Nutrient Analysis of Soil and Soilless Strawberries and Raspberries Grown in a Greenhouse

Abstract

Soilless (hydroponic) vegetables and fruits grown in greenhouses are gaining popularity and potentially represent a compliment toward sustainable food sources. Only a few studies have looked at the nutrient quality of strawberries (Fragaria × ananassa) and raspberries (Rubus idaeus) grown in soilless systems. Dry weights, content of ascorbic acid, tocopherol, total polyphenolic compounds, glucose, fructose, and soluble solids (BRIX) of strawberries and raspberries grown in soilless systems were compared to their counterpart grown in soil. There was no change in dry weights but BRIX values (28% - 31%), glucose (158% - 175%), and fructose (75% - 102%) content for strawberries and raspberries respectively were significantly higher for the soil grown berries compared to soilless grown berries. Contents of ascorbic acid, tocopherol and total polyphenolic compounds were significantly higher in soilless grown strawberries compared to soil grown strawberries by 74%, 53%, and 22% respectively, and contents of ascorbic acid and total polyphenolic compounds were significantly higher in soil grown raspberries by 83% and 67% respectively compared to soilless grown raspberries. Soilless grown produce warrants future research to strive toward the potential to provide nutrient dense crops and opportunities toward optimized sustainable production.