Effect of packaging materials on lycopene vitamin C and water activity of dried tomato (Lycopersicon esculentum Mill.) powder during storage.

In this work, a storage study was conducted to find suitable packaging material for tomato powder storage. Experiments were laid out in a single factor completely randomized design (CRD) to study the effect of packaging materials on lycopene, vitamin C moisture content, and water activity of tomato powder; The factor (packaging materials) has three levels (low-density polyethylene bag, polypropylene bottle, wrapped with aluminum foils, and packed in low-density polyethylene bag) and is replicated three times. During the study, a twin layer solar tunnel dried tomato slices of var. Galilea was used. The dried tomato slices were then ground and packed (40 g each) in the packaging materials and stored at room temperature. Samples were drawn from the packages at 2-month interval for quality analysis and SAS (version 9.2) software was used for statistical analysis. From the result, higher retention of lycopene (80.13%) and vitamin C (49.32%) and a nonsignificant increase in moisture content and water activity were observed for tomato powder packed in polypropylene bottles after 6 months of storage. For low-density polyethylene packed samples and samples wrapped with aluminum foil and packed in a low-density polyethylene bag, 57.06% and 60.45% lycopene retention and 42.9% and 49.23% Vitamin C retention were observed, respectively, after 6 months of storage. Considering the results found, it can be concluded that lycopene and vitamin C content of twin layer solar tunnel dried tomato powder can be preserved at ambient temperature storage by packing in a polypropylene bottle with a safe range of moisture content and water activity levels for 6 months.

Design of Plant-Based Food: Influences of Macronutrients and Amino Acid Composition on the Techno-Functional Properties of Legume Proteins.

Imitating animal-based products using vegetable proteins is a technological challenge that can be mastered based on their techno-functional properties. These properties of legume proteins can be influenced by multiple factors, among which the macronutrients and amino acid contents play an important role. Therefore, the question arises as to what extent the techno-functional properties are related to these factors. The water- and oil-holding capacities and the emulsion and foaming properties of commercially available legume protein powders were analyzed. Correlations between macronutrient, amino acid content, steric structure, and techno-functional properties were conducted. However, the protein concentration is the focus of techno-functional properties, as well as the type of protein and the interaction with the non-protein ingredients. The type of protein is not always quantified by the quantity of amino acids or by their spatial arrangement. In this study, the effects of the three-dimensional structure were observed by the used purification method, which overshadow the influencing factors of the macronutrients and amino acid content. In summary, both the macronutrient and amino acid contents of legume proteins provide a rough indication but not a comprehensive statement about their techno-functional properties and classification in an adequate product context.

Non-destructive monitoring of quality attributes kinetics during the drying process: A case study of celeriac slices and the model generalisation in selected commodities.

The potential of Visual-NIR hyperspectral imaging (VNIR-HSI, 425-1700 nm) to predict celeriac quality attributes during the drying process was investigated. The HSI-Gaussian Process Regression (GPR) fusion method excellently predicted moisture content (MC, R2 ≈ 1.00, RMSE = 0.77 gw 100 gs-1) and water activity (aw, R2 = 0.98, RMSE = 0.04). Moreover, the rehydration ratio (RR, R2 = 0.89, RMSE = 0.04) and colour indices (R2 = 0.80-0.93, RMSE = 0.17-1.45) were reasonably predicted. However, antioxidant activity (AA) and total phenolic compounds (TPC) were poorly predicted. These results are potentially due to MC variations dominating the NIR region, masking phenolic compounds. Finally, the celeriac-based-trained model was assessed by predicting the MC of apple, cocoyam, and carrot slices. The results were encouraging; however, a GPR model trained on the data of all four commodities was more robust (R2 ≈ 1.00, RMSE = 1-2 gw 100 gs-1).

Comparative quality analysis and economic feasibility of solar assisted yogurt processing unit for decentralized dairy value chain.

