This review covers the meaning, reasons, mechanisms, types and effectiveness of hurdles, cost implications, merits and the future of hurdle technology. Hurdle technology is a smart, effective, efficient and intelligent combination of preservation techniques to achieve microbial safety and stability of foods as well as to retain their organoleptic and nutritional quality, together with the economic viability of food products. Mechanisms of hurdle technology through which it destroys micro-organisms include homeostasis, metabolic exhaustion (auto-sterilization), stress reaction and multi-target preservation. The types of hurdles include physical, physico-chemical, microbial and emerging/novel hurdles and their combined application give rise to hurdle effects like microbial safety, nutritional and organoleptic quality retention of food. More importantly, the intelligent use and effective combination of some hurdles like pulsedelectric field, thermal process/heat, ozone, pressure, uv-light, microwave, gamma irradiation and electrolyzed water is very important in achieving optimal results in terms of microbial inactivation, sensory and nutritional quality of food products. Hurdle technology offers better promise in inactivating target microorganisms, food shelf life extension, quality retention and reduction of undesired effects than the conventional food preservation methods. The present contribution reviews recent researches on shelf life extension of foods using hurdle technology with special attention on the combined hurdles and microbial log reduction. Keywords: Preservation, hurdle, hurdle technology, microbial, thermal.
This study was mainly carried out to assess the quality of street vended ‘Pito’ in some selected markets in Ibadan, Oyo State. The safety of street vending practices was also assessed. The chemical (proximate and physicochemical composition), microbiological and observational check list of eight street vended ‘Pito’ samples collected from four markets (Agbeni, Ogunpa, Beere and Bodija) in Ibadan, Oyo state were investigated. The result showed that street vended ‘Pito’ is significantly (p<0.05) high in moisture, low in protein, ash, fat and carbohydrate. Total coliform, Salmonella spp and Shigella spp were within specification limits of microbiological quality while total viable count (TVC) and total fungi were above the limits. Significant (p<0.05) differences exist among the samples in their chemical composition, microbiological and colour parameters. Keywords: Microbial quality, street vended, ‘pito’ , sorghum based beverage, hygiene practice.
Tomato (Solanum lycopersicon L) fruit is rich in nutrient and antioxidant properties. Drying accelerates some reactions that adversely affect the product quality especially nutritional value. Optimization of the drying process for Eva tomato was conducted to obtain a powder with high nutritional value and functional properties. The physical, chemical and microbiological properties of fresh Eva tomato fruit were determined. Central composite design of response surface methodology was used to obtain 13 combinations of drying temperature (60-70 ° C) and drying time (12-18 h). Tomato powder samples from the experimental runs were analyzed for chemical, functional and antioxidant properties using standard laboratory procedures. Tomato powder dried at optimum drying conditions were stored in low density polyethylene (LDPE) and laminated aluminum foil (LAF)] for three months at room temperature (28±2 °C) and analyzed for selected properties. Optimum tomato powder was obtained at 66.32 °C for 16 h and characterized by moisture (9.91%), lycopene (45.67 mg/100 g), vitamin C (15.23 mg/100 g), and redness (53.46) among other properties. Generally, an increase in the drying temperature and drying time caused a decrease in moisture content, β-carotene, pH, and bulk density while ash, total soluble solid, total titratable acidity, ascorbic acid, lycopene, non-enzymatic browning, total phenol, antioxidant activity, scavenging activity, bulk density, water absorption capacity and solubility content increased. Optimized powder stored in LAF had better properties. Keywords: Tomato, drying, optimization, food quality.
The effects of processing (boiling and roasting) on the bioactive components of African walnut extracts using gas chromatography mass spectroscopy (GC-MS) was investigated. The dried powder of the raw, boiled and roasted African walnuts was extracted using n-hexane. All the prepared extracts were analyzed by GC-MS to identify and characterize the volatile compounds present in the crude extracts. GC-MS results revealed the presence of 13, 13 and 16 volatile compounds in raw, boiled and roasted extracts respectively. The most prevailing compounds were 9,12,15-octadecatrienoic acid, (Z,Z,Z)- (67.61%) in raw extract, 9,12,15-otadecatrienoic acid, (Z, Z,Z)- (30.33%) in boiled extract and Ethyl 9,12,15-octadecatrienoate (54.04%) in roasted extract. The results show that processing, particularly roasting, has effects on the bioactive components of the African walnut extracts. However, the extracts of the raw and boiled African walnut possess major bioactive compounds and further identification of different biologically active compounds in the roasted extracts could be studied. Keywords: Extraction, bioactive compounds, African walnut, GC-MS, volatile.
Milk is vitally important for young animals and has great nutritional value. This study aims to detect MecA gene in the S. aureus isolated from Nono.Three hundred and eighty-four (384) milk samples (Nono and yoghurt) were purchased from different selling points and were evaluated for the occurrence of S. aureus .Of the 384 samples examined, 104 (27.1%) samples were contaminated with S. aureus. The antibacterial susceptibility testing of the isolates of S. aureus examined showed sensitivity to Oxacillin (100%), Tetacycline (23.3%), Cefoxitin (18.6%), Clindamycin (23.3%), Erythromycin 1(2.3%), Vancomycin 1(2.3%), and Chloramphenicol 1 (2.3%). Staphylococcal enterotoxin investigation was carried out, 19 of the isolates were found to produce one or more staphylococcal enterotoxin. All the isolates were susceptible to Ciprofloxacin. Most of the isolates tested exhibited multiple antibiotic resistances. Only one of the isolates was genotypically confirmed as MRSA and MecA positive. This calls for a better control of the spread of the antibiotic resistant strains and the contamination of milk sources. There should be proper pasteurization of raw milk and proper hygienic handling to help eliminate MRSA before human consumption. Keywords: MecA Gene, Staphylococcus aureus, antibiotic resistance, milk, enterotoxin.
