Effect of Smoking Method on Quality Attributes of Traditional Smoked Silver Catfish (Chrysichthys Nigrodigitatus) from Lagos State, Nigeria

Effect of smoking methods on quality and safety of traditional smoked silver catfish from Lagos State, Nigeria was carried out with a focus on investigating the quality indices of traditional smoked silver catfish in twenty different fish processing centres.  Fresh unsmoked silver catfish and smoked silver catfish samples were collected from different processing centres and and control samples were smoked with convectional smoke kiln. Proximate and quality analyses revealed that moisture content of fresh unsmoked silver catfish samples ranged from 71.66% – 74.92% and that of smoked silver catfish samples and control samples ranged from 11.18% - 14.77% and 8.48% – 10.43% respectively. Protein content of fresh unsmoked silver catfish samples ranged from 15.70% – 17.96% and that of smoked silver catfish samples and control samples ranged from 52.96% – 58.36% and 56.81% – 61.42%. Fat content of fresh unsmoked silver catfish samples ranged from 7.58% – 9.86% and that of smoked silver catfish samples and control samples ranged from 16.52% – 20.41% and 17.52% – 20.57%. The pH value of fresh unsmoked silver catfish samples ranged from 6.78 – 7.42 and that of smoked silver catfish samples and control samples ranged from 6.27 – 6.73 and 6.51 – 6.86. The TBA values of fresh unsmoked silver catfish samples ranged from 0.90 - 1.18mgMol/kg and that of smoked silver catfish samples and control samples ranged from 1.01 - 1.15mgMol/kg and 1.00 – 1.12 mgMol/kg. The TVB-N of fresh unsmoked silver catfish samples ranged from 13.15 - 15.40mgN/kg and that of smoked silver catfish samples and control samples ranged from 17.59 - 19.69mgN/kg and 15.63 - 17.86mgN/kg. The TMA of fresh unsmoked silver catfish samples was 2.04 – 2.61mgN/kg and 2.36 – 2.96mgN/kg and 2.11 – 2.72mgN/kg for smoked silver catfish samples. This study revealed PV of 6.13 – 8.85 mgEq.peroxide/kg for fresh unsmoked silver catfish samples and 8.24 - 9.39mgEq.peroxide/kg and 7.13 - 8.67mgEq.peroxide/kg for smoked silver catfish samples. FFA of fresh unsmoked silver catfish samples was 1.00 – 1.16% while that of smoked silver catfish samples ranged from 1.03 – 1.26% and 1.00 – 1.24%. Convention smoke kiln (used for control samples) did not significantly affect pH and composition of smoked silver catfish. The study concluded that smoking method affect quality as convention smoke kiln significantly reduced the moisture content of smoked silver catfish and the quality indices such as FFA, TBA and PV. Keywords: silver catfish, smoking, traditional, quality, smoking metho

Bio-preservative activities of Lactobacillus plantarum strains in fermenting Casssava ‘fufu’

The growth of three pathogens, namely Escherichia coli, Staphylococcus aureus and Salmonella typhii were investigated in fermenting and non-fermenting cassava. The pH of the steeped cassava was also examined during fermentation. Antimicrobial effects of the Lactobacillus plantarum on the pathogens were also determined by agar diffusion method. All the pathogens were inhibited by L. plantarum strains with Staph. aureus having the highest inhibitory zone followed by E. coli and S. thyphii. However, in the fermenting cassava, the pathogens increased in population within the first 36 h of the process and decreased to complete extinction after the 96 h of fermentation. The L. plantarum exhibited high but varying degree of inhibition on the pathogens. The findings justify the bio-preservative roles of lactic acid bacteria in traditional cassava products.Key words: Bio-preservation, Lactobacillus plantarum, fermentation, cassava and pathogens

Adsorption isotherms and thermodynamics properties of water yam flour

Adsorption isotherms of water yam flour were determined by static gravimetric method of saturated salt solutions in the range of water activities between 0.11 and 0.96 and at temperatures of 25, 35 and 45 °C. The experimental sorption data was fitted to five models: Guggenheim-Anderson-De Boer (GAB), Peleg, Iglesias-Chirife, Exponential and Oswin and the differential enthalpy and entropies were determined. Equilibrium moisture contents decreased with increase in temperature at all the water activities studied. Peleg model gave the best fit for the sorption isotherm of water yam flour. Monolayer moisture content values estimated from the GAB-model were found to decrease with increases in temperature. The differential enthalpy and entropy decreased with increases in moisture content. The isokinetic temperature was 371.32 K and the compensation theory was satisfied

Optimization of some processing parameters and quality attributes of fried snacks from blends of wheat flour and brewers' spent cassava flour

