CN109007198B

CN109007198B - Fermented sugar-free preserved papaya and processing method thereof

Info

Publication number: CN109007198B
Application number: CN201810849078.9A
Authority: CN
Inventors: 黄名正; 刘晓柱; 赵湖冰; 张振; 于志海; 许存宾; 刘晓辉
Original assignee: Guizhou Institute of Technology
Current assignee: Guizhou Institute of Technology
Priority date: 2018-07-28
Filing date: 2018-07-28
Publication date: 2022-01-21
Anticipated expiration: 2038-07-28
Also published as: CN109007198A

Abstract

The invention discloses fermented sugar-free preserved papaya, which is prepared from the following raw materials: the main raw materials of the beverage comprise pawpaw parts, bacteriostatic and bactericidal agents parts, softening agents parts, yeast nutrition auxiliary agents parts, dry yeast parts, sweetening agents parts, color fixative parts, acidity regulator parts and edible moisture. The sugar degree of the pawpaw is changed into 0brix during low-temperature fermentation, so that the hardness and the crude fiber content of the product are reduced, sugar and acid and astringent tastes in the pawpaw are removed, and the processed pawpaw product is sugar-free; the pawpaw juice beverage is prepared from pawpaw pomace, can greatly keep the integrity and the nutritive value of pawpaw, and improves the comprehensive utilization efficiency of the pawpaw; the prepared pawpaw preserved fruit slices are bright and pleasant in color and luster, soft in tissue, aromatic and special in flavor, complex in body fragrance, sweet and refreshing in taste, have the characteristic of wrapping up and perfuming, are cool and refreshing in nature, are sugar-free, maintain beauty and keep young, have high nutritional value, have a good health care effect on a human body, are suitable for people of all ages, and are particularly suitable for weight-losing crowds and diabetics.

Description

Fermented sugar-free preserved papaya and processing method thereof

Technical Field

The invention belongs to the technical field of food processing, relates to a deep processing method of fresh pawpaw, and particularly relates to fermented sugar-free preserved pawpaw and a processing method thereof.

Background

The pawpaw (Chaenomeles sinensis (thun) Koehne) is a plant of the rosaceous pawpaw, commonly known as pawpaw, wax gourd, pomelo and the like, is a tropical evergreen fruit tree, is a multipurpose plant integrating appreciation, eating and medicine, is rich in vitamins, trace elements, enzymes, polysaccharides, pigments, alkaloids, flavonoids, terpenes, steroids, glycosides and the like, has multiple activities of inflammation resistance, bacteria resistance, tumor resistance, cancer resistance, virus resistance, liver protection, immune regulation, beauty treatment and the like, is evaluated as a top of ten nutritious health-care fruits by American scientists, and is called 'Bai Yi fruit king'. The pawpaw is delicious and has the food therapy effect, and especially has the beauty treatment effect on women. The proteolytic enzyme contained in the pawpaw can compensate the secretion of pancreas and intestinal tract, supplement the insufficiency of gastric juice and is helpful for decomposing protein and starch. The pawpaw contains carotene and abundant vitamin C, and the carotene and the vitamin C have strong oxidation resistance, help the organism to repair tissues, eliminate toxic substances, enhance the immunity of the human body and help the organism to resist virus invasion including influenza A. The effective components in fructus Chaenomelis can improve phagocytic effect.

The medicinal value of the pawpaw is high, and the pawpaw has early research and clinical application in traditional Chinese medicine. For example, as recorded in "Qing Yi Lu" (records of abnormal records of Qing dynasty): the pawpaw is named as Tiejiaoli because it is good for the lower part and is essential for the people with the disease of the foot, knee, muscle and bone. The said Chinese patent medicine is named as famous medical records, the pawpaw has the functions of treating damp arthralgia and beriberi and not only changing tendon, so that the ancient people can use the pawpaw as main material to make "rheumatic pawpaw wine", "tiger bone pawpaw wine" and "pawpaw pill". Modern medicine believes that papaya contains an enzyme (digestive enzyme) which can digest protein, help digestion and absorption, and is beneficial to patients with dyspepsia and gastric diseases. Especially, in recent years, the pawpaw can also inhibit the growth of cancer cells. Pawpaw is also a good food. According to the compendium of materia Medica, mu Gua is everywhere with its good taste and beauty, and good appetite. In recent years, many foods such as papaya wine, papaya sugar, papaya beverage, papaya rice porridge and the like are made from papaya. However, the preserved fruits made of papaya are rare, and even if the preserved fruits are some, the preserved fruits have high sugar content and are hard, and the astringent taste of papaya is difficult to remove.

At present, fresh pawpaw is used as fruit, and is mostly directly used for brewing pawpaw wine. In the papaya wine brewing process, the papaya wine brewing is carried out by squeezing the papaya flesh to obtain the juice, the papaya dregs are directly discarded, the utilization rate of the papaya is not high, the papaya cannot be sufficiently utilized, and even the resource waste is caused. In addition, although the pawpaw contains rich nutrient components and has various curative effects on human bodies, the pawpaw belongs to respiration transition type fruits, and is easy to soften, mature, attack and rot under the action factors of climate, plant diseases and insect pests and the like after being picked, so that the original commodity value is lost; meanwhile, the fruit is sour and astringent, has high hardness and more crude fiber, and is not suitable for being directly eaten by people as fresh fruit.

The bottleneck of the development of the pawpaw is promoted by the reasons, so that a deep processing method which can better and more fully utilize the pawpaw and improve the added value of a pawpaw product is particularly important to develop.

