Method for adjusting and controlling running off of microorganisms and juice of unfrozen fresh-cut fruits through pretreatment

Abstract

The invention relates to a method for adjusting and controlling running off of microorganisms and juice of unfrozen fresh-cut fruits through pretreatment, and belongs to the technical fields of processing of fruits and vegetables and safety control. According to the method, epsilon-polylysine and ultrasonic waves are in synergistic treatment, kelp carbon quantum dot / chitosan film coating bacterialpretreatment can be combined, and microorganisms on surfaces of fresh-cut fruits can be effectively controlled; and then through infrared-vacuum drying pre-dehydrating, the fresh-cut fruits are quickly frozen to minus 18 DEG C at the temperature of minus 40 DEG C, and then the quick-frozen fresh-cut fruits are stored at the temperature of minus 18 DEG C. By the bacterial pretreatment method, thetotal quantity of the microorganisms can be effectively controlled to be within 10<3> CFU / g, and coliform groups (or escherichia coli) can reach the standard (negative). After frozen fruits obtained through pretreatment adjustment and control are unfrozen, the texture of the fruits can be maintained to the maximum extent, and the hardness value is increased by 13%-17% than that of frozen fruits not be subjected to pretreatment adjustment and control treatment; and besides, the running off rate of the juice of the fruits and the running off of nutrient components of the fruits are reduced, andthe running off rate of the juice of the fruits is reduced by 13%-16% than that of fruits not subjected to pretreatment adjustment and control.

Description

technical field

[0001] The invention relates to a pretreatment method for regulating and controlling the loss of microorganisms and juice of thawed fresh-cut fruits, and belongs to the technical field of fruit and vegetable processing and safety control. Background technique

[0002] my country is a big fruit producing country, and its fruit output ranks first in the world for many years. Fresh fruit is favored in people's daily life because of its rich nutrition. A series of physiological and biochemical reactions will occur after the fruit is harvested, and it is extremely vulnerable to microorganisms, resulting in the loss of its nutritional quality, changes in tissue structure, color and flavor decline, and other problems. Therefore, it is of great significance to seek a kind of fruit processing and safety control technology. Freezing is a way to preserve perishable foods for a long time. The method also preserves the original organoleptic characteristics of the food ...

Examples

Embodiment 1

[0032] Example 1 A pretreatment method for regulating and controlling the loss of microorganisms and juice of thawed fresh-cut strawberries

[0033] Clean and cut fresh strawberries without mechanical damage, put them into an ultrasonic cleaner, add 400 mg / L ε-polylysine, and start ultrasonic treatment at an ultrasonic frequency of 20kHz, ultrasonic power of 400W, and temperature of 30°C 15min.

[0034] After the treatment, take out the water and put it into the kelp carbon quantum dots / chitosan solution with a volume concentration of 4.5% of the kelp carbon quantum dots / chitosan solution. After pretreatment, place it in an infrared-vacuum drying equipment at a temperature of 50 ° C. Pre-dehydrated strawberries were obtained under a vacuum degree of 0.08MPa, and then placed in a single-unit quick-freezer to quickly freeze the strawberry core temperature at -40°C to -18°C, packed in polyethylene bags and stored at -18°C.

[0035] Compared with untreated frozen strawberries, th...

Embodiment 2

[0036] Example 2 A pretreatment method for regulating and controlling the loss of microorganisms and juice of thawed fresh-cut kiwifruit

[0037] Clean and cut fresh kiwifruit without mechanical damage, put it into an ultrasonic cleaner, add 200mg / L ε-polylysine, and start ultrasonic treatment at an ultrasonic frequency of 20kHz, an ultrasonic power of 400W, and a temperature of 30°C for 15 minutes .

[0038] After the treatment, take out the drain, and then put it into the kelp carbon quantum dot / chitosan solution with a volume concentration of 1.5% of the kelp carbon quantum dot / chitosan solution. After pretreatment, place it in an infrared-vacuum drying equipment at a temperature of 50 ° C. The pre-dehydrated kiwifruit was obtained under a vacuum of 0.08MPa, and then placed in a single quick freezer to quickly freeze the kiwifruit core temperature at -40°C to -18°C, packed in polyethylene bags and stored at -18°C.

[0039] Compared with untreated frozen kiwifruit, the syne...

Embodiment 3

[0040] Example 3 A pretreatment method for regulating and controlling the loss of microorganisms and juice of thawed fresh-cut apples

[0041] Clean and cut fresh apples without mechanical damage, put them into an ultrasonic cleaner, add 300mg / L ε-polylysine, and start ultrasonic treatment for 15 minutes at an ultrasonic frequency of 20kHz, an ultrasonic power of 400W, and a temperature of 30°C. .