The effect of some processing parameters (frying temperature [140–160°C], frying time [2–4 min], level of brewers' spent cassava flour (BSCF) [20–40%], and thickness [2–4 mm]) on some quality attributes of wheat-BSCF fried snack was investigated. Response surface methodology based on Box–Behnken design was used to optimize the effect of process parameters on product quality. Sensory evaluation of the optimized sample to determine its level of acceptability was carried out as well as the comparison with fried snack from 100% wheat flour. Increasing temperature had significant (P < 0.05) negative effect on the texture. Based on the desirability (0.771) concept, a frying temperature of 140 °C, frying time of 4 min, 32% level of BSCF, and 2 mm thickness was obtained as the optimized conditions. Sensory analyses showed that the optimized sample was preferred in terms of texture and its oiliness to fried snack prepared from 100% wheat flour, but, the aroma, taste and appearance of the wheat snack were preferred

Mineral and antinutrient content of high quality cassava-tigernut composite flour extruded snack

This study investigated the mineral and antinutrient composition of extruded snack produced from different blends of high quality cassava and tigernut flour. The extruded snacks were produced using a single-screw laboratory extruder at constant feed moisture (27%), screw speed (60 rpm) and barrel temperature (80C). It was observed that the extrudates had higher values for mineral composition (phosphorus, calcium, magnesium, potassium and iron) than the composite flour which showed that extrusion cooking improves the absorption of the minerals. The antinutrient (tannin, phytate, saponin, oxalate, alkaloids and total phenolic) contents of all the flour blends significantly (P < 0.05) increased with tigernut flour inclusion. Extrusion cooking resulted in significant (P < 0.05) reduction in the antinutrients of the extrudates. The study showed that extrusion cooking reduced the antinutritional factors thereby increasing the bioavailabilty of minerals. Also, the minerals were not affected by the extrusion cooking process probably because minerals are heat stable

Microbiological Safety Assessment of Fermented Cassava Flour “ Lafun

The microorganisms involved in the fermentation and spoilage of fermented cassava flour were investigated. The water samples used at the different processing sites were also investigated to determine their safety status. There was predominance of Staphylococcus aureus, Aspergillus spp., and Escherichia coli in all samples. Coliforms were observed to be present in all of the processing water. In the fermented cassava flour, the total bacterial count ranged between 4.9×106 cfu/mL from Eleso, Bakatari, and Oja Odan processing sites and 8.10×106 cfu/mL in Eruku processing site. The majority of the microorganisms involved in the spoilage of “lafun” were found to be Aspergillus niger which ranged between 4.6×105 cfu/mL in Eleso and 8.1×105 cfu/mL in Kila. The control sample prepared in the laboratory had a low microbial load compared to samples collected from various sites and markets

Effect of species, pretreatments, and drying methods on the functional and pasting properties of high-quality yam flour

The study investigated the functional properties of HQYF (high-quality yam flour) from tubers of four dioscorea species. The tubers were processed into HQYF using two pretreatments (potassium metabisulphite: 0.28%, 15 min; blanching: 70°C, 15 min) and drying methods (cabinet: 60°C, 48 h; sun drying: 3 days). Significant differences (P < 0.05) were observed in pasting characteristics of flours among the four species. The drying method significantly affected only the peak viscosity. The interactive effect of species, pretreatment, and drying methods on the functional properties was significant (P < 0.05) except for emulsification capacity, angle of repose, and least gelation concentration. The significant variation observed in most of the functional properties of the HQYF could contribute significantly to breeding programs of the yam species for diverse food applications. The pastes of flour from Dioscorea dumetorum pretreated with potassium metabisulphite and dried under a cabinet dryer were stable compared to other samples, hence will have better applications in products requiring lower retrogradation during freeze/thaw cycles

Emerging issues and key focus areas in food science, technology, and engineering higher education

Food studies is an interdisciplinary field involving food production, distribution, consumption, and social, economic, and environmental impacts. Food science, technology, and engineering have undergone a significant transformation over the past few decades. Moreover, the food industry faces numerous critical challenges ranging from food safety, sustainability, health, and nutrition to changing consumer preferences and global food security. The food industry needs a workforce prepared for the most recent technical developments and also highly skilled. Working group 1.2, on Emerging Issued, Key Focus Areas, of IUFoST (International Union of Food Science and Technology) activities address education materials and methods on topics such as sustainability of food systems, emerging technologies, food safety, food insecurity, ethical considerations, among others. The working group organizes webinars series on teaching methods and methodologies, current critical topics in food studies, and, more recently, is opening an international web forum. This forum will promote effective communication and sharing of information in the field. It will cover topics such as curricula development, education in specific world regions, opportunities of collaboration, research education-related topics, and industry collaborations. Working group 1.2 of IUFoST is also a key element for networking with several other organizations working towards a new generation of food science, technology, and engineering professionals with the skills and knowledge required to drive innovation and reshape the industry.info:eu-repo/semantics/publishedVersio