AU2020201318B1

AU2020201318B1 - Manufacturing method of high-brittleness mashed potato chips with red rose petals

Info

Publication number: AU2020201318B1
Application number: AU2020201318A
Authority: AU
Inventors: Bhesh Bhandari; Lu Chang; Liqing QIU; Bin Wang; Min Zhang
Original assignee: Shandong Huamei Biotechnology Ltd Co; Jiangnan University
Current assignee: Shandong Huamei Biotechnology Ltd Co; Jiangnan University
Priority date: 2019-03-01
Filing date: 2020-02-23
Publication date: 2020-09-10
Anticipated expiration: 2040-02-23
Also published as: CN109699976B; CN109699976A

Abstract

A manufacturing method of high-brittleness mashed potato chips with red rose petals belongs to the field of deep processing of fruits and vegetables. The present invention uses rose fragments of rose planting enterprises as raw materials. The raw materials are subjected to pretreatment, color protection, ultrasonic pretreatment of mashed potatoes, uniform mixing with auxiliary materials, seasoning and shaping with a mold. Then, the mixture is pre-frozen at -70°C for 8h, and then is subjected to pulse spout microwave freeze drying so that a sample has a moisture content of 10-15%. Then, the mixture is subjected to pulse spout radio frequency vacuum drying so that the final moisture content is less than 5%. A finished product is vacuum-packaged with an opaque aluminum foil bag. The present invention provides a new method for the full use of the rose fragments, and develops a recombinant chip having natural rose flavor. The product has loose texture, chip brittleness of 540-630g, contains active ingredients such as Vitamin C and flavonoid, has high nutritional value and natural rose flavor, and is healthy leisure recombinant food.

Description

MANUFACTURING METHOD OF HIGH-BRITTLENESS MASHED POTATO CHIPS WITH RED ROSE PETALS

Technical Field The present invention relates to a manufacturing method of high-brittleness mashed potato chips with red rose petals. Rose fragments are used as main raw materials; ultrasonic pretreatment of mashed potatoes is conducted to form a porous microstructure to increase the brittleness; and pulse spout microwave freeze drying and pulse spout radio frequency vacuum drying with high drying speed and high nutrient retention rate are used to produce a rose recombinant chip having natural rose flavor. The present invention belongs to the field of deep processing of fruits and vegetables, and has great practical significance and economic significance.

