Modified atmosphere packaging affects the incidence of cold storage disorders and keeps 'flat' peach quality

Firm-breaker and firm-mature flat peaches (Prunus persica L. Bastch cultiva r 'Paraguayo') were stored in air for 10 days at 20 degrees C, or precooled and sealed in either one of two unperforated or one macroperforated polypr opylene film for 14 or 21 days at 2 degrees C. The atmosphere inside the ma croperforated film bags remained close to the composition of air during sto rage. In unperforated bags, steady state atmospheres were reached within 6 and 9 days: firm-breaker fruit (12% CO2 and 4% O-2 in standard type polypro pylene, 23% CO2 and 2% O-2 in oriented type polypropylene); firm-mature fru it (22% CO2 and 3% O-2 in standard polpropylene and 21% CO2 and 2% O-2 in o riented polypropylene). After 14 days storage plus a 3-day shelf-life test, woolliness and slight internal browning developed in fruit stored in macro perforated polypropylene. Ethanol and acetaldehyde accumulated to higher le vels in oriented polypropylene bags for both firm-breaker and firm-mature f ruit. Modified atmospheres in both unperforated bags were associated with l ower weight loss, less senescence and chilling injury, absence of decay, an d delayed ripening changes of the fruit after a shelf-life period. (C) 1999 Canadian Institute of Food Science and Technology. Published by Elsevier S cience Ltd. All rights reserved.