Effects of type and quantity of flours used on the quality of frozen fish balls

Fish balls were produced from thread-fin-bream based surimi. Three types and quantities of flours were used in this study: tapioca flour, Purity 4 and National Frigex. Three, 5 and 8% were added during kneading. The cooked fish balls were then frozen by nitrogen tunnel and stored at -18°C in order to determine their quality during storage. Samples were removed to determine total viable count (TVC), total volatile base (TVB), gel strength, drip loss, moisture and protein content and for sensory assessment. The addition of 8% National Frigex reduced drip loss up to 50% compared to control samples (fish balls without addition of flour) and gave better results than the use of tapioca flour. Type and quantity of modified starches did not affect general appearance, surface, succulence, texture, glossiness and flavour of the fish ball samples. The samples stored more than 60 days caused outer surface dryness and reduced glossiness resulting in unacceptability by the panelists

A continuous flow packed bed photocatalytic reactor for the destruction of 2-methylisoborneol and geosmin utilising pelletised TiO₂

Taste and odour compounds, especially geosmin (GSM) and 2-methylisoborneol (2-MIB), cause major problems in both drinking water and aquaculture industries world-wide. Aquaculture in particular has experienced significant financial losses due to the accumulation of taint compounds prior to harvest resulting in consumer rejection. UV–TiO2 photocatalysis has been demonstrated to remove GSM and 2-MIB at laboratory scale but the development of a continuous flow reactor suitable for use in water treatment has not been investigated. In this study, a pilot packed bed photocatalytic reactor was developed and evaluated for water treatment with both laboratory and naturally tainted samples. A significant reduction of both 2-MIB and GSM was achieved in both trials using the packed bed reactor unit. With the laboratory spiked water (100 ng L−1 of each compound added prior to treatment), detectable levels were reduced by up to 97% after a single pass through the unit. When the reactor was used to treat water in a fish farm where both compounds were being produced in situ (2-MIB: 19 ng L−1 and GSM: 14 ng L−1) a reduction of almost 90% in taint compounds was achieved. These very encouraging promising results demonstrate the potential of this UV–TiO2 photocatalytic reactor for water treatment in fish rearing systems and other applications