Hydroponic Cultivation Improves the Nutritional Quality of Soybean and Its Products

Abstract

Hydroponic cultivation allows the control of environmental conditions, saves irrigation water, increases productivity, and prevents plant infections. The use of this technique for large commodities such as soybean is not a relevant issue on fertile soils, but hydroponic soybean cultivation could provide proteins and oil in adverse environmental conditions. In this paper, the compositions of four cultivars of soybean seeds and their derivates, soy milk and okara, grown hydroponically were compared to that of the same cultivar obtained from soil cultivation in an open field. Besides proximal composition, the concentrations of phytic acid and isoflavones were monitored in the seeds, soy milk, and okara. Results demonstrated that, independent from the cultivar, hydroponic compared to soil cultivation promoted the accumulation of fats (from 17.37 to 21.94 g/100 g dry matter) and total dietary fiber (from 21.67 to 28.46 g/100 g dry matter) and reduced isoflavones concentration (from 17.04 to 7.66 mg/kg dry matter), whereas protein concentration was unaffected. The differences found in seed composition were confirmed in the respective okara products, but the effect of cultivation system was not significant looking at the soy milk composition. Data showed that hydroponic cultivation improved the nutritional quality of soybean seeds with regard to fats and dietary fiber. They also suggest that specific cultivars should be selected to obtain the desired nutritional features of the soybean raw material depending on its final destination.

The effect of cooking on the phytochemical content of vegetables

“…Only two authors compared different cooking methods, evaluating their effect on isoflavones concentration; in both papers, steaming was identified as the best cooking method in preserving isoflavones. It is also noteworthy that the heat treatments change the pattern of isoflavones in soy products with a reduction in malonyl‐glycosides and a shift towards the β ‐glucoside and aglycone forms …”

Hydroponic Production Systems: Impact on Nutritional Status and Bioactive Compounds of Fresh Vegetables

“…Different studies have claimed that vegetables produced from hydroponics have better qualities than those from conventional soil-based cultivation [32,33]. On the other hand, other studies have claimed that the exact differences between qualities of vegetables grown in soil or hydroponics are difficult to establish [10,34,35].…”

Changes in Leaf Anatomical Traits Enhanced Photosynthetic Activity of Soybean Grown in Hydroponics with Plant Growth-Promoting Microorganisms

“…Together with durum wheat, bread wheat and potato, soybean has been selected as a candidate crop for CELSS due to the high nutritional value of seeds (Palermo et al, 2012). To maximize crop performance, once crops have been chosen, the most suitable cultivar for CELSS has to be selected by considering plant adaptability to the hydroponic environment and other relevant agronomical requirements, such as small size, short growing cycle, high harvest index (as ratio of edible part to total biomass per plant), and good tolerance to biotic and abiotic stresses (De Micco et al, 2012).…”