Due to the lack of farm-gate milk processing facilities, dairy farmers have to sell raw milk, resulting in economic and quality compromises. The study compared the quality of yogurt processed in solar assisted yogurt processing unit with the existing milk value chain and its techno-economic feasibility. For this, an investigation of the experiment was executed where four different milk processing approaches were compared. The quality attributes for processed milk like fat (5.283%), solid-not-fat (9.0833%), salts (0.6833%), protein (3.8%), lactose (4.1%), total solids (14.383%), pH (6.87), density (1.031 kg/L) and freezing point (- 0.532 °C) were found within the standardized ranges. Similarly, for the case of yogurt, these attributes were found as fat (5.5%), solid-not-fat (8.683%), acidity (0.93%), lactose (4.73%), total solids (14.183%), pH (4.3433), density (1.039 kg/L) syneresis (9.87 mL/100 g), S. thermophilus count range (10.18-10.30 log cfu/mL) and L. bulgaricus count range (10.26-10.34 log cfu/mL). Moreover, no detection of coliform count in solar-processed yogurt, endorsed the current idea to perform three processes of heating, fermentation, and cooling in a single unit. Based on the energy sources utilized, the payback period was calculated to be 1.3-9 years with an expected lifespan of 15 years while in terms of product profit, the payback period was predicted to be 1.78 years. The processing cost per liter of milk for yogurt production was calculated to be 0.0189 USD. Considering CO2 emission savings, it is anticipated that a solar-powered yogurt processing unit can generate 107.73 MWh of useful energy during its operating life with zero CO2 emission.

Simulation of transient heat transfer during forced convection cooling of cocoyam (Colocasia Esculenta (L.) Schott) tubers.

In this study, a prediction model based on transient heat transfer was modified and validated using experimental data. The time required to cool tubers from field temperature of 30 ± 2 °C to the target storage temperature of 12 ± 0.2 °C was predicted directly from the model. Moreover, total cooling time ranged from 127.8 - 154.2 min for small tubers and 190.8-262.2 min for large tubers while the field heat removed ranged from 9.61 - 10.17 kJ for small tubers and 24.78-31.90 kJ for large tubers between the extremes of the air velocity. Tuber orientation to airflow neither influenced the heat transfer coefficients and Biot numbers nor the cooling time and amount of field heat removed. The results from this study could be applied in the design and optimisation of forced convection cooling systems to precool tubers immediately after harvest and for extended duration storage.

Optimization of roughing filtration unit for a handwashing wastewater recirculation point-of-use system.

A downward roughing filter unit consisting of silica sand as the filter medium was optimized for performance towards removal of turbidity and suspended solids from handwashing wastewater. Design-Expert software was employed to optimize media particle size, filter depth, and flowrate. Linear and quadratic models were found to best fit the responses of turbidity and suspended solids removal, respectively. Particle size and flow rate were the only parameters with significant effects on removal of turbidity and suspended solids. Optimal conditions were found to be media particle size 0.6 mm, filter depth 12 cm, and flow rate 0.3 Lmin-1, corresponding to removal efficiencies of 62 and 67% for turbidity and total suspended solids (TSS), respectively, as predicted by the model. Validation of model at optimal conditions resulted in turbidity and TSS removal of 55 and 53%, respectively. Additionally, removal efficiencies of the roughing filter towards apparent colour, true colour, biochemical oxygen demand (BOD5), and chemical oxygen demand (COD) from handwashing wastewater were 56, 20, 32, and 5%, respectively. Overall, although turbidity of filtered water was >50 NTU, the reduction achieved by roughing filtration is a significant step in enhancing the performance of water treatment processes downstream, including filtration and adsorption by slow sand filters and activated carbon, respectively.

Physical properties of technosols as evapotranspiration covers on potash tailings piles.