Background At present, rose is the most important crop in the flower industry in the world. As a popular garden and cut flower plant, the rose has been planted for thousands of years. The rose is one of the five largest ornamental plants in the world. The cut rose cut accounts for 21% and 31% of all cut flowers in Chinese trade market and European trade market respectively. The rose plays an important role in various industries such as food, spices, cosmetics, and ornamental plants. The rose contains many compounds, including vitamins, fatty acid, amino acid, trace elements, carbohydrates, anthocyanins, flavonoids, alkaloids and other active ingredients. The rosehip extract contains a large amount of flavonoids (quercetin, rutin and catechin), phenolic acid (ferulic acid, syringic acid and methyl gallate), and ascorbic acid (vitamin C or AA). Because the rosehip contains a large amount of phenolic substances and vitamin C, the rosehip is widely used in the industries of traditional medicine, food, cosmetics and textile in Asia. In recent years, due to the medicinal value and nutritional value, the rosehip is increasingly concerned by people. Understanding of the current research status of bioactive substances in the rose and reasonable use of the rose not only can bring health for people, but also can generate a positive impact on the national economy through reasonable processing. There are many rose products on the market, such as rose tea, rose jam, rose essential oil, rose dew and rose cream. Nowadays, the demand of the public for healthy snacks prompts food manufacturers to produce novel food that has good flavor, fresh taste and rich nutrients. Drying is the most important method for preserving high-moisture food. Agricultural products are generally stored by several drying techniques such as vacuum drying, spray drying, hot air drying and freeze drying. Dewatering not only prevents bacteria from multiplying, but also improves the storage of the food at room temperature. Traditional drying methods (spray drying, vacuum drying and hot air drying) are drying methods widely used around the world, and have the characteristics of simple operation, low cost and high thermal efficiency. The drying methods have low drying speed, especially during the period of speed reduction in the drying process. In addition to the above disadvantages, the color, physical and chemical properties, and sensory attributes of the food may be deteriorated due to long-time exposure to heat. Due to the above limitations, freeze drying (FD) is a special drying method. Freeze drying is a dehydration process for producing high-quality (crumbly texture, natural color, good sensory characteristic, etc.) food and storing thermosensitive materials and other biological materials. In the freeze drying process, ice crystals are sublimated from the raw materials of the food, which is conducive to minimization of structural change and maintenance of bioactive substances and flavors of dry products. In addition to the advantages, high cost and long drying time prevent the use of freeze drying. To overcome the disadvantages of freeze drying, researchers focus on other novel drying modes. Compared with traditional drying methods, the traditional drying of physical field combination can significantly improve drying efficiency, shorten drying cycle, reduce drying energy consumption, reduce environmental pollution and improve product quality. Microwave drying and radio frequency drying can achieve higher drying rates and higher energy efficiency. In the microwave drying process, the heat generated inside the food material forms a porous structure in the food material. Compared with traditional drying methods, microwave drying and radio frequency drying have the advantages of short drying time, high flexibility and high drying speed. However, the physical field combination drying also has the problems of poor uniformity and serious quality deterioration, thereby limiting the application in food. Pulse spout microwave freeze drying is a novel drying technology that combines microwave, freezing and spout fluidized bed under vacuum conditions, provides a solution for overheating and improves the quality of a final product. Pulse spout radio frequency vacuum drying has the advantages of high efficiency, energy saving and uniform drying. The present invention produces a rose recombinant leisure chip by using broken petals produced in the production process of a rose manufacturing enterprise through two-stage microwave vacuum freeze drying and pulse spout radio frequency vacuum drying, and has great practical significance and economic significance. Zhang Min et al. publishes a manufacturing method for potato and fruit recombinant mixed chips (patent number: CN 101999609 A). Potatoes and fruits are used as raw materials, subjected to drying by microwave freeze drying and microwave vacuum drying in manners of washing, pulping and forming, and subjected to hot air drying in the later stage of microwave vacuum drying so that the moisture content of the product is less than 6%, so as to produce a leisure chip with crisp texture and suitability for people of all ages. However, microwave vacuum freeze drying used in the drying in the method will overheat the product, which is not conducive to the preservation of active substances and nutrients of the product. The use of such a method that vacuum microwave drying is used and hot air drying is used later to an end point will bring the disadvantages of high drying temperature and low nutrient retention rate, which is not conducive to maintenance of the nutritional quality of the chip. However, the present invention adopts pulse spout microwave freeze drying, which not only solves the characteristics of uneven heating in the microwave heating process, but also preserves the nutritional ingredients in the chip. Zhang Fei (2011) et al. produces a sea asparagus recombinant chip by using a combined drying technology of vacuum microwave drying and vacuum drying. With respect to the characteristics of high salt content and poor taste after processing in sea asparagus, some fragrance enhancing substances, coloring substances, flavoring substances and substances that help shaping are added in the sea asparagus, then cooked and seasoned, and dehydrated and dried through a combination of vacuum microwave drying and vacuum drying to produce the sea asparagus chip with good color, fragrance and taste. However, the method also ignores the phenomenon of deterioration of product quality caused by the overheating phenomenon in the microwave drying process. Zhang Yongmao et al. publish a method for producing puffed apple slices by microwave-pressure differential technology (patent number: CN 1895086 A). Fresh apples are used as raw materials, subjected to a series of pretreatment and microwave pre-drying and puffing, and then subjected to pressure differential puffing by using an instant pressure reducing device. The produced apple chip has the advantages of unique flavor, crisp taste and uniform puffing of apples. However, in puffing of the pressure reducing device in the present invention, in-tank temperature is kept between 89°C and 85°C for 50-70 min, and then kept between 79°C and 76°C for -40 min. During this period, the apple slices are processed at higher temperature for too long time, which is not conducive to the preservation of the nutrients. However, the present invention is performed under freezing conditions, and in the whole drying process, the temperature of the material in the frozen state is low, so that the nutrition and the fragrance of the recombinant rose chip are better preserved. Liu Zhenbin et al. disclose a manufacturing method for high-fiber recombinant asparagus chips (publication number: CN104522551A). Asparagus roots discarded by asparagus production enterprises are used as main raw materials, subjected to pretreatment, hot water blanching, color protection, pulping and mixing with auxiliary materials, then cooked for a short time and spread on the dishes, then subjected to two-stage microwave vacuum drying to a moisture content of 10% to %, and then subjected to medium and short wave vacuum infrared drying to a moisture content of less than 5%, to manufacture a recombinant chip with rich dietary fiber and high nutrient content. However, the microwave vacuum drying is used, and the local overheating phenomenon brought by microwave drying is ignored, which is not conducive to the preservation of the nutrients. Sun Jincai et al. disclose a method for preparing coordinated fruit and vegetable chips by vacuum freeze drying and impregnation treatment (publication number: CN101138358). Fruit and vegetable raw materials are subjected to vacuum freeze drying, and low-temperature vacuum impregnation at the same time in the process to produce homogeneous coordinated fruit and vegetable chips. A vacuum impregnation technology can greatly increase the performance of fruit and vegetable food, improve the utilization rate of food processing, and shorten the processing time. However, freeze drying is used in the production process. Although a product with a loose texture and high nutritional value can be obtained, the energy consumption in the production process is greatly increased and the cost is increased. Wang Yuchuan et al. (2013) find through research that a negative pressure pulse spout device can improve the uniformity of microwave drying: compared with turntable microwave vacuum drying, the maximum temperature difference of lettuce is reduced from 41°C to 2.1°C, and the color shrinkage rate is improved relative to the turntable microwave vacuum drying, which indicates that the negative pressure pulse spout device has good uniformity. However, the damage caused by the local overheating phenomenon from microwave in the later drying process to the nutrients of the material is not considered. The patent combines pulse spout microwave freeze drying and negative pressure pulse spout radio frequency drying, and can better reduce the damage caused by the microwave to the nutrients of the food material to increase the retention rate of the nutrients. Huang Jiapeng et al. disclose a method for preparing instant crispy okra through three-stage pulse spout negative pressure low frequency microwave drying (publication number: CN104522552A). Pulse spout microwave vacuum drying is used for drying, which greatly reduces the non-uniformity of microwave heating. Pulse spout vacuum drying has the characteristics of high drying rate, good quality of dried products, and high retention rate of the nutrients. The patent adopts a combination of pulse spout microwave freeze drying and negative pressure pulse spout radio frequency drying for conducting drying. The adopted temperature is lower, which is more conducive to maintenance of the integrity of the structural states of the nutrients and raw materials.

