Effect of high pressure carbon dioxide processing on pectin methylesterase activity and other orange juice properties

Abstract

6Inactivation of pectinmethylesterase (PME) and quality parameters of orange juice have been 7 studied after high pressure carbon dioxide (HPCD) treatment. The HPCD treatment conditions 8 covered a wide range of temperature from 2 to 40 ºC, far below normal thermal treatment, while 9 operating pressure was varied from 10 to 30 MPa and exposure time from 3 to 60 min. A 10 decrease in PME activity was found, even at the lowest temperature studied in this work, 2 ºC. 11Different inactivation kinetic models were used to correlate the PME residual activity: the two-12 fraction model, the fractional-conversion model and the Weibull model. The two-fraction model 13 presents the lowest mean relative deviation. Some quality parameters such as colour, pH, ºBrix, 14 turbidity, ascorbic acid, total acidity and particle size distribution (PSD) were also determined 15 right after HPCD treatment and along storage at 4ºC up to 12 days. PSD shows that HPCD 16 treatment results in a volume increase of small particles and a volume decrease of large particles

Effect of thermosonication batch treatment on enzyme inactivation kinetics and other quality parameters of cloudy apple juice

“…Typically, operating pressure does not exceed 50 MPa and temperature ranges between 20 and 50 ºC (Briongos et al, 2016), being lower than the temperature employed in this work in TS. Figure 7 compares the PPO inactivation kinetics by TS at 44 ºC, temperature of the plateau, (V=80 mL and 100 % of amplitude) in the presence of air and by displacing the air with nitrogen, with results obtained in a previous study on inactivation kinetic of PPO from apple juice at 45ºC by HPCD at 20 MPa (Illera et al, 2018).…”

“…50 mL of pectin solution were mixed with 1 mL of cloudy apple juice and pH was adjusted to 7.5 with NaOH 0.005 N. During pectin hydrolysis at 30 ºC, pH was maintained at 7.5 by adding NaOH 0.005 N. The amount of NaOH added for 15 min was recorded. One PME activity unit (UPE) is defined as the micromoles of carboxylic groups produced per minute and mL of juice, at pH 7.5 and 30 ºC (Briongos et al, 2016).…”

“…One of the most accepted theories of cloud loss in juices, is based on the action of pectinmethylesterase (PME). This enzyme causes pectin demethylation that could expedite pectin precipitation with calcium ions present in the juice, causing clarification and turbidity loss (Briongos et al, 2016) Thermal treatments are widely used in the food industry to inactivate microorganisms and enzymes that cause deleterious effects on foods. However, consumers demand of natural and fresh-like products has driven the food industry to investigate alternative technologies to replace conventional food heat treatments, wich may affect food quality in terms of nutritional and physicochemical parameters.…”

Effect of high‐pressure carbon dioxide on the quality of cold‐ and hot‐break tomato pulps

“…The increase in viscosity after HPCD treatment might also be related to the decrease of particle size. Effect of HPCD on particle size distribution has been reported in previous publications (Briongos et al, 2016;Illera et al, 2018). It demonstrated that HPCD led to homogenization effect causing smaller particles of juice colloid.…”

“…Most of the published studies were performed on the effects of HPCD on juices with small consistency such as those from orange (Briongos et al, 2016), apple (Liao, Zhang, Hu, & Liao, 2010), carrot (Zhu, Wang, Ramaswamy, & Yu, 2017), mulberry (Zou et al, 2016), coconut (Cappelletti et al, 2015), and watermelon (Liu, Hu, Zhao, & Song, 2012). However, there were fewer papers published on the HPCD potentials for pasteurization of a relatively consistent and viscous pulp.…”