Charles Tortoe

Multilinear Regression Approach in Predicting Osmo-Dehydration Processes of Apple, Banana and Potato

The potential for improving food quality through osmo-dehydration is tremendous but limited by quantitative data and methods. A Multiple Linear Regression (MLR) approach was developed for water loss and solid gain during osmo-dehydration of apple, banana and potato taking into account the effect of temperature, concentration, time of immersion, sample size, sample type and agitation. Temperature was the most important factor influencing osmodehydration of the plant materials whereas agitation was the least. A regression coefficient of determination (R2 = 0.886) indicating a good correlation coefficient (r = 0.941) between experimental and predicted data was identified for water loss. However, the regression coefficient of determination (R2 = 0.305) for the solid gain did not show a good regression correlation coefficient (r = 0.552) between the experimental data and the predicted data. Prediction of water loss was more adequate than solid gain due to the variability of the pathways of water and solid diffusion into the different plant materials in favour of water loss.

Proximate composition and sensory evaluation of root and tuber composite flour noodles

Abstract Noodles are popular convenient wheat-based food consumed throughout the world. In this study, different proportions (50, 60, and 70%) of cocoyam, plantain, yam, cassava or sweet potato flour was used to replace wheat flour in the production of noodles. Proximate composition and organoleptic properties of the noodles were analyzed by standard methods. Results of the proximate composition showed that protein ranged between 10.9% for plantain noodles to 14.2% for cocoyam noodles. Fat and ash also ranged from 5.4 to 8.8% and 1.9 to 2.9% correspondingly for these nutrients. Variations in proportions of wheat flour replaced resulted in significant changes in the nutritional content of the composite flour noodles. Sensory evaluation also revealed differences in the scores for some of the attributes assessed. Generally the aroma, taste and texture of noodles did not vary with increasing proportions of tuber flours, except for the taste of cassava flour noodles and the texture of cocoyam flour noodles, in which significant differences were observed. Cassava-wheat composite flour noodles showed promising results, with its acceptability closely following the acceptability of commercial noodles used as a control.

Unearthing the Potential of the Frafra potato (Solenostemon rotundifolius) Flour in Culinary Application: Sensory and Nutritional Analysis of its Pastry Products

ABSTRACT Frafra potato is an underutilized crop with enormous potential as a food security crop. Sensory attributes of bread and koose (a traditional Ghanaian pastry) produced from 10 varieties of Frafra potato flour as composite flour and nutritional values were analyzed. Bread and koose produced from partial substitution of Frafra potato flour were comparable to wholly wheat flour, especially 20% substitution with variety UW022 for bread and 30% substitution with variety UE021 for koose. Using a 9-point Hedonic scale, overall acceptability level was 7.8 for variety UW022 for bread compared to 7.9 for wheat flour, similar to koose. Variety UW022 bread was carbohydrate dense (72.58 g/100 g) whereas variety UE023 bread was richer in ash, fat, protein, crude fiber and energy. Variety UE023 koose at 20% was highest in protein content (20.75 g/100 g) but lower carbohydrates (47.3 g/100 g).

Physicochemical characteristics and microbiological quality of senescent plantain products

Abstract Senescent plantains have relatively very rapid deterioration rate compared to plantains at other ripening stages. In Ghana, they are used for products which are consumed either as a snack or a main meal. This paper presents results of a study conducted in five regions of Ghana to investigate processing of senescent plantain products and evaluate their physicochemical characteristics and microbial quality. Survey data were collected on product types and processing methods. Freshly prepared products obtained from respondents were packaged in Ziploc bags and transported in a clean ice chest to the lab for physicochemical and microbial analyses. Samples were stored in the refrigerator (5°C) prior to analyses. Products made by respondents include Apitsi or Apiti, Bodongo, Akankyie, Ofam, Kumaku, Agbetenya; which were either baked or steamed. There were variations in cooking methods, time, type and quantity of ingredients used to produce these products. The products had relatively high moisture (47.63% − 68.42), appreciable crude fat (0.06% − 9.50%), crude protein (1.66% − 7.87%) contents and were good sources of energy (129.64 kcal/g − 241.19/g). The products were slightly acidic, with pH ranging from 4.53 to 5.38. Aerobic plate count, yeast and mold, coliform and E. coli ranged between <10 to 1.7 × 105 CFU/g; 0 and 3.9 × 105 CFU/g; 0 and 1.5 × 102 CFU/g; and 0 and <10 CFU/g, respectively. The bacteriological quality of samples A to I are more superior than samples J and K. Product standardization is required.

