Food Science

The monitoring of toxic heavy metals in fish is essential for protecting public health against the hazards of metal toxicity. The concentrations of metals (Hg, Pb and Cd), in different fish species were analyzed using Atomic Absorption Spectroscopic (AAS) procedures. The objective of this study was to look at the distribution of heavy metals in different species of fish on Ghanaian markets. Levels of cadmium (Cd) 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). Amongst the metals analysed, Lead (Pb; 0.1-0.49, average 0.24 mg/kg) showed the highest concentration, followed Mercury (Hg; 0.01-0.37, average 0.073mg/kg) and Cadmium (Cd; 0.06-0.11, average 0.084 mg/kg).  Amongst the species analysed, tuna had high lead concentrations with lobsters having the lowest concentration of lead. With respect to Hg contamination, shark specimen had the highest with cephalopods and octopus having the least Hg concentrations. Levels of cadmium in the examined species averaged from 0.06 mg/kg for octopus to 0.11 mg/kg for tuna. The study revealed that the studied metals concentrations were generally low in species of fish in the two study areas. Although the levels of these heavy metals are not high, a potential danger may emerge in the future depending on pollution sources and frequency of exposure.

Two essential oils bearing plants (Eucalyptus camadulensis and Eucalyptus citriodora leaves) were investigated for their nutraceutical properties. Results showed the percentage proximate composition of E.citriodora and E. camadulensis as ; moisture (4.32 and 4.11), ash (2.26 and 4.15), crude fibre (16.74 and 16.55), crude fat (3.87 and 3.96), crude protein (5.26 and 7.13), and carbohydrate (84.29 and 80.64), respectively while the level of the mineral elements are; potassium (1.42 % and 1.53 %), calcium (2.72 % and 2.5 %), manganese (0.24 ppm and 0.26 ppm), iron (0.81 ppm and 0.42 ppm) and copper (0.03 ppm and 0.034 ppm). Nickel and Zinc were not detected in E.citriodora but present in E.camadulensis (0.003 ppm, 0.05 ppm) respectively. The samples fixed oils were analyzed for fatty acid concentration by gas chromatography. The percentage saturation, monounsaturation and polyunsaturation of E. citriodora are; 40.85, 37.79, 21.36 while that of E.camadulensis are; 41.83, 36.35, 21.20 respectively. The fatty acid composition of the two species contains a healthy mixture of all the types of fatty acids.

Shea butter is a vegetable fat of nutritional importance. This research work investigated on some minerals, vitamins, phytate and oxalate profiles of shea butters from fried, toasted, boiled and parboiled shea kernels. Minerals, vitamins and phytate and oxalate profiles of the shea butters were determined using standard methods. The method of heat treatment significantly influenced their distribution. Shea butters are minor sources of calcium (2.2×10-3 to 9.5×10-3mg/kg), magnesium (0.8×10-3 to7.9×10-3mg/kg), sodium (0.1×10-3 to 2.4×10-3mg/kg) and potassium (0.9×10-3 to 3.3×10-3mg/kg). The heat treatment methods did not destroy phytates and oxalates of shea butter. The shea butters have good arrays of vitamins.

Cookies are one of the best known quick snack products. Cookies play important role in human diet since these contain naturally high amounts of valuable nutrients like soluble fibers, carbohydrates, proteins, unsaturated fatty acids, vitamins, minerals, etc. In the present study, the cookies samples were analyzed for their physicochemical properties, proximate composition and microbial load and were compared with each other. The results revealed that there was significant difference in the proximate composition between the samples with respect to each other at p>0.05. No significant difference was observed in most of the determined physicochemical properties of the samples. Moreover, the microbial load of the samples was found to be in acceptable range. Hence the study ascertains that the sensory qualities may be similar as there was very slight change in the physicochemical characteristic and which are acceptable for everyone.

Herbal preparation of Butea monosperma (Lam.) Taub. bark had been considered as effective, economical and safe ethnomedicine for various ailments in Indian traditional system of medicine. The present study was aimed to investigate scientifically the antidiabetic potential of B. monosperma bark. Both kinds diabetes; insulin dependent diabetes mellitus (IDDM) and non insulin dependent diabetes mellitus (NIDDM) were induced in the rats by treating with alloxan monohydrate (150 mg/kg b wt ;ip) and hydrocortisone (5mg/100g b wt; ip) respectively. Fasting plasma glucose (FPG) levels were measured at periodic intervals during the test period. The blood samples were collected with care sino-ocular puncture method and serum was isolated by centrifugation to analyze plasma glucose and serum lipid profile. The results of preliminary phytochemical analysis depicts that B monosperma bark has the presence of steroids and tannins and absence of terpenoids, glycosides, alkaloids and flavonoids. The moisture content and total ash values of bark was 3.0%and 9.7% respectively. The treatment with bark aqueous extract of B monosperma substantially declined the plasma glucose level in both IDDM and NIDDM animal subjects by 7.2% and 26.6% respectively. This treatment also appreciably (P= 0.05 and P=0.01) lowered the serum lipid profile. In conclusion, the aqueous extract of Butea monosperma reflected hypoglycemic and hypocholesterolemic potential through glucose and lipid profile lowering activity in experimental animals. It supported the folklore state of antidiabetic potential of the plant.

