Estudo das possibilidades de utilização de morango de hidroponia na estratégia de inovação da Frulact

: firmeza, processamento e microbiologia

Abstract

The strawberry cultivation by hydroponic is a technique of growing interest in both food and plant science. However, due to high costs, such cultivation technique requires further evaluations concerning its effects on productivity, firmness and microbiological load of fruit in order to support further decimintionation of the technique. The aim of this study was to evaluate the potential of hydroponic cultivation methods compared with the traditional methods, as well as assess the effect of a commercial bio-stimulant (based in algae extracts) and (Ca(NO3)2) on productivity and quality of strawberries produced in hydroponic system. Whereas, three application frequencies were tested, in the rooth (every 7, 15 and every 30 days during the whole culture cycle) and three doses of bio-stimulant (1,5, 3,0 and 4,5 L/ha), and two doses of Ca(NO3)2 (5,0 and 10,0 kg/ha). Generally, the results demonstrate that application of the bio-stimulant throughout the crop cycle is more effective in obtaining a higher productivity compared to the application only after the onset of flowering. Applications with 1,5 L/ha induced an early harvesting and were more effective when applied at a higher frequency. However, administrations with a concentration of 4,5 L/ha are more effective when applied less frequently. Application of bio-stimulant and Ca(NO3)2 influenced the mineral concentration in the fruit and led to an increase in antioxidant activity of the fruit due to increased contents of phenolic compounds, anthocyanins , and Vitamin C. It was also observed different behaviour among the cultivars tested for firmness and microbiological parameters. It was found that strawberries grown in hydrponic circunstances presented higher microbilogical stability when compared with strawberries produced in soil. The degree of maturity and caliber of the strawberries was also found to influence the firmeness of the fruit. Notwhitstanding, it was also shown that acetic acid at 2% effectively reduced microbial load on strawberries produced under both conditions. The results of this study clearly show that the choice of the type of crop, doses of bio-stimulant and Ca(NO3)2 has an impact on production levels and physical-chemical characteristcs of the fruits.

Date of Award	2015
Original language	Portuguese
Awarding Institution	Universidade Católica Portuguesa
Supervisor	Marta Vasconcelos (Supervisor), Susana Maria Pinto de Carvalho (Co-Supervisor), Helena Teixeira Gomes (Co-Supervisor) & Pilar Morais (Co-Supervisor)