The covering of potash tailings piles with technosols (artificial soils) is a modern and promising method for decreasing the saline drainage of these piles. In this context, it is important to determine whether technosols have appropriate physical properties for crop growth. In evapotranspiration covers, physical properties, such as bulk density, particle size distribution, total porosity, proportion of large pores, and available water are particularly important because they allow for robust crop growth, which subsequently determines the evapotranspiration capacity. However, few studies have been performed to assess the physical properties of technosols and their ability to act as evapotranspiration covers on potash tailings piles. Therefore, the present study aims to evaluate the physical properties of four different technosols made of municipal solid waste incineration bottom ash and coal combustion residues installed on a potash tailings pile located in Heringen, Germany. The total porosity, infiltration capacity, particle size distribution, bulk density, wettability, water retention curve, pH, electrical conductivity, and water content were determined. The pH of the technosols averaged 8.5, the electrical conductivity varied from 2.8 to 3.3 mS/cm, the mean bulk density was 1.21 g/cm³, the total porosity was 52.8%, and the rate of medium pores was 13.9% of the technosol volume. On average, the coarse fraction accounted for 42% of the technosol mass, whereas the fine fraction accounted for 52% of the sand-size particles, 43% of the silt-size particles and 5% of the clay-size particles. Likewise, no wetting restrictions for the technosols were found. To conclude, the different technosols present no limitations for crop growth, although the heavy metal contents of municipal solid waste incineration bottom ash and coal combustion residues should be considered in future studies.

Toward the Next Generation of Digitalization in Agriculture Based on Digital Twin Paradigm.

Digitalization has impacted agricultural and food production systems, and makes application of technologies and advanced data processing techniques in agricultural field possible. Digital farming aims to use available information from agricultural assets to solve several existing challenges for addressing food security, climate protection, and resource management. However, the agricultural sector is complex, dynamic, and requires sophisticated management systems. The digital approaches are expected to provide more optimization and further decision-making supports. Digital twin in agriculture is a virtual representation of a farm with great potential for enhancing productivity and efficiency while declining energy usage and losses. This review describes the state-of-the-art of digital twin concepts along with different digital technologies and techniques in agricultural contexts. It presents a general framework of digital twins in soil, irrigation, robotics, farm machineries, and food post-harvest processing in agricultural field. Data recording, modeling including artificial intelligence, big data, simulation, analysis, prediction, and communication aspects (e.g., Internet of Things, wireless technologies) of digital twin in agriculture are discussed. Digital twin systems can support farmers as a next generation of digitalization paradigm by continuous and real-time monitoring of physical world (farm) and updating the state of virtual world.

The Effect of Pre-Drying Treatment and Drying Conditions on Quality and Energy Consumption of Hot Air-Dried Celeriac Slices: Optimisation.

Celeriac is a good source of fibre, trace minerals, and phenolic compounds; it has a pleasant aroma but is a perishable material, prone to discolouration. This research investigated the optimisation of the quality and energy demand in hot-air dried celeriac slices. The experiment utilised the I-optimal design of response surface methodology with 30 experiment runs. Pre-drying treatments (blanching at 85 °C, three minutes; dipping in 1% citric acid solution, three minutes; no pre-drying treatment), drying temperatures (50, 60, and 70 °C), air velocities (1.5, 2.2, and 2.9 m/s), and thickness (three-, five, and seven-mm) were applied. The drying conditions affected drying time significantly (p < 0.0001). The model by Midilli and others and the logarithmic model fitted best with celeriac slices drying kinetics. Blanched samples had a higher ΔE*ab (total colour difference) and BI (browning index) but lower WI (whiteness index) than samples with other pre-drying treatments. The rehydration ratio decreased with the increase of sample thickness and blanching (p < 0.0001). A quadratic model described the specific energy consumption (Es) best. The dried samples compared with fresh samples had increased antioxidant activity but decreased total phenolic compound value. The optimisation solution chosen was 58 °C drying temperature, 2.9 m/s air velocity, and 4.6 mm sample thickness with acid pre-drying treatment.

Maternal dietary practices, dietary diversity, and nutrient composition of diets of lactating mothers in Jimma Zone, Southwest Ethiopia.

