CN1954691A - Processing method of puffed vegetable fruit crisp slice - Google Patents

Abstract

The invention provides a processing method of puffed fruit and vegetable crisps, which comprises the steps of selecting, cleaning, slicing, color protection, drying, vacuum puffing and vacuum packaging of the fruit and vegetable raw materials. The vacuum puffing process is carried out under microwave conditions. During the vacuum puffing process, the microwave power is 2.0-50.0w/g, the vacuum degree is -0.075--0.098Mpa, the drying temperature is below 40°C, and the puffing time is within 30 minutes. It is carried out under the condition of 70° C., and the drying time is 1 to 3 hours. The dry basis water content of the heat-dried vegetable slices is 20% to 150%. The processing method greatly shortens the drying and puffing time, lowers the drying and puffing temperature, and can complete the drying and puffing of fruit and vegetable crisps within a few minutes below 40°C, and the fruit and vegetable crisps processed by the present invention are crispy in taste, high in nutrients, and energy-saving. The original color and fragrance of fruits and vegetables are better preserved, and it is a brand-new, pure natural non-fried fruit and vegetable food.

Description

Processing method of puffed fruit and vegetable chips

technical field

The invention relates to a food processing method, in particular to a processing method of puffed fruit and vegetable chips.

Background technique

In recent years, fruit and vegetable crisps have become a very popular leisure fruit and vegetable food because of their crisp taste, low fat, high fiber, rich in vitamins and various minerals, easy to carry, and long shelf life. At present, fried puffed fruit and vegetable chips are still the main products in the market. The fried puffed fruit and vegetable chips started in the 1970s. Due to the high oil temperature caused by frying under normal pressure conditions, the nutrients of the product were destroyed. The color, aroma, and taste are poor, and the oil used for production is processed and reused at high temperature, which is easy to introduce oxidation and rancidity of the oil. Some components in the oil undergo chemical changes to produce certain harmful substances. Frequent consumption will be harmful to human health. Influence; In the early 1990s, research began on the vacuum low-temperature frying of fruit and vegetable crisps under vacuum conditions, which lowered the oil temperature, but the feeding and discharging were intermittent, prolonging the frying time, resulting in a decrease in product quality; in the late 1990s, low-temperature frying Vacuum puffed fruit and vegetable crisps, for example, disclose the basic principle and processing technology of vacuum low temperature puffing technology in the article titled "Introduction to Vacuum Low Temperature Puffing Technology" in 2002 No.4. Chinese Fruits and Vegetables. Peel (core), slice (block), blanching, color protection, pre-drying, uniform humidity, puffing and packaging. This method uses hot air heat transfer for drying and puffing under vacuum conditions, and realizes crispy puffed fruits and vegetables without frying. It avoids the disadvantages of frying and puffing. The product has good color and little loss of flavor, but the equipment is huge and the puffing time is long, usually 2 to 5 hours, so it is not easy to realize industrial production.

Contents of the invention

The main purpose of the present invention is to provide a processing method for puffed fruit and vegetable chips, which uses microwave vacuum drying and puffing technology to process the fruit and vegetable chips, so as to realize rapid low-temperature puffing of the fruit and vegetable chips.

In order to achieve the above object, the processing method of puffed fruit and vegetable crisps provided by the present invention includes the steps of selecting raw fruits and vegetables, cleaning, slicing, color protection, drying, vacuum puffing and vacuum packaging, and is characterized in that the vacuum puffing process It is carried out under microwave conditions. During the vacuum puffing process, the microwave power is 2.0-50.0w/g, the vacuum degree is -0.075--0.098Mpa, the drying temperature is below 40°C, and the puffing time is within 30 minutes.

In the slicing process, the thickness of the fruit and vegetable slices is between 2mm and 16mm.

In the color protection process, the color protection process is soaked in a color protection solution, and the soaking time is 20 minutes to 1 hour. Color protection solution is a combined aqueous solution with added formula. The added formula is: 0.2-0.5% citric acid, 0.05-0.2% sodium bisulfite, 0.2-0.5% calcium chloride, 0.3-0.7% table salt.

In the above-mentioned heat-drying process, the heat-drying process is carried out under the condition of 50-70°C for 1-3 hours, and the dry basis water content of the dried vegetable slices after heat-drying is 20%-150%. Hot air drying includes normal pressure hot air drying and vacuum hot air drying.

