Effects of growing zones on nutritional and bioactive compounds of by-products of two tomato cultivars

Abstract

Despite its specific climatic and soil conditions, tomato has adapted to a wide range of conditions that can influence its yield and the nutritional quality of its fruits. The objective of this study was to evaluate the influence of production zones on the nutritional and nutraceutical quality of by-products of two tomato cultivars. Levels (dry matter basis) of biochemical and phytochemical parameters were found to be dependent on the cultivar and growing area. The levels of carbohydrates, proteins and lipids were affected. Their contents varied significantly in all by-products from 9.93% ± 0.76–16.19% ± 0.3; 10.6% ± 0.93–64.35% ± 0.83 and 4.06% ± 0.4–22.62% ± 0.03 for proteins, carbohydrates and lipids respectively. In peels, phenolic compound contents varied significantly according to cultivar and growing zone. Thus, total polyphenol contents varied from 181.28 ± 11.4 to 344.4 ± 3.4 mg/100 g; total flavonoids, anthocyanins, and salicylic acid varied from 31.21 ± 0.33 to 139.88 ± 0.1 mg GAE/100 g; 0.76 ± 0.1 to 16.72 ± 0.25 mg/100 g; and 0.95 ± 0.21 to 3.99 ± 0.72 mg/100 g, respectively. Diversities in these parameters indicated that cultivars have adaptation in according to agroclimatic zones. Antioxidant activity in seeds was neither influenced by cultivar nor by production zone, whereas in peels it varied from 38.44 ± 2.36% to 59.18 ± 1.04% for DPPH inhibition and from 75.52 ± 6.48 μg EAA/100 g to 119.29 ± 1.86 μg EAA/100 g for FRAP. Despite the variation in parameters between cultivars in different zones, this study reveals that tomato by-products can be considered as natural sources of bioactive compounds regardless of the production zone.

Keywords

• Tomato
• By-products
• Antioxidant activity
• Nutraceutical potential
• Phytochemical composition