Storage of sweet cherries in low oxygen and high carbon dioxide atmospheres

Abstract

Acetaldehyde and ethanol are already present in detectable levels at the time of harvest, under aerobic conditions and in healthy, undamaged fruit. Both metabolites can be detected, at different concentrations, in all cultivars. Several hours after harvest, the levels of acetaldehyde in cultivars Summit, Těchlovan and Kordia were 6.41, 9.78 and 22.00 mg/l, respectively. Both ethanol and acetaldehyde accumulate to significant levels in anaerobically stored cherries, particularly in atmospheres with high levels of CO 2 . The highest levels of ethanol observed, after 31 days of exposure to anaerobic conditions, were in the cultivars Těchlovan (1,159 mg/l) and Summit (1,168 mg/l); both concentrations are are broadly similar. The metabolites decreased after a return to aerobic conditions, but remained higher than the levels first observed. Sweet cherries stored in anaerobic conditions are also sensitive to the development of off-flavours in the first 24 hours after opening the storage box. The very slow ripening of the fruit under anaerobic conditions was satisfactorily quantified by measuring the higher degree of fruit firmness, when the usual, visual attributes of ripeness were almost undetectable. Stems also remained green, in contrast to the usual browning that occurs under normal atmospheres. Discrimination analysis of various parameters observed gave a good resolution of different cultivars. 27tential of ultra-low oxygen (ULO) storage as a practical technique for extending sweet cherry shelf-life. MATERIAL AND METHODS Fruit preparationSweet cherries (Prunus avium cv. Těchlovan, Summit and Kordia) with stems attached were hand harvested on July 6, two days before the optimal harvest stage, from the commercial orchard Agro Stošíkovice at the Horticultural Faculty in Lednice. The fruits were sorted to exclude those with obvious defects or dissimilar states of maturity, based primarily on their appearance. Selected fruits were then transported into small boxes and during two hours they were chilled to 3°C before placing in the various gas mixtures. Preparation of the atmospheres Preparation of atmospheres:Immediately after cooling, the final atmosphere composition was obtained by flushing with nitrogen. To eliminate the possibly excessive influence of CO 2 as a respiration inhibitor, the chambers were connected to absorption tubes filled with solid tablets of KOH, which were mixed with an inert material (polystyrene). Gas mixtures were monitored twice a day, using a dual CO 2 /O 2 analyzer (Arelco, ARC, France). Ethanol and acetaldehyde levelsThe cherries were temporarily stored in a freezer and then defrosted prior to analysis. The juice produced was filtered (25 mm diameter syringe filter, 0.2 μm nylon with glass, Alltech Associates Inc., Belgium). 1 μl aqueous samples were injected into a sample block fitted with Teflon, and analyzed with a gas chromatograph equipped with FID (Chrom 5, Laboratory Equipment, Prague). Separation was achieved on a packed column (Porapak P, 3 mm i.d., 120 cm length), gas...

Evaluation of sweet cherry fruit quality after short-term storage in relation to the rootstock

“…Sweet cherry fruits are characterized by low resistance to diffusion through the skin and a higher surface area vs. volume than other fruits (Wani et al 2014). Our study recorded weight losses only in relation to the storage conditions (three times higher in NA than in both CA combinations), and many other authors have observed the same trend in other sweet cherry cultivars (Szymczak et al 2003;Padilla-Zakour et al 2004;Goliáš et al 2007). Loss of fruit mass during storage affects the shelf-life and deteriorates fruit quality after storage (Serrano et al 2005).…”

Postharvest properties of sweet cherry fruit depending on rootstock and storage conditions

“…This finding is in agreement with the results obtained by other authors. For example, Rutkowski et al (2000), Szymczak et al (2003) for 'Kordia', Padilla-Zakour et al (2004) for 'Hedelfingen' and 'Lapins', and Goliáš et al (2007) for 'Techlovan', 'Summit' and 'Kordia' sweet cherry reported significant weight losses after storage in normal atmosphere. Weight loss in cherry fruits is high due Table 2 to their low skin diffusion resistance (Serrano et al 2005), and also due to a high surface/volume ratio.…”

Sweet cherry: Composition, postharvest preservation, processing and trends for its future use

“…al., 2009). However an extension in the storage life of cherries at low temperature is possible when used in combination with controlled atmosphere (CA) or modified atmosphere packaging (MAP), where lower levels of oxygen (O2) and higher levels of carbon dioxide (CO2) in the storage atmospheres have been shown to improve the storage life of cherries (Goliáš, Němcová, Čaněk, & Kolenčíková, 2007).…”