Search results for "Carrot"
showing 9 items of 19 documents
Natural reduction of willow carrot aphids by Coccinellidae on a carrot crop
1993
Effect of Pulsed Electric Field Pretreatment on Drying Kinetics, Color, and Texture of Parsnip and Carrot.
2018
The aim of the study was to evaluate the effect of pulsed electric field (PEF) pretreatment on drying kinetics and on color and textural changes in sliced parsnip and carrot. Cell disintegration index measured in parsnips after PEF pretreatment significantly differed from the ones measured for carrots and, consequently, the reduction of the time needed to dry both samples to a final moisture content up to 5% (wet basis). The drying time of the PEF pretreated parsnip was reduced by up to 28% at 70 °C and by up to 21% at 60 °C in carrot, in comparison to untreated samples. The PEF pretreatment influenced the effective diffusivity of water into the samples going from 50 °C to 70 °C: in carrots…
La ética como coartada / 1
2007
Ascorbic acid stability during refrigerated storage of orange–carrot juice treated by high pulsed electric field and comparison with pasteurized juice
2006
Abstract The degradation kinetics of ascorbic acid was determined in orange–carrot juice treated by PEF in order to establish its shelf life. Different electric field intensities (25, 30, 35, and 40 kV/cm) and different treatment times (from 30 to 340 μs) were studied. The ascorbic acid degradation rate (k) obtained was −0.009 ± 0.0008 μs−1, −0.0140 ± 0.0009 μs−1, −0.0220 ± 0.0023 μs−1 and −0.0187 ± 0.0049 μs−1 for fields of 25, 30, 35, and 40 kV/cm, respectively. The treatment selected was 25 kV/cm. The shelf life of the orange–carrot juice treated by pulses at 25 kV/cm for two times (280 μs and 330 μs) was compared with a heat-treated juice (98 °C, 21 s) kept in refrigerated storage at 2 …
Evaluation of carotenoids and furosine content in air dried carrots and parsnips pre-treated with pulsed electric field (PEF)
2019
Carrot and parsnip slices were subjected to hot drying at 50, 60 and 70 °C with or without pulsed electric field (PEF) pre-treatment at 0.9 kV/cm and 1000 and 10,000 pulses. The effect of drying on processed samples was assessed by analysis of carotenoids, the furosine value, total phenols and the Whiteness Index (WI). PEF pre-treatment is effective in reducing drying times, but the degree of cellular breakdown makes the compounds more susceptible to chemical and enzymatic reactions. In our condition PEF pre-treatment increased the carotenoid degradation and promoted the Maillard reaction above all at the highest temperature of 70 °C. The assessment of carotenoid stability, together with th…
Effect of high-intensity pulsed electric fields processing and conventional heat treatment on orange-carrot juice carotenoids.
2005
Liquid chromatography (LC) was the method of choice for quantification of carotenoids (including geometrical isomers) to evaluate the effects of high-intensity pulsed electric field (HIPEF), a nonthermal preservation method, with different parameters (electric field intensities and treatment times), on an orange−carrot juice mixture (80:20, v/v). In parallel, a conventional heat treatment (98 °C, 21 s) was applied to the juice. HIPEF processing generally caused a significant increase in the concentrations of the carotenoids identified as treatment time increased. HIPEF treatment at 25 and 30 kV/cm provided a vitamin A concentration higher than that found in the pasteurized juice. Keywords: …
A study of the chemical composition and biological activity of extracts from wild carrot (Daucus carota l.) seeds waste
2015
Waste (wild carrot seeds, Daucus carota L.) formed after the industrial extraction of 96% ethanol were re-extracted with 40% and 70% ethanol in order to recover of valuable substances for potential use as a safe food additives and functional food ingredients or nutraceuticals. In this study we compared chemical composition and activity of two obtained extracts (70% EtOH and 40% EtOH). The results indicated that the 70% EtOH extract has a higher total phenol and flavonoid content than 40% EtOH extract. The antioxidant activity of 70% EtOH extract was 86.88 % ± 3.018, whereas of 40% EtOH extract scavenging activity was 78.72% ± 3.276. The extracts were also active against bacteria with MIC ag…
The influence of carrot seed oil and its main component carotol on development and behaviour of Aphis fabae aphids
2005
The behaviour of some aphid species is influenced by different plant odours, especially by plant essential oils, which are the mixtures of terpenes. In our study, carrot seed oil and its main sesquiterpenic component - carotol - were examined as factors influencing the behaviour and development of Aphis fabae Scop. The results of the olfaction experiments showed, that especially carrot seed oil exhibited various activities in the dose-dependent manner. When tested in the amount which did not exceed 0.01 mL of 1% v/v of suspension in water, this substance exhibited strong attractancy toward adult females of Aphis fabae. In contrast, if similar tests were carried out using > 0.1 mL of suspens…