Effect of high carbon dioxide atmosphere packaging and soluble gas stabilization pre-treatment on the shelf-life and quality of chicken drumsticks.

The effects of an aerobic modified atmosphere packaging (MAP) (70% CO2, 15% O2 and 15% N2) with and without a CO2 3-h soluble gas stabilization (SGS) pre-treatment of chicken drumsticks were determined for various package and product quality characteristics. The CO2 dissolved into drumsticks was determined. The equilibrium between CO2 dissolved in drumsticks and CO2 in head space was reached within 48h after packaging, showing highest values of CO2 in SGS pre-treated samples. This greater availability of CO2 resulted in lower counts of TAB and Pseudomonas in SGS than in MAP drumsticks. Package collapse was significantly reduced in SGS samples. The average of CO2 dissolved in the MAP treatment was 567mg CO2kg(-1) of chicken and, 361mg CO2kg(-1) of chicken during the MAP treatment, in SGS pre-treated samples. This difference could be the quantity of CO2 dissolved during SGS pre-treatment. These results highlight the advantages of using SGS versus traditional MAP for chicken products preservation.

Effect of UHPH on indigenous microbiota of apple juice: a preliminary study of microbial shelf-life.

The effect of ultra high pressure homogenisation (UHPH) at 100, 200 and 300 MPa on apple juice at two different inlet temperatures (4 and 20 degrees C) was studied. Raw and conventional heat treated (PA) apple juice was compared with UHPH treated juice after treatment and during 60 days of storage at 4 degrees C. The microbial quality was studied by enumerating aerobic mesophilic counts (AM), psychrotrophs (PS), moulds and yeasts (MY), lactobacilli (LB), enterobacteriaceae (EB), and faecal coliforms (FC). PA samples were below detection level (< or = -2 log cfu/mL) for all groups, the same as UHPH treated juices at 200 MPa and above but for around 1 log cfu/mL for AM. Those AM counts did not change during 60 days storage at 4 degrees C and proved to be spores. Juices treated at 100 MPa shown little reductions in microbial counts, and surviving microorganisms significantly increased their numbers during storage. This research work showed that non-thermal methods such a UHPH technology may give new opportunities to develop "fresh like" apple juice with a shelf-life equivalent to PA in terms of microbiological characteristics without affecting the product quality.