Technical and Economic Parameters for the Adoption of Solar Drying Systems on Small Farms

Solar cabinet dryers appear suitable for use by small Caribbean farmers, many with farms less than 1 ha in size. Perishable products like sorrel, hot peppers, sweet potatoes and mango slices may be dried for safe storage. In a solar cabinet dryer of the multi-rack design, an overall drying efficiency of 25% can be expected. Crops can be dried in thin layers with loading densities of less than 5 kg/m2, in two days of fair weather. For the small farmers, with holdings ranging from 0.125 to 1 ha, and with 50% of their annual crop yield dried, dryers with cover areas ranging approximately from 3.8 m2 to 30.8 m2 respectively, will be adequate for a crop like sorrel. The minimum estimated cost of such dryers would correspondingly increase from US$75 to US$600

Factors influencing the ammonia treatment of rice straw

Small samples of ground rice straw (initial moisture content 7%) were treated at ambient temperatures with aqueous NH3 at 2, 4, 6 and 8 % levels (on a dry matter basis). The final moisture content was 21%. Samples at each level of ammoniation were held for 7, 14, 21 and 28 days. The IVDMD of the samples, predicted from the pepsin-cellulose method, indicated a strong trend towards higher digestibility with increasing levels of NH3 application, although the difference between 6% and 8% NH3 was small. Treatment at ambient temperatures was completed in 7 days. In a second set of experiments, samples of straw were treated with 6% NH3, such that the final moisture contents were 13% and 25%. These samples were stored at 30, 60 and 90°C, and for 6, 18, 72 and 168 hrs. IVDMD analyses indicated that increasing treatment time, temperature and moisture content of the straw, all had positive effects on the IVDMD

Unpacking Impact: Exploring Impact Measurement for Social Enterprises in Ontario

Produced by the Mowat Centre at the School of Public Policy and Governance, University of Toronto.With support from the Ontario Ministry of Economic Development and Growth (MEDG), Mowat NFP developed this report to examine the concept of common impact measurement frameworks and standardization globally, and identify specific opportunities to strengthen impact measurement practices for the social enterprise ecosystem in Ontario

DRYING OF THE DASHEEN LEAF

The drying behavior of the dashecn leaf under natural convection conditions at temperatures ranging from 40-70C was studied in an attempt to develop a dehydrated product from this popular vegetable often used in soups and commonly called - 'callaioo.' The effects of various pretreatments on the drying behavioral of the vegetable at 60°C were also studied, viz. steam blanching (96°C for 6 min ), water blanching (near boiling for 10s) and blanching in 0.06% magnesium carbonate at near boiling for 10 s prior to immersion in a mixed chemical bath consisting mainly of 20% sucrose, for 4 h at 21°C. Two falling rate periods of drying were observed for dashecn leaves dried at 40-70°C. However, a single falling rate period of drying was found for the water and magnesium carbonate blanched-infused vegetable at 60°C. Although drying rates markedly increased with increasing drying temperature, drying at high temperatures particularly at 60°C and 70°C resulted in a deleterious color change from green, typical of the fresh vegetable, to an unattractive olive-brown or brown discoloration. Steam blanching appeared to have no significant effect on the drying rate of the dasheen leaf compared to fresh leaves while for the water blanched vegetable, the drying rate was reduced by 50%. Compared to water blanching, alkali blanching was found to have no significant effect on the drying rate of the dasheen leaf. Blanching in water or alkali resulted in a superior dehydrated product which, unlike the steam blanched vegetable, showed minimal loss of green color

POSTHARVEST STORAGE OF THE POMERAC UNDER REFRIGERATION

A postharvest storage trial was conducted to determine the effects of four different storage temperatures, ambient (28°C), 5°C, 10°C and 15°C on the shelf-life of the ponierac (Eugenia malaccensis) or French Cashew. The aim of the experiment was to determine the best storage conditions for extending the shelf-life of the pomerac, while maintaining acceptable physical, chemical and organoleptic properties. The physical parameters measured included fruit firmness, percent fresh weight loss and specific gravity. The chemical parameters studied were ascorbic acid, titratable acidity, total soluble solids, pH and anthocyanins. Sensorymeasurements included color, firmness, odor, decay and shrivelling. Preliminary results showed that under ambient conditions the pomerac had a shelf-life of 4-6 days. Fruits held at 10°C and ^"C were shrivelled, decayed and showing color loss in the skin after 10-15 days in storage. At 5°C fruits were acceptable in terms of color, firmness, taste and odor even after 20 days in storage

A DEHYDRATED PRODUCT FROM THE CULINARY HERB, SHADO BENI {Eryngium foetidum Linn.)