Summary The purpose of the present invention is to provide a manufacturing method of rose recombinant leisure chips. Firstly, raw materials are subjected to pretreatment, color protection and ultrasonic pretreatment of mashed potatoes, then mixed with potato/purple potato/sweet potato matrices and seasoned, and shaped and pre-frozen for conducting combined drying (pulse spout microwave freeze drying and pulse spout radio frequency vacuum drying) to obtain recombinant chips having natural rose flavor. A manufacturing method of high-brittleness mashed potato chips with red rose petals mainly comprises the following steps: (1) raw material pretreatment: selecting roses with good colors and cutting into pieces; cleaning, peeling, slabbing and cooking potatoes/purple potatoes or sweet potatoes, and then stirring the materials with a blender to manufacture mashed potatoes for later use; (2) color protection: immersing the shredded rose pieces in a roselle aqueous solution with a mass percent of 0.01% for 3 to 5 min, and then taking out the rose pieces and absorbing residual water on the rose pieces by using absorbing paper; (3) ultrasonic pretreatment of the mashed potatoes: putting the mashed potatoes into a cell crusher, turning on an ultrasonic crusher, setting the power as 300W, ultrasonically treating for 2h, and taking out the mashed potatoes every 10 min for stirring uniformly; (4) mixing and seasoning: taking the mashed potatoes after ultrasonic pretreatment; adding 10% of rose pieces, 2% of xylitol, 1% of sucrose and 3% of milk powder according to the mass of the mashed potatoes; and continuously stirring and mixing uniformly;

