The response of unripe Conference pears to modified atmosphere retail packaging

Summary Unripe green Conference pears with initial firmness values of 46–55 N were sealed in modified atmosphere (MA) low density polyethylene (LDPE, 30μ) pillow packs and in perforated control packs on three dates during 1985–1986. Changes in pack atmosphere composition, skin chlorophyll content, flesh firmness and sensory quality were monitored during 14–20 days simulated shelf‐life at 20°C. In MA packs, equilibrated atmospheres containing 5–9% CO2 and < 5% O2 developed within c. 3 days. Chlorophyll degradation was completely inhibited by MA and resumed when packs were perforated, but MA only partially retarded the rate of flesh softening. Variations in the rate of ripening changes in duplicate MA packs could not be explained simply by differences in pack atmospheres. Furthermore, pears retarded by MA packaging failed to develop the normal sweet, aromatic flavour and succulent, juicy texture of ‘eating‐ripe’ fruit, even when the packs were perforated after 4 days. The differences in the responses of pears and apples to MA packaging, and the limitations of using this technique for the commercial marketing of English pears are discussed.