BACKGROUND: Optimal nutrition during lactation is essential for the well-being of the mother and the infant. Studies have shown that access to nutrient-rich foods during lactation is critical as minimal stores of nutrients can have adverse effects. This study aimed to investigate the diversity, composition, and nutrient adequacy of diets of lactating mothers in Southwest Ethiopia. METHODS: A community-based cross-sectional survey was carried out in three districts of Jimma Zone, Southwest Ethiopia, in February 2014. A stratified multistage sampling technique was used to select 558 lactating mothers. Data were collected using a pre-tested and structured interviewer-administered questionnaire. Minimum dietary diversity for women (MDD-W) was computed from a single 24-h recall. A cut off value of 5 was used to classify the dietary diversity into achieving MDD-W or not. The proximate, mineral and anti-nutritional compositions of 12 commonly consumed foods were analysed using standard methods. Nutrient adequacy ratio (NAR) and Mean adequacy ratio (MAR) of these foods were estimated. RESULTS: The mean (±SD) dietary diversity score (DDS) of the study participants was 3.73±1.03. Meeting MDD-W was positively associated with agricultural production diversity (P = 0.001) and educational level of the women (P = 0.04). Conversely, district of the study (P = 0.003) and place of residence (P = 0.019) were negatively associated with meeting MDD-W. The proximate composition (g/100g) of the sampled foods ranged between 24.8-65.6 for moisture, 7.6-19.8 for protein, 2.1-23.1 for crude fat, 2.0-27 for crude fibre, 1.0-21.2 for total ash, and 0.9-45.8 for total carbohydrate content. The calorific value ranged between 124.5-299.6 Kcal/100g. The mineral contents (mg/100g) ranged between 9.5-52.5 for iron, 2.2-4.2 for zinc, 42.6-318.2 for calcium, and 150.7-379.9 for phosphorus. The content of anti-nutritional factors (mg/100g) ranged between 11.1-178.9 for phytate and 3.7-315.9 for tannin. All the commonly consumed maternal foods were not sufficient to meet the energy, fat and protein requirements, (NAR<1). However, all diets provided adequate iron and most of the cereal-based foods provided adequate carbohydrate and minerals. The overall nutrient adequacy was below the cut-off point for all food types. CONCLUSIONS: The diets of lactating mothers in Southwest Ethiopia lack diversity and nutrient adequacy. A community-based nutrition education program on the importance of diet diversity and nutrient intake during lactation based on a multi-sectoral approach is needed.

Microstructure and Physicochemical Properties of Light Ice Cream: Effects of Extruded Microparticulated Whey Proteins and Process Design.

This study aimed to understand the influence of extruded microparticulated whey proteins (eMWPs) and process design in light ice cream processing by evaluating the microstructure and physicochemical properties. The inulin (T1), a commercial microparticulated whey protein (MWP) called simplesse (T2), a combination (T3), as well as eMWPs (as 50% volume of total particles): d50 < 3 µm (T4), and d50 > 5 µm (T5) were used as fat replacers. The first process design was pasteurization with subsequent homogenization (PH). The second process was homogenization with subsequent pasteurization (HP) for the production of ice cream (control, 12% fat, w/w; T1 to T5, 6% fat, w/w). The overrun of light ice cream treatments of PH was around 50%, except for T4 (61.82%), which was significantly higher (p < 0.01). On the other hand, the overrun of HP was around 40% for all treatments except T1. In both the PH and HP groups, the color intensities of treatments were statistically significant (p < 0.001). The melting behavior of light ice cream was also significantly different. The viscosity of all treatments was significant (p < 0.05) at a shear rate of 64.54 (1/s) for both cases of process design. A similar firmness in both the PH and HP groups was observed; however, the products with eMWPs were firmer compared to other light ice creams.

Physicochemical quality of twin layer solar tunnel dried tomato slices.

