Employing differential privacy for big data security

Big data frequently contains huge amounts of personal identifiable information and therefore the protection of user’s privacy becomes a challenge. Lots of researches had been carried out on securing big data, but still limited in efficient privacy management and data sensitivity. This paper designs a mechanism that employs Differential Privacy for protection of personal data, which enforces privacy and access restriction level. The Differential Privacy technique acts on the request by introducing a minimum distortion to the information provided by the database system. The mechanism, DP-Data was implemented with Python scripting and Java Programming languages, Mysql and VmWare on Apache Hadoop platform. To test the effectiveness of DP-Data, a medical dataset with 1,048,576 instances and 12 attributes was employed. It was evaluated based on its utility, scalability, accuracy, sensitivity, specificity and processing time. The results indicated accuracy of 95.80 %, sensitivity of 93.60 %, specificity of 98.00 % and 0.40 ms processing time with high utility and good scalability which shows that the time it takes to preserve a data of 5000 tuples or less are almost similar. From these results, the application of differential privacy in solving privacy issue proved a high level of efficiency. Hence, the deployment of a secure big data framework that is based on access restriction and preserved level of privacy poses a higher level of protection of user’s privacy in comparison with other techniques.Keywords: Big Data, Privacy Preservation, Differential Privac

Microbial quality of raw and ready to eat eggs from open markets and hawkers in Nigeria

In Nigeria, the eggs sold to the public are exposed to high storage temperature, without any indication of best buy dates. There is therefore a need to evaluate the microbial quality of eggs sold to the public. Forty-five pieces of raw and 15 pieces of boiled eggs were randomly procured from 9 vendors, in three open markets and motor parks. Samples were divided into batches containing 15 eggs each. For the microbial load of shell, the sample making a batch was washed in water and rinse water serially diluted and plated. The egg content for each batch was pooled, serially diluted and plated. Other biochemical evaluation methods for microbial identification were performed. All the raw (shell and contents) samples were positive for microbial growth on the agar plates. Total viable count ranged from 1.5 x 105 to 1.0 x 108 CFU/ml and 5.3 x 104 to 1.1 x 107 CFU/ml for egg shell and content respectively. Enterobacteriaceae count ranged from 3.3 x 105 to 1.0 x 107 CFU/ml. Boiled egg shell had high Salmonella-Shigella 1.2 x 107CFU/ml count. Isolates from the raw samples included: Proteus spp, Escherichia coli, Staphylococcus spp, Streptococcus spp, Pseudomonas aeruginosa, Salmonella spp, Aspergillus and Penicillium spp. Isolates from the RTE eggs were Enterococcus fecalis, Serratia spp, Salmonella spp, Shigella spp and Staphylococcusspp. Eggs are contaminated with diverse microorganisms, therefore consumption of raw egg should be discouraged. Street vendors or hawkers need to be educated on safe food handling techniques.Keywords: Eggs, hawked, eggs, RTE, food-hazar

Quality assessment of selected drinkable yoghurt brands sold in Iwo, Osun State, Nigeria

Background: Yoghurt is increasingly becoming a popular snack among children, adults and the elderly in Nigeria because of the ease of consumption and digestion. During local fermentation process of milk to produce yoghurt, there are conditions that encourage contamination and unintended adulteration of the yoghurt.Objective: This study examined the quality of four drinkable yoghurt brands (coded LVY, DDY, FPY and FYY) sold in Iwo metropolis in Nigeria.Methods: Four different drinkable yoghurt samples in plastic bottles displayed for sale at temperature of 22 - 36 0C were randomly purchased. Physicochemical, proximate; and microbial qualities of the yoghurts were analyzed using standard methods. The data obtained were subjected to statistical analysis.Results: All the yoghurt samples exceeded 2 months of storage. The pH of ranged from 3.31- 4.23 total titratable acidity 0.28 - 0.88 % and total soluble solids 18.9-38.9%. The fat content ranged from 2.97±0.01 to 9.85±0.01 %; protein 1.37±0.11 to 3.19±0.2 %; moisture 57.4±4.7 to 84.1±2.7 % and ash 0.18±0.02 to 0.43±0.0 %. Fibre was not detected in the samples. The microbial analysis indicated that the FPY had the highest total viable count of 2.7±0.1×106 CFU/ml and staphylococcal of 1.4±0.2×105 CFU/ml counts; the DDY had the highest enteric bacteria of 2.1±0.2×106 CFU/ml; the LVY the highest yeast and mold of 2.6±0.3×106 CFU/ml and lactic acid bacteria (4.5±0.4×105 CFU/ml) counts. Bacterial species isolated included Lactobacillus spp., Proteus spp., Enterococcus faecalis and two fungal species.Conclusion: The physicochemical and proximate quality of yoghurts analyzed were within international standards but showed high microbial contamination.Keywords: Yoghurt, local production, quality, microbial loa

