The impact of different thermal processing of tomato to its antioxidant activity, vitamin E, dry matter and sugar content

The objective of this study was the determination of total antioxidant activity, contents of vitamin E, sugar and total dry matter in fresh and thermally processed (dried and juiced) tomato fruits of different selected tomato lines with the aim to establish the nutritive profile and distinguish superior genotypes in order to obtain high-quality final product with more benefit to human health. Content of vitamin E, total antioxidant activity, dry matter and total sugars, in fresh and dried fruits (dried in parallel hot air dryer at 60 °C, until the final product reached the moisture lower than 10% and in tomato juice pasteurized at 100 °C, for 7 minutes) was studied. Comparative trial with 7 genotypes: one commercial variety (SP-109) and 6 selected high inbreeding generation lines (SPP, SPSM, SPRZ, SPRM-20, S-60 and SPO), was set up. Genotype SPRZ had the highest vitamin E content and total antioxidant capacity, both in fresh fruit and after the treatments. Thermal processing by drying at 60°C and pasteurization of tomato changed the level of total sugar and dry matter content. Total antioxidant activity decreased by drying, comparing to fresh fruit while the level of vitamin E decreased in juice pasteurized at high temperature (100 °C).

Antioxidant nutritional quality and the effect of thermal treatments on selected processing tomato lines

© Wydawnictwo Uniwersytetu Przyrodniczego w Lublinie. The aim of this study was to choose the genotypes of industrial tomato for the content of bioactive components (ascorbic acid, β-carotene, lycopene, total phenols and flavonoids) in fruits and its preservation during thermal treatment (by drying with parallel warm air at 60°C) and making of tomato juice (by pasteurization – cooking at 100°C for 7 minutes). For this research, a comparative trial has been set up with 7 genotypes, 1 commercial variety (SP-109) and 6 selected lines (SPP, SPSM, SPRZ, SPRM-20, S-60 and SPO) of high inbreeding generations. Experimental design has been done according to standard method of growing industrial tomato in random block system with three replications. By analysing the cumulative results of all researched genotypes for processing industry, the best for drying and fresh consumption was SPRZ and for juice extraction, SPSM was the best line

Antioxidant capacity and contents of phenols, ascorbic acid, β-carotene and lycopene in lettuce

The antioxidant activity of three lettuce varieties (Lactuca sativa L.) Emerald, Vera and Neva, cultivated in two kinds of protected spaces, a glasshouse and a plastic greenhouse, under controlled conditions, was determined. The content of antioxidant compounds: total phenols, flavonoids, L-ascorbic acid, β-carotene and lycopene, were determined in etha- nolic extracts of the lettuce with spectrophotometric methods. The largest content of total phenols (78.98±0.67 mg GAE/g of dry extract) was found in ethanolic extract of the lettuce variety Neva cultivated in a plastic greenhouse, whereas the largest content of flavonoids (35.45±0.95 mg RU/g of dry extract) was displayed in the lettuce Emerald cultivated in a glasshouse. It was observed that the lettuce cultivated in the glasshouse contained a somewhat higher content of L-ascorbic acid than the lettuce same variety from plastic greenhouse. The content of lycopene in the examined lettuce is negligible, and the content of β-carotene is low. On the other hand, the high content of phenolic components causes favourable antioxidant properties found in all varieties of examined lettuce

Antioxidant activity of ultrasonic extracts of leek Allium porrum L.

This study was aimed at evaluating the antioxidant activity and efficacy of the ethanolic extract of the ultrasonic extracts of leek Allium porrum L. Ethanolic (50%; v/v) extracts of edible leek parts (stem and leaf) were prepared by ultrasound-assisted extraction, which was followed by evaluation of total phenols, flavonoids and antioxidant activity. Total phenols were determined using the modified Folin-Ciocalteu method. Antioxidant activity was assessed by scavenging the stable free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). The results of antioxidant activity were compared with control antioxidants: vitamin C and BHT. The higher content of phenols (69.46 mg GAE/g dry extract) and flavonoids (33.53 mg CE/g dry extract) was found in the ethanolic extract of leek stem. The measured values of IC50 were 98.90 g/ml and 61.05 g/ml for the ethanolic extract of leek leaf and stem, respectively