DESIGN, FABRICATION AND EVALUATION OF PORTABLE SOLAR DRYER FOR DRYING FISH AND FISHERY PRODUCTS

A study was conducted with the aim of designing, fabrication and evaluating the drying efficiency of newly designed solar dryers for fish and fishery products. The material used for drying was salted fish (Sardinella longiceps). Rate of drying was found to be influenced by the atmospheric temperature and humidity, either using aluminium based solar dryer (ASD) or HDPE (High density Polyethylene) based solar dryer (HSD). In the case of ASD the drying period was 7 hrs compared to HSD which took about 12 hrs. Various parameters such as proximate composition, moisture content, TPC, TFC, TVBN content and PV during drying and storage were monitored. The quality of dried samples of ASD showed significantly superior compared to HSD dried samples. Hence, the aluminium based solar dryer is recommended for drying fishery products for a small scale production.

In our country the majority of those involved in drying or salting of fish is low income group. Sun drying hardly involves any expenditure as sun's radiation is plentifully available free of cost. Disadvantages in sun drying are contamination, over drying, long drying period, maggots infestation etc. To overcome this disadvantage an attempt was taken to design a solar dryer. It will be cost effective, simple to construct, compact and efficient for fishery products.  

A scaled down version of ASD and HSD of dimension 120x 80x 80cm was fabricated (Fig.1). Sardinella longiceps was dry salted and subjected for drying in the dryers. Various parameters such as moisture content, TPC, TFC, TVBN content and PV during drying were monitored. The quality variations fish samples were significantly lower when dried using the ASD compare to HSD. For conducting storage studies, the dried fish samples of both the dryers were packed in low permeable polypropylene- polyamide bags and stored at room temperature for about 60 days. Quality parameters viz., moisture content, TPC, TFC, TVBN and PV content were evaluated during storage. Both ASD and HSD remained acceptable throughout the storage period. However, the quality of fish dried in ASD was found to be superior compared to their respective HSD dried control samples