Disclosure of Invention

The invention provides fermented sugar-free preserved papaya and a processing method thereof to solve the technical problems. According to the invention, the yeast is inoculated for low-temperature fermentation after soaking and softening, the sugar degree change of the papaya is monitored in real time through the low-temperature fermentation, and the fermentation is stopped until the sugar degree is 0brix, so that the hardness and the crude fiber content of the papaya are reduced, the sugar and the acid taste of the papaya are removed, the processed papaya product is sugar-free, and further, the color and the smell of the papaya are improved by adopting the sweetening agent for soaking, and the palatability and the quality of the preserved papaya are improved; the pawpaw juice beverage is prepared from pawpaw pomace, the industrial chain of pawpaw is prolonged, the added value of products is improved, the pawpaw is fully utilized, the comprehensive utilization efficiency of the pawpaw is improved, the processing process is carried out in a low-temperature environment, and the integrity and the nutritive value of pawpaw fruits can be reserved to a great extent; the prepared pawpaw preserved fruit slices are bright and pleasant in color and luster, soft in tissue, aromatic and special in flavor, complex in body fragrance, sweet and refreshing in taste, have the characteristic of 'unpacking and perfuming', are cool and refreshing in nature, sugar-free, beautifying and high in nutritional value, have a good health-care effect on a human body, are suitable for people of all ages, are particularly suitable for weight-losing crowds and diabetics, and solve the technical bottlenecks of sourness and acerbity, high hardness, more crude fibers, high sugar content and the like of pawpaw products processed by the prior art.

In order to achieve the above purpose, the invention adopts the following technical scheme:

a fermented sugar-free preserved papaya is prepared from the following raw materials in parts by weight: 1000-1500 parts of pawpaw, 0.3-0.9 part of bacteriostatic bactericide, 0.3-0.8 part of softener, 4-12 parts of yeast nutrition auxiliary agent, 4-12 parts of dry yeast, 25-45 parts of sweetener, 5-15 parts of color fixative, 1-10 parts of acidity regulator and 1000-1500 parts of edible water.

Further, the fermented sugar-free preserved papaya is prepared from the following raw materials in parts by weight: 1250 parts of pawpaw, 0.6 part of bacteriostatic bactericide, 0.5 part of softener, 8 parts of yeast nutrition auxiliary agent, 8 parts of dry yeast, 35 parts of sweetening agent, 10 parts of color fixative, 5 parts of acidity regulator and 1250 parts of edible water.

Further, the bacteriostatic bactericide is one of potassium metabisulfite, sulfur dioxide, sodium metabisulfite, sodium sulfite, sodium bisulfite and sodium hyposulfite.

Further, the concentration of the antibacterial bactericide is 50-100 mg/L; the concentration of the pectinase is 0.02 g/L; the concentration of the yeast nutrition auxiliary agent is 0.2 g/L; the concentration of the dry yeast is 0.2 g/L.

Further, the sweetener is one or more of xylitol, maltitol, sorbitol, stevioside and isomaltulose.

Further, the softener is pectinase; the color fixative is food-grade glycerol; the acidity regulator is tartaric acid.

Further, the processing method of the fermented sugar-free preserved papaya comprises the following steps:

(1) selection and pretreatment of pawpaw: selecting residual pomace obtained by squeezing fresh pawpaw pulp in pawpaw wine brewing, quickly selecting the pawpaw pomace which is hard in texture, free of rotting and insect pests, good in taste and moderate in maturity as a raw material in a cool low-temperature environment at the temperature of 2-6 ℃, washing away stains and impurities which affect the quality of preserved fruits in the pawpaw pomace by using clear water, and naturally draining for later use;

(2) slitting: placing the pawpaw pomace in a shady and low-temperature environment at 1-5 ℃, and cutting into pawpaw slices with the thickness of 0.3-0.6 cm according to the textures to obtain falcate pawpaw slices;

(3) soaking and softening: feeding the papaya slices into a fermentation tank, adding edible water and a softener at the same time, and uniformly mixing for later use;

(4) bacteriostasis and sterilization: weighing the antibacterial bactericide according to the weight part ratio, adding the antibacterial bactericide into the soaked and softened papaya slices, uniformly mixing, sealing and standing for 22-26 hours;

(5) and (3) acidity adjustment: measuring the pH value of the bacteriostatic and bactericidal papaya slices by using a pH meter, adding an acidity regulator into a fermentation tank, and regulating the pH value of the papaya slices to 3.0-3.5 for later use;

(6) yeast inoculation: weighing dry yeast and a yeast nutrition aid according to the weight part ratio, firstly activating the dry yeast and the yeast nutrition aid for 28-33 min at the temperature of 33-37 ℃ until the yeast is reactivated, then inoculating the dried yeast and the yeast nutrition aid into the papaya slices with the adjusted acidity, and uniformly mixing;

(7) low-temperature fermentation: standing the pawpaw slices inoculated with the dry yeast in a fermentation tank for 21-26 hours, then placing the pawpaw slices in a temperature-controllable low-temperature environment at 16-18 ℃, and then starting the fermentation tank for fermentation;

(8) soaking: calculating the sweetness of a 15% sucrose water solution at 20 ℃ to be 1.0, preparing a solution with the sweetness of 2.0-2.6 by adopting a sweetening agent, adding the papaya slices into the sweetening agent solution, soaking for 20-26 h, taking out, filtering to remove filtrate, and draining filter residues for later use;

(9) drying: sending the soaked papaya slices into a dryer for drying treatment, and stopping drying when the water content of the papaya slices is below 20%;

(10) color protection: coating a layer of color fixative on dried papaya slices with water content of 20%, and drying in a dryer to obtain semi-finished product of fermented sugar-free papaya preserved fruit;

(11) and (3) nitrogen filling and packaging: selecting nitrogen with the purity of more than or equal to 96 percent, filling nitrogen by using an automatic nitrogen filling machine, quantitatively packaging the semi-finished product of the fermented sugar-free preserved papaya by using a polyethylene bag, and checking to be qualified to obtain the finished product of the fermented sugar-free preserved papaya.

