ABSTRACT
Aims: To evaluate the effect of packaging materials and storage temperatures on the microbiological quality of Hibiscus sabdarifa drinks produced with: 1) commercial pineapple flavour (HCPF) and; 2) Phoenix dactylifera (38%) and pineapple extract (2%) (HPPE). Methodology: Pasteurized drinks packaged in polyethylene sachets, plastic and glass bottles were stored at refrigeration (4.4±2oC) and ambient (25±2oC) temperatures for 27 and 9 days respectively. Results: There was significant (P≤0.05) decrease in total bacterial count in HCPF (≤4.51-≥2.14 Log10CFU/ml) with higher death rate (0.06) in plastic bottles at 4.4±2oC while at 25±2oC it increased significantly (P≤0.05) in HPPE samples (4.00-≤4.95 Log10CFU/ml) with least growth rate in plastic bottles (0.02). Yeast count at 25±2oC (1.28 – 2.15 Log10CFU/ml) was significantly (P≤0.05) higher than at 4.4±2oC (1.00 – 1.60 Log10CFU/ml) and drinks in plastic bottles had the least growth rates (≤0.03). Coliform (2.04 – 2.59 Log10CFU/ml), Escherichia coli (2.00 – 2.93 Log10CFU/ml) and Staphylococcus (2.00 – 2.50 Log10CFU/ml) sparingly detected, were unable to grow in the drinks with greater inhibition at 25±2oC in all packaging materials. No growth of Salmonella was observed in the drinks. Glass bottles favoured more microbial growth but the levels were satisfactory for all packaging which is indicative of microbiological safety. Conclusion: Any of the packaging material can be used for packaging of Hibiscus sabdarifa drinks with storage at refrigeration temperature for ≤ 21 days. It is informative to both consumers and producers that the then wasted pineapple peels can serve as an ingredient in Hibiscus sabdarifa drink production.
ABSTRACT
Objective: To investigate the ability of the methanolic extract of pineapple peel to modulate alcohol-induced lipid peroxidation, changes in catalase activities and hepatic biochemical marker levels in blood plasma. Methods: Oxidative stress was induced by oral administration of ethanol (20% w/v) at a dosage of 5 mL/kg bw in rats. After 28 days of treatment, the rats were fasted overnight and sacrificed by cervical dislocation. Blood was collected with a 2 mL syringe by cardiac puncture and was centrifuged at 3000 rpm for 10 min. The plasma was analyzed to evaluate malondialdehyde (MDA), catalase activity, aspartate aminotransferase (AST), alkaline phosphatase (ALP) and alanine aminotransferase (ALT) concentrations. Results: Administration of alcohol caused a drastic increase (87.74%) in MDA level compared with the control. Pineapple peel extract significantly reduced the MDA level by 60.16% at 2.5 mL/kg bw. Rats fed alcohol only had the highest catalase activity, treatment with pineapple peel extract at 2.5 mL/kg bw however, reduced the activity. Increased AST, ALP and ALT activities were observed in rats fed alcohol only respectively, treatment with pineapple peel extract drastically reduced their activities. Conclusions: The positive modulation of lipid peroxidation, catalase activities as well as hepatic biomarker levels of blood plasma by the methanolic extract of pineapple peels under alcohol-induced oxidative stress is an indication of its protective ability in the management of alcohol-induced toxicity.