CA storage strongly suppressed fruit decay of all genotypes in red raspberry

Fruit of 9 genotypes of red raspberry (Rubus idaeus L.) were assessed for market-life when held at 1?C in air or controlled atmosphere (CA, 12.5 kPa CO2 / 7.5 kPa O2) with 95% RH over 2 harvest years. Fruit were assessed for firmness, soluble solids and titratable acids as well as sugar, acid and volatile composition immediately after harvest. Groups of 16 fruit were individually assessed for decay and physiological breakdown (PB) every 2?3 d. The lag period of decay and PB development was the number of days until the first sign of deterioration. The rate of fruit loss was the linear rate of deterioration following the lag period. CA storage strongly suppressed fruit decay of all genotypes with the lag period extended to >45 d compared to 19?29 d for genotypes stored in air. The lag of PB, which was expressed as juice leakage, ranged from 6 to 28 d in air-stored fruit and increased by ?1.0 to 9.7 d in CA-stored fruit depending on genotype. Loss of fruit firmness was similar during storage in air and CA. Sugar content of fruit averaged 51% fructose, 26% glucose and 23% sucrose. Acids averaged 75% citric, 13% quinic, 6% succinic and 6% malic. Both sugar and acid composition varied among genotypes. The majority of fruit volatiles were composed of C13 norisoprenoids, which totaled 65?93% of the total volatile content. Monoterpenes comprised 2.6?20.2% of total volatiles. Firmness prior to storage correlated with resistance to PB during storage. The development of PB negatively correlated with C13 norisoprenoid content, while correlations with other volatiles had no significant correlation with decay or PB development. No relationship between sugar and acid content and fruit storage-life was found. SourcesRelationships between fruit composition and storage life in air or controlled atmosphere of red raspberryCharles F. Forney, Andrew R. Jamieson, Kathleen D. Munro Pennell, Michael A. Jordan, Sherry A.E. Fillmore Agriculture & Agri-Food Canada, Atlantic Food & Horticulture Research Centre, 32 Main Street, Kentville, NS B4N 1J5, CanadaPostharvest Biology and Technology, Volume 110, December 2015, Pages 121?130 Picture by www.natural-motherhood.com