Further, in the step (7), the fermentation process also comprises monitoring the change of the sugar degree in real time, and the fermentation is stopped until the sugar degree is changed to 0 brix.

Further, in step (9), the drying process is: firstly, drying the papaya slices at 50-60 ℃ for 0.8-1.5 h, and then raising the temperature to 70-80 ℃ for continuous drying.

Further, in the step (10), the painting amount of the color fixative is 0.8-1%; and the drying treatment is carried out at the temperature of 18-23 ℃ for 25-35 min until the water content of the papaya slices is lower than 15%.

0brix means the sugar degree.

Due to the adoption of the technical scheme, the invention has the following beneficial effects:

(1) the papaya preserved fruit slices prepared by the invention have bright and pleasant color, soft tissue, aromatic and special flavor, complex body, sweet and refreshing taste, the characteristics of 'unpacking and perfuming', cool nature, sugar-free property, beauty and face maintenance, high nutritive value, better health care effect on human bodies, suitability for people of all ages, and particular suitability for weight-losing crowds and diabetic patients.

(2) The invention provides a deep processing method of papaya products, which is prepared by adopting papaya pomace generated in the papaya wine brewing process, prolongs the industrial chain of papaya, improves the added value of products, fully utilizes papaya and improves the comprehensive utilization efficiency of papaya.

(3) The processing process is carried out in a low-temperature environment, the integrity and the nutritive value of the papaya fruits can be kept to a greater degree, and the technical bottlenecks of high sourness, high hardness, more crude fibers, high sugar content and the like of papaya products processed by the prior art are solved.

(4) According to the invention, the pawpaw is soaked and softened by the softener, then the yeast is inoculated for low-temperature fermentation, the low-temperature fermentation is used for monitoring the change of the sugar degree in real time, and the fermentation is stopped until the sugar degree is 0brix, so that the hardness and the crude fiber content of the product are reduced, the sugar and the sour and astringent taste of the pawpaw are removed, the processed pawpaw product is free of sugar, and further, the sweetening agent is adopted for soaking, so that the color and smell of the pawpaw are improved, and the palatability and the quality of the preserved pawpaw are improved.

Detailed Description

The following is a detailed description of the embodiments of the present invention, but the present invention is not limited to these embodiments, and any modifications or substitutions in the basic spirit of the embodiments are included in the scope of the present invention as claimed in the claims.

Example 1

A fermented sugar-free preserved papaya is prepared from the following raw materials in parts by weight: 1000 parts of pawpaw, 0.3 part of bacteriostatic bactericide, 0.3 part of softener, 4 parts of yeast nutrition auxiliary agent, 4 parts of dry yeast, 25 parts of sweetening agent, 5 parts of color fixative, 1 part of acidity regulator and 1000 parts of edible water.

Further, the bacteriostatic bactericide is one of potassium metabisulfite, sulfur dioxide, sodium metabisulfite, sodium sulfite, sodium bisulfite and sodium hyposulfite; the concentration of the antibacterial bactericide is 50 mg/L; the concentration of the pectinase is 0.02 g/L; the concentration of the yeast nutrition auxiliary agent is 0.2 g/L; the concentration of the dry yeast is 0.2 g/L; the sweetener is one or more of xylitol, maltitol, sorbitol, stevioside and isomaltulose; the softener is pectinase; the color fixative is food-grade glycerol; the acidity regulator is tartaric acid.

A processing method of the fermented sugar-free preserved papaya comprises the following steps:

(1) selection and pretreatment of pawpaw: selecting the residual pomace obtained by squeezing fresh pawpaw pulp in pawpaw wine brewing, quickly selecting the pawpaw pomace which is hard in texture, free of rotting and insect pests, good in taste and moderate in maturity as a raw material in a cool low-temperature environment at the temperature of 2 ℃, washing away stains and impurities which affect the quality of preserved fruits in the pawpaw pomace by using clear water, and naturally draining for later use;

(2) slitting: placing the pawpaw pomace in a cool low-temperature environment at 1 ℃, cutting into pawpaw slices with the thickness of 0.3cm according to the textures to obtain falcate pawpaw slices;

(4) bacteriostasis and sterilization: weighing the antibacterial bactericide according to the weight part ratio, adding the antibacterial bactericide into the soaked and softened papaya slices, uniformly mixing, sealing and standing for 22 hours;

(5) and (3) acidity adjustment: measuring the pH value of the antibacterial and bactericidal papaya slices by using a pH meter, adding an acidity regulator into a fermentation tank, and regulating the pH value of the papaya slices to 3.0 for later use;

(6) yeast inoculation: weighing dry yeast and yeast nutrition auxiliary agent according to the weight part ratio, firstly activating the dry yeast and yeast nutrition auxiliary agent for 28min at 33 ℃ until the yeast is reactivated, then inoculating the dried yeast and yeast nutrition auxiliary agent into the papaya slices with the adjusted acidity, and uniformly mixing;

(7) low-temperature fermentation: standing the pawpaw slices inoculated with the dry yeast in a fermentation tank for 21 hours, then placing the pawpaw slices in a temperature-controllable low-temperature environment at 16 ℃, and starting the fermentation tank for fermentation; the fermentation process also comprises monitoring the change of the sugar degree in real time, and stopping fermentation until the sugar degree is 0 brix;

