Effects of power ultrasound on immersion freezing parameters of potatoes

Purnell

Food Bioprocess Technol

2015

186

Freezing is a very well-established food preservation process that produces high quality nutritious foods with a long storage life. However, freezing is not suitable for all foods, and freezing can cause physical and chemical changes in some foods that are perceived as reducing the quality of either the thawed material or the final product. This paper reviews the many innovative freezing processes that are currently being researched and developed throughout the world to improve freezing conditions and product quality. Some inn o v a t i v e f r e e z i n g p r o c e s s e s ( i m p i n g e m e n t a n d hydrofluidisation) are essentially improvements of existing methods (air blast and immersion, respectively) to produce far higher surface heat transfer rates than previous systems and thus improve product quality through rapid freezing. In these cases, the advantages may depend on the size of the product, since the poor thermal conductivity of many foods limits the rate of cooling in large objects rather than the heat transfer between the heat transfer medium and the product. Other processes (pressure shift, magnetic resonance, electrostatic, microwave, radiofrequency, and ultrasound) are adjuncts to existing freezing systems that aim to improve product quality through controlling the way that ice is formed in the food during freezing. Another alternative is to change the properties of the food itself to control how ice is formed during freezing (such as in dehydrofreezing and the use of antifreeze and ice-nucleation proteins).

Section: Ultrasound-assisted Freezing (Uaf)mentioning

confidence: 99%

Section: Ultrasound-assisted Freezing (Uaf)mentioning

confidence: 99%

A Review of Novel and Innovative Food Freezing Technologies

Purnell

Food Bioprocess Technol

2015

186

Food Bioprocess Technol

“…Furthermore, the increase in the number of defect was found to be linear with the sonication power. Comandini et al (2013) studied the application of ultrasound produced through a 35-kHz sonotrode during immersion freezing of potatoes and concluded that the treatment affected important freezing parameters, like the anticipation of nucleation and the reduction of freezing time. Karizaki et al (2013) investigated the possibility of using ultrasound-assisted osmotic dehydration as a pretreatment prior to frying and its effects on the quality of fried potatoes.…”

Section: Introductionmentioning

confidence: 99%

A First Approach of Using Ultrasound as an Alternative for Blanching in Vacuum-Packaged Potato Strips

Amaral

Benedetti

Pujolà

et al. 2016

The effect of ultrasound (US) (40 kHz, 200 W, 3 min), blanching (85°C, 3.5 min), and the combination of both methods was evaluated on the quality of vacuumpackaged potato strips stored at 3 ± 1°C for up to 10 days. For this study, two cultivars of potatoes were assessed. For blanched Agata samples, the lightness (L*) decreased over 12 % (p < 0.05). Moreover, their hue increased up to 100, obtaining lesser yellow potato strips. In contrast, US did not affect the hue values. The losses of firmness of blanched potato strips were notable (35 % for Agata and 51 % for Agria), whereas US did not change this property (p < 0.05). Nevertheless, no significant differences were found in the total starch content at 10 days. Agata and Agria showed different metabolic behaviors of sucrose in the refrigerated storage. Therefore, Agria cultivar retained better color after frying. These results suggest that US had less impact on color and improve the firmness in vacuum-packaged potato strips with no added chemicals.

International Journal of Refrigeration

“…Ultrasound is defined as the energy generated by sound waves of frequencies above the human hearing, from 16 kHz up to the MHz range (Awad et al, 2012;Comandini et al, 2013;Mason et al, 2003;Sch€ ossler et al, 2012). Power ultrasound, in particular, a kind of ultrasound wave with frequencies in the range from 20 to 100 kHz and high sound power or sound intensity (generally higher than 1 W cm À2 ) has been addressed as a novel technique to improve the freezing and crystallization processes (Chang et al, 2012;Delgado et al, 2009;Fernandes et al, 2008;Fonteles et al, 2012;Guan et al, 2011;Kiani et al, 2012b;Mason, 1998).…”

Section: Introductionmentioning

confidence: 99%

Influence of power ultrasound on ice nucleation of radish cylinders during ultrasound-assisted immersion freezing

Zhang

Bhandari

et al. 2014

a b s t r a c tThe effect of ultrasound-assisted immersion freezing on the dynamic nucleation of ice and the delay from ultrasound application onset to nucleation commencement of radish cylinder samples were studied. The samples were frozen in 30% (w v À1 ) CaCl 2 solution (À20 C) in an ultrasonic bath system. To evaluate nucleation, ultrasound irradiation (20 kHz) was carried out with different durations (0 s, 3 s, 7 s, 10 s or 15 s), onset temperature (À0.5, À1, À1.5 and À2 C) and intensities (0.09, 0.17, 0.26 and 0.37 W cm À2 ). The results showed that ultrasound irradiation was able to induce nucleation and the nucleation temperature of radish cylinder samples exhibited a good fit to linear equation with the ultrasound irradiation temperature under 7 s duration and 0.26 W cm À2 intensity. Ultrasound irradiation temperature at À0.5 C for 7 s duration with intensity of 0.26 W cm À2 , was an optimal ultrasound application conditions for the nucleation inducement of radish cylinder samples. The results of the current study implied that ultrasound offered promising application to control the crystallization process in freezing of solid foods.