Sensory quality, bioactive constituents and microbiological quality of green and red fresh-cut lettuces ( Lactuca sativa L.) are influenced by soil and soilless agricultural production systems

• Published in: Postharvest biology and technology 2012, Vol.63 (1), p.16-24
• Main Authors: Selma, María V., Luna, María C., Martínez-Sánchez, Ascensión, Tudela, Juan A., Beltrán, David, Baixauli, Carlos, Gil, María I.
• Format: Article
• Language: English
• Subjects: Agricultural production; Antioxidants; Ascorbic acid; Biological and medical sciences; Coliforms; Contamination; Food industries; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; Genotypes; Hydroponic; Lactic acid bacteria; Lactuca; Leaves; Maintenance; Maturity; Microbial contamination; Microorganisms; Minimally processed; Open field; phenolic compounds; Phenolics; Phytochemicals; Planting; Sensory properties; Shelf life; Soil; Storage; Vitamin C; Vitamins; Winter
• ISSN: 0925-5214; 1873-2356
• DOI: 10.1016/j.postharvbio.2011.08.002

► Lollo rosso, red oak leaf and butterhead lettuces were cultivated in soil, as the traditional production system and soilless, as an innovative one. ► In the winter season, a longer growing period was neededto obtain the same maturity stagein the soil than in the soilless (102 and 63 d after planting, respectively). ► The high content of antioxidants was linked to a better maintenance of visual quality and the control of browning of the fresh-cut produce cultivated in soilless. ► Lettuce cultivated in the soilless system had less initial microbial load and slower microbial growth during storage. ► The combination of adequate production systems and suitable cultivars is considered essential to ensure the post-cutting life of lettuce. Quality characteristics and shelf-life of fresh-cut lettuce cultivated in soil, as the traditional production system, and soilless, as an innovative production system, were investigated. Three lettuce genotypes, lollo rosso and red oak leaf as red-leafed genotypes, and butterhead as a green-leafed genotype, were studied. Lettuces from both production systems were grown in the same open field and at the same time in the winter season. A longer growing period was needed, to obtain the same maturity stage, in the soil than in the soilless (102 and 63 d after planting, respectively). After harvest, the visual quality of the fresh-cut produce from red-leafed lettuce cultivated in soilless was better than those in soil. In the case of green-leafed genotype, the soilless system gave a lower visual quality of the fresh-cut product. Lollo rosso cultivated in the soilless system had a higher content of phytochemicals, including vitamin C and individual and total phenolics, than that cultivated in soil. At the end of storage, fresh-cut lollo rosso and red oak leaf grown in the soilless system showed significantly higher content of vitamin C than those in soil. This high content of antioxidants was linked to a better maintenance of visual quality and the control of browning when compared with the fresh-cut product from lettuces cultivated in soil. The soilless system was more effective in controlling microbial contamination as lettuce cultivated in the soilless system had a lower initial microbial load and slower microbial growth during storage. At the end of shelf-life, differences in microbial counts between soil and soilless lettuce were 3 and 1.5 log units higher for lactic acid bacteria and total coliforms, respectively, in soil. Thi