Comparison of growth characteristics, functional qualities, and texture of hydroponically grown and soil-grown lettuce. (October 2021)

• Record Type: Journal Article
• Authors: Lei, Chunli; Engeseth, Nicki J.
• Is Part Of: Lebensmittel-Wissenschaft + Technologie =. Volume 150(2021)
• Publication Date: 2021-10
• Subjects: Lettuce quality -- Hydroponically grown -- Soil-grown -- Comparison; Food industry and trade -- Periodicals; Food -- Composition -- Periodicals; Microbiology -- Periodicals; Nutrition -- Periodicals; 664.005
• DOI: 10.1016/j.lwt.2021.111931
• Languages: English
• ISSNs: 0023-6438

Abstract

Abstract: Hydroponics has become one of the most popular approaches in today's agricultural production. Yet it is questionable whether hydroponics produce vegetables with comparable quality to soil-grown vegetables. In this study, hydroponically and soil-grown lettuce were compared for morphology, texture, antioxidant capacity, and functional quality. Giant Caesar lettuce was grown in laboratory-constructed hydroponic or soil systems for 35 days. Above-ground plant size, biomass, and leaf size of hydroponic lettuce were not significantly different from soil-grown lettuce. Hydroponic lettuce had significantly ( p < 0.05) longer roots, higher moisture and lower ash. No significant difference in ascorbic acid, chlorophyll, β -carotenes, and total phenolics was found in freeze-dried lettuce. However, all compounds analyzed were significantly higher in soil-grown lettuce based on fresh weight. Antioxidant capacity of soil-grown lettuce was significantly higher on both dry- (15.32%) and wet-basis (41.20%). Hydroponic lettuce had softer leaves and firmer midribs; potentially linked to increased lignin (24.18%) in plant cell walls. This represents the first comprehensive side-by-side growth study demonstrating that lettuce grown hydroponically is not the same quality as that grown in soil. Highlights: Hydroponic lettuce had stronger roots than soil-grown lettuce. No significant difference in the head of hydroponic and soil-grown lettuce. Hydroponic lettuce had increased moisture leading to lower bioactive compounds. Hydroponic lettuce had lower antioxidant capacity than soil-grown lettuce. Hydroponics modified lettuce texture by increasing lignin accumulation of lettuce.