(8) soaking: calculating the sweetness of 15% sucrose water solution at 20 ℃ to be 1.0, preparing a solution with the sweetness of 2.0 by adopting a sweetening agent, adding the papaya slices into the sweetening agent solution, soaking for 20 hours, taking out, filtering to remove filtrate, and draining filter residues for later use;

(9) drying: sending the soaked papaya slices into a dryer for drying treatment, and stopping drying when the water content of the papaya slices is below 20%; the drying treatment comprises the following steps: firstly, drying the papaya slices at 50 ℃ for 0.8h, and then raising the temperature to 70 ℃ for continuous drying;

(10) color protection: coating a layer of color fixative on dried papaya slices with water content of 20%, and drying in a dryer to obtain semi-finished product of fermented sugar-free papaya preserved fruit; the coating amount of the color fixative is 0.8%; the drying treatment temperature is 18 ℃, the drying treatment time is 25min, and the drying is carried out until the water content of the papaya slices is lower than 15%;

Example 2

A fermented sugar-free preserved papaya is prepared from the following raw materials in parts by weight: 1500 parts of pawpaw, 0.9 part of bacteriostatic bactericide, 0.8 part of softener, 12 parts of yeast nutrition auxiliary agent, 12 parts of dry yeast, 45 parts of sweetener, 15 parts of color fixative, 10 parts of acidity regulator and 1500 parts of edible water.

Further, the bacteriostatic bactericide is one of potassium metabisulfite, sulfur dioxide, sodium metabisulfite, sodium sulfite, sodium bisulfite and sodium hyposulfite; the concentration of the antibacterial bactericide is 100 mg/L; the concentration of the pectinase is 0.02 g/L; the concentration of the yeast nutrition auxiliary agent is 0.2 g/L; the concentration of the dry yeast is 0.2 g/L; the sweetener is one or more of xylitol, maltitol, sorbitol, stevioside and isomaltulose; the softener is pectinase; the color fixative is food-grade glycerol; the acidity regulator is tartaric acid.

(1) selection and pretreatment of pawpaw: selecting the residual pomace obtained by squeezing fresh pawpaw pulp in the pawpaw wine brewing, quickly selecting the pawpaw pomace which is hard in texture, free of rot and insect pests, good in taste and moderate in maturity as a raw material in a cool low-temperature environment at 6 ℃, washing away stains and impurities which affect the quality of preserved fruits in the pawpaw pomace by using clear water, and naturally draining for later use;

(2) slitting: placing the pawpaw pomace in a shady and cool low-temperature environment at 5 ℃, cutting into pawpaw slices with the thickness of 0.6cm according to the textures to obtain falcate pawpaw slices;

(4) bacteriostasis and sterilization: weighing the antibacterial bactericide according to the weight part ratio, adding the antibacterial bactericide into the soaked and softened papaya slices, uniformly mixing, sealing and standing for 26 hours;

(5) and (3) acidity adjustment: measuring the pH value of the antibacterial and bactericidal papaya slices by using a pH meter, adding an acidity regulator into a fermentation tank, and regulating the pH value of the papaya slices to 3.5 for later use;

(6) yeast inoculation: weighing dry yeast and yeast nutrition auxiliary agent according to the weight part ratio, firstly activating the dry yeast and yeast nutrition auxiliary agent for 33min at 37 ℃ until the yeast is reactivated, then inoculating the dried yeast and yeast nutrition auxiliary agent into the papaya slices with the adjusted acidity, and uniformly mixing;

(7) low-temperature fermentation: standing the pawpaw slices inoculated with the dry yeast in a fermentation tank for 26 hours, then placing the pawpaw slices in a temperature-controllable low-temperature environment at 18 ℃, and then starting the fermentation tank for fermentation; the fermentation process also comprises monitoring the change of the sugar degree in real time, and stopping fermentation until the sugar degree is 0 brix;

(8) soaking: calculating the sweetness of 15% sucrose water solution at 20 ℃ to be 1.0, preparing a solution with the sweetness of 2.6 by adopting a sweetening agent, adding the papaya slices into the sweetening agent solution, soaking for 26 hours, taking out, filtering to remove filtrate, and draining filter residues for later use;

(9) drying: sending the soaked papaya slices into a dryer for drying treatment, and stopping drying when the water content of the papaya slices is below 20%; the drying treatment comprises the following steps: firstly, drying the papaya slices at 60 ℃ for 1.5h, and then raising the temperature to 80 ℃ for continuous drying;

(10) color protection: coating a layer of color fixative on dried papaya slices with water content of 20%, and drying in a dryer to obtain semi-finished product of fermented sugar-free papaya preserved fruit; the coating amount of the color fixative is 1%; the drying treatment temperature is 23 ℃, the drying treatment time is 35min, and the drying is carried out until the water content of the papaya slices is lower than 15%;

Example 3

A fermented sugar-free preserved papaya is prepared from the following raw materials in parts by weight: 1100 parts of pawpaw, 0.4 part of bacteriostatic bactericide, 0.4 part of softener, 5 parts of yeast nutrition auxiliary agent, 5 parts of dry yeast, 26 parts of sweetener, 6 parts of color fixative, 2 parts of acidity regulator and 1100 parts of edible water.

Further, the bacteriostatic bactericide is one of potassium metabisulfite, sulfur dioxide, sodium metabisulfite, sodium sulfite, sodium bisulfite and sodium hyposulfite; the concentration of the antibacterial bactericide is 60 mg/L; the concentration of the pectinase is 0.02 g/L; the concentration of the yeast nutrition auxiliary agent is 0.2 g/L; the concentration of the dry yeast is 0.2 g/L; the sweetener is one or more of xylitol, maltitol, sorbitol, stevioside and isomaltulose; the softener is pectinase; the color fixative is food-grade glycerol; the acidity regulator is tartaric acid.

