0000000000486185
AUTHOR
Francisco Torregrosa
Carotenoid Profile Modification during Refrigerated Storage in Untreated and Pasteurized Orange Juice and Orange Juice Treated with High-Intensity Pulsed Electric Fields
A comparative study was made of the evolution and modification of various carotenoids and vitamin A in untreated orange juice, pasteurized orange juice (90 degrees C, 20 s), and orange juice processed with high-intensity pulsed electric fields (HIPEF) (30 kV/cm, 100 micros), during 7 weeks of storage at 2 and 10 degrees C. The concentration of total carotenoids in the untreated juice decreased by 12.6% when the juice was pasteurized, whereas the decrease was only 6.7% when the juice was treated with HIPEF. Vitamin A was greatest in the untreated orange juice, followed by orange juice treated with HIPEF (decrease of 7.52%) and, last, pasteurized orange juice (decrease of 15.62%). The decreas…
Quality characteristics of horchata (a Spanish vegetable beverage) treated with pulsed electric fields during shelf-life
Abstract The application of pulsed electric fields (PEF) is one of the new non-thermal technologies being studied to evaluate their potential as alternative or complementary processes to thermal pasteurization. “Horchata de chufa” (tiger nut milk or earth almond milk) is of high nutritional quality and therefore has great potential in the food market, limited by its very short shelf-life. The present work studies whether PEF can be used to obtain a quality horchata and increase its shelf-life while maintaining its organoleptic characteristics. In order to do so we determined pH, total fat, peroxide index, thiobarbituric acid-reactive substances index, formol index, and peroxidase activity i…
Ascorbic acid stability during refrigerated storage of orange–carrot juice treated by high pulsed electric field and comparison with pasteurized juice
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 …
Effect of high-intensity pulsed electric fields processing and conventional heat treatment on orange-carrot juice carotenoids.
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: …
Identification and quantification of carotenoids including geometrical isomers in fruit and vegetable juices by liquid chromatography with ultraviolet-diode array detection.
A method was established for the identification and quantification of carotenoids including geometrical isomers in fruit and vegetable juices by liquid chromatography with an ultraviolet−diode array detector, using a C18 Vydac 201TP54 column. The mobile phase used was the ternary methanol mixture (0.1 M ammonium acetate), tert-butyl methyl ether and water, in a concentration gradient, and a temperature gradient was applied. Retinol palmitate was added as an internal standard. An extraction process (ethanol/hexane, 4:3, v/v) was performed, followed by saponification with diethyl ether/methanolic KOH (0.1%, w/v, BHT) (1:1, v/v) for 0.5 h at room temperature. Seventeen different (cis and trans…
Changes of colour and carotenoids contents during high intensity pulsed electric field treatment in orange juices
Abstract Liquid chromatography (LC) was the method chosen to evaluate the effects of high intensity pulsed electric fields (HIPEF), with different electric field intensities (25, 30, 35 and 40 kV/cm) and different treatment times (30–340 μs), on orange juice cis / trans carotenoid contents. In parallel, a conventional heat treatment (90 °C, 20 s) was applied to the orange juice in order to compare the effect on the carotenoid contents. HIPEF processing of orange juice is an alternative to the thermal treatment of pasteurization, provided that it is kept refrigerated, because, when the most extreme conditions of this kind of treatment are applied, the decrease in the concentration of caroten…