In an attempt to develop a dehydrated product, the food flavouring herb Eryngium foetidum Linn, commonly called 'shado beni' or 'bhandhanya' in Trinidad and Tobago, was dried in a natural convection cabinet dryer at 35, 45, 55 and 65 °C. The effects of various pre-drying treatments on the quality of the herb at 55 °C were also studied: steam blanching, water blanching and magnesium carbonate blanching. Drying of the fresh herb at high temperatures, e.g. 55 and 65 °C, resulted in an undesirable colour change from the green, typical of the fresh herb, to olive-brown/brown. This was paralleled by a decline in the herb's volatile oil constituent from 0.276% d.b for fresh shado beni to 0.049 and 0.030% d.b for the herb dried at 55 and 65 °C respectively. Shado beni dried at 35 °C appeared olive-green with an oil content of 0.095% d.b. Loss of green colour was considerably reduced by blanching in either water or magnesium carbonate prior to drying at 55 °C. Compared to the unblanched dried herb, oil yield was unaffected by the pre-drying treatments investigated

MODELLING THE WATER BALANCE OF CUT ANTHURIUMS IN STORAGE

Expérimental trials were conducted to investigate the basic components of water balance (water uptake, transpiration, water accumulation) and their relationship to senescence and vase life in cut anthuriums stored under ambient and refrigerated conditions. Anthuriums were held in distilled water and stored under ambient conditions (28 °C; rh 60-80%) and in refrigerated storage chambers set at 18, 13 and 8 °C (rh 80-90%) for a maximum of 30 days. Water uptake, transpiration, water accumulation, flower fresh weight, moisture content and keeping quality (determined through spathe blueing, spathe gloss, spadix necrosis and abscission) were monitored at 5-day intervals. Storage of anthuriums in water at 18 and 13 °C extended shelf-life. The changes in water uptake, transpiration, transpiration:uptake ratio, fresh weight and moisture content were accurately described by logarithmic, exponential and inverse quadratic models. Post-harvest life was directly related to flower turgidity and the rate of water accumulation, which was dependent on the balance between the rates of uptake and transpiration

REFRIGERATED STORAGE OF THE JULIE MANGO

The shelf-life of the Julie mango was investigated with respect to the temperature and time in storage. Fruits were stored underambient conditions (28°C), and at refrigerated temperatures (6°C, 10°C and 14°C). On the day of harvest and at 7 day intervals, fruits were removed from storage and chemically and physically analysed. Weight and volume loss in storage, fruit firmness, starch content, total soluble solids and acidity were measured. On removal from storage some fruits were allowed to ripen under ambiant conditions after which they were similarly analysed. Fruits kept under ambient conditions were used as the control, and these were analysed as they ripened. Fruits under ambient conditions ripened after a maximum of 8 days while fruits stored at 14°C ripened in storage after 21 days to an acceptable quality. Fruits at 6°C and 10°C did not attain any significant degree of ripeness in storage up to 42 days. At this time however, there were signs of chilling injury, particularly for fruits held at 6°C. At 10°C a storage life of 4 weeks appears promising. ----- La conservation de la mangue Julie a été étudiée en fonction du temps et de la température. Les fruits sont conservés dans les conditions ambiantes à 28°C et aux températures de 6°C, 10°C et 14°C. Les fruits sont analysés chimiquement et physiquement le jour de la récolte et 7 jours après conservation. Les pertes de poids et de volume au cours de la conservation, la fermeté du fruit, la teneur en amidon, les composés solubles totaux et l'acidité sont mesurées. A la sortie de la conservation certains fruits sont laissés à mûrir et analysés comme témoins et analysés dès maturation. Dans les conditions ambiantes les fruits mûrissent au bout de 8 jours alors que les fruits conservés à 14°C mûrissent après 21 jours avec une qualité acceptable. Les fruits à 6°C et à 10°C n'ont atteint aucun degré de maturation en conservation observable au bout de 42 jours. Au bout de ce moment apparaissent des signes de détérioration surtout sur les fruits à 6°C. A 10°C une conservation pendant 4 semaines parait prometteuse