(1) selection and pretreatment of pawpaw: selecting the residual pomace obtained by squeezing fresh pawpaw pulp in pawpaw wine brewing, quickly selecting the pawpaw pomace which is hard in texture, free of rotting and insect pests, good in taste and moderate in maturity as a raw material in a cool low-temperature environment at the temperature of 3 ℃, washing away stains and impurities which affect the quality of preserved fruits in the pawpaw pomace by using clear water, and naturally draining for later use;

(2) slitting: placing the pawpaw pomace in a shady and cool low-temperature environment at the temperature of 2 ℃, cutting into pawpaw slices with the thickness of 0.4cm according to the textures to obtain falcate pawpaw slices;

(4) bacteriostasis and sterilization: weighing the antibacterial bactericide according to the weight part ratio, adding the antibacterial bactericide into the soaked and softened papaya slices, uniformly mixing, sealing and standing for 23 hours;

(5) and (3) acidity adjustment: measuring the pH value of the antibacterial and bactericidal papaya slices by using a pH meter, adding an acidity regulator into a fermentation tank, and regulating the pH value of the papaya slices to 3.1 for later use;

(6) yeast inoculation: weighing dry yeast and yeast nutrition auxiliary agent according to the weight part ratio, firstly activating the dry yeast and yeast nutrition auxiliary agent for 29min at the temperature of 34 ℃ until the yeast is reactivated, then inoculating the dried yeast and yeast nutrition auxiliary agent into the papaya slices with the adjusted acidity, and uniformly mixing;

(7) low-temperature fermentation: standing the pawpaw slices inoculated with the dry yeast in a fermentation tank for 22 hours, then placing the pawpaw slices in a temperature-controllable low-temperature environment at 16 ℃, and starting the fermentation tank for fermentation; the fermentation process also comprises monitoring the change of the sugar degree in real time, and stopping fermentation until the sugar degree is 0 brix;

(8) soaking: calculating the sweetness of 15% sucrose water solution at 20 ℃ to be 1.0, preparing a solution with the sweetness of 2.1 by adopting a sweetening agent, adding the papaya slices into the sweetening agent solution, soaking for 21 hours, taking out, filtering to remove filtrate, and draining filter residues for later use;

(9) drying: sending the soaked papaya slices into a dryer for drying treatment, and stopping drying when the water content of the papaya slices is below 20%; the drying treatment comprises the following steps: firstly, drying the papaya slices at 51 ℃ for 0.9h, and then raising the temperature to 71 ℃ for continuous drying;

(10) color protection: coating a layer of color fixative on dried papaya slices with water content of 20%, and drying in a dryer to obtain semi-finished product of fermented sugar-free papaya preserved fruit; the coating amount of the color fixative is 0.85 percent; the drying treatment temperature is 19 ℃, the drying treatment time is 26min, and the drying is carried out until the water content of the papaya slices is lower than 15%;

Example 4

A fermented sugar-free preserved papaya is prepared from the following raw materials in parts by weight: 1400 parts of pawpaw, 0.8 part of bacteriostatic bactericide, 0.7 part of softener, 11 parts of yeast nutrition auxiliary agent, 11 parts of dry yeast, 43 parts of sweetener, 14 parts of color fixative, 9 parts of acidity regulator and 1400 parts of edible water.

Further, the bacteriostatic bactericide is one of potassium metabisulfite, sulfur dioxide, sodium metabisulfite, sodium sulfite, sodium bisulfite and sodium hyposulfite; the concentration of the antibacterial bactericide is 90 mg/L; the concentration of the pectinase is 0.02 g/L; the concentration of the yeast nutrition auxiliary agent is 0.2 g/L; the concentration of the dry yeast is 0.2 g/L; the sweetener is one or more of xylitol, maltitol, sorbitol, stevioside and isomaltulose; the softener is pectinase; the color fixative is food-grade glycerol; the acidity regulator is tartaric acid.

(1) selection and pretreatment of pawpaw: selecting the residual pomace obtained by squeezing fresh pawpaw pulp in pawpaw wine brewing, quickly selecting the pawpaw pomace which is hard in texture, free of rotting and insect pests, good in taste and moderate in maturity as a raw material in a cool low-temperature environment at the temperature of 5 ℃, washing away stains and impurities which affect the quality of preserved fruits in the pawpaw pomace by using clear water, and naturally draining for later use;

(2) slitting: placing the pawpaw pomace in a cool low-temperature environment at 4 ℃, cutting into pawpaw slices with the thickness of 0.5cm according to the textures to obtain falcate pawpaw slices;

(4) bacteriostasis and sterilization: weighing the antibacterial bactericide according to the weight part ratio, adding the antibacterial bactericide into the soaked and softened papaya slices, uniformly mixing, sealing and standing for 25 hours;

(5) and (3) acidity adjustment: measuring the pH value of the antibacterial and bactericidal papaya slices by using a pH meter, adding an acidity regulator into a fermentation tank, and regulating the pH value of the papaya slices to 3.4 for later use;

(6) yeast inoculation: weighing dry yeast and yeast nutrition auxiliary agent according to the weight part ratio, firstly activating the dry yeast and yeast nutrition auxiliary agent for 32min at 36 ℃ until the yeast is reactivated, then inoculating the dried yeast and yeast nutrition auxiliary agent into the papaya slices with the adjusted acidity, and uniformly mixing;

