Effects of PEF and heat pasteurization on PME activity in orange juice with regard to a new inactivation kinetic model

PubMedID: 25038650The inactivation kinetics of pectin methyl esterase (PME) during the shelf life (4 °C-180 days) of freshly squeezed orange juice samples processed by both pulsed electric fields (PEF) and heat pasteurization (HP) was evaluated in the study. The PME inactivation level after the PEF (25.26 kV/cm-1206.2 µs) and HP (90°C-20 s) treatments were 93.8% and 95.2%, respectively. The PME activity of PEF-processed samples decreased or did not change, while that of HP samples increased during storage (p < 0.01). A kinetic model was developed expressing PME inactivation as a function of the PEF treatment conditions, and this enabled the estimation of the reaction rate constant (587.8-2375.4 s -1), and the time required for a 90% reduction (De, 3917.7-969.5 s). Quantification of the increase in PEF energy to ensure a ten-fold reduction in De (ze, 63.7 J), activation electric fields (-921.2 kV cm-1mol-1), and electrical activation energy (12.9 kJ mol-1) was also carried out. Consequently, PEF processing was very effective for the inactivation of PME and for providing stability of orange juice during storage. © 2014 Published by Elsevier Ltd.DPT 2009K 120 410 ZF2010BAP4, ZF2009YL87 104 O 585The authors would like to thank the State Planning Organization (Project No: DPT 2009K 120 410), TUBITAK (Project No: 104 O 585) and Cukurova University (Project No: ZF2010BAP4 and ZF2009YL87) for financial supports

Comparison of phenolic compounds of orange juice processed by pulsed electric fields (PEF) and conventional thermal pasteurisation

Processing of orange juice by pulsed electric fields (PEF) and thermal pasteurisation was carried out to compare changes in total phenolic concentration, hydroxybenzoic acid, hydroxycinnamic acids, flavonols, flavones and flavonones before and after being stored at 4 °C for 180 days. Changes in the initial total phenolic concentration of the samples varied depending on the applied electric field intensity and thermal pasteurisation. Hesperidin and chlorogenic acids were detected as the most abounded flavonoid and phenolic acids in the orange juice, respectively. Except for syringic acid and neoeriocitrin, the concentration of the phenolic compounds indentified in the orange juice samples enhanced after the PEF or thermal pasteurisation. The samples treated with PEF had more stable flavonoids and phenolic acids than those treated with the thermal pasteurisation. The PEF-treated samples had higher sensory scores than the heat-treated samples. © 2013 Elsevier Ltd. All rights reserved.DPT 2009 K 120 410 ZF2010BAP4 104 O 585The authors would like to thank the Ministry of Development State Planning Organisation ( Project No. DPT 2009 K 120 410 ), TUBITAK ( Project No. 104 O 585 ) and Cukurova University ( Project No: ZF2010BAP4 ) for financial supports

Optimization of anthocyanins extraction from black carrot pomace with thermosonication

PubMedID: 28764021A study was conducted to identify optimal ultrasound processing conditions (ultrasound energy density and temperature) to maximize the extraction of anthocyanin colorants from black carrot pomace. The treatment maximized the yield of five different anthocyanin compounds from black carrot pomace with cyanidin-3-xyloside-galactoside-glucoside-ferrulic acid (C3XGGF, 60.85–74.22 mg/L) as the most abundant anthocyanin compound, followed by cyanidin-3-xyloside-galactoside (C3XG, 49.56–70.12 mg/L). The response surface models predicted that if extraction conditions were conducted at 183.1 J/g energy density and 50 °C, the yield of various anthocyanin compounds would be maximized from the black carrot pomace. Response surface models were developed correlating anthocyanin yield with ultrasonication treatment parameters. The study showed the synergy of combining ultrasonication and temperature for the extraction of anthocyanin pigments from black carrot pomace. Results of the study also further demonstrate the potential of ultrasonication technology as a tool for the extraction of valuable components waste products from fruits and vegetables juice industry. © 2017 Elsevier Lt

A comparative assessment of long-term storage stability and quality attributes of orange juice in response to pulsed electric fields and heat treatments

