Charles T. Akanbi

Effect of Processing and Packaging on the Lycopene Content of Tomato Products

Abstract The lycopene content and its stability in two commonly available tomato cultivars (Lycopersicon esculentum var. Roma VF and L. esculentum var. Ibadan Local), during processing and in-package storage were studied. Estimates of lycopene concentration in fresh tomato and tomato products were determined by measuring the absorbance of lycopene solution in hexane at 472 nm. The results indicated that Roma VF had more lycopene (5.95 mg/100 g) compared to the Ibadan Local (4.76 mg/100 g) cultivars. More lycopene was retained in the dried slices than in dried pulp and better in the presence of antioxidant (sodium metabisulphite). On storage at 29°C, the profile of lycopene degradation rate in Roma VF and Ibadan Local pulp in different packaging materials was: can<plastic bottle<laminated metalized aluminium (LMA) foil<glass bottle and glass bottle<plastic bottle< can<LMA foil. At 40°C, lycopene degraded by three to six times faster than that at 29°C and degraded faster in Ibadan Local than Roma VF pulp on storage.

The effects of soaking and cooking time on the cooking properties of two cowpea varieties

The effects of soaking and cooking time on water absorption capacity, cookability, percent split, and texture of two varieties of cowpea, IITA-2246 and IFE-BPC, were investigated. Soaking prior to cooking had an effect only on the cookability, while the amount of water absorbed and the penetration depth (a measure of texture) of a penetrometer head in the seeds increased with cooking time. The properties were found to differ notably for the two varieties with IITA-2246 having a softer texture than IFE-BPC. Splitting in cooked beans increased with cooking time with maximum of 92% split in IITA-2246 and 63% split for IFE-BPC. Higher temperature soaking reduced the cooking time of both varieties.

Effect of heat-moisture pre-treatment on physical characteristics of dehydrated yam

Abstract Moisture distribution in whole yam tuber and the effect of heat-moisture treatment on the physical characteristics and drying rate of yam pieces were investigated. The sampling scheme showed that the moisture was uniform throughout each slice; however, the values for slices in the tail end were 18% more than those in the head end. Heat-moisture treated samples had significantly different density, shrinkage, drying rate and diffusion coefficients from the untreated sample. However, the observed effects were found to depend on the mode and temperature of the heat treatment. Heat treated yam pieces have greater densities than the untreated samples. Shrinkage was more when the yam was pre-heated in a sealed container (conduction heating) than samples heated in contact with water.

Regression relationships for the soaking and cooking properties of two cowpea varieties

Abstract Water absorption and penetration depth (a measure of texture) of two cowpea varieties as influenced by varying soaking time (0.15–6 h) and soaking temperature (28–75 °C) were determined. The effects of different soaking treatments prior to cooking and cooking time on percent split, drained weight and the penetration depth of the cooked cowpeas were also investigated. The aim of the study is to establish mathematical relations between the product characteristics by regression statistics. Water absorption correlated positively with soaking time but the goodness of fit was temperature and variety dependent. Poor correlation coefficients were obtained when the penetration depth of the seeds was expressed as a sole (linear) function of soaking time or amount of water absorbed. However, equations involving both variables described the penetration depth of soaked cowpeas better. Cooking time correlated very well with drained weight (0.883 ≤ r ≤ 0.979), percent split (0.797 ≤ r ≤ 0.962) and penetration depth of cooked seeds (0.895 ≤ r ≤ 0.982). Equations involving drained weight and cooking time as variables were developed to predict the penetration depth of cooked cowpeas. The degree of fit increased with the inclusion of the product or higher order terms (0.841 ≤ r ≤ 0.996).

Thermal properties of ground and hydrated cowpea

Abstract The effects of temperature (50–80 °C) and moisture content 9.1–41.2% (wet basis) on the specific heat of ground and hydrated cowpea were investigated using the method of mixtures. For most of the samples, the specific heat was highest either at 60 °C or 28.6% moisture content. Further increase beyond these levels resulted in a decrease in the specific heat. Density was determined at room temperature. An initial decrease was observed in density of the samples as moisture level increased from 9.1%, but above 23.1% moisture content, the density increased with higher moisture levels. Thermal conductivity was determined by the line probe method. The thermal conductivity of ground and hydrated cowpea was dependent on moisture content and bulk density but independent of temperature.