The invention overcomes the shortcomings of fried puffing and low-temperature vacuum puffing, and realizes rapid low-temperature non-fried puffing of fruit and vegetable chips. The vacuum environment can ensure that the material is dried and processed under low temperature conditions, and can also prevent the oxidation reaction of the material. The microwave penetrating power is strong, it can penetrate deep into the material, so that the inside and outside of the material can be heated at the same time to form an overall heating, and the drying time is greatly shortened. Due to the rapid vaporization and migration of internal moisture, a strong radial driving force is generated to expand the internal tissue structure, which can make the product form Loose and uniform microporous structure plays a puffing role. The instantaneous high efficiency of microwave can make the fruit and vegetable crisps achieve puffing effect within a few minutes, which greatly improves the production capacity. The fruit and vegetable crisps puffed by microwave vacuum drying have beautiful appearance, good color and fragrance, crisp taste, high nutritional content, and the product quality is better than fried puffed and vacuum puffed fruit and vegetable crisps.

According to the specific description of the preferred embodiment of the present invention, in conjunction with the accompanying drawings, the detailed content and characteristics of the present invention can be better understood.

Description of drawings

Fig. 1 is the process flow chart of the specific scheme that the present invention is used to produce apple chips.

Fig. 2 is the process flow diagram of the specific scheme for producing carrot chips according to the present invention.

Detailed ways

In order to better understand the essence of the present invention, the specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

The method of the invention is suitable for processing different fruit and vegetable products. After the raw materials are selected, cleaned, peeled and cored, they are sliced, and then treated with color protection and heat drying, and finally processed into crisp vegetable chips by microwave vacuum drying and puffing. The following description mainly refers to apples, but "apple" can be construed to mean any other fruit and vegetable product which can be treated according to the present invention. Of course, according to different types of raw materials, it is necessary to adjust the appropriate operating process parameters in order to give full play to the technical advantages of microwave vacuum drying and puffing. aroma and other characteristics.

Fig. 1 is the process flow chart of the specific scheme that the present invention is applicable to apple chips. Apples need to be selected first, and choose fresh, complete fruit shape, loose pulp, uniform maturity and size, and no damage, no rot and no deterioration for processing; rinse the surface of the apples with clean water to remove the sediment on the surface and impurities, and then peeled and de-nucleated.

In the apple slicing process, the apple slices can be in the shape of semi-circular slices, circular slices, or strips, preferably semi-circular slices. It is preferred that the above-mentioned slicing process makes the thickness of the fruit and vegetable slices between 2 and 16mm, and special slicing equipment can be used in production. operation to increase production efficiency. However, the slice thickness of apple slices has a great influence on the quality of finished products. Apple slices will shrink to a certain extent after heat-drying treatment. During the microwave vacuum drying and puffing process, too thick apple slices will increase the microwave energy reach The distance between the centers is greatly weakened before the microwave penetrates into the material, and the microwave energy obtained by the center part is reduced, and the puffing effect cannot be achieved. If the apple slices are too thin, the microwave energy will be reflected from the inside to the surface, resulting in a large energy loss, resulting in insufficient puffing power, thereby reducing the puffing effect. The appropriate slice thickness should be determined according to the specific material variety. The thickness of the apple slices is selected as 8mm in the present invention.

Soak the cut apple slices in the color protection solution for 20 minutes to 1 hour, preferably 30 minutes. The color protection solution is 0.25-0.6% citric acid, 0.05%-0.25% sodium bisulfite, 0.2 -0.5% calcium chloride, 0.3-0.7% salt mixture, preferably 0.5% citric acid, 0.2% sodium bisulfite, 0.4% calcium chloride and 0.5% salt. Citric acid can reduce the pH value of the solution, reduce the activity of polyphenol oxidase, has antioxidant effect, and can also adjust the taste of apple chips; sodium bisulfite can prevent enzymatic browning, and can also inhibit non-enzymatic browning, which has Antioxidant and bleaching effect; Calcium chloride acts as a hardening effect, which can keep the product in better shape, and the puffing effect is more uniform; Salt has a certain inhibitory and destructive effect on the activity of enzymes, so it has a certain color protection effect.