Towards the development of shelf stable ‘iru’ (Parkia biglobosa) condiment bouillon cubes using corn, cassava and potato starch extracts as binders

AbstractAfrican locust bean (Parkia biglobosa), fermented into “iru” or “dadawa” is a nutritious condiment featured frequently in the diet of people of Nigeria and other West African countries. Many consumers benefit from the nutrients, and enjoy the aroma of fermented locust bean seed in their foods. However, some dislike seeing the locust beans and would pick them out of their meals depriving themselves of the nutrients. The availability of iru as fermented, ground and shelf stable bouillon cube may increase the acceptability of this condiment. The objective was to develop a shelf stable iru bouillon with starches as binders. Fermented, dried and ground locust bean with binders were prepared in the ratio of 40:10 and 30:20 locust bean:binder and cubed. Microbial and proximate analyses of the cubes were carried out. Bacillus spp., Lactobacillus spp., and Staphylococcus spp. were isolated following bouillon cube production. Cassava starch bouillons had the highest moisture content (24.5% and 29.3%). Bouillons with corn starch had the highest amount of fat (22.0%), followed by cassava starch (19.6%), while bouillon cubes with potato binder had the highest crude protein content (33.9%). Iru without binders had the lowest moisture (11.5%) and ash (1.7%), the highest crude fat (30.0%) and the highest crude protein (46.3%) contents. Only Bacillus subtilis was isolated from all the samples after 9 months of storage, indicating that shelf stable iru bouillon cubes is possible, without chemical preservatives. Conclusively, iru bouillon cubes with binders improved the shelf life from few days to over nine months without compromising the safety of the product

Effect of hydrocolloids (xanthan or gelatin) on the quality of plantain-soy-wheat composite bread

The focus of this study was to investigate the effects of hydrocolloids (xanthan or gelatin) on composite bread from plantain, defatted soy and wheat. Four bread samples were produced from plantain/wheat /soy /gum: (B), 40:40:20+xanthan (C), 40:40:20+gelatin (D), 40:40:20 + no gum and (A), 100% wheat flour (control). Microbial quality and functional properties of the flour blends were analysed. Bread characteristics, proximate and sensory evaluation were also performed, using standard methods, in order to assess the effect of hydrocolloid on the breads. The results show that all the dry ingredients were contaminated; composite flour with xanthan gum had the highest water absorption capacity (386.7%). Composite flour without hydrocolloid had the highest oil absorption capacity (110.0%); protein (11.6 – 17.2 %), fibre (0.47 – 0.58%) and ash (2.03 – 3.54%) contents increased in the composite bread but fat content (0.76 – 3.98%) reduced. Bread with xanthan had higher loaf volume, oven spring and specific loaf volume compared with bread with gelatin and without gum. Consumers preferred bread with xanthan gum to bread with gelatin. In conclusion, the bread produced using plantain and soy flours to substitute wheat is more nutritious because of the high protein and reduced fat contents. Furthermore, inclusion of xanthan gum could be an effective means of improving the quality of reduced gluten bread.Keywords: Hydrocolloids, gum, plantain flour, defatted soy flour, composite brea