Innovative techniques for traditional dried fish products

Abstract

Three innovative techniques were developed for producing value-added traditional fish products, namely hot-air oven and vacuum oven drying to process dried shrimp instead of sun-drying and puff machine to cook the fish cracker instead of deep-frying. Shrimp was dried for 5 hours at 85°C in the hot-air oven and 2.5 hours at 130°C in the vacuum oven. The moisture content for hot-air dried shrimp was 7.9% and water absorption ability was 48%. The vacuum dried shrimp had a moisture content of 3.4% and a water absorption ability of 118%. Using the vacuum oven drying, drying time was greatly reduced and dried shrimp with a low moisture content, high water absorption ability and a new crispy texture was obtained. The vacuum dried shrimp is suitable to be eaten directly as a snack food and can also be used as an ingredient for instant noodles. Storage studies were also conducted on the dried shrimp products produced by both techniques under two packaging conditions, i.e. air-pack and vacuum-pack. Apart from the vacuum-dried air-pack shrimp which gave off an ammoniacal smell, all other shrimp samples were found to remain acceptable after 7 months of storage at 28 ± 2°C. Fish cracker cooked by the puff machine had a greater amount of linear expansion than those cooked by deep-frying with the added advantage that no oil was used in the puffing process resulting in a healthier product.