Microbiological, chemical, and sensory assessment of Pacific oysters (Crassostrea gigas) stored at different temperatures

• Published in: Czech Journal of Food Sciences 2009-01, Vol.27 (2), p.102-108
• Main Authors: Cao, R.,Ocean University of China, Qingdao (China). Coll. of Food Science and Engineering, Xue, C.H.,Ocean University of China, Qingdao (China). Coll. of Food Science and Engineering, Liu, Q.,Chinese Academy of Fishery Sciences, Qingdao (China). Yellow Sea Fisheries Research Inst, Xue, Y.,Ocean University of China, Qingdao (China). Coll. of Food Science and Engineering
• Format: Article
• Language: English
• Subjects: Aerobic bacteria; ALMACENAMIENTO; ANALISIS MICROBIOLOGICO; ANALISIS ORGANOLEPTICO; ANALYSE MICROBIOLOGIQUE; ANALYSE ORGANOLEPTIQUE; APTITUD PARA LA CONSERVACION; APTITUDE A LA CONSERVATION; AZOTE; CHEMICAL COMPOSITION; COLOR; COLOUR; COMPOSE VOLATIL; COMPOSICION QUIMICA; COMPOSITION CHIMIQUE; COMPUESTO VOLATIL; CONTROL DE CALIDAD; CONTROLE DE QUALITE; COULEUR; CRASSOSTREA GIGAS; DETERIORATION; DETERIORO; DURACION; DURATION; DUREE; FLAVEUR; FLAVOUR; http://www.fao.org/aos/agrovoc#c_10350; http://www.fao.org/aos/agrovoc#c_10893; http://www.fao.org/aos/agrovoc#c_15578; http://www.fao.org/aos/agrovoc#c_16006; http://www.fao.org/aos/agrovoc#c_1773; http://www.fao.org/aos/agrovoc#c_1794; http://www.fao.org/aos/agrovoc#c_2412; http://www.fao.org/aos/agrovoc#c_24933; http://www.fao.org/aos/agrovoc#c_25302; http://www.fao.org/aos/agrovoc#c_31156; http://www.fao.org/aos/agrovoc#c_4082; http://www.fao.org/aos/agrovoc#c_4807; http://www.fao.org/aos/agrovoc#c_5192; http://www.fao.org/aos/agrovoc#c_5399; http://www.fao.org/aos/agrovoc#c_5484; http://www.fao.org/aos/agrovoc#c_5753; http://www.fao.org/aos/agrovoc#c_6304; http://www.fao.org/aos/agrovoc#c_6401; http://www.fao.org/aos/agrovoc#c_7427; http://www.fao.org/aos/agrovoc#c_7657; HUITRE; KEEPING QUALITY; Lag phase; Marine; MICRO-ORGANISME; microbial flora; MICROBIOLOGICAL ANALYSIS; MICROORGANISMOS; MICROORGANISMS; NITROGEN; NITROGENO; ORGANOLEPTIC ANALYSIS; ORGANOLEPTIC PROPERTIES; OSTRA; OYSTERS; pacific oyster; PROPIEDADES ORGANOLEPTICAS; PROPRIETE ORGANOLEPTIQUE; PSEUDOMONAS; quality assessment; QUALITY CONTROLS; SABOR; Sensory properties; Shelf life; STOCKAGE; STORAGE; Storage temperature; TEMPERATURA; TEMPERATURE; TEXTURA; TEXTURE; Vibrionaceae; VOLATILE COMPOUNDS
• ISSN: 1212-1800; 1805-9317
• DOI: 10.17221/166/2008-CJFS

The objective of this study was to evaluate changes in microbiological, chemical, and sensory properties of Pacific oysters stored at 10 deg C, 5 deg C, and 0 deg C. Pseudomonas (22%) and Vibrionaceae (20%) species were dominant in raw oysters. The dominant bacteria found in the spoiled samples were Pseudomonas regardless of the storage temperature. During storage, rapid increases in aerobic plate count (APC) values of the samples stored at 10 and 5 deg C were observed, while no obvious lag phases were detected. With the samples stored at 0 deg C, a decrease in APC value during the first 4 days and a lag phase of about 6 days were observed. The APC values of the samples stored at 10 deg C, 5 deg C, and 0 deg C reached the level of 10,000,000 CFU/g on day 6, 10, and 18, respectively. All the tested samples stored at different temperatures revealed a slight decrease in pH and a significant increase of total volatile basic nitrogen (TVB-N) during storage. The average TVB-N concentration of about 22.0 mg N/100 g was observed at the end of the shelf life as determined by APC. Combined with the sensory assessments, the shelf life of 6-7, 10-11, and 17-18 days for oysters stored at 10 deg C, 5 deg C, and 0 deg C, respectively, was determined.