Effect of Packaging Materials and Storage Temperatures on the Microbiological Quality of Hibiscus sabdarifa Drinks during Ambient and Refrigeration Storage

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.

Microbiological quality and antibiotics sensitivity of potential pathogens from roasted groundnuts sold in Rivers State University and its environs

“…Serial dilution to enumeration was carried out as described by Obinna-Echem and Cookey, [17] while the method by Harrigan [18] was followed during isolation and characterization. Antibiotic sensitivity test was as described by Barber et al [19].…”

“…This was carried out as described by Obinna-Echem and Cookey, [17]. Serial dilution for each sample was prepared by homogenizing 10 g of the sample with 90 mL of sterile peptone water.…”

“…Following the method described by Obinna-Echem and Cookey, [17], aliquots (100 uL) of appropriate dilutions: 10 -5 for Nutrient agar (NA), 10 -2 for Eosin methylene blue agar (EMB), Salmonella Shigellla agar (SSA), MacConkey agar (MCA) and Mannitol salt agar (MSA), and 10 -1 for Potato dextrose agar (PDA), and Sabaroud dextrose agar (SDA) were plated on appropriate microbial medium for each microorganism. Total aerobic bacteria, coliform, Escherichia coli and Salmonella were respectively, enumerated on NA, MCA, EMB and SSA.…”

“…After incubation, visible colonies were counted and the microbial numbers calculated as CFU/g = (Number of colonies X Dilution factor)/Volume of inoculum. Values obtained were converted to Log10 CFU/g [17].…”

Utilization of Tigernut Milk in Yoghurt Production: Physicochemical Properties and Growth of Lactobacillus bulgaricus and Streptococcus thermophiles in Tigernut Yoghurt

“…The milk is very popular in Nigeria and some studies have established the quality and effect of packaging on tigernut milk (Obinna-Echem and Torporo, 2018, Obinna-Echem, et al, 2019aand 2019b. The milk has a very short shelf-life (48 h) due to its low acidity and rich nutrient content that supports microbial growth.…”