The mango plays an important part in the diet and cuisine of many diverse cultures. During the processing of ripe mango, the waste (peel and seed) is a problem. As seed kernel is not currently utilized for any commercial purposes, it is discarded as a waste and becomes a source of pollution. This waste should be treated as a specialized residue due to the high levels of phenol compounds and stable fat rich in saturated fatty acids. Hence the investigator incorporated MKP in sponge cakes in order to utilize the health benefits from it. The physico chemical properties were comparatively favorable than the unincorporated sponge cakes, which may favour extension of shelf life in sponge cakes. The sensory scores for acceptability of incorporated sponge cake were found higher with MKP upto 20g than the other incorporations.

Recently, the focus of scientific investigations has moved from the primary role of food as the source of energy and body-forming substances to the more subtle action of biologically active food components on human health. There has been an explosion of consumer interest in the active role of food in the well-being and life prolongation, as well as in the prevention of initiation, promotion, and development of non-transmissible chronic diseases. As a result, a new term—functional food—was proposed. Among these foods, probiotics exert positive effects on the composition of gut micro biota and overall health, and the market is increasing annually. In the current study the probiotic bacterium Lactobacillus acidophilus was encapsulated in microcapsules of sodium alginate. These encapsulated microbes were used in the fermentation and production of curd with high nutritional values. On comparing the curd fermented with microencapsulated bacterium with that of the non-encapsulated forms (traditional fermentation technique) it was found out that there was a considerable reduction in the fat content of the sample prepared with the microencapsulated form (2.20 gm) to the non-encapsulated organisms (3.90 gm). The protein and the vitamin-C content were found to be more or less the same in both the cases. The iron content of the sample prepared with microencapsulated form was found to be 7.2 gm to 3 gm of iron content for the sample produced through non-encapsulated bacterium. It was found out that the curd fermented through the microencapsulated L. acidophilus was found to be nutritionally rich and that the organism could also act survive as a probiotic in the gut in the presence of a protective microencapsulation.

The study was carried out to investigate the bacteriological status of freshly sliced water melon in mile III market Port Harcourt. A total of 20 sliced water melons was collected while one whole water melon collected was used as control in this study. The control sample was properly washed with sterile water and sliced aseptically. A sterile knife was used to cut 1.0g from each water melon sample and homogenized on a sterile mortar and pestle. The resultant homogenate was pipette (1.0ml) into 9.0ml of distilled water and serially diluted. The 104 dilution was plated out on Nutrient and MacConkey agar plates respectively using spread plate technique. The plates were incubated at 370c for 24 hours. The cultured plates were examined for colony growth and identification of isolates. The result showed that bacteria isolated from the sliced water melon were Staphylococcus aureus, Escherichia coli , Bacillus spp and Proteus with percentage bacterial count of 414 (45.8%). 324 (35.5%), 144 (15.8%), and 30 (3.3%.) respectively. The control sample showed a scanty growth of staphylococcus aurus. In conclusion, since the control had only a colony of staphylococcus on culture plate after it has been hygienically processed, contamination of the sliced water melon maybe due to poor sanitary condition employed by the vendors during processing and packaging. This is of public health concern as these organisms are known causes of food born diseases and food poisoning.

The nutrient and phytochemical constituents of four eggplant cultivars (Solanum. marcrocarpon (round), Solanum aetheopicum, Solanum Marcrocapon (oval), Solanum gilo) were evaluated by standard procedures. The moisture content in the cultivars was high ranging from 88.31±0.023–91.94±0.11% while the protein, ash, energy and fat content were low. There were significant differences (P<0.05) in the moisture, fiber and ash contents among the cultivars. The K+ content of all the cultivars was higher than other elements analyzed ranging from 821.00±13.10 to 764.00±10.00mg/100g. Na+, Ca2+ and Cu2+ were higher in S. gilo while S. aetheopicum had the lowest concentrations in all the elements analyzed except Na+ and Ca2+. The concentrations of alkaloids, tannins and saponins were very high. S. marcrocarpon (round) cultivar had the least values for both alkaloids and tannins while S. Macrocarpon (oval) and S. gilo had the highest concentrations of both phytochemicals. S. marcrocarpon (round) eggplant had the highest concentration of flavonoid (16.88±0.08mg/100g), S. aetheopicum (12.53±0.03mg/100g), S. gilo 12.87±0.06mg/100g and S. marcrocarpon (oval) (16.22±0.06 mg/100g). The results revealed that eggplants have rich mineral content and various important of phytochemicals which may account for their medicinal properties acclaimed. Thus, they could be valuable raw material for health and pharmaceutical industries.

The flesh, seed, placenta and the whole fruit samples of a variety of tropical chillies (peppers) commonly found in Nigeria Capsicum annum L (bell pepper), were examined in the laboratory for their proximate compositions and some nutritionally valuable minerals on wet weight basis. The results showed that the seeds have the highest concentrations of ash (2.06 g/100 g), protein (14.1 g/100 g) and fibre (32.4 g/100 g), flesh had the highest concentration of crude fat (6.66 g/100 g) while the placenta had the highest concentrations of moisture (88.2 g/100 g) and carbohydrate (3.35 g/100 g). The seeds were also the best sources of most of the nutritionally valuable minerals (Ca, Mg, Zn, P, Fe, K and Na) determined. These parameters were good in the samples: Ca/P, Ca/Mg and [K/(Ca +Mg)] but Na/K was poor. In the mineral safety index (MSI), only Zn results were seriously aggravated. Bell pepper would serve as a good source of the following minerals: Ca, Mg, Zn and Fe which are important components of bones and supporting tissue, enzymes and blood formation respectively.