Trace metal concentrations in three pastry products prepared from root and tuber and cereal crops composite flours

Abstract The concentrations of Arsenic (As), Lead (Pb), Mercury (Hg), Copper (Cu), Iron (Fe), and Zinc (Zn) in doughnuts, cookies, and bread prepared from root and tuber and cereal crops composite flours were quantitatively measured by Atomic Absorption Spectrophotometry. Varying concentrations of trace metals were identified in three pastry products. Concentration of Hg was <0.01 mg/kg wet weight in all three pastry products. The As levels in all three pastry products ranged between <0.01 and 0.03 mg/kg. Concentrations of Pb was <0.01–0.05 mg/kg, far lesser than 10 mg/kg recommended limit by World Health Organization (WHO). The highest Fe level of 66.3 mg/kg occurred in cookies made from millet composite flour, whereas the lowest value of 10.4 mg/kg was in doughnuts made from water yam composite flour. Concentrations of Cu (1.03–1.83 mg/kg) and Zn (5.49–13.72 mg/kg) were lower than the tolerance limit of 40 mg/kg set by WHO. The presence of trace metals at varying concentrations in all three pastry products demonstrates the need for observing food safety controls in sourcing for raw materials and during processing of flours from root and tuber and cereal crops.

Investigating the adoption of the root and tuber composite flour (RTCF) technology transferred among micro- and small-scale entrepreneurs (MSEs) in the bakery industry in Ghana

A survey was conducted to investigate the extent of adoption of root and tuber composite flour (RTCF) technology transferred among micro- and small-scale entrepreneurs (MSEs) in the bakery and pastry industry in Ghana. A total of 268 respondents were surveyed from the Brong Ahafo, Ashanti, Eastern, Volta, Western and Central regions in Ghana. The overall adoption rate of the RTCF technology among the 268 respondents was estimated at approximately 40%; Ashanti (75.7%), Eastern (43.1%), Volta (41%) and Brong Ahafo (21.4%). Results confirmed that adoption rate of the RTCF was tied to availability, accessibility and affordability of the RTCF in the local communities. Modelling adoption decision of the RTCF technology using the Probit model indicated that process innovation and age of bakers had significant positive influence on the decision to adopt the RTCF technology. Younger bakers with less experience also increased the probability of adoption It is therefore important to encourage bakers to be innovative through the adoption of best practices and technologies that have the potential to increase productivity and efficiency. Adoption of the RTCF technology has significant implications for enhanced food security situation in Ghana.

Examining the physicochemical, functional and rheological properties in flours of farmers’ 7 key yam (Dioscorea spp.) varieties in Ghana to enhance yam production

Abstract Yam (Dioscorea spp.) is an important tuber crop in Ghana with high industrial potential. However the suitability of some yam varieties for diverse culinary and industrial purposes have not been widely studied to inform in their production. This study determined the physicochemical, functional and pasting characteristics in flours of farmers’ 7 key varieties of Dioscorea rotundata (white yam) and Dioscorea alata (water yam). Colour, pH, proximate composition, solubility index, swelling power and pasting properties were determined. Flours from the yam varieties were light in colour and fairly neutral in pH (6.3–6.6). Crude protein levels were between 3.7% for matches and 5.9% Serwah varieties, whereas crude fat was less than 0.5% and the mean ash content was 2.1%. Although significant differences existed between the flours, no clear trend was established to differentiate between D. rotundata and D. alata varieties based on their proximate composition. Swelling power (SP), solubility index (SI) and water absorption capacity (WAC) of the flours differed clearly. D. rotundata varieties had a relatively higher SP (12.5%) and WAC (7.1%), whereas D. alata (20.1%) had the highest SI. Significant differences (p < 0.05) in pasting behaviour were observed. Apart from Serwah and Mutwumudoo varieties, higher peak viscosity and positive retrogradation tendency were observed in the D. rotundata varieties. Among the 7 varieties, pastes from Akaba and Pona varieties were the most stable. The study has revealed that the properties of these varieties of Ghanaian yams make them suitable in diverse culinary and industrial applications.