The objective of this experimental study was to evaluate the effect of twin layer solar tunnel drying on physicochemical quality of tomato slices. The novelty of this dryer is that it has two layers of trays unlike Hohenheim solar tunnel dryer which makes it to have drying capacity of more than two times compare to type hohenheim solar tunnel dryer with equal collector area. The experiment consists of two (tray position and drying position) factors with two levels of tray position (upper tray (samples exposed to direct solar radiation) and lower tray (samples are exposed to only heated air)) and three levels of drying position (collector out let,middle of the dryer and dryer out let) with three replications. During the experiment 180 kg of Tomato slices of Galilea variety with 5mm thickness were dried in the twin layer solar tunnel dryer. Data on physicochemical quality of tomato were collected and analyzed using SAS (version 9.2). software. From the experimental result; an increase in lycopene and phenolic content retention along the length of the dryer was observed while Vitamin C retention showed a decreasing trend. Large retention of total phenol, lycopene and beta carotene content were observed for the lower tray dried tomato slices compared to the upper tray dried ones. The water activity and PH values of the solar tunnel dried tomatoes were within the safe range from microbial growth, enzymatic and non-enzymatic browning. Compared to sun drying; solar tunnel dried tomatoes showed a much better nutrient retention for all quality parameters which is comparable with the data reported for energy intensive mechanical dryers.

Impact of drying temperature and salt pre-treatments on drying behavior and instrumental color and investigations on spectral product monitoring during drying of beef slices.

Drying behavior and instrumental color development of beef slices untreated or pretreated with salt or salt and vinegar solutions were monitored by determining the moisture content and the color change by measuring CIELAB values during drying at 50, 60, and 70 °C. Time-series hyperspectral imaging (400-1000 nm) was applied with regard to the development of non-invasive measurement systems based on robust models to predict moisture and color independent of the pre-treatment and drying temperature. Samples pretreated with salt dried the slowest which became more prominent at increasing drying temperatures and the least color change (∆E = 23) was observed at 60 °C drying temperature. Robust prediction models for moisture content and CIELAB values irrespective of pre-treatment and processing conditions were developed successfully and improved by wavelengths selection with high R2 (0.94-0.98) and low RMSEP (1.05-5.22) which will support the future development of simple and cost-effective applications regarding non-invasive product monitoring systems for beef drying processes.

Smart apiculture management services for developing countries-the case of SAMS project in Ethiopia and Indonesia.

The European Union funded project SAMS (Smart Apiculture Management Services) enhances international cooperation of ICT (Information and Communication Technologies) and sustainable agriculture between EU and developing countries in pursuit of the EU commitment to the UN Sustainable Development Goal "End hunger, achieve food security and improved nutrition and promote sustainable agriculture". The project consortium comprises four partners from Europe (two from Germany, Austria, and Latvia) and two partners each from Ethiopia and Indonesia. Beekeeping with small-scale operations provides suitable innovation labs for the demonstration and dissemination of cost-effective and easy-to-use open source ICT applications in developing countries. SAMS allows active monitoring and remote sensing of bee colonies and beekeeping by developing an ICT solution supporting the management of bee health and bee productivity as well as a role model for effective international cooperation. By following the user centered design (UCD) approach, SAMS addresses requirements of end-user communities on beekeeping in developing countries, and includes findings in its technological improvements and adaptation as well as in innovative services and business creation based on advanced ICT and remote sensing technologies. SAMS enhances the production of bee products, creates jobs (particularly youths/women), triggers investments, and establishes knowledge exchange through networks and initiated partnerships.

Effects of storage temperature and packaging material on physico-chemical, microbial and sensory properties and shelf life of extruded composite baby food flour.