(5) shaping: putting the mixed material obtained in the step (4) into a mold for shaping; and putting a shaped sample into an ultra-low temperature refrigerator at -70°C for 8h for later use; (6) pulse spout microwave freeze drying: adjusting vacuum as -0.1 MPa, microwave power as 4 W/g, cold trap temperature as -42°C, and upper temperature limit as 50°C; performing pulse spout microwave freeze drying; and drying to a moisture content of 10-15% to obtain recombinant rose chips; (7) pulse spout radio frequency vacuum drying: drying the recombinant rose chips obtained in the step (6) in a pulse spout radio frequency vacuum dryer; setting the vacuum as -0.1 MPa, a spacing between two plates as 70 mm and the temperature as 30°C, until the recombinant rose chips are dried to a moisture content of less than %; (8) packaging: cooling the recombinant rose chips dried in the step (7) to room temperature; conducting vacuum packaging with an opaque aluminum foil bag; and storing in a cool and dry place to obtain a finished product. In the step (1), the size of the cut pieces is 1 x 1.5 mm; the cooking time is 10 min; and the stirring time is 5 min. In the step (3), the ultrasonic crusher stops for 30s after working for every 5 min to prevent local overheating of an instrument. In the step (5), the mold is circular, and has a diameter of 2.5 cm and a height of 3 mm. In the step (6) and the step (7), the pulse spout frequency is once every 10 min to prevent local overheating of the materials and increase the uniformity of drying. In the step (3), the mashed potatoes are subjected to ultrasonic pretreatment, so as to increase the porosity of the recombinant chips and make the product crisper. The combined drying mode of the pulse spout microwave freeze drying and the pulse spout radio frequency vacuum drying adopted in the step (6) and the step (7) has the advantages of high drying speed, good drying quality and high nutrient retention rate, and reduces the local overheating phenomenon of microwave drying to a certain extent.

The rose recombinant leisure chips manufactured by the method has high nutrient content; the product contains 2.26-2.54 mg/100g of vitamin C, and 77.88-80.08 mg/100g of flavonoid. The processed chips have a shrinkage rate of %-15.04%, and brittleness of 540-630 g, and has good external color. The present invention has beneficial effects: The product uses the residual rose fragments from production of rose production enterprises as raw materials to manufacture rose chips, which avoids the waste of the rose fragments and saves energy. The mashed potatoes are used as the matrices, and supplementary materials such as milk powder, sucrose and white sugar are added to provide pleasant smell and taste for the recombinant rose chips. A part of xylitol replaces sucrose to reduce the calorie of the product. Different molds can be used later for shaping, so as to increase the style of the recombinant rose chips and attract eyeballs. The mashed potatoes are subjected to ultrasonic pretreatment, which increases the microscopic pore structure of the mashed potatoes and makes the recombinant rose chips crisp and delicious. The pulse spout microwave freeze drying and the pulse spout radio frequency vacuum drying are used for drying, which reduces the time required for the drying. The pulse reduces non-uniformity in the drying process, improves the product quality and the nutrient retention rate, and obtains the recombinant chips with good color, fragrance, taste and brittleness. The product contains 2.26-2.54 mg/100g of vitamin C, and 77.88-80.08 mg/100g of flavonoid. The processed chips have a shrinkage rate of 15%-15.04%, and brittleness of 540-630 g, and has good external color. Description of Drawings Fig. 1 is an electronic nose diagram of a rose chip manufactured by different matrices.

