EFFECTIVENESS OF SOLAR THERMOELECTRIC COOLER FOR FISH PRESERVATION: EXPERIMENTAL STUDY ON QUALITY CHARACTERISTICS OF Pangasius bocourti FISH FILLETS DURING STORAGE

Preservation of fish products is a big issue where inconsistent electricity supply. In the current study, a solar thermoelectric cooler (STC) was fabricated by exploiting the solar energy and its cooling potential for fish preservation was evaluated. The STC consists of a photovoltaic (PV) panel, battery, PV charge controller, thermoelectric cooling system, and cooler box. The temperature of the STC decreased to 7.4ºC within 90 minutes and then reached 5±0.2ºC in 150 min. The cooling capacity and coefficient of performance of the STC were 23.8 W and 0.44, respectively, at an input electric current of 3.5 A. The Pangasius bocourti fish fillets were stored in the STC for 10 days and tested its quality at 2 days intervals. On day 10, thiobarbituric acid, peroxide, pH, water binding ability, total plate count values were 1.65mg MDA/kg, 5.04 mEqO2/kg, 7.16, 26.18%, and 4.26 log CFU/g, respectively. A significant reduction in hardness, springiness, and chewiness values was observed, whereas no cohesiveness changes. The color values L* and a* decreased significantly, whereas b* and ΔE increased. The sensory attributes were found in the range of 5.2-6.0 on the 10th day. As the quality parameters showing an acceptable level, STC could be an alternate green option for fish preservation.

Artificial seed production of Pangasiid catfish in the Mekong Delta, Vietnam.

The two pangasiid catfish, Pangasius bocourti and P. hypophthalmus, are widely cultured in the Mekong Delta, Vietnam. However, seed supply until recently was dependent on fry and fingerlings caught from the Mekong River. In 1994, a research programme was carried out on artificial seed production of these two species in captive conditions. In 1995, about 30,000 fingerlings were first produced in An Giang and Can Tho provinces and a proper technique of induced breeding, progressive human chorionic gonadotropin (hCG) treatment, was determined. This technique, involving two steps of hCG injections, successfully induced ovulation in 66% of 67 treated females of P. bocourti. Application of this technique to other pangasiid catfish species such as P. conchophilus, P. hypophthalmus, P. mekongensis, and P. larnaudii also resulted in breeding success. Research on larval rearing has also been conducted to improve the growth and survival of pangasiid larvae. Extension of research findings of induced breeding and larval rearing has allowed mass seed production of pangasiid catfish in the Mekong Delta.

Método de Índice de Qualidade aplicado para o Pangasius bocourti (Sauvage, 1880) (Suriliformes; Pangasidae)

No estudo foi aplicado o Método de Índice de Qualidade (MIQ) adaptado para o Pangasius bocourti inteiro armazenado em gelo durante 25 dias, foi avaliado o frescor e estimado seu tempo de vida de prateleira e consumo humano aceitável, utilizando 80 exemplares despescados em uma piscicultura localizada no município de Bom Jardim - MA. Foram aplicadas análises sensoriais de atributos de qualidade por cinco julgadores treinados, em 10 exemplares/dia. Os escores foram tabulados, estimando-se a média e os desvios padrões para cada um dos cinco julgadores, para cada atributo e subatributo obtido. As análises microbiológicas utilizaram oito exemplares consistindo na utilização do primeiro exemplar/dia em cada dia de análise sensorial. O Protocolo MIQ proporcionou de 0 - 33 pontos deméritos, com seis atributos e 15 subatributos de qualidade. Nas análises microbiológicas foi verificado que as amostras se encontravam dentro do padrão estabelecido pela legislação brasileira mesmo após os 25 dias de estocagem. Conclui-se que o Método do Índice da Qualidade do P. bocourti foi eficaz para avaliar o frescor e estimar a vida útil da espécie. O P. bocourti inteiro armazenado em gelo permaneceu com seus índices sensoriais aptos para o consumo humano avaliadas pelo MIQ por até 12 dias.