Drying Characteristics and Microbiological Quality Assessment of Solar-Dried Tomato.

Tomato (Lycopersicon esculentum) is an important vegetable used in cooking most local foods in Ghana. At the peak season of harvesting, high loses are incurred because of the absence of tomato processing facilities to store, process, and extend the shelf life of fresh tomatoes. Solar drying has been proven to be a more efficient and low-cost method of enhancing quality and adding value to tomato and other vegetables. However, there are concerns about the functionality and quality of the dried products by consumers due to the methods of drying used. In this study, a passive mixed-mode solar dryer suitable for drying tomato was adapted and used to investigate the dehydration characteristics and microbiological quality of the dried tomato. The efficiency of a passive solar dryer was evaluated and used in the processing of fresh tomato to powder. The processing involved the pretreatment of 6 mm slices of fresh Roma variety of tomato by dipping in potassium metabisulfite solution and ascorbic acid solution. The moisture content, moisture ratio, and dehydration rate of solar-dried tomato were assessed. The 24 h dryer efficiency of 24.2% facilitated the drying process of tomato (final moisture content of 12-14%). Aerobic mesophile counts were lower in solar-dried tomato pretreated with potassium metabisulfite (3.90 CFU/g) compared with sun-dried samples (4.85 CFU/g). Solar-dried tomato powder is safer for consumption compared with open sun-dried tomato samples.

Sensory profiling and consumer evaluation of solar dried tomato powder in Ghana.

BACKGROUND: Tomato (Lycopersicon esculentum) is an important vegetable in Ghana, with high post-harvest losses due to absence of facilities to store, process and extend the shelf life of fresh tomatoes. Solar drying has been proven to be a more efficient and low-cost method of enhancing quality and adding value to tomato and other vegetables. However, there are concerns about sensory appeal of the dried products. In this study a natural mixed mode solar dryer was developed to dry pre-treated fresh Roma tomatoes. The sensory characteristics of the solar dried product was profiled and compared to the sensory properties of similar commercial dried tomato on the market using quantitative descriptive analysis methodology. Consumer testing using qualitative methods provided consumer feedback on the appeal of the solar dried tomatoes. RESULTS: Results showed that the solar dried tomato powder had a stronger tomato aroma intensity (scoring 127 on a 150 mm intensity scale) than the market products (0.7 on the same 150 mm intensity scale). When reconstituted, the solar dried tomato powder had a coarse appearance and texture, and a strong cooked tomato aroma compared to tomato paste. Consumers indicated that tomato powder was used as a thickener because it was highly viscous and when reconstituted imparted a desirable cooked tomato aroma and flavor. CONCLUSION: Considering the positions of the tomato products in the sensory space, although tomato powder had its own unique sensory properties, it also exhibited some sensory characteristics found in tomato paste. From this study, high-quality tomato powder has great potential for commercialization. © 2021 Society of Chemical Industry.

Effect of home processing methods on the levels of heavy metal contaminants in four food crops grown in and around two mining towns in Ghana.

Unregulated small-scale mining activities, by young untrained men using some poisonous chemicals, occur in several agricultural forest belts in Ghana. These activities contaminate water bodies in these areas, which happen to be the main farming sites where food crops are intensively cultivated. The presence of these heavy metal contaminants in popular food staples is therefore worrying because of its adverse health implications. Previous studies have shown that processing is able to decrease the concentrations of heavy metals in foods. This study investigated the effectiveness of home processing methods (boiling, frying and roasting) in significantly reducing the levels of heavy metal contaminants in food crops grown in and around two main mining centers in Ghana. The heavy metals contaminants analyzed for, were Arsenic (As), Cadmium, (Cd), lead (Pb), Manganese (Mn), and Mercury (Hg), determined using atomic absorption spectrometry (AAS) and inductively-coupled plasma mass spectrometry (ICP-MS). From the data, the average daily intakes of the heavy metals and the associated long-term health risks to consumers were assessed. Unprocessed samples from Akwatia had higher levels of contaminants than those from Obuasi. Levels of Mn, Pb and As recorded in all unprocessed samples were higher compared to WHO permissible limits in foods. The levels showed a decreasing trend in the processed samples; with the lowest As and Pb content recorded after frying and boiling. The study showed that roasting allowed for the least reduction in the heavy metal contaminations in the four food crops. The levels of Cd in both processed and unprocessed samples were within safe WHO specifications. Except for Pb in unprocessed cassava, boiled cassava and unprocessed plantain and Hg (unprocessed yam and roasted yam), the hazard indices of all metals in all food crops were less than one and posed no risk to consumers. The study therefore reveals that the normal home processing methods are able to reduce the levels of heavy metal contaminants found in cassava, cocoyam, plantain and yam considerably.

Comparison of Micronutrient Intervention Strategies in Ghana and Benin to Cover Micronutrient Needs: Simulation of Bene-Fits and Risks in Women of Reproductive Age.

Overlapping micronutrient interventions might increase the risk of excessive micronutrient intake, with potentially adverse health effects. To evaluate how strategies currently implemented in Benin and Ghana contribute to micronutrient intake in women of reproductive age (WRA), and to assess the risk for excess intakes, scenarios of basic rural and urban diets were built, and different on-going interventions were added. We estimated micronutrient intakes for all different scenarios. Four types of intervention were included in the scenarios: fortification, biofortification, supplementation and use of locally available nutrient-rich foods. Basic diets contributed poorly to daily micronutrient intake in WRA. Fortification of oil and salt were essential to reach daily requirements for vitamin A and iodine, while fortified flour contributed less. Biofortified products could make an important contribution to the coverage of vitamin A needs, while they were not sufficient to cover the needs of WRA. Iron and folic acid supplementation was a major contributor in the intake of iron and folate, but only in pregnant and lactating women. Risk of excess were found for three micronutrients (vitamin A, folic acid and niacin) in specific contexts, with excess only coming from voluntary fortified food, supplementation and the simultaneous overlap of several interventions. Better regulation and control of fortification and targeting of supplementation could avoid excess intakes.

