Organic and conventional vegetables: Comparison of the physical and chemical characteristics and antioxidant activity

Abstract

The objective of this research was to compare the physical and chemical characteristics and antioxidant activity of organic and conventional carrot (Daucus carota), green pepper (Capsicum annuum) and lettuce (Lactuca sativa). Five representative samples of conventional vegetables, certified organic and non-certified organic vegetables were gotten from farms and supermarkets in the city of Rio de Janeiro. The result shows that the organic carrot showed higher acidity (0.11 g % citric acid) and total sugar (5.68 g %) than those found in standard samples and certified organic ones (p<0.05). Regarding the density analysis and total soluble solids, there was no statistical difference between carrots, green peppers and lettuce from all types (p>0.05). It was observed that the vitamin C levels in carrot samples levels had no significant difference between the different forms of production (p>0.05). Conventional lettuce and certified organic pepper showed higher vitamin C than the other samples (p<0.05). The antioxidant activity of the samples was analysed by the capacity to reduce the DPPH (1,1diphenyl-2-picryl-hydrazyl) radical, in which carrot and conventional pepper showed lower antioxidant activity (p<0.05) when compared to organic samples. There were no significant differences among the different forms of production in the lettuce samples (p>0.05). Carrot and green pepper, with seal certification or not, showed higher capacity to reduce DPPH than the conventional ones, this suggests that the form of cultivation has a direct relationship with the nutritional values of the vegetables.

Nutritional value of conventional, wild and organically produced fruits and vegetables available in Baja California Sur markets

“…Chard and purslane obtained conventionally showed the lowest antioxidant power. All data obtained agree with the studies carried out by De Oliveira et al (2016), who found that organic crops contain higher amounts of phenolic compounds and higher antioxidant capacity than conventional crops. Interestingly, the content if soluble solids of a given group correlates with the antioxidant capacity, possibly because of water soluble antioxidants like vitamin C (Thaipong et al, 2006).…”

Organic Carrot (Daucus carota L.) Production Has an Advantage over Conventional in Quantity as Well as in Quality

“…Some earlier studies have similarly found that the production method did not affect the total sugar content in carrots [48,49,64]. However, several studies have concluded that organic vegetables, including carrots, contain more sugars than conventional ones [58,[65][66][67][68]. Total sugar content in carrots could be affected more by climate-related factors than by management methods [69].…”

Nutritional quality of organically grown carrot (Daucus carota L.) and effect of processing

“…The potential toxic effects on human health are associated with pesticide overuse in conventional production systems. If technical recommendations are not adequately followed, the conventional system can be detrimental to human health and contribute to environmental pollution (Fernanda et al, 2016). An alternative to conventionally grown carrots is the organic system, even though it is often considered more expensive.…”

“…An alternative to conventionally grown carrots is the organic system, even though it is often considered more expensive. Some studies indicate that crops grown in organic production systems have higher levels of protective substances, such as polyphenols, flavonoids, phenols, and antioxidants in general (Castro et al, 2014;Fernanda et al, 2016).…”