After the apple slices have been treated for color protection, they are taken out, rinsed repeatedly, and then the surface water of the apple slices is drained, and then put into an oven for heat drying to adjust the initial moisture of the apple slices before microwave vacuum drying and puffing. Apple slices must contain a certain amount of moisture. Enough moisture inside can produce puffing power and form a uniform pore-like structure. Sufficient moisture will not cause excessive heating inside the material and cause burnt, so the puffing effect is better, but the moisture content If the temperature is too high, a large amount of water evaporates quickly, causing the water and air in the internal voids of the material to quickly migrate to the surface of the material, which cannot form enough puffing power, thereby reducing the puffing effect. Moreover, hot air drying is a heat conduction drying method, and the inside and outside are not heated at the same time, so a fine protective film is formed on the surface of the apple slices, which produces a certain evaporation resistance to the internal moisture, which is beneficial to the puffing effect of the microwave vacuum drying puffing process. Heat-drying is drying under the condition of 50-70°C for 1-3 hours, and the dry basis water content of the apple slices after heat-drying is controlled between 20%-150%. Preferably, the drying temperature of the heat drying is 65° C., and the moisture content of the dry basis of the apple slices after heat drying is 60%. Then place the baked apple slices in a dry environment for 5 hours to keep the moisture content of the apple slices uniform.

The baked apple slices are put into a microwave vacuum drying equipment for drying and puffing. During the drying and puffing process, microwave power and vacuum degree play a vital role in the product quality of apple crisps. If the microwave power is too small, the steam pressure generated by the internal moisture vaporization is insufficient to play a puffing effect. The apple slices are in a dry state, and the volume will shrink to a certain extent. The greater the microwave power, the greater the steam pressure generated, forming a larger The radial driving force makes the internal tissue structure of apple slices expand rapidly, forming a microporous structure, and the puffing effect is good. However, too much microwave power will generate an excessive pressure difference, so that part of the moisture in the material will be directly pumped out of the surface in the form of liquid water, which will weaken the puffing effect. The higher the degree of vacuum, the lower the evaporation temperature of water, the lower the steam transmission resistance, the greater the radial driving force, and the puffing effect is more ideal. However, the higher the vacuum degree, the stricter the requirements on the vacuum system, which increases the equipment cost and operating cost of the system. Process parameters The microwave power is in the range of 2.0-50.0w/g, the vacuum degree is -0.075--0.098MPa, and the drying and puffing time is within 30 minutes. It can be processed into high-quality apple chips, and the final moisture content of the product on a dry basis is 4. %±1%. The microwave power is preferably 12.0w/g, the vacuum degree is -0.015MPa, the drying and puffing time is 4 minutes, the drying and puffing temperature of the apple slices is kept at about 33°C to 35°C, and the puffing rate of the puffed apple chips can reach 3.21, The product is fluffy, crispy and delicious, light yellow in color, close to the original color of apples, and has a strong apple flavor.

As shown in Figure 1, select 3kg apples, the initial moisture content on a dry basis is 6.46 (step 1), rinse the apple surface with clear water, remove surface silt and impurities (step 2), and perform peeling and core removal (step 2). 3), and cut into 8mm thick semicircle (step 4), the sliced apples are soaked in the color protection solution, the color protection solution is 0.5% citric acid+0.2% sodium bisulfite+0.4% chlorine Calcium+0.5% salt, soaking time is half an hour (step 5). After the apple slices are treated for color protection, they are taken out, rinsed repeatedly, and then the surface water of the apple slices is drained.

After the color protection treatment, the apple slices are subjected to thermal drying treatment, put into an oven for low-temperature drying, and dry for 3 hours under the condition of a thermal drying temperature of 65°C. After thermal drying, the dry basis moisture content of the apple slices is 60%. The apple slice weight after baking is 0.417kg (step 6). Place the baked apple slices in a dry environment for 5 hours to keep the moisture content of the apple slices uniform (step 7).

After heat-bake treatment, adopt microwave vacuum drying puffing procedure to carry out the dry puffing treatment of apple slice, select microwave power 5kW for use, vacuum tightness is made as-0.085MPa, and drying puffing time is 4 minutes (step 8), and the dry basis content of apple slice is The water content reaches 6%, and the puffed apple chips have 276 grams. The product is fluffy, crisp and delicious, with a light yellow color close to the original color of apples and a strong apple fragrance. The temperature of the apple slices is maintained at about 33° C. to 35° C. during the drying and puffing process, and then vacuum-packed (step 9).

Taking carrot as an example again below, the processing method of the present invention is specifically described.

As shown in Figure 2, select 2kg carrots with an initial water content of 7.25, pay attention to rejecting defective products with variegated colors, deformities, small size, and severe pests and diseases (step 10), cut off the top leaf clusters with a knife, and then clean the mud with water Sand and impurities (step 20), peeling (step 30), cutting the carrot slices into 6×6mm blocks (step 40), blanching the sliced carrots in boiling water for 5 minutes, subject to scalding thoroughly , but can not be scalded until soft and rotten (step 50).

