Table 1.
Some studies using different UIF treatments and patents in solid foods processing.
| Product/Patent No. | Method | Results/Description of invention | Reference |
|---|---|---|---|
| SUIF | |||
| Lotus root | Frequency of 30 kHz and a power of 90 W, 150 W and 210 W | The results showed that compared with ultrasonic waves with other powers, ultrasonic waves with 150 W had a rapid freezing rate, improved hardness, reduced drip loss and protected microstructure of lotus root. | [87] |
| Patent | |||
| EP2269474A2 | – | An apparatus for reducing a temperature of a product which can facilitate heat transfer at the surface of the product. | [109] |
| TW103207050 | – | A kind of impregnated freezing dedicated unit of lift of ultrasonic freezing. | [110] |
| CN111955535A | – | An invention discloses a processing method for ultrasonic-assisted oyster freezing which can reduce muscle tissue and nutrient loss of oyster. | [111] |
| CN:201310100237:A | – | A method for enhancing brine salting-process frozen fish fillets through ultrasonic. | [113] |
| CN103168828A | – | A method of improving the freezing speed and quality of litchi chinensis through variable frequency ultrasonic enhancement. | [114] |
| MUIF | |||
| Potato | The same ultrasonic power (270 W), single frequency (20 kHz), double frequency (20 kHz, 28 kHz) and multi-frequency (20 kHz, 28 kHz, 40 kHz) | The results showed that MUIF can cut down freezing time and reduce juice loss compared with SUIF and DUIF. | [78] |
| Potato | the same ultrasonic power (270 W), single frequency (respectively 20 kHz and 28 kHz), orthogonal (upper and lower 20 kHz, left and right 20 kHz) and orthogonal (upper and lower 20 kHz, left and right 28 kHz). | The experiment showed that, comparing with other freezing methods, orthogonal ultrasonic wave increased the freezing rate faster and reduced the juice loss rate more obviously, which was more beneficial to the freezing preservation of potatoes. | [79] |
| Patent | |||
| CN202110049445.9 | – | An ultrasonic freezing equipment which can quickly take away a heat of a food to be frozen, so as to efficiently freeze the food. | [108] |
| UIF combined with other technologies | |||
| Surimi of grass carp | Power of 300 W and frequency of 28 kHz combined with soluble soybean sugar | The results showed that compared with ultrasonic freezing, the new ultrasonic technology added SSPS effectively reduced the contents of sulfhydryl group, carbonyl group and fibrin protein, and maintained the quality of surimi. | [88] |
| Patent | |||
| CN107198149A | – | A method for freezing surimi by ultrasonic waves together with water-soluble soybean polysaccharide which can reduce ice crystals and improve the quality of surimi comparing with single using ultrasonic mechanism. | [112] |