Physicochemical and functional properties of dried okra (Abelmoschus esculentus L.) seed flour.

The physicochemical and functional properties of dried okra seed flour of two genotypes Agbagoma and Balabi were evaluated. The samples Agbagoma and Balabi had 8.90%-9.00% moisture, 16.80%-17.40% protein, 47.80%-48.00% fat, 7.70%-7.80% ash, and 18.20%-18.40% carbohydrate. The mean values of functional properties revealed significant differences (p < .05) between okra seed flour samples studied. The samples' bulk density range was 0.80-0.83 g/ml. Water absorption capacity and oil absorption capacity ranged from 511.65% to 504.32% and 88.38 to 160.67%, respectively. The solubility was 14.10% for Agbagoma and 10.97% for Balabi, whereas swelling power was 16.37% and 14.68% for Agbagoma and Balabi, respectively. All pasting properties except peak time and pasting temperature of Agbagoma seed flour were higher than those of Balabi seed flour. The study revealed that dried okra seed flour is rich in nutrients, which could be used for baking and fortification of foods.

Starches of two water yam (Dioscorea alata) varieties used as congeals in yogurt production.

The physicochemical properties of water yam (Dioscorea alata var. Akaba and Matches) starches were determined prior to their use as congeals for yogurt production. The moisture content ranged from 9.34% to 15.8% for A100 (100% Akaba) and M100 (100% Matches), respectively, indicating lower moisture content in the Akaba variety compared to Matches variety. Similar trend was observed for their water activity. The pH ranged from 5.88 to 6.93 indicating low acidity of the water yam starches. The water absorption capacity (WAC) ranged from 4.10 to 4.89 g/g, seemingly restricted reflecting protein-moisture interaction of the starches. Although the swelling power did not differ significantly (p > 0.05) ranging from 10% to 14%, they were quite restrictive as the WAC. The L* values of the starches were predominantly lightness in color, highest for A100 sample. The pasting temperatures of Akaba (A100), Matches (M100), and A50:M50 were not significantly different (p > 0.05). Peak viscosity of the water yam starches was in a range of 509-528 BU. The highest attributes were for taste (6.4), mouthfeel (5.4), flavor (5.4) sourness (4.6) and consistency (5.9), which were obtained from 1.5 % Matches, 0.5 % Akaba + 0.5 % Matches, 1.0 % Akaba + 1.0 % Matches samples. The overall acceptability (5.8) was higher than the control yogurt (4.7), indicating sample 0.5% Akaba + 0.5% Matches as the best-bet yogurt.

Determination of the chemical and functional properties of yam bean (Pachyrhizus erosus (L.) Urban) flour for food systems.

Many plant species that are suitable for food across the world are neglected and underutilized. In order to increase their diversified food uses and thus help enhance food and nutrition security, we studied the chemical and functional properties of Pachyrhizus erosus (yam bean), which is a neglected and underutilized legume species. The chemical properties of flour produced from the yam bean include 5.8% moisture content, 5.7% crude fat, 6.2% crude fiber, and 85% available carbohydrate, indicating appropriate shelf-stable flour, low fat, and abundant energy. The results also showed a reducing sugar content of 2.0% and 21.0% starch. Pasting temperature was 70.6°C with peak viscosity of 14.5 BU, which supports ease of cooking of the flour. The swelling power obtained was 752.9 g/100 g at 85°C with a solubility index of 54%. Water holding capacity (WHC) obtained for the flour was 363.88%, whereas swelling volume was 14.0 ml and makes the flour appropriate for the production of infant foods. The P. erosus flour therefore exhibits good functional and chemical properties that would make the flour quite suitable as a substitute for other flours in food systems.

Consumer knowledge, preference, and perceived quality of dried tomato products in Ghana.

Postharvest losses (PHL) are incurred in the tomato value chain in Ghana and solar drying of tomato is a promising technology for reducing the loss. However, there are concerns on the usage, functionality and sensory appeal of the dried products to consumers, compounded with the lack of information and research on dried tomato processing in Ghana. A survey was carried out by administering semistructured questionnaires to 395 randomly selected and willing respondents in the Accra Metropolis. Information was obtained on the socioeconomic profile, consumption pattern, knowledge, and acceptance of tomato processing technologies and assessment of quality attributes important to consumers. Most consumers (74%) preferred tomato powder that is conveniently packaged to retain the characteristic intense taste and the flavor using Friedman's rank mean procedure. The study indicated that consumers were more concerned about good manufacturing practices during the production of solar-dried tomato (48.8%) rather than the quality attributes (8.6%). These findings indicate the need for safe solar drying procedures in order to increase consumer acceptability of solar-dried tomato products in Ghana.

Microstructural changes of osmotically dehydrated tissues of apple, banana, and potato.

Scanning electron microscopy examination was conducted on osmotically dehydrated tissues of apple, banana, and potato. High-quality stereo images and surface parameters were recorded from two sets of samples: fresh samples and osmotically dehydrated samples for each material studied. Scanning electron microscopy micrographs revealed that osmotic treatment had a significant effect on the structural properties (cell wall, middle lamella) for the different plant materials. The intercellular spaces were larger for materials treated at higher temperature (55 degrees C) and higher concentration of sucrose solution (70%). The cell wall and middle lamella observed in Golden Delicious apple appeared larger than those in Cox apple, banana, and potato, and probably contributed to the observed descending order of water loss and solid gain as: Golden Delicious > Cox > potato > banana.