.04 mg/kg for mercury. Although these products pose no risk with respect to the concentrations of tin and mercury, some of the samples had contents of lead and cadmium higher than the acceptable limits. Comprehensive and intermittent monitoring of heavy metals in canned fish is needed to assess the safety of these products with respect to human health.

Residual levels of organophosphorous pesticides were determined in 44 fermented and dried cocoa beans samples collected from two cocoa beans storage warehouses located in Tema and Takoradi; cities in Ghana from November 2010 to January 2011. The main objective of the study was to monitor and assess the residue levels of 13 organophosphorous pesticides in fermented and dried cocoa beans produced from Ghana. The extraction method uses acetonitrile as the extracting solvent. Two solid phase extraction clean-up cartridges were employed; bond elut C18 cartridge, followed by envi-carp/LC-NH2 superclean cartridge; using acetonitrile and a mixture of toluene/acetonitrile in the ratio 1:3 as eluting solvents, respectively. The determination was done using gas chromatography with pulse flame photometric detector (GC-PFPD). The targeted compounds were methamidophos, ethoprophos, phorate, fonofos, diazinon, dimethoate, pirimiphos-methyl, chlorpyrifos, malathion, fenitrothion, parathion, chlorfenvinphos and profenofos. The percentage recoveries ranged from 70-95 percent, with instrumental method determination limit of 5.0 ?g/kg. The results indicated that ethoprophos is not being used in cocoa production in Ghana. However, there were appreciable amounts of Dimethoate (22.3 µg/kg), Pirimiphos-methyl (29.5 µg/kg), Malathion (20.6 µg/kg), Chlorpyrifos (50.2 µg/kg) and Fenitrothion (93.8 µg/kg). These notwithstanding, residue levels of all organophosphorous pesticides detected were below both the EU and Japanese maximum residue limits; with the exception of Methamidophos, Chlorpyrifos, Malathion and Profenofos which average residue values were comparable with either one of the two international maximum residue limits set.

Age effect, intestinal site and pH influence on phytate hydrolysis were assayed in brush border membrane vesicles isolated from chicks and layers proximal and distal intestinal segments using MgCl2 precipitation and differential centrifugation. The ascertained BBMVs purity and functional integrity depicted alkaline phosphatase enzyme marker to range between 20-fold to 37-fold greater for chicks’ and layers’ proximal and distal BBMVs than in their mucosal homogenates, their integrity suggestive to presence of Na+-dependent transport while electron micrograph showed a vesicular form. Both chicks’ and layers’ BBMVs, had significant decrease in phytate-P hydrolysed/mg.

Graviola, Annona Muricata, leaves is known for its efficacy in the treatment and management of complex disorders in man. Most research work available however targets on their organic contents, viz. essential oils, glycosides, vitamins, alkaloids and other active components. This research work aimed at investigating their elemental composition which is most often overlooked, though they play important roles in the fight against diseases. In order to determine the presence of these elements, even at trace levels, and to minimize chemical contamination during sample preparation, the sensitive analytical technique (which is free from the use of chemicals), instrumental neutron activation analysis (INAA) was used. Potassium, Ca, Cl, Mg, Fe, Na, Br, Mn, Cu, Cr and Co were present in the leaves at detectable concentrations. The concentrations of the elements Cu, Fe and Mn were found to be below their tolerable upper intake levels. The presence of these elements in the leaves of Annona Muricata indicates its potential for use in medicinal preparations for the management and treatment of certain diseases.

Anaemia is a nutritional problem affecting all segments of the population in general and children, woman & pregnant woman in particular. In the latter groups, prevalence of anaemia may be as high as 60 – 70 per cent. Anaemia in our country is essentially due to iron deficiency although in children, woman & pregnant woman, folate deficiency also plays a part. Although our diets contain fairly good amount of iron, its absorption is very poor (2- 3 per cent).9 Micronutrient malnutrition commonly referred as “Hidden Hunger”, causes learning disabilities, impaired work capacity, illness & ultimately death. Forty per cent of the world suffers from iron deficiency.