Quality indicators and shelf life of red octopus (Octopus maya) in chilling storage

Abstract There are no precedents concerning the quality of Octopus maya during chilled storage. This study evaluated the shelf life of the red octopus in chilling storage (4oC) and the correlation of the sensory quality index with microbiological counting and the biochemical indicators (hypoxanthine, histamine and volatile amines). A total of 112 whole raw octopi (average weight of 896 g) were randomly selected from seven batches and exposed to 4°C for 18, 24, 48, 72, 84, 96, and 100 h. The histamine concentration (91.7%), followed by the counts of psychrotrophic bacteria (5.5%) and hypoxanthine (2.2%), were the predictors from the redundancy analysis that better explained the changes taking place during the chilling hours. After 72 h of chilling, the microbial count was determined to be log 4.7 CFU/g, and the octopus samples were classified as B quality (minor sensory quality defects) based on the sensory quality scale. Although the samples were not classified as unacceptable at 100 h of refrigeration by the sensory index, the level of histamine reached the defect action level (5 mg/100 g) as ruled by the International Food Safety Authorities. The shelf life of the red octopus in chilling storage was predicted to be 119 h.

Osmotic priming methodologies in relation to the physiological performance of rangpur lime seeds (Citrus limonia Osbeck)

Several mechanisms have been used to promote rapid germination of citrus seeds and uniform seedling emergence. We evaluated the effects of osmotic priming on the physiological performance of Rangpur lime seeds (Citrus limonia Osbeck). Seeds were treated with 30 g of Captan and 10 g of Tecto 600 in 20-litre batches and stored, without drying, at 10 ºC and 50% relative humidity for periods of 3, 6 and 9 months. After each period, seeds were primed at 25 ºC, in the light, by immersion in Poliethylenoglicol (PEG 6000), potassium nitrate (KNO3) and 70% PEG 6000 plus 30% KNO3, all at an osmotic potential of -1.1MPa, for priming periods of 3, 6, 9 and 12 days. Percentage germination, tray emergence and the emergence rate index (ERI) were evaluated. Priming in PEG 6000 solution, independent of priming period, or in KNO3 or PEG 6000 plus KNO3 for up to 9 days, were efficient at improving the physiological performance of seeds stored for up to 3 months. Osmotic priming appears to be a promising technique for improving the physiological quality of Rangpur lemon seeds.

Survey, survival and control of Alternaria alternata in wheat seeds

The fungus Alternaria alternata was quantified in 75 wheat seed samples collected from three different regions of southern Brazil for Cropping and Use Value (CUV) I, II and III. Fungal presence was evaluated in two hundred disinfested seeds per sample before sowing in a potato-dextrose-agar medium + antibiotic (PDA+A). Fungus survival was evaluated every 45 days for 180 days for three seed batches from six wheat cultivars stored in propylene bags in a storehouse, with air temperature varying between 18 to 22 °C and relative air humidity around 60%. The efficacy of carboxin+thiram, difenoconazol, thiram, triadimenol, triticonazol and triticonazol + iprodione fungicides to control A. alternata was determined. A. alternata was detected in all the samples with an incidences of 39.6 %, 38.8% and 35.9% for the CUV I, CUV II and CUV III regions, respectively. The highest mean incidence of the fungus was found in the CUV I region, the coolest and most humid, and was significantly different from the other two regions. The average reduction in A. alternata viability in the wheat cultivar seeds was 49.5% during the 180 days of storage (inter-harvest period), demonstrating that infected seeds are the primary inoculum source for the fungus. The triticonazol + iprodione fungicide mixture efficiently controls A. alternata.