Processing of orange juice by pulsed electric fields (PEF) and heat treatments was carried out to determine the quality variables during storage of 180 days at 4 °C. Depending on the magnitude of applied electric field strength (13.82-25.26 kV cm-1), energy (10.89-51.32 J), in comparison with heat treatment (90 °C for 10 and 20 s); significant changes in pH, titration acidity, total dry matter, and browning index were found during the storage period. With no significant change in shelf-life period, the PEF processing better preserved orange juice quality than did the heat processing. Ascorbic acid content peaked with PEF-treated orange juice under the electric field strength of 17 kV cm-1, the treatment time of 1034 µs, and the energy of 17.37 J through which no significant degradation occurred during the storage with the longest half-life (1112 days). Although ascorbic acid retention of the most of the PEF processed samples was higher than that of the heat processed ones; samples processed by 10.89, 12.70 and 29.57 J energies resulted in lower ascorbic acid content than did the heat processing (90 °C for 20 s). Except for the samples treated by 43.99 and 51.32 J energies on 180th day, the PEF processing led to no hydroxyl methyl furfural formation during and at the end of the storage, unlike the heat treatment. © 2016 Published by Elsevier B.V. on behalf of The Institution of Chemical Engineers.DPT 2009K 120 410 ZF2010BAP4, ZF2009YL87 104 O 585The authors would like to thank the State Planning Organization (YENIGIDAM project no: DPT 2009K 120 410), TUBITAK (project no: 104 O 585) and Cukurova University (project no: ZF2010BAP4 and ZF2009YL87) for financial supports

Assessing impacts of pulsed electric fields on quality attributes and furfural and hydroxymethylfurfural formations in apple juice

Effects of pulsed electric fields (PEF) processing on physical properties, bioactive compounds, and formations of furfural and hydroxylmethylfurfural (HMF) were determined for apple juice. A central composite design to determine the optimal number and order of experimental runs and the best-fit multiple nonlinear regression (BF-MNLR) models to quantify and predict rates of change in the response variables as a function of the PEF processing were used. No significant difference was detected between the control and PEF-treated apple juice in terms of physical properties, organic acids, and polyphenols of (-)-epicatechin, caffeic acid, p-coumaric acid, ferrulic acid, quercetin, and gallic acid. The highest predictive power (R2 pred) belonged to a* (88%), (+)-catechin (90.7%), and HMF (93.8%). Except for chlorogenic acid, no significant decrease was detected in the initial concentrations of the bioactive compounds. PEF processing provided retention of quality attributes and bioactive compounds without significant formation of furfural and HMF. Practical applications: Heat processing causes degradation of bioactive compounds, changes in physical properties, and formation of undesirable compounds in apple juice; however, PEF processing provided the preservation of most bioactive compounds without significant changes in physical properties. Thus, findings in this study revealed that PEF processing is a viable option for fruit juice industry, especially, for apple juice pasteurization. © 2016 Wiley Periodicals, Inc

Investigation on fruit quality of grafted watermelon

10th EUCARPIA Meeting on Genetics and Breeding of Cucurbitaceae -- OCT 15-18, 2012 -- Antalya, TURKEYWOS: 000345687100045In this study, grafted and ungrafted watermelon cultivars were grown in Cukurova region to determine fruit pH, titratable acidity, soluble solids, yantioxidant activity, total phenolic compounds and analysis of sensory evaluation. The highest soluble solids (11.32%) and titratable acidity 0.190 g/100g were in seedless cultivars. The highest antioxidant activity and total phenolic content was in Argentario+TP84, 80.21% and 137.40 (GAE) mg/kg fresh weight (fw) respectively. For sensory analysis, the most popular cultivars were grafted type.European Assoc Res Plant Breeding, Cukurova Univ, Minis Food, Agr & Livestock, Turkish Sci & Technol Council, Antalya Tarim, Manier Seed, Yuksel Seed, Syngenta, AG Seed, Fito Seed, Multi Seed, Nunhems, Rijk Zwaan, Bati Akdeniz Agr Res Inst, Alata Hort Res Sta

Avaliação do armazenamento a frio sobre os compostos bioativos e as características físico-químicas e microbiológicas do suco de umbu pasteurizado

Resumo Este trabalho teve como objetivo avaliar o efeito do armazenamento a 6 °C nas características do suco de umbu pasteurizado. A pasteurização foi realizada a 86 °C por 25 s em um pasteurizador de superfície raspada, sendo o suco de umbu mantido a 6 °C por 90 dias. O suco pasteurizado atendeu ao padrão estabelecido pela legislação brasileira com contagem <3 NMP.g-1 para coliformes a 45 °C e ausência de Salmonella sp. Nesta condição de processo, a pasteurização foi eficiente também para a redução de bactérias aeróbias mesófilas. O teor de compostos fenólicos totais e, em particular, da rutina, assim como a atividade antioxidante do suco, não foram afetados pelo tratamento térmico. Ao longo do armazenamento, apesar de não perceptível visualmente, os parâmetros de cor do suco variaram significativamente (p<0,05). Apesar de pequena, também houve variação significativa (p<0,05) nos teores dos compostos fenólicos e de carotenoides. Por outro lado, o suco de umbu se manteve microbiologicamente estável durante o armazenamento, sendo, portanto, possível sua conservação por um período de 90 dias sem o uso de aditivos, quando submetido à pasteurização e mantido sob refrigeração