Detailed Description In order to make the purpose, technical solutions, and advantages of the present invention clearer, the present invention is further described in detail in combination with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Embodiment 1 Recombinant rose chips using mashed purple potatoes as matrices A formula of rose recombinant leisure chips has the following ratios according to parts by weight: taking 100g of mashed purple potatoes and adding the following materials according to the mass of the mashed purple potatoes: 10% of rose pieces, 2% of xylitol, 1% of sucrose and 3% of milk powder. The manufacturing method is as follows: (1) raw material pretreatment: selecting roses with good colors and cutting into pieces of 1x1.5 mm; cleaning, peeling, slabbing and cooking purple potatoes for 10 min, and then stirring the materials with a blender for 5 min for later use; (2) color protection: immersing the shredded rose pieces in a roselle aqueous solution of 0.01% for color protection for 5 min, and then taking out the rose pieces and absorbing residual water on the rose pieces by using absorbing paper; (3) ultrasonic pretreatment of the mashed purple potatoes: putting the mashed potatoes into a cell crusher; turning on ultrasonic power of 300W; ultrasonically treating for 2h; taking out the mashed purple potatoes every 10 min for stirring uniformly; and enabling an ultrasonic crusher to stop for 30s after working for every min to prevent local overheating of the ultrasonic crusher; (4) mixing and seasoning: taking 100g of the mashed potatoes after pretreatment; adding 10% of rose pieces, 2% of xylitol, 1% of sucrose and 3% of milk powder according to the mass of the mashed purple potatoes; and continuously stirring and mixing uniformly; (5) shaping: putting the above uniformly mixed material into a circular mold with a diameter of 2.5 cm and a height of 3 mm for shaping; and putting a shaped sample into an ultra-low temperature refrigerator at -70°C for 8h for later use; (6) two-stage pulse spout microwave freeze drying: adjusting vacuum as -0.1 MPa, microwave power as 4 W/g, cold trap temperature as -42°C, and upper temperature limit as 50°C; drying to a moisture content of 13%; and setting the pulse spout frequency to be once every 10 min in the whole drying process to prevent local overheating of the materials; (7) pulse spout radio frequency vacuum drying: drying the recombinant rose chips with a reduced moisture content of 13% in the step (6) in a pulse spout radio frequency vacuum dryer; setting the vacuum as -0.1 MPa, a spacing between two plates as 70 mm and the temperature as 30°C; and drying to a moisture content of 4%. Packaging: cooling the chips dried in the step (7) to room temperature; conducting vacuum packaging with an opaque aluminum foil bag; and storing in a cool and dry place to obtain a finished product. In the processed recombinant rose chips using the mashed purple potatoes as matrices, the brittleness is 545g larger than 439g of a pure pulse spout microwave freeze-dried product; the content of vitamin C is 2.52 mg/100g, which is higher than 1.98 mg/100g of the pure pulse spout microwave freeze-dried product; the content of flavonoid is 79.34 mg/100g, which is larger than 67.98 mg/100g of the pure pulse spout microwave freeze-dried product; the shrinkage rate is 15.01%, which is smaller than 16.31% of the pure pulse spout microwave freeze-dried product; the measurement result of a color difference meter for the color indicates that L value is 50.59, a value is 15.18 and b value is -8.37, which have no significant difference from the pulse spout microwave freeze-dried product; and the chips have natural rose flavor, and strong aroma. Embodiment 2 Recombinant rose chips using mashed sweet potatoes as matrices A formula of rose recombinant leisure chips has the following ratios according to parts by weight: taking 100g of mashed sweet potatoes and adding the following materials according to the mass of the mashed sweet potatoes: 10% of rose pieces, 2% of xylitol, 1% of sucrose and 3% of milk powder. The manufacturing method is as follows: (1) raw material pretreatment: selecting roses with good colors and cutting into pieces of lxl.5 mm; cleaning, peeling, slabbing and cooking sweet potatoes for 10 min, and then stirring the materials with a blender for 5 min for later use;

