Development and Performance Evaluation of a Multi-Heat Source Plantain Roaster

The increasing demand for roasted plantain has brought about recent interest to upgrade the local method of roasting to be more user-friendly, hygienic and versatile. The objective of this work was to design, fabricate and evaluate the performance of a low cost and affordable multi-heat source plantain roaster and to determine the effects of different heat sources (charcoal, gas and electricity) on the proximate and micronutrients composition of the roasted plantain. Heat supplied to each compartment and medium of transfer was determined. The roasted products from different heat sources were evaluated for moisture, crude protein, ash, crude fat, crude fibre and total carbohydrate contents of the samples. Potassium, magnesium and vitamin B6 were also determined. The proximate and micronutrient composition analyses were carried out. The results show that the average capacity and efficiency of the machine is 3.74 kg/h and 96.32% respectively. Moisture content of the fresh plantain is 58.27% while that of roasted plantain using gas, electricity and charcoal are 46.26%, 45.94% and 39.59% respectively. Ash content of fresh plantain is 5.89% while that of roasted plantain using gas, electricity and charcoal are 7.45%, 8.30% and 7.00% respectively. Crude fibre content of fresh plantain is 2.83% while that of roasted plantain using gas, electricity and charcoal are 3.27%, 3.41% and 3.43% respectively. Carbohydrate content of fresh plantain is 23.80% while that of roasted plantain using gas, electricity and charcoal are 33.41%, 32.35% and 43.02% respectively. Keywords: Machine design, plantain, moisture content, micronutrient analysis, heat source, roastin

A Critical Evaluation of Survey Results of Vitamin A and Fe Levels in the Mandatory Fortified Food Vehicles and Some Selected Processed Foods in Nigeria

ABSTRACTA nationwide survey was conducted to ascertain the levels of Vitamin A and Fe in wheat and maize flours, sugar and vegetable oils and some flour-based processed foods to assess compliance to the Nigerian Industrial Standard. Samples were collected from factories and markets in all the 36 states of the six geopolitical zones of the country; comprising 94 (vegetable oil), 42 (sugar), 95 (flour) and 62 (processed foods) and subjected to vitamin A and iron analyses using HPLC and AAS respectively. Using a 50% acceptable range of the specified minimum standards as basis for compliance, the results showed that only 14.9 – 20.2 % of the samples of vegetable oils analyzed fell within acceptable level (10,000-20,000IU/kg) but there was no significant difference (p>0.05) in the results obtained for the six zones. For sugar, only 11.9 – 16.7 % of the samples collected complied with the acceptable range of the standards (12,500 – 25,000IU/kg) but this varied significantly (p>0.05) with the zones. The levels of compliance for vitamin A and Fe in flours were found to be 12.2 – 33.3 % and 1.0 – 21.0 % respectively at the acceptable range of 15,000 – 30,000IU/kg and 34.6 – 46.8mg/kg, respectively. In all cases, the compliance levels at the 50% range were only marginally higher than at the 30% WHO acceptable range. For the levels of these micronutrients in the processed foods, the values obtained ranged between 5,139 – 7,687IU/kg for vitamin A and 11.9 – 16.7mg/kg for Fe. These results call for a critical and holistic review of the fortification strategy in Nigeria

Effect of optimizing process variables on the quality characteristics of cassava-wheat composite bread

The optimisation of bread-making process can have a positive impact in ramping up the quality characteristics of cassava-wheat bread to  that of whole wheat bread. In this study, a threevariable Box-Behnken design response surface methodology was employed to investigate and optimise independent variables namely cassava flour composition, water content and proofing time in relation to response variables namely dough yield, loaf specific volume and loaf protein of cassava-wheat-composite bread. The data from the experimental design were fitted into second-order regression models and their validity and reliability were confirmed by analysis of variance. Optimal cassava flour composition, water content and proofing time were derived as; 100 g/kg, 589 g/kg and 90 min, respectively. It was revealed that cassava flour composition had the most effect on the quality characteristics of cassava-wheat-composite bread. At constant cassava flour  composition, increase in water content and proofing time had a positive effect on all the studied quality characteristics of cassava-wheat composite bread. Increase cassava flour composition regardless of proofing time and water content had a negative effect on loaf specific volume and protein. This study has provided bread-making conditions which can be utilised in enhancing the consumer acceptability of cassava-wheat composite bread. &nbsp

Recent Developments in Processing Technologies for Roasted, Fried, Smoked and Fermented Food Products

Progress in the research efforts to upgrade various traditional processing technologies, especially roasting, deep-fat frying, smoking, and fermentation, is presented in this chapter. The importance of these studies is in the need for more user-friendly, adaptable, and affordable low-cost machinery and equipment for sustainable food processing, especially in communities where electricity is a challenge, and alternative energy sources such as gas and charcoal are critical. The design considerations and characteristics of the various types of machinery as well as the design calculations and performance evaluation results aimed at standardizing the upgraded machinery are therefore presented from various studies. The effects of these technologies on the quality of the resulting products are discussed particularly in relation to the variations in process losses of micronutrients in the fortified products, with examples of vitamin A and iron losses in pan bread and fried doughnuts obtained from baking fortified wheat flours

Markets for Nutrition: What Role for Business?

