Effect of Ultra High Hydrostatic Pressure on Concentrations of Limonene, Α‐terpineol and Carvone in Navel Orange Juice

Abstract

Response surface methodology (RSM) was used to compare the effects of the selected variables on the changes of concentrations of limonene,α‐terpineol and carvone by ultra‐high hydrostatic pressure (UHP) treatment. A Box–Behnken experimental design was used with control variables of pressure (100–500 MPa), temperature (20–40C) and treatment time (10–20 min). Pressure, temperature and treatment time were found to be critical factors influencing changes of concentrations. Both pressure and temperature could cause limonene degradation, resulting in significant increase ofα‐terpineol and carvone concentrations. Limonene degradation was increased with increasing processing pressure or temperature. An interaction effect of pressure and temperature on limonene degradation was also found. This study showed that Box–Behnken design and RSM could be used to model the changes in concentrations of limonene,α‐terpineol and carvone in orange juice by UHP treatment. PRACTICAL APPLICATIONS As we know, ultra‐high hydrostatic pressure (UHP) processing has been an attractive way to replace conventional heat treatments for the preservation of foods. In our study, models of changes in the key aroma compounds in orange juice under UHP process were established. The changes of these aroma compounds in orange juice under UHP process could be understood further by these models. An improved understanding of the effect of UHP on critical aroma quality compounds of orange juices was helpful for us to facilitate industrial adoption of this technology. An effective research way to study the effect on aroma compounds by UHP process was also offered. Base on the data, there was a reference for us to establish an establishment of UHP processing criteria for commercial production of high‐aroma‐quality orange juice.

Effect of Storage, Oxygen and Concentration on the Levels of Key Volatiles in Processed Orange Juice

“…Carvone, which is a product of limonene oxidation (Pan et al . ), did not increase as expected in the samples that were exposed to oxygen in either manufacturer or consumer conditions (Fig. ).…”

“…Carvone is an important volatile because it is commonly used as a measure of degradation in orange juice quality (Pan et al . ).…”

“…Limonene is converted to carvone in the presence of oxygen, and under acidic conditions, it is converted into α‐terpineol (Pan et al . ). However, a reduction in oxygen does not always improve the sensory quality (Trammell et al .…”

“…Volatiles such as carvone are regularly used as a measure of degradation, and an indicator of aging using gas chromatograph-olfactometry (Perez-Cacho and Rouseff 2008). Limonene is converted to carvone in the presence of oxygen, and under acidic conditions, it is converted into α-terpineol (Pan et al 2009). However, a reduction in oxygen does not always improve the sensory quality (Trammell et al 1986).…”

Recent Developments in High Pressure Processing of Foods

“…The odor and fl avor (volatile content, 20 key aroma compounds) of the high-pressure-processed orange juice was acceptable to consumers even after storage for 12 weeks at lower temperatures of up to 10 °C (Baxter et al 2005 ). Pan et al ( 2011 ) demonstrated that limonene degradation in case of freshly squeezed navel orange juice increased with increasing processing pressure or temperature. The limonene degradation was found to result in significant increase of α-terpineol and carvone concentrations.…”