Extending postharvest life of ready-to-use zucchini flowers: effects of the atmosphere composition

Male zucchini flowers (Cucurbita pepo L.) are greatly appreciated by consumers although, due to their high perishability, they are destined only to local markets. The effects of four different atmosphere compositions (air, 3% O2 in nitrogen, 3% O2 + 10% CO2 in air, and 10% CO2 in air) on quality attributes of fresh male zucchini flowers (color, weight loss, respiration, fermentative volatiles, and vitamin C) were studied. Storage in controlled atmosphere significantly (P<0.05) affected postharvest quality and marketability of zucchini flowers. At 5 °C, atmosphere containing 3% O2 in nitrogen resulted in a reduction in respiration rate and weight loss, and preserved visual appearance, sensorial and nutritional quality, maintaining the Vitamin C content during the entire cold storage. In this condition fresh zucchini flowers were scored marketable and with a good appearance after 9 days of storage. On the other hand flowers stored in air deteriorated rapidly, resulting in a score just above the limit of marketability (score 3) after 5 days of storage, whereas e adding CO2 to air only slightly increased flower shelf-life. Flowers stored in air (with or without CO2) showed the same spoilage symptoms, defined by water soaking, wilting and brightness loss, all symptoms which were reduced in low oxygen atmosphere. Based on these results the proper atmosphere conditions for male zucchini flowers should attain low oxygen levels (3%) and avoid excessive accumulation of CO2. Further studies will be needed to investigate the possibility of introducing washing in the processing, due to the high sensitivity to manipulation of this product.