A review of emerging technologies for food refrigeration applications

“…Because a wide range of processing steps is involved in food production, it is a step forward to establish these standards based on the concept of unit operations. Although there are lots of data about frozen foods (Pelletier and Tyedmers 2010;Schmidt Rivera et al 2014;Vázquez-Rowe et al 2013;Ziegler et al 2013) and food refrigeration systems (James and James 2010;Tassou et al 2009Tassou et al , 2010Wu et al 2013) on global warming, no research has been done to investigate the effects of different freezing methods on the CF of frozen foods. Therefore, this current study aimed to compare the CF of immersion freezing with or without ultrasound application to find a more environmentally friendly freezing method.…”

Section: Introductionmentioning

confidence: 99%

Potential Life Cycle Carbon Savings for Immersion Freezing of Water by Power Ultrasound

Sun

Zhu

2015

Food Bioprocess Technol

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Since the food cold chain produces large amounts of greenhouse gases (GHGs), its carbon footprint (CF) has caused widespread concern. The process of freezing, one of the most common operations, is used in numerous food processes, and new freezing methods appear constantly. Ultrasound-assisted immersion freezing is an emerging technique that can significantly improve product quality compared to the conventional immersion freezing. In the current study, the CFs of conventional immersion freezing and ultrasoundassisted immersion freezing were investigated according to the principle of life cycle assessment (LCA). The freezing time of 1 mL of deionized water in a flask was 264±15 s for conventional freezing, while the time of 1 mL of deionized water in a flask for the ultrasonic-assisted freezing could be lowered to 188±5, 182±5, 193±6, and 201±8 s under the four ultrasonic frequencies of 28, 40, 50, and 80 kHz, respectively. By improving heat transfer and enhancing ice nucleation, the freezing time of ultrasonic-assisted freezing was reduced significantly (P<0.05) compared to conventional immersion freezing. In addition, electricity use and carbon emissions from electricity use at four frequency levels were reduced significantly (P<0.05) compared to conventional immersion freezing. The final CFs of the freezing process for 1 mL of frozen water were 11.65±0. 52, 9.16±0.24, 8.95± 0.17, 9.33±0.22, and 9.60±0.27E−5 kgCO 2 eq (equivalent) for the control, 28, 40, 50, and 80 kHz, respectively. Most of the final product CF was related to electricity and the flask used, contributing 78.1 and 19.7 % respectively for the conventional freezing, and about 70 and 25 % respectively for the ultrasound-assisted freezing. This research demonstrated that ultrasonic-assisted freezing as an emerging technology could not only improve the food quality but can also reduce the CF of a product. In addition, sensitivity analysis showed that the use of flask and improving the electricity use efficiency could decrease the carbon emissions of the product significantly.

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“…Moreover, it can be transported by pumps (Kalaiselvam et al, 2009). Therefore, ice slurry is a promising second refrigerant in various cooling processes, such as chemical, fishery and food industries (Tassou et al, 2010), central air-conditioning systems, and thermal energy storage systems (Wang and Kusumoto, 2001).…”

Section: Introductionmentioning

confidence: 99%

Analysis of ice slurry production by direct contact heat transfer of air and water solution

Zhang

Zheng

Wang

et al. 2013

J. Zhejiang Univ. Sci. A

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Abstract:In this paper, a novel system using direct contact heat transfer between air and water solution was proposed to generate ice slurry. The heat transfer process and the system performance were studied; energy efficiency coefficients of 0.038, 0.053, and 0.064 were obtained using different solutions. An empirical relationship between the volumetric heat transfer coefficient U v and the main parameters was obtained by fitting the experimental data. The U v calculated from the empirical formula agreed with the experimental U v quite well with a relative error of less than 15%. Based on the empirical formula, a laboratory-scale direct contact ice slurry generator was then constructed, with practical application in mind. If the air flow rate is fixed at 200 m 3 /h, the ice production rate will be 0.091 kg/min. The experimental results also showed that the cold energy consumption of the air compressor accounted for more than half of the total amount. To improve the system energy efficiency coefficient, it is necessary to increase the air pipes insulation and the solution's thermal capacity, and also it is appropriate to utilize the free cold energy of liquefied natural gas (LNG).

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A review of emerging technologies for food refrigeration applications

Cited by 205 publications

References 36 publications

Design of a Dairy Cooling Thermal Storage supported with Secondary Refrigeration Cooling Unit

Design of a Dairy Cooling Thermal Storage supported with Secondary Refrigeration Cooling Unit

Potential Life Cycle Carbon Savings for Immersion Freezing of Water by Power Ultrasound

Analysis of ice slurry production by direct contact heat transfer of air and water solution

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