Effect of Processing Factors on Rheological Properties of Ogi

Abstract Maize flours were obtained by wet milling or dry milling processes in traditional fermented ogi flour with or without fortification with soy fractions. The rheological and paste characteristics of the products were assessed. Inclusion of soy fractions affected the rheological and paste characteristics of the products, specifically in improving the gelatinization index of the products. The products could be described as pseudoplastic, which increase in consistency value with increasing concentration of ogi flour. The consistency index (K) values are much lower in dry milled ogi flour than the wet milled ogi flour. This correlates the patterns of the peak viscosities of dry milled ogi flours compared to the wet milled ogi flour. Changes in rheological characteristics were more noticeable with increase in temperature and addition of souring (fermentation) water.

A STUDY ON THE NIGERIAN FOOD INDUSTRY AND THE IMPACT OF TECHNOLOGICAL CHANGES ON THE SMALL-SCALE FOOD ENTERPRISES

Industrial processing of foods assists the nation to maintain a steady supply of food products. This study assessed some factors influencing the growth of the Nigerian food industry with the view to identify some technological changes within the small-scale food enterprises and their impact in the last ten years. Information on the Nigerian food industry was compiled from a secondary source while a survey of small-scale food enterprises was conducted in SouthWest Nigeria using a structured questionnaire and interviews. Results showed that the number of food manufacturing companies (FMCs) increased over the years with the largest number of FMCs established in the 1980s. The range of products produced is still small, with several FMCs producing similar products. More than 50% of the FMCs in the country are located in the SouthWest, with Lagos State as the major host. About 91% of the FMCs are listed as private and 7.3% are publicly quoted. Indigenous entrepreneurs wholly own 56.9% of the FMCs. Percent local sourcing is high in the FMCs. Areas of technological changes include expanded capacity utilization, expansion of production lines and expanded market shares, which arose as a result of the active involvement of management in the production process, acquisition of new packaging systems, and participation of the work force in process improvement. The study identified the need to standardize locally fabricated equipment to facilitate ready production of spare parts. Recommendations were made on how to increase the financial base of the small-scale enterprises.

Evaluation of starters for the fermentation of African oil bean (Pentaclethra Macrophylla Benth) seeds

Purpose – The purpose of this paper is to examine pure culture isolates from traditionally fermented product of African oil bean seeds (ugba) with a view to identifying the appropriate starters.Design/methodology/approach – The isolates were purified and characterized, and used singly and in combination to ferment freshly prepared oil bean seed slices for 72 h at 37 ○C. The pH and microbial load of fermenting beans were monitored daily, and organoleptic tests using semi‐trained panelists were employed to assess the fermented products based on quality attributes of flavour, appearance, texture and overall acceptability.Findings – The isolates included Bacillus subtilis, Bacillus licheniformis and Pseudomonas fluorescens. Total viable counts ranged from 1.3 × 107‐9.3 × 109 cfu/g, 7.0 × 106‐4.0 × 109 cfu/g, and 3.0 × 106‐1.5 × 109 cfu/g, respectively for the three isolates; while counts for the mixed culture fermentation ranged from 7.0 × 106‐1.72 × 1010 cfu/g. The mixed culture fermentation gave the best ra...

Effect of addition of ripe bananas on some physico-chemical properties of maize ‘extract’

Flour mixes obtained by the addition of banana pulp in various proportions (0–50%) to maize ‘extracts’ were evaluated for some quality characteristics. All the mixes had significantly lower values of crude protein, fat and water-holding capacity. Gelation, however, significantly increased the water-holding capacity in all cases. The ash content, titratable acidity and total sugars increased tremendously with an increase in the level of banana substitution. While both Adams consistency values and equilibrium moisture content decreased with an increase in the level of banana substitution, the syneresis values did not show any consistent pattern. The consistently low moisture content and the results of the moisture sorption isotherms suggest a good storage stability of all the mixes, especially when kept under conditions of water activity of 0.30 and below, and their possible suitability for baked products.

Effect of gamma irradiation on physicochemical properties of stored pigeon pea (Cajanus cajan) flour

The effect of gamma irradiation at various doses (5, 10, 15, 20 kGy) was observed on pigeon pea flour stored for 3 months on proximate composition, functional properties, and peroxide value. Sensory evaluation was also carried out on bean cake (moinmoin) made from nonirradiated and irradiated pigeon pea flour. The results showed that stored gamma-irradiated samples had significantly lower (P < 0.05) value of protein and little or no effect on moisture content. There were slight decreases in crude fiber and ash content of the irradiated samples compared with the control sample. The result of functional properties of the irradiated flours showed slight increase in water absorption capacity, swelling capacity and bulk density. The peroxide value of crude oil increased significantly with dose increases for the period of storage. The sensory evaluation of moinmoin samples prepared from irradiated pigeon pea flour showed no significant difference from the moinmoin sample prepared from nonirradiated flour. It can be concluded that gamma irradiation can extend the shelf life of pigeon pea flour.