Microbiological and biochemical changes in pearl spot (Etroplus suratensis Bloch) stored under modified atmospheres

Abstract

Aims: This study aimed to determine the effect of packaging [air, modified atmosphere (MA)] on microbial growth, sensory and chemical parameters and also on shelf life of fresh pearl spot (Etroplus suratensis Bloch) and on the selection of microbial association. Methods and Results: Fresh pearl spot (whole, gutted) were packaged under both 100% air and MAs (40%CO 2 / 60% O 2 , 50%CO 2 /50%O 2 , 60% CO 2 /40%O 2 , 70% CO 2 /30% O 2 and 40% CO 2 /30% O 2 /30% N 2 ) and stored at 0°C. Microbial growth (counts of total aerobic bacteria, H 2 S-producing bacteria, Lactic acid bacteria, Brochothrix thermosphacta, yeast and mould), chemical spoilage indicators (pH, total volatile basic nitrogen) and sensory characteristics were monitored. Microbial changes in Pearl spot packed under 100% air and 40% CO 2 /30%O 2 / 30% N 2 were similar. The total volatile basic nitrogen values increased, but the values never exceeded the acceptability limit of 25 mg 100 g )1 .Conclusions: MA 60% CO 2 : 40%O 2 was found to be better with a shelf life of 21 days whereas air stored samples had a shelf-life of 12-14 days only. Significance and Impact of the Study: Storage of pearl spot under MAs 60% CO 2 : 40%O 2 is a promising method to extend shelf-life. Longer shelf life expands the market potential of pearl spot and reduces waste during distribution and retail display.

Effect of Chilling on Microbiological, Biochemical and Sensory Attributes of Whole Aquacultured Rainbow Trout (Oncorhynchus mykiss Walbaum, 1792)

“…pH values for whole ungutted trout samples increased with storage time from an initial value of 6.74 (Table 2) indicating bacterial growth and production of volatile basic compounds such as ammonia by fish spoilage bacteria. Increase in pH due to accumulation of alkaline compounds through autolytic activities and microbial metabolism has been reported in earlier studies [65,73,74]. Many microbes including Pseudomonas produce ammonia during amino acid metabolism.…”

“…TMAO quantity in fish varies with the species and the environment. A wide range of TMA-N values have been reported by several investigators as acceptability limit i.e., 1-5mg N/100 g [62][63][64][65]. Sikorski et al [66] and Dalgaard et al [67] reported that a population of 108-109 cfu/g of S. putrefaciens was considered crucial for TMA production.…”

EFFECT OF MODIFIED ATMOSPHERE PACKAGING ON CHEMICAL, TEXTURAL, MICROBIOLOGICAL AND SENSORY QUALITY OF SEER FISH (SCOMBEROMORUS COMMERSON) STEAKS PACKAGED IN THERMOFORMED TRAYS AT 0–2C

“…(1990) reported that a mixture of 80% CO 2 and 20% O 2 was more beneficial in extending the shelf life of Catla catla , and total viable counts were significantly higher in fish stored under air than that stored under MAP. Lalitha et al. (2005) reported a delay in the growth of aerobic bacteria in pearl spot packaged under gas mixtures 60% CO 2 : 40% O 2 and 70% CO 2 : 30% O2.…”

“…In India, research on MAP of freshwater as well as marine fish were carried out (Gopal et al. 1986, 1990, 1996; Lalitha et al. 2005).…”

Effects of Modified Atmosphere Packaging on the Microbiological Properties of Fresh Common Carp (Cyprinus carpio L.)

“…There is little information on the effect of MAP with elevated O 2 level on bacterial growth retardation in the literature. Based on microbiological, chemical and sensory analyses, Sivertsvik Sankar et al (2008) and Lalitha et al (2005) examined the effect of various modified atmospheres on pearl spot, including a 60% O 2 /40% CO 2 atmosphere. During storage they detected a microbial growth decrease resulting in a longer shelf life when compared to air packaging.…”