(2) color protection: immersing the shredded rose pieces in a roselle aqueous solution of 0.01% for color protection for 5 min, and then taking out the rose pieces and absorbing residual water on the rose pieces by using absorbing paper; (3) ultrasonic pretreatment of the mashed sweet potatoes: putting the mashed sweet potatoes into a cell crusher; turning on ultrasonic power of 300W; ultrasonically treating for 2h; taking out the mashed sweet potatoes every 10 min for stirring uniformly; and enabling an ultrasonic crusher to stop for 30s after working for every 5 min to prevent local overheating of the ultrasonic crusher; (4) mixing and seasoning: taking 100g of the mashed sweet potatoes after pretreatment; adding 10% of rose pieces, 2% of xylitol, 1% of sucrose and 3% of milk powder according to the mass of the mashed sweet potatoes; and continuously stirring and mixing uniformly; (5) shaping: putting the above uniformly mixed material into a circular mold with a diameter of 2.5 cm and a height of 3 mm for shaping; and putting a shaped sample into an ultra-low temperature refrigerator at -70°C for 8h for later use; (6) two-stage pulse spout microwave freeze drying: adjusting vacuum as -0.1 MPa, microwave power as 4 W/g, cold trap temperature as -42°C, and upper temperature limit as 50°C; drying to a moisture content of 13%; and setting the pulse spout frequency to be once every 10 min in the whole drying process to prevent local overheating of the materials; (7) pulse spout radio frequency vacuum drying: drying the recombinant rose chips with a reduced moisture content of 13% in the step (6) in a pulse spout radio frequency vacuum dryer; setting the vacuum as -0.1 MPa, a spacing between two plates as 70 mm and the temperature as 30°C; and drying to a moisture content of 4%. Packaging: cooling the chips dried in the step (7) to room temperature; conducting vacuum packaging with an opaque aluminum foil bag; and storing in a cool and dry place to obtain a finished product. In the processed recombinant rose chips using the mashed sweet potatoes as matrices, the brittleness is 587g larger than 521g of a pure pulse spout microwave frozen product; the content of vitamin C is 2.41 mg/100g, which is higher than 2.01 mg/100g of the pure pulse spout microwave frozen product; the content of flavonoid is 78.39 mg/100g, which is larger than 70.98 mg/100g of the pure pulse spout microwave frozen product; the shrinkage rate is 15.00%, which is smaller than 17.67% of the pure pulse spout microwave frozen product; the measurement result of a color difference meter for the color indicates that L value is 81.77, a value is 1.05 and b value is 21.60, which have no significant difference from the pulse spout microwave frozen product. The chips have natural sweet taste of roses and sweet potatoes, and strong flavor and aroma. Embodiment 3 Recombinant rose chips using mashed potatoes as matrices A formula of rose recombinant leisure chips has the following ratios according to parts by weight: taking 100g of mashed potatoes and adding the following materials according to the mass of the mashed potatoes: 10% of rose pieces, 2% of xylitol, 1% of sucrose and 3% of milk powder. The manufacturing method is as follows: (1) raw material pretreatment: selecting roses with good colors and cutting into pieces of lx1.5 mm; cleaning, peeling, slabbing and cooking potatoes for 10 min, and then stirring the materials with a blender for 5 min for later use; (2) color protection: immersing the shredded rose pieces in a roselle aqueous solution of 0.01% for color protection for 5 min, and then taking out the rose pieces and absorbing residual water on the rose pieces by using absorbing paper; (3) ultrasonic pretreatment of the mashed potatoes: putting the mashed potatoes into a cell crusher; turning on ultrasonic power of 300W; ultrasonically treating for 2h; taking out the mashed potatoes every 10 min for stirring uniformly; and enabling an ultrasonic crusher to stop for 30s after working for every 5 min to prevent local overheating of the ultrasonic crusher; (4) mixing and seasoning: taking 100g of the mashed potatoes after pretreatment; adding 10% of rose pieces, 2% of xylitol, 1% of sucrose and 3% of milk powder according to the mass of the mashed potatoes; and continuously stirring and mixing uniformly; (5) shaping: putting the above uniformly mixed material into a circular mold with a diameter of 2.5 cm and a height of 3 mm for shaping; and putting a shaped sample into an ultra-low temperature refrigerator at -70°C for 8h for later use; (6) two-stage pulse spout microwave freeze drying: adjusting vacuum as -0.1 MPa, microwave power as 4 W/g, cold trap temperature as -42°C, and upper temperature limit as 50°C; drying to a moisture content of 13%; and setting the pulse spout frequency to be once every 10 min in the whole drying process to prevent local overheating of the materials; (7) pulse spout radio frequency vacuum drying: drying the recombinant rose chips with a reduced moisture content of 13% in the step (6) in a pulse spout radio frequency vacuum dryer; setting the vacuum as -0.1 MPa, a spacing between two plates as 70 mm and the temperature as 30°C; and drying to a moisture content of 4%. Packaging: cooling the chips dried in the step (7) to room temperature; conducting vacuum packaging with an opaque aluminum foil bag; and storing in a cool and dry place to obtain a finished product. In the processed recombinant rose chips using the mashed potatoes as matrices, the brittleness is 600g larger than 578g of a pure pulse spout microwave freeze-dried product; the content of vitamin C is 2.53 mg/100g, which is higher than 1.99 mg/100g of the pure pulse spout microwave freeze-dried product; the content of flavonoid is 80.04 mg/100g, which is larger than 73.65 mg/100g of the pure pulse spout microwave freeze-dried product; the shrinkage rate is 15.01%, which is smaller than 16.23% of the pure pulse spout microwave freeze-dried product; the measurement result of a color difference meter for the color indicates that L value is 74.85, a value is 6.20 and b value is 3.70, which have no significant difference from the pulse spout microwave freeze-dried product; and the chips have natural rose flavor, and strong aroma.

