Quality Evaluation of Solar Tent Dried Puntius sophore and Mystus gulio of North East India Kapil Deb Nath and R. K. Majumdar* College of Fisheries, Central Agricultural University, Lembucherra, Tripura - 799 210, India Fishery Technology 50 (2013) : 146 - 153 Abstract Two commercially important small variety fish of north-east India, namely, Puntius sophore and Mystus gulio were dried using indigenously made solar tent dryer. The quality of the dried products was compared with the market sample of dry fish dried under open sun. Biochemical, microbiological and organoleptic characteristics were compared. Mois- ture and ash components were found higher in market sample in addition to protein and lipid degraded products. Although, bacteriological count was within the acceptable limit in both the products, fungal colonies were detected in market samples. Rehydration properties of market samples were lower than the solar tent dried products. The average temperature difference in the peak hours (12  3 oclock) between outside and inside of the solar tent dryer was 9.94 o C and 11.43 o C while drying Puntius sophore and Mystus gulio respectively for 3 days. Sensory scores for appearance, colour, odour and texture of the solar tent dried products were above 4 in the case of both the fishes, whereas, in the case of market samples, the scores for the similar quality attributes were between 3 and 4 and were within the acceptable limit. Keywords: Puntius sophore, Mystus gulio, solar tent dryer, dry fish, rehydration property Received 11 July 2012; Revised 27 November 2012; Accepted 20 December 2012 * E-mail: drrkmcof@gmail.com Introduction Drying is an efficient and cheap method for food preservation. The demand for dried fish and shrimp has been driven by the characteristic flavour of each product. In India, about 17% of the total fish catch is being used for salting and drying (Anon, 2001). The fish must be cleaned and dried quickly to protect it from microbes, insects and dirt. Tradition- ally, fishes are sun dried on ground, rocks, wooden platforms, palm leaves and also on the sandy beaches. The fishes dry slowly and unhygienically in direct sunlight in the absence of moving air. Also, there is every possibility of contamination when fish is dried using these traditional methods. During the past few years, there has been a decline in the export of Indian cured fishery products (Sugumar et al., 1995) mainly because of their poor quality. This causes considerable loss to the fish curing industry in India. Several methods have been reported to arrest different problems usually encountered during open sun drying of fish, of which solar tent drying is the one most reported. Solar tent dryer has replaced traditional sun drying practices in some areas. Different types of solar tent dryer and their advantages over the open sun drying has been reported by different authors (Doe et al., 1977; Chakraborti, 1995; Wazed et al., 2009). Bala & Janjai (2005) dried fish using Solar Tunnel Dryer (STD) where Bombay duck was dried to a moisture content of 15 from 89.8% in 9 h of drying as compared to 20 h of open sun drying. Several investigations proved that the use of solar tunnel fish drier leads to a considerable reduction of the drying time. The efficiency of solar dryer is evaluated depending on the temperature difference between inside and outside the tent. Mukherjee et al. (1990) developed a green house type of solar fish dryer by which it was possible to dry fresh fish of mixed variety and size to the desired moisture content within 2-3 days. Chakraborti (1995) designed another type of dryer based on the principle of green house effect. Solar drying systems must be properly designed in order to meet particular drying requirements of specific crops and to give satisfactory performance with ' 2013 Society of Fisheries Technologists (India)