(7) low-temperature fermentation: standing the pawpaw slices inoculated with the dry yeast in a fermentation tank for 25 hours, then placing the pawpaw slices in a temperature-controllable low-temperature environment at 18 ℃, and starting the fermentation tank for fermentation; the fermentation process also comprises monitoring the change of the sugar degree in real time, and stopping fermentation until the sugar degree is 0 brix;

(8) soaking: calculating the sweetness of 15% sucrose water solution at 20 ℃ to be 1.0, preparing a solution with the sweetness of 2.5 by adopting a sweetening agent, adding the papaya slices into the sweetening agent solution, soaking for 25 hours, taking out, filtering to remove filtrate, and draining filter residues for later use;

(9) drying: sending the soaked papaya slices into a dryer for drying treatment, and stopping drying when the water content of the papaya slices is below 20%; the drying treatment comprises the following steps: firstly, drying the papaya slices at 59 ℃ for 1.4h, and then raising the temperature to 70-80 ℃ for continuous drying;

(10) color protection: coating a layer of color fixative on dried papaya slices with water content of 20%, and drying in a dryer to obtain semi-finished product of fermented sugar-free papaya preserved fruit; the coating amount of the color fixative is 0.95 percent; the drying treatment temperature is 22 ℃, the drying treatment time is 34min, and the drying is carried out until the water content of the papaya slices is lower than 15%;

Example 5

A fermented sugar-free preserved papaya is prepared from the following raw materials in parts by weight: 1250 parts of pawpaw, 0.6 part of bacteriostatic bactericide, 0.5 part of softener, 8 parts of yeast nutrition auxiliary agent, 8 parts of dry yeast, 35 parts of sweetening agent, 10 parts of color fixative, 5 parts of acidity regulator and 1250 parts of edible water.

Further, the bacteriostatic bactericide is one of potassium metabisulfite, sulfur dioxide, sodium metabisulfite, sodium sulfite, sodium bisulfite and sodium hyposulfite; the concentration of the antibacterial bactericide is 75 mg/L; the concentration of the pectinase is 0.02 g/L; the concentration of the yeast nutrition auxiliary agent is 0.2 g/L; the concentration of the dry yeast is 0.2 g/L; the sweetener is one or more of xylitol, maltitol, sorbitol, stevioside and isomaltulose; the softener is pectinase; the color fixative is food-grade glycerol; the acidity regulator is tartaric acid.

(1) selection and pretreatment of pawpaw: selecting residual pomace obtained by squeezing fresh pawpaw pulp in pawpaw wine brewing, quickly selecting the pawpaw pomace which is hard in texture, free of rotting and pest damage, good in taste and moderate in maturity as a raw material in a cool low-temperature environment at 4 ℃, washing away stains and impurities which affect the quality of preserved fruits in the pawpaw pomace by using clear water, and naturally draining for later use;

(4) bacteriostasis and sterilization: weighing the antibacterial bactericide according to the weight part ratio, adding the antibacterial bactericide into the soaked and softened papaya slices, uniformly mixing, sealing and standing for 24 hours;

(6) yeast inoculation: weighing dry yeast and yeast nutrition auxiliary agent according to the weight part ratio, firstly activating the dry yeast and yeast nutrition auxiliary agent for 30min at 35 ℃ until the yeast is reactivated, then inoculating the dried yeast and yeast nutrition auxiliary agent into the papaya slices with the adjusted acidity, and uniformly mixing;

(7) low-temperature fermentation: standing the pawpaw slices inoculated with the dry yeast in a fermentation tank for 24 hours, then placing the pawpaw slices in a temperature-controllable low-temperature environment at 16-18 ℃, and then starting the fermentation tank for fermentation; the fermentation process also comprises monitoring the change of the sugar degree in real time, and stopping fermentation until the sugar degree is 0 brix;

(8) soaking: calculating the sweetness of a 15% sucrose water solution at 20 ℃ to be 1.0, preparing a solution with the sweetness of 2.0-2.6 by adopting a sweetening agent, adding the papaya slices into the sweetening agent solution, soaking for 24 hours, taking out, filtering to remove filtrate, and draining filter residues for later use;

(9) drying: sending the soaked papaya slices into a dryer for drying treatment, and stopping drying when the water content of the papaya slices is below 20%; the drying treatment comprises the following steps: firstly, drying the papaya slices at 55 ℃ for 1h, and then raising the temperature to 75 ℃ for continuous drying;

(10) color protection: coating a layer of color fixative on dried papaya slices with water content of 20%, and drying in a dryer to obtain semi-finished product of fermented sugar-free papaya preserved fruit; the coating amount of the color fixative is 0.8-1%; the drying treatment is carried out at the temperature of 20 ℃ for 30min until the water content of the papaya slices is lower than 15%;

Example 6

A fermented sugar-free preserved papaya is prepared from the following raw materials in parts by weight: 1150 parts of pawpaw, 0.5 part of bacteriostatic bactericide, 0.5 part of softener, 6 parts of yeast nutrition auxiliary agent, 6 parts of dry yeast, 30 parts of sweetener, 8 parts of color fixative, 3 parts of acidity regulator and 1150 parts of edible water.

Further, the bacteriostatic bactericide is one of potassium metabisulfite, sulfur dioxide, sodium metabisulfite, sodium sulfite, sodium bisulfite and sodium hyposulfite; the concentration of the antibacterial bactericide is 70 mg/L; the concentration of the pectinase is 0.02 g/L; the concentration of the yeast nutrition auxiliary agent is 0.2 g/L; the concentration of the dry yeast is 0.2 g/L; the sweetener is one or more of xylitol, maltitol, sorbitol, stevioside and isomaltulose; the softener is pectinase; the color fixative is food-grade glycerol; the acidity regulator is tartaric acid.

