Acidified sodium chlorite optimisation assessment to improve quality of fresh-cut tatsoi baby leaves

BACKGROUND: The fresh‐cut industry commonly uses sodium hypochlorite (NaClO) for disinfection. However, there are certain problems related to its use, and acidified sodium chlorite (ASC) could be an alternative sanitiser to replace it. There is limited research evaluating the effect of ASC on the overall quality of fresh‐cut produce, especially sensory quality. In this study the decontamination efficacy and quality attribute effects of ASC on fresh‐cut tatsoi after application and during storage were investigated. RESULTS: Tatsoi baby leaves were minimally processed at 8 °C and stored under passive modified atmosphere packaging for up to 11 days at 5 and 10 °C. Low to moderate doses of ASC (100–500 mg L^?1) showed an initial antimicrobial efficacy on natural microflora and Escherichia coli as effective as that of NaClO. Regarding contact time, ASC was effective in reducting the E. coli population during the first 30 s of washing, and an increase in contact time did not improve the antimicrobial effect. Sensory quality attributes were well kept for up to 11 days at 5 °C but for only 5 days at the abusive temperature of 10 °C. CONCLUSION: ASC provides an alternative sanitising technique to NaClO for maintaining the quality and safety of fresh‐cut tatsoi baby leaves for up to 11 days at 5 °C. Copyright © 2011 Society of Chemical Industry     

FERC regulation—electricity: FERC and NERC speed processing of electric reliability violations

The North American Electric Reliability Corporation (NERC) is the organization responsible for ensuring the reliability of the bulk-power system (BPS) in the United States, Mexico, and Canada. NERC recently received approval from the Federal Energy Regulatory Commission (FERC) to streamline the process for tracking and reporting violations of electric reliability standards. On March 15, FERC issued an order conditionally approving the proposed “Find, Fix, Track, and Report” (FFTR) process to expedite the enforcement process for violations of NERC Reliability Standards that pose lesser risk to the BPS. 1 In its approval of NERC's new process, however, FERC included several conditions that narrow the range of potential violations eligible for the expedited process. FERC Chairman Jon Wellinghoff hailed the new process as “a major change in how [FERC] will enforce compliance with the Reliability Standards going forward.” 2     

Assessing the performance of methods to detect and quantify African dust in airborne particulates

African dust (AD) contributions to particulate matter (PM) levels may be reported by Member States to the European Commission during justification of exceedances of the daily limit value (DLV). However, the detection and subsequent quantification of the AD contribution to PM levels is complex, and only two measurement-based methods are available in the literature: the Spanish-Portuguese reference method (SPR), and the Tel Aviv University method (TAU). In the present study, both methods were assessed. The SPR method was more conservative in the detection of episodes (71 days identified as AD by SPR, vs 81 by TAU), as it is less affected by interferences with local dust sources. The mean annual contribution of AD was lower with the TAU method than with SPR (2.7 vs 3.5 ± 1.5 μg/m(3)). The SPR and TAU AD time series were correlated with daily aluminum levels (a known tracer of AD), as well as with an AD source identified by the Positive Matrix Factorization (PMF) receptor model. Higher r(2) values were obtained with the SPR method than with TAU in both cases (r(2) = 0.72 vs 0.56, y = 0.05x vs y = 0.06x with aluminum levels; r(2)=0.79 vs 0.43, y = 0.8x vs y = 0.4x with the PMF source). We conclude that the SPR method is more adequate from an EU policy perspective (justification of DLV exceedances) due to the fact that it is more conservative than the TAU method. Based on our results, the TAU method requires adaptation of the thresholds in the algorithm to refine detection of low-impact episodes and avoid misclassification of local events as AD.     

Quality changes of fresh-cut kohlrabi sticks under modified atmosphere packaging

ABSTRACT:  The aim of this study was to determine the effect of different gas compositions on quality attributes and shelf life of kohlrabi sticks stored in modified atmosphere up to 14 d at 0 °C. Two commercial films were tested: oriented polypropylene (OPP) and amide-polyethylene (amide-PE). As a control, a microperforated OPP film was used. In order to study the changes in metabolic activity by minimal processing, the respiration rate and ethylene production at 0 °C were monitored for both intact stems and sticks. Changes in color, chemical parameters, sugars and organic acid contents, and sensorial quality of kohlrabi sticks were evaluated. An initial ethylene production of sticks was 13-fold higher than that of intact stems; meanwhile CO₂ production was 2-fold higher. However after 4 d of storage, a similar respiration rate for stems and sticks was found. Also the ethylene production of sticks and stems was steady around 15 to 20 nL/kg^/h after 10 d. Kohlrabi sticks showed a little change in chemical parameters and very low weight losses during cold storage. Sticks under an equilibrium atmosphere of 7 kPa O₂ and 9 kPa CO₂ at 0 °C reached by amide-PE kept an acceptable sensorial quality for 14 d.     

Hot water,UV‐C and superatmospheric oxygen packaging as hurdle techniques for maintaining overall quality of fresh‐cut pomegranate arils

BACKGROUND: In recent years there has been increasing consumer pressure to avoid the use of agrochemicals such as chlorine on fresh plant products for extending their shelf life. The combined use of eco‐sustainable techniques may be an alternative. The effect of hot water (HW), ultraviolet‐C (UV‐C) light and high oxygen packaging (HO) on the overall quality of fresh‐cut pomegranate arils stored under modified atmosphere packaging (MAP) for up to 14 days at 5 °C was studied. RESULTS: Arils extracted manually, washed with chlorine (100 µL L^?1 NaClO, pH 6.5, 5 °C water), rinsed and drained were exposed to single or combined (double and triple) hurdle techniques. The HW treatment consisted of a 30 s immersion in water at 55 °C followed by air surface drying. A 4.54 kJ m^?2 dose was used for the UV‐C treatment before packaging. Active MAP with initial 90 kPa O₂ was used in the HO treatment. The respiration rate remained relatively constant throughout shelf life, with no differences among treatments. CO₂ accumulation was higher within HO packages. HW induced a slight reduction in total soluble solids, while no changes in titratable acidity were found. HO‐treated arils had the highest phenolic content, while the lowest was found in HW‐treated arils. The lowest antioxidant activity was found in HW + UV‐C + HO and the highest in UV‐C + HO and HO treatments. HW alone or in combination with UV‐C and HO inhibited mesophile, mould and yeast growth, while UV‐C + HO was most effective for controlling yeast and mould growth. CONCLUSION: UV‐C and HO either alone or in combination are promising techniques to preserve the quality of pomegranate arils for up to 14 days at 5 °C. © 2012 Society of Chemical Industry