Policymakers are increasingly seeking to use food systems to help reduce rates of chronic undernutrition and to use markets to deliver nutrient?rich foods to vulnerable populations. This article examines how this might be achieved, drawing lessons from three intervention types: ready?to?use therapeutic foods (RUTFs), mandatory fortification and voluntarily fortified products. We find that a common set of constraints tends to inhibit markets from delivering nutrition and makes it difficult to reach populations at the ‘bottom of the pyramid’. Overcoming these constraints requires a shift from working at the level of individual businesses to that of market and food systems. It also suggests a need for renewed focus on the effectiveness of products in reaching key groups, on the informal markets that serve the poor and on the inherent complexity of market systems. These findings suggest that food and nutrition policies and partnerships should be based on principles of experimentation and adaptive learning

Volatile Bioactive Components of Boiled and Roasted African Walnut (Tetracapidium conophorum) Extracts Using GC-MS

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

Effect of Soil Micronutrient Status on the Fermentation Characteristics and Organoleptic Quality of Nigerian Tea

The status of micronutrients (Cu2+, Zn2+, Fe2+ and Mn2+) in soils and foliage of three commercial tea clones 68, 143, and 35 collected from the Ardo-Gore tea estates of the Mambilla Plateau in Gongola State of Nigeria was evaluated. Leaf samples were also batch-processed and examined for fermentation characteristics including average fermentation time and organoleptic cup quality, and analytical quality indices, namely total phenol and tannin. Results showed that while Cu and Mn contents are adequate, Fe and Zn are marginal. A high negative correlation was obtained for soil Fe and leaf Cu (r = 0.98) and Zn (r = 1.00) probably due to substitution ability of these essential nutrients which could have limiting consequences on the fermentation process. Leaf Cu showed a significantly positive relationship with total phenol and tannin contents of the samples (r = 0.77 and 0.73, respectively) while the relationship between leaf Zn and total phenol (r = 0.64) was statistically insignificant. Sensory evaluation of the samples from the three clones showed that close 35 had the least fermenting ability and poorest cup quality. This trend was in agreement with the levels of leaf Cu, Zn, total phenol and tannin of the samples, indicating high variability in clonal requirements of micronutrients for physiological and processing functions

Effect of Some Thermal Processing Methods on the Caffeine Content and Colour Absorbance of Kola Nuts

Fresh kola nuts (Cola nitida) were thermally processed (blanched, boiled and roasted) for different periods of time (5, 10, 15 and 20 minutes respectively) at different temperatures (65, 75, 85 and 95oC). Boiling was done at 80oC while roasting was at 108.5oC, and steam blanching duration was 5, 7.5, 15 and 20 seconds respectively. The nuts were then diced, grated and stored for subsequent analysis in a Haier thermocool freezer. Subsequent study of the effects of the various treatments on the proximate and the caffeine contents of the kola nuts revealed that increase in temperature and duration of boiling resulted in product with lower caffeine content. However, product with the lowest caffeine content was produced during steam blanching at 108.5oC for 5 seconds. The various treatments also produced kola nut powder with darker colour but to varying degrees of darkness. These results are discussed in relation to the quality of kola nut powders for different product applications

Cookies-making potentials of sorghum-wheat flour blends

Background: Composite flours provide possibilities in enhancing the nutritional and quality characterises of baked foods. Objectives: In this study, the proximate, functional and pasting characteristics of sorghum-wheat composite flours consisting of 20 % and 40 % sorghum flour substitution levels were investigated. Methods: The sorghum-wheat composite flours were utilised in the production of cookies and their proximate and sensory acceptability were examined. Results: It was revealed that an increase in sorghum flour levels in the composite flours increased ash, crude fibre, carbohydrates (2.62% and 3.95%) and dry-matter (8%) while decreasing protein and fat compositions. Also, increase in bulk density (5% and 9%), water absorption (24% and 31%), swelling power, solubility, peak viscosity (52% and 37%), breakdown viscosity and setback viscosity of the composite flour increased with increase in sorghum flour levels. Cookies produced from the composite flours showed increased protein contents. Consumers preferred the colour, appearance and taste of cookies produced from composite flour containing 40% sorghum flour than that of wheat flour cookie. Conclusions: This study has demonstrated the baking functionality and nutritional qualities of sorghum-wheat composite flour. Keywords: Sorghum; Cookies; Baking functionality; Pasting characteristics; Swelling powe