BACKGROUND: The storability and eventual quality of flour is influenced by the optimality of the storage conditions. The present study assessed the effect of storage temperature on extruded composite flour packed in different packages. METHODS: Oats, soybean, linseed and premix (sugar, salt, Moringa & fenugreek) were blended and extruded. The extruded flour was packed in paper, polyethene and woven polypropylene bags and stored at -18, 25, 35, 45 °C. Moisture content, fat content, water activity, bulk density, aroma, color and microbial load were measured fortnightly for three months. RESULTS: The physico-chemical and sensory properties of the flour samples were significantly (p < 0.05) affected by the storage temperature and packaging material along the storage period. The highest moisture content (4.02 g/100g) was recorded on the 90th day of storage for flour stored in polypropylene bag at -18 °C. The highest water activity (0.68) was recorded from flour packed in woven polypropylene bags stored at 25 °C for 45 days and flour packed in paper bags at days 15 and 45 at 35 °C, whereas the lowest aw (0.18) was recorded for samples stored for 90 days at 45 °C packed in polypropylene bags. Flour samples packed in polyethene bags retained their moisture content. The highest bulk density (0.61 g/ml) was recorded on day 0 and it decreased gradually where the lowest value (0.51 g/ml) was recorded for flour samples packed in polypropylene for 90 days at -18 °C. The highest fat content (9.4g/100g) was recorded at day 0 and it decreased slowly during the storage period where the lowest value (8.2g/100g) was measured from flour samples packed in polypropylene for 90 days at 45 °C. None of the treatments had a microbial load exceeding the standards which could be attributed to extrusion of the food samples. The highest aroma and color liking scores were recorded on the 90th day of storage for woven polypropylene packed flour at 25 °C and for polyethylene packed flour at -18 °C, respectively. The predicted shelf life was 17 months for samples packed in polyethene and kept at 25 °C and 6.2 months for samples packed in polypropylene and held at 45 °C. CONCLUSIONS: Woven polypropylene flour bags could be laminated or have a polyethylene liner, so that the flour does not absorb moisture. Shelf stability of the flour can help its successful marketing and distribution.

Influence of pre-drying storage time on essential oil components in dried hops (Humulus lupulus L.).

BACKGROUND: It is well known that duration of pre-drying storage impacts on hop quality. However, little knowledge exists regarding its actual effects on valuable hop components. To investigate these effects, fresh hop cones were stored for 5 or 24 h and dried for 210 min at 65 °C thereafter. Furthermore, to understand the effect of freezing hop cones on the essential oil content, both fresh and stored samples were frozen before and after drying. RESULTS: The results from gas chromatography analysis show an increase in linalool, ß-caryophyllene, humulene, geraniol content and decrease in myrcene content dependent on the period of storage. Total colour difference ΔE values of 4.61 and 5.27 were obtained for fresh and stored hops respectively, indicating discoloration of hops during storage. Modelling of moisture curves revealed the Wang and Singh model to be suitable, with R adj 2 values of 0.978 and 0.989 and root-mean-square error values of 0.037 and 0.019 for fresh and stored hops respectively. CONCLUSION: The results from this study provide an in-depth understanding on the changes occurring within the hop cones both during storage and drying and will further help hop processors optimize their storage times.

Relationship between mustard pungency and allyl-isothiocyanate content: A comparison of sensory and chemical evaluations.

The correlation of sensory and chemically evaluated pungency of mustard products was investigated via a time-intensity (TI) study and quantification of allyl isothiocyanate (AITC) contents using high-performance liquid chromatography (HPLC). Sweet, medium hot, hot, and extra hot commercial mustard products from different brands were examined. Notably, we found significant differences (p < 0.05) between the maximum perceived pungency intensity of various mustard products. The maximum perceived intensity (Imax ), the duration of the decreasing phase (DURDec ), and the area under the curve (AUC) values increased proportionally to the increase in the sample AITC content and were also higher in products classified as hot than in sweet mustards. The AITC concentration varied greatly between products from different brands and also between different sensory evaluated pungency levels. Furthermore, sensory evaluations and analytical results were correlated using regression analysis. The best correlation (correlation coefficient 0.891) was observed between the AITC concentration and AUC, when compared to that between the AITC concentration and DURDec (correlation coefficient 0.856) or the Imax value (correlation coefficient 0.803). The calculated regression model indicates that a higher AITC content induces an intensified trigeminal pungency sensation and that the sensory and chemical evaluations of mustard products were positively correlated. Therefore, by using this regression model, the sensory rating of mustard products may be predicted by chemical analysis of the AITC contents. PRACTICAL APPLICATION: This research paper provides a method to quantify the pungency inducing irritant allyl isothiocyanate in commercial mustard products and demonstrates a correlation between sensory and chemical data. Therefore, the amounts of sensory tests in product quality assurance can be reduced and replaced or at least supported by chemical quantification of pungent substances (especially AITC) in mustard products.

Effects of fermentation and malt addition on the physicochemical properties of cereal based complementary foods in Ethiopia.