[0042] After the treatment, take out the water and put it into the kelp carbon quantum dots / chitosan solution with a volume concentration of 3% of the kelp carbon quantum dots / chitosan solution. After the antibacterial pretreatment, place it in an infrared-vacuum drying equipment at a temperature of 50°C. The pre-dehydrated apples were obtained under a vacuum of 0.08MPa, and then placed in a single-unit quick freezer at -40°C to rapidly freeze the apples at a central temperature of -18°C, packed in polyethylene bags and stored at -18°C.

[0043] Compared with untreated frozen appl...

technical field

[0001] The invention relates to a pretreatment method for regulating and controlling the loss of microorganisms and juice of thawed fresh-cut fruits, and belongs to the technical field of fruit and vegetable processing and safety control. Background technique

[0002] my country is a big fruit producing country, and its fruit output ranks first in the world for many years. Fresh fruit is favored in people's daily life because of its rich nutrition. A series of physiological and biochemical reactions will occur after the fruit is harvested, and it is extremely vulnerable to microorganisms, resulting in the loss of its nutritional quality, changes in tissue structure, color and flavor decline, and other problems. Therefore, it is of great significance to seek a kind of fruit processing and safety control technology. Freezing is a way to preserve perishable foods for a long time. The method also preserves the original organoleptic characteristics of the food ...

Examples

Embodiment 1

[0032] Example 1 A pretreatment method for regulating and controlling the loss of microorganisms and juice of thawed fresh-cut strawberries

[0033] Clean and cut fresh strawberries without mechanical damage, put them into an ultrasonic cleaner, add 400 mg / L ε-polylysine, and start ultrasonic treatment at an ultrasonic frequency of 20kHz, ultrasonic power of 400W, and temperature of 30°C 15min.

[0034] After the treatment, take out the water and put it into the kelp carbon quantum dots / chitosan solution with a volume concentration of 4.5% of the kelp carbon quantum dots / chitosan solution. After pretreatment, place it in an infrared-vacuum drying equipment at a temperature of 50 ° C. Pre-dehydrated strawberries were obtained under a vacuum degree of 0.08MPa, and then placed in a single-unit quick-freezer to quickly freeze the strawberry core temperature at -40°C to -18°C, packed in polyethylene bags and stored at -18°C.

[0035] Compared with untreated frozen strawberries, th...

Embodiment 2

[0036] Example 2 A pretreatment method for regulating and controlling the loss of microorganisms and juice of thawed fresh-cut kiwifruit

[0037] Clean and cut fresh kiwifruit without mechanical damage, put it into an ultrasonic cleaner, add 200mg / L ε-polylysine, and start ultrasonic treatment at an ultrasonic frequency of 20kHz, an ultrasonic power of 400W, and a temperature of 30°C for 15 minutes .

[0038] After the treatment, take out the drain, and then put it into the kelp carbon quantum dot / chitosan solution with a volume concentration of 1.5% of the kelp carbon quantum dot / chitosan solution. After pretreatment, place it in an infrared-vacuum drying equipment at a temperature of 50 ° C. The pre-dehydrated kiwifruit was obtained under a vacuum of 0.08MPa, and then placed in a single quick freezer to quickly freeze the kiwifruit core temperature at -40°C to -18°C, packed in polyethylene bags and stored at -18°C.

[0039] Compared with untreated frozen kiwifruit, the syne...

Embodiment 3

[0040] Example 3 A pretreatment method for regulating and controlling the loss of microorganisms and juice of thawed fresh-cut apples

[0041] Clean and cut fresh apples without mechanical damage, put them into an ultrasonic cleaner, add 300mg / L ε-polylysine, and start ultrasonic treatment for 15 minutes at an ultrasonic frequency of 20kHz, an ultrasonic power of 400W, and a temperature of 30°C. .

[0042] After the treatment, take out the water and put it into the kelp carbon quantum dots / chitosan solution with a volume concentration of 3% of the kelp carbon quantum dots / chitosan solution. After the antibacterial pretreatment, place it in an infrared-vacuum drying equipment at a temperature of 50°C. The pre-dehydrated apples were obtained under a vacuum of 0.08MPa, and then placed in a single-unit quick freezer at -40°C to rapidly freeze the apples at a central temperature of -18°C, packed in polyethylene bags and stored at -18°C.

[0043] Compared with untreated frozen appl...