Influence of harvest date and storage conditions on the content of chlorophyll pigments in pear peels

During each season, pears were harvested on three dates at four-day intervals. The fruit was stored for 150 days in temperatures of 0-0.5°C in common cold storage (NA - normal atmosphere) and also in controlled atmospheres (CA) of different gaseous content: 0.8% CO₂ + 2% O₂, 2% CO₂ + 2% O₂ and 3% CO₂ + 3% O₂. After removing the pears from storage they were additionally stored for seven days in a temperature of 17°C - simulated shelf life. The content of chlorophyll pigments (chlorophyll a + b) was determined after each harvest date, storage time and simulated shelf life. Based on the results, I concluded that the a + b chlorophyll content in the peel of both pear cultivars significantly decreased along with the subsequent harvest date. In addition, the storage conditions had a significant influence on the studied factor. Compared to the normal atmosphere, the controlled atmosphere conditions were more efficient in slowing the yellowing of the fruit due to reduced chlorophyll degradation. The atmosphere consisting of 3% CO₂ + 3% O₂ or 2% CO₂ + 2% O₂ was more favourable for the higher content of chlorophyll a + b in the peel of ‘Conference’ pears than 0.8% CO₂ + 2% O₂. In the case of ‘Concorde’ pears, the influence of particular compositions of CA on the content of chlorophyll a + b changed over the years.