Adande Refrigeration’s parent company, Applied Design & Engineering, has commissioned Assured Quality Solutions to assist in scientific trials of its Aircell ‘air curtain’ technology.
Over a 7 day period, bags of baby leaf salad and house salad bowls, provided by a major industry supplier, were held in a commercially available open front multi deck and an identical model, modified with the patented Aircell air flow management system. Salad was selected for the tests due to its sensitivity to temperature abuse and its relatively short shelf life, typically 6 days.
During the trials, the conventional single air curtain cabinet demonstrated a temperature bandwidth of 11.2°C compared with a span of 5.4°C in the Aircell model. Relative humidity was measured at 9% higher in the cabinet with Aircell.
Salad bags and bowls were taken from the cabinets at the end of each day of the trials and transported, in a refrigerated container, to a local independent microbiology laboratory for measurement of yeasts, moulds and total viable counts (TVC) for bacterial growth. On each day of the tests, the TVC were reportedly consistently higher in the baby leaf salad bags displayed in the conventional cabinet.
The highest TVC in the cabinet with Aircell was 5.0 x 107 colony forming units per gram (cfu/g) compared with 2.8 x 108 cfu/g in the conventional cabinet. By day 5 there was also a substantial difference in the total yeast count of 1.6 x 104 cfu/g in the cabinet with Aircell, compared with 3.0 x 105 cfu/g in the conventional cabinet, indicating that bacterial proliferation occurred sooner and was greater in the conventional cabinet.
Similarly, the TVC for bacterial growth in the house salad bowls were consistently higher in the conventional cabinet. By day 5 the total yeast on the salad displayed in the conventional cabinet was 2.8 x 105 cfu/g compared with 4.0 x 103 cfu/g cabinet with Aircell, demonstrating more rapid bacterial proliferation in the conventional cabinet.
In addition to the laboratory assessments, David Vagg of Assured Quality Solutions conducted organoleptic (taste, sight, smell and touch) tests and found that there was a higher degree of product degradation in the salad packs and bowls displayed in the conventional cabinet. The majority of the baby leaf salad displayed in the conventional cabinet scored below 25% in the sensory assessment, compared with a score of above 60% in the cabinet with Aircell. The overall sensory quality score of house salad bowls was rated at 68% in the cabinet with Aircell and 44% in the conventional cabinet.
At the end of the trials, Vagg commented: “The tighter temperature control demonstrated by the cabinet with Aircell offers up a number of opportunities for the retailer. There is real potential for longer shelf life and fewer customer complaints associated with poor quality, deteriorating products.
“The current focus on limiting single use plastic packaging is likely to shorten shelf life and increase food waste. Aircell, with its tighter temperature bandwidth, has the potential to mitigate the impact of reduced packaging on product quality.”
Applied Design & Engineering’s chairman, Nigel Bell, added: “Aircell is a unique and disruptive technology for open front refrigerated displays. It is currently the only system which helps ensure consistently narrower temperature bandwidths for maintaining perishable merchandise at optimum quality over extended periods.
“We believe these trials demonstrate that refrigerated cabinets incorporating Aircell will help make a tangible contribution to reducing food waste in the retail cold chain.”