After the color protection treatment, the carrot pieces are heat-baked, put into an oven for low-temperature drying, and dry for 2 hours at a heat-baking temperature of 70°C. After heat-baking, the dry basis moisture content of the apple slices is 47%. The baked carrot particle weight is 0.277kg (step 60). Place the baked carrots in a dry environment for 5 hours to keep the moisture of the apple slices uniform (step 70).

After the thermal drying treatment, the microwave vacuum drying and puffing procedure is adopted to carry out the drying and puffing treatment of the carrot pieces. The microwave power 2.5kW is selected, and the vacuum degree is set to -0.092MPa. After 3 minutes of dry puffing (step 80), the dry basis of the carrot pieces The water content reaches 5%, and the weight of the puffed carrot grains is 182 grams. The product is fluffy, crisp and delicious, and the color is orange-red, which is close to the natural color of carrots, and has the original fragrance of carrots. The carrot grains are kept at a temperature of about 30° C. to 32° C. during the drying and puffing process, and then vacuum-packed (step 90 ).

The present invention is also suitable for puffing and drying processing of bananas, pineapples, carrots and other fruit and vegetable products. The processing process is the same as that of apples. The specific processing parameters are related to the types of raw materials. The finished product has a crisp taste, high nutritional content, and can better retain materials. The original color and fragrance. The fruit and vegetable chips processed by the invention is a brand-new, pure natural non-fried fruit and vegetable food.

Compared with the prior art, the present invention has the following advantages:

(1) The drying and puffing time is greatly shortened, reducing energy consumption. Microwave heating is used to heat the inside and outside of the raw material at the same time, heating the medium as a whole, without other heat transfer media, so the speed is fast and the efficiency is high.

(2) Processing under low vacuum state reduces the drying and puffing temperature, and the drying and puffing temperature is below 40°C.

(3) It is easy to realize continuous production. Due to the characteristics of short processing time, simple operation and rapid adjustment of microwave power, the adjustment and determination of process parameters are also very convenient, and it is easy for continuous production and real-time control.

(4) The product of the present invention is high-quality non-fried vacuum puffed apple chips. The finished product tastes crisp and retains the original color and aroma of apples.

Through the above introduction to the present invention, the above description of the specific embodiments of the present invention does not limit the present invention, and those skilled in the art can easily make corresponding changes according to the present invention, as long as they do not depart from the essence of the present invention, all should belong to the present invention scope of the appended claims.

Claims (10)

1, a kind of processing method of puffed vegetable fruit crisp slice comprises look, drying, expanded and vacuum-packed treatment process are chosen, clean, cut into slices, protected to the raw material fruits and vegetables, it is characterized in that described expanded operation is the microwave vacuum puffing process.

2, the described method of claim 1 is characterized in that, in described microwave vacuum puffing process, microwave power be 2.0～50.0w/g, vacuum be-0.075～-0.098Mpa, baking temperature is below 40 ℃, the expanded time is in 30 minutes.

3, the described method of claim 2 is characterized in that, microwave power in 12.0w/g, vacuum is-0.085MPa, and baking temperature carries out the dry expanding processing of fruit and vegetable tablet at 33～35 ℃, and the dry expanded time is 4 minutes.

4, the described method of claim 1 is characterized in that, section back fruits and vegetables slice thickness is between 2～16mm.

5, the described method of claim 1 is characterized in that, it protects the look process is to add the combination solution of prescription, and its interpolation prescription is: 0.2～0.5% citric acid, 0.05%～0.2% sodium hydrogensulfite, 0.2～0.5% calcium chloride, 0.3～0.7% salt.

6, the described method of claim 5 is characterized in that, the colour protecting liquid of fruit and vegetable tablet is 0.5% citric acid, 0.2% sodium hydrogensulfite, the aqueous solution of 0.4% calcium chloride and 0.5% salt.

7, the described method of claim 1 is characterized in that, described dry run is carried out under 50～70 ℃ of conditions, and 1～3 hour drying time, the dry basis moisture content of dry back fruit and vegetable tablet is 20%～150%.

8, the described method of claim 7 is characterized in that, the baking temperature of fruit and vegetable tablet is 65 ℃, and 3 hours drying times, dried dry basis moisture content is 60%.

9, the described method of claim 1 is characterized in that, described fruits and vegetables are meant a kind of of the fruit and vegetable food that comprises apple, carrot.

10, any described method in the claim 3,6,8 is characterized in that described fruit and vegetable tablet is an apple flakes.