(5) and (3) acidity adjustment: measuring the pH value of the antibacterial and bactericidal papaya slices by using a pH meter, adding an acidity regulator into a fermentation tank, and regulating the pH value of the papaya slices to 3.2 for later use;

(6) yeast inoculation: weighing dry yeast and yeast nutrition auxiliary agent according to the weight part ratio, firstly activating the dry yeast and yeast nutrition auxiliary agent for 30min at the temperature of 34 ℃ until the yeast is reactivated, then inoculating the dried yeast and yeast nutrition auxiliary agent into the papaya slices with the adjusted acidity, and uniformly mixing;

(7) low-temperature fermentation: standing the pawpaw slices inoculated with the dry yeast in a fermentation tank for 23 hours, then placing the pawpaw slices in a temperature-controllable low-temperature environment at 17 ℃, and starting the fermentation tank for fermentation; the fermentation process also comprises monitoring the change of the sugar degree in real time, and stopping fermentation until the sugar degree is 0 brix;

(8) soaking: calculating the sweetness of 15% sucrose water solution at 20 ℃ to be 1.0, preparing a solution with the sweetness of 2.3 by adopting a sweetening agent, adding the papaya slices into the sweetening agent solution, soaking for 22 hours, taking out, filtering to remove filtrate, and draining filter residues for later use;

(9) drying: sending the soaked papaya slices into a dryer for drying treatment, and stopping drying when the water content of the papaya slices is below 20%; the drying treatment comprises the following steps: firstly, drying the papaya slices at 52 ℃ for 1.1h, and then raising the temperature to 72 ℃ for continuous drying;

(10) color protection: coating a layer of color fixative on dried papaya slices with water content of 20%, and drying in a dryer to obtain semi-finished product of fermented sugar-free papaya preserved fruit; the coating amount of the color fixative is 0.8%; the drying treatment temperature is 20 ℃, the drying treatment time is 28min, and the drying is carried out until the water content of the papaya slices is lower than 15%;

Example 7

A fermented sugar-free preserved papaya is prepared from the following raw materials in parts by weight: 1350 parts of pawpaw, 0.7 part of bacteriostatic bactericide, 0.6 part of softener, 9 parts of yeast nutrition auxiliary agent, 9 parts of dry yeast, 40 parts of sweetener, 12 parts of color fixative, 7 parts of acidity regulator and 1350 parts of drinking water.

Further, the bacteriostatic bactericide is one of potassium metabisulfite, sulfur dioxide, sodium metabisulfite, sodium sulfite, sodium bisulfite and sodium hyposulfite; the concentration of the antibacterial bactericide is 80 mg/L; the concentration of the pectinase is 0.02 g/L; the concentration of the yeast nutrition auxiliary agent is 0.2 g/L; the concentration of the dry yeast is 0.2 g/L; the sweetener is one or more of xylitol, maltitol, sorbitol, stevioside and isomaltulose; the softener is pectinase; the color fixative is food-grade glycerol; the acidity regulator is tartaric acid.

(5) and (3) acidity adjustment: measuring the pH value of the antibacterial and bactericidal papaya slices by using a pH meter, adding an acidity regulator into a fermentation tank, and regulating the pH value of the papaya slices to 3.3 for later use;

(6) yeast inoculation: weighing dry yeast and yeast nutrition auxiliary agent according to the weight part ratio, firstly activating the dry yeast and yeast nutrition auxiliary agent for 31min at 36 ℃ until the yeast is reactivated, then inoculating the dried yeast and yeast nutrition auxiliary agent into the papaya slices with the adjusted acidity, and uniformly mixing;

(9) drying: sending the soaked papaya slices into a dryer for drying treatment, and stopping drying when the water content of the papaya slices is below 20%; the drying treatment comprises the following steps: firstly, drying the papaya slices at 58 ℃ for 1.3h, and then raising the temperature to 70-80 ℃ for continuous drying;

(10) color protection: coating a layer of color fixative on dried papaya slices with water content of 20%, and drying in a dryer to obtain semi-finished product of fermented sugar-free papaya preserved fruit; the coating amount of the color fixative is 0.9%; the drying treatment temperature is 21 ℃, the drying treatment time is 32min, and the drying is carried out until the water content of the papaya slices is lower than 15%;

To further illustrate that the present invention can achieve the technical effects, the following experiments were performed:

comparative experiment

Comparative example 1

The differences from the embodiments 1 to 7 are as follows: the soaking softening step is not carried out, and other conditions are not changed.

Comparative example 2

The differences from the embodiments 1 to 7 are as follows: the low temperature fermentation step was not performed and other conditions were unchanged.

Selection of softening agent

Selecting pectinase, cellulase, protease, amylase, hydrolase and oxidase as softeners, respectively preparing softener solutions with the same concentration, soaking the softener solutions in papaya slices, taking out the papaya slices, testing the softening effect of each raw material on papaya, and grading. The results and the efficacy scores of the softeners are shown in table 1.

Table 1 efficacy scoring criteria and results for softeners

Softening agent	Soaking time/h	Scoring criteria and result scoring
			Pectinase	24	Moderate hardness (10 minutes)
Cellulase enzymes	24	Softer (5 points)
			Protease enzyme	24	Relatively hard (5 minutes)
Amylase	24	Harder (4 minutes)
			Hydrolytic enzyme	24	Softer (5 points)
Oxidase enzyme	24	Harder (4 minutes)

As can be seen from the experimental data in Table 1, the softening effect of pectinase is the best softener after soaking pawpaw softener for 24 h.