Complementary foods (CFs) in Ethiopia are characterised by bulkiness, and poor nutrient density as these foods are primarily made of starchy staples. Meanwhile, several modification techniques are available to improve the quality of the starch-based CFs. The objective of this study was to examine the effect of fermentation time and malt concentration on cereal-based CFs in Ethiopia, intending to improve the nutrient density and reduce dietary bulkiness. Oats, barley and teff flours, with added malt at different concentrations (0, 2 and 5%), were spontaneously fermented for 0, 24 and 48 h. The physical, chemical and sensory properties of the fermented CFs flour were evaluated. The protein, fat, fibre, energy, phytate, tannin, bulk density, water absorption capacity (WAC) and viscosity ranged between 8.12-16.82%, 1.63-4.55%, 1.58-5.96%, 359.33-380.26kcal/100g, 18.63-175.07mg/100g, 0.84-42.89mg/100g, 0.66-0.99 g/ml, 61.33-143.12%, 235cP-1016.33cP, respectively. For all the three kinds of cereal, fermentation for 24 h resulted in a better sensory quality regardless of the malt concentration. Crude fibre, crude fat, total carbohydrate, phytate, tannin, bulk density and viscosity of the three kinds of cereal were significantly reduced due to the interaction of fermentation and addition of malt. Conversely, crude protein and calorific value were significantly increased by the interaction. Addition of 2% malt and fermentation of the cereal flours for 24 h increased energy density and palatability, reduced dietary bulkiness and viscosity of CFs, which in turn will increase food intake by infants and young children.

A modification of a traditional Ethiopian maize store for solar powered ambient drying to reduce post-harvest losses.

A gombisa is a traditional Ethiopian structure widely used for maize storage over several months. It lacks adequate ventilation for timely moisture removal, which promotes mold development and aflatoxin production. In this study, a traditional gombisa was compared to one modified by installing a solar powered fan to provide forced ambient air ventilation during daytime. Approximately 900 kg of moist ear maize were loaded into each structure and samples from selected locations were weighed periodically to monitor moisture loss. Temperature and relative humidity of ambient air and inside the maize bulk were continuously recorded. Significantly faster drying was achieved in the modified gombisa, where drying occurred from bottom to top. In the traditional store, drying was much faster at the surface, with drying rate declining sharply with increasing depth in the bulk due to more limited air exchange. Relative humidity in the bulk center of the traditional structure remained above 90% for more than 4 weeks while in the modified gombisa it decreased progressively from the beginning of the trial. The results are promising and the modifications simple to implement, with the potential to effectively reduce post-harvest losses of maize. Field tests in Ethiopia are recommended.

Effect of Sieve Particle Size and Blend Proportion on the Quality Properties of Peeled and Unpeeled Orange Fleshed Sweet Potato Composite Flours.

Orange fleshed sweet potato (OFSP) has great potentials to improve the nutritional benefits of bakery products when processed into quality flour. This study investigated the effects of sieve particle sizes (250 µm and 500 µm) and flour blend proportions on the physicochemical, nutritional, functional and pasting properties of peeled and unpeeled OFSP composite flours. Peeled OFSP composite flours had significantly (p < 0.05) higher crude protein (CP), lightness (L*), oil absorption capacity (OAC) and water solubility (WS) but lower crude fiber (CF), bioactive compounds (except ascorbic acid), water absorption capacity (WAC) and swelling capacity (SC) than the unpeeled OFSP composite flours. The sieve particle size had no significant (p> 0.05) effect on nutritional and pasting properties. However, OFSP-based flours sieved with 500 µm mesh particle size had a significantly (p < 0.05) higher WAC and SC but a lower WS than corresponding 250 µm mesh flours. The proportions of flour blends greatly (p < 0.001) influenced all quality properties of OFSP composite flours. Generally, OFSP composite flours had higher CF, bioactive compounds, WAC, SC and WS, but lower CP, fat, OAC and pasting properties than wheat flour. The quality properties indicated that peeled and unpeeled OFSP flours sieved with a 250 µm or 500 µm mesh size have great potentials as ingredients in the bakery industry.