It is to be understood that any prior art publication referred to herein does not constitute an admission that the publication forms part of the common general knowledge in the art. In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

Claims

CLAIMS:

1. A manufacturing method of high-brittleness mashed potato chips with red rose petals, comprising the following steps: (1) raw material pretreatment: selecting roses with good colors and cutting into pieces; cleaning, peeling, slabbing and cooking potatoes/purple potatoes or sweet potatoes, and then stirring the materials with a blender to manufacture mashed potatoes for later use; (2) color protection: immersing the shredded rose pieces in a roselle aqueous solution with a mass percent of 0.01% for color protection for 3 to 5 min, and then taking out the rose pieces and absorbing residual water on the rose pieces by using absorbing paper; (3) ultrasonic pretreatment of the mashed potatoes: putting the mashed potatoes into a cell crusher, turning on an ultrasonic crusher, setting the power as 300W, ultrasonically treating for 2h, and taking out the mashed potatoes every 10 min for stirring uniformly; (4) mixing and seasoning: taking the mashed potatoes after ultrasonic pretreatment; adding 10% of rose pieces, 2% of xylitol, 1% of sucrose and 3% of milk powder according to the mass of the mashed potatoes; and continuously stirring and mixing uniformly; (5) shaping: putting the mixed material obtained in the step (4) into a mold for shaping; and putting a shaped sample into an ultra-low temperature refrigerator at -70°C for 8h for later use; (6) pulse spout microwave freeze drying: adjusting vacuum as -0.1 MPa, microwave power as 4 W/g, cold trap temperature as -42°C, and upper temperature limit as 50°C; performing pulse spout microwave freeze drying; and drying to a moisture content of 10-15% to obtain recombinant rose chips; (7) pulse spout radio frequency vacuum drying: drying the recombinant rose chips obtained in the step (6) in a pulse spout radio frequency vacuum dryer; setting the vacuum as -0.1 MPa, a spacing between two plates as 70 mm and the temperature as 30°C, until the recombinant rose chips are dried to a moisture content of less than %; (8) packaging: cooling the recombinant rose chips dried in the step (7) to room temperature; conducting vacuum packaging with an opaque aluminum foil bag; and storing in a cool and dry place to obtain a finished product.

2. The manufacturing method according to claim 1, wherein in the step (1), the size of the cut pieces is 1 x 1.5 mm; the cooking time is 10 min; and the stirring time is 5 min.

3. The manufacturing method according to claim 1 or 2, wherein in the step (3), the ultrasonic crusher stops for 30s after working for every 5 min.

4. The manufacturing method according to claim 1 or 2, wherein in the step (5), the mold is circular, and has a diameter of 2.5 cm and a height of 3 mm.

5. The manufacturing method according to claim 3, wherein in the step (5), the mold is circular, and has a diameter of 2.5 cm and a height of 3 mm.

6. The manufacturing method according to claim 1, 2 or 5, wherein in the step (6) and the step (7), the pulse spout frequency is once every 10 min to prevent local overheating of the materials and increase the uniformity of drying.

7. The manufacturing method according to claim 3, wherein in the step (6) and the step (7), the pulse spout frequency is once every 10 min to prevent local overheating of the materials and increase the uniformity of drying.

8. The manufacturing method according to claim 4, wherein in the step (6) and the step (7), the pulse spout frequency is once every 10 min to prevent local overheating of the materials and increase the uniformity of drying.

9. The manufacturing method according to claim 1, 2, 5, 7 or 8, wherein the finished product contains 2.26-2.54 mg/100g of vitamin C, and 77.88-80.08 mg/100g of flavonoid; a shrinkage rate is 15%-15.04%, and brittleness is 540-630 g.

10. The manufacturing method according to claim 6, wherein the finished product contains 2.26-2.54 mg/100g of vitamin C, and 77.88-80.08 mg/100g of flavonoid; a shrinkage rate is 15%-15.04%, and brittleness is 540-630 g.