Third, sensory evaluation

The preserved pawpaw prepared in the examples 1-7 and the comparative examples 1-2 is tasted and evaluated by a food expert, the scoring standard is shown in the following table 2, and the scoring result is shown in the following table 3.

TABLE 2

TABLE 3

Group of	Color and luster (fen)	Mouthfeel (fen)	Smell (fen)	Hardness (minutes)	Plumpness (minutes)	Transparency (fen)	General score (score)
								Example 1	24	23	25	24	25	24	145
Example 2	25	24	25	24	24	25	147
								Example 3	24	24	24	25	23	24	144
Example 4	25	25	24	24	24	25	147
								Example 5	25	25	25	25	25	25	150
Example 6	25	24	25	24	24	24	146
								Example 7	24	25	24	25	25	25	148
Comparative example 1	19	14	20	13	19	19	104
								Comparative example 2	20	15	15	18	18	19	105

The experimental data in table 3 show that the preserved papaya prepared by the invention has better color, taste, smell, hardness, plumpness and transparency than the prior art, wherein the preserved papaya prepared by the invention in example 5 has the highest evaluation in all aspects and the highest comprehensive score.

In conclusion, the papaya preserved fruit slices prepared by the invention have the characteristics of bright and pleasant color and luster, soft tissue, aromatic and special flavor, complex body and sweet and refreshing taste, have the characteristics of 'unpacking and perfuming', are cool in nature, have no sugar, maintain beauty and keep young, have high nutritional value, have better health-care effect on human bodies, are suitable for people of all ages, and are particularly suitable for weight-losing crowds and diabetic patients. The deep processing method of the papaya product is provided, the papaya product is prepared from papaya pomace generated in the papaya wine brewing process, the industrial chain of papaya is prolonged, the added value of the product is improved, the papaya is fully utilized, and the comprehensive utilization efficiency of the papaya is improved. The processing process is carried out in a low-temperature environment, the integrity and the nutritive value of the papaya fruits can be kept to a large extent, and the technical bottlenecks of high sourness, high hardness, more crude fibers, high sugar content and the like of papaya product processing in the prior art are solved. After the pawpaw is soaked and softened by the softener, yeast is inoculated for low-temperature fermentation, the change of the sugar degree of the pawpaw is monitored in real time by the low-temperature fermentation, and the fermentation is stopped until the sugar degree is 0brix, so that the hardness and the crude fiber content of the product are reduced, sugar and acid and astringent taste of the pawpaw are removed, the processed pawpaw product is free of sugar, and further, the color and smell of the pawpaw are improved by soaking the pawpaw by adopting the sweetening agent, and the palatability and the quality of the preserved pawpaw are improved.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims

1. The fermented sugar-free preserved papaya is characterized by being prepared from the following raw materials in parts by weight: 1000-1500 parts of pawpaw, 0.3-0.9 part of bacteriostatic bactericide, 0.3-0.8 part of softener, 4-12 parts of yeast nutrition auxiliary agent, 4-12 parts of dry yeast, 25-45 parts of sweetener, 5-15 parts of color fixative, 1-10 parts of acidity regulator and 1000-1500 parts of edible water;

the processing method comprises the following steps

(8) soaking: calculating the sweetness of a 15% sucrose water solution at 20 ℃ to be 1.0, preparing a solution with the sweetness of 2.0-2.6 by adopting a sweetening agent, adding the pawpaw slices fermented at the low temperature into the sweetening agent solution, soaking for 20-26 h, taking out, filtering to remove filtrate, and draining filter residues for later use;

(11) and (3) nitrogen filling and packaging: selecting nitrogen with the purity of more than or equal to 96%, filling nitrogen by using an automatic nitrogen filling machine, quantitatively packaging the semi-finished product of the fermented sugar-free preserved papaya by using a polyethylene bag, and checking to be qualified to obtain the finished product of the fermented sugar-free preserved papaya;

the antibacterial bactericide is one of potassium metabisulfite, sulfur dioxide, sodium metabisulfite, sodium sulfite, sodium bisulfite and sodium hyposulfite;

the concentration of the antibacterial bactericide is 50-100 mg/L; the concentration of the pectinase is 0.02 g/L; the concentration of the yeast nutrition auxiliary agent is 0.2 g/L; the concentration of the dry yeast is 0.2 g/L;

the sweetener is one or more of xylitol, maltitol, sorbitol, stevioside and isomaltulose;

the softener is pectinase; the color fixative is food-grade glycerol; the acidity regulator is tartaric acid.

2. The fermented sugar-free preserved papaya according to claim 1 is characterized by being prepared from the following raw materials in parts by weight: 1250 parts of pawpaw, 0.6 part of bacteriostatic bactericide, 0.5 part of softener, 8 parts of yeast nutrition auxiliary agent, 8 parts of dry yeast, 35 parts of sweetening agent, 10 parts of color fixative, 5 parts of acidity regulator and 1250 parts of edible water.

3. The fermented sugar-free preserved papaya according to claim 1, wherein: in step (7), the fermentation process also comprises monitoring the change of the sugar degree in real time, and stopping the fermentation until the sugar degree is changed to 0 DEG Brix.

4. The fermented sugar-free preserved papaya according to claim 1, wherein: in step (9), the drying process is: firstly, drying the papaya slices at 50-60 ℃ for 0.8-1.5 h, and then raising the temperature to 70-80 ℃ for continuous drying.

5. The fermented sugar-free preserved papaya according to claim 1, wherein: in the step (10), the painting amount of the color fixative is 0.8-1%; and the drying treatment is carried out at the temperature of 18-23 ℃ for 25-35 min until the water content of the papaya slices is lower than 15%.