AU601477B2 - Process for producing fried food and device therefor - Google Patents

Description

CO MO N WEB A LT H O UTAI 0 F A U S T R A L I A PATENT ACT 1952 COMPLETE SPECIFICATION

-(ORIGINAL)

FOR OFFICE USE CLASS INT. CLASS Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority: Related Art-: 60147 Fhis document contains Uth a1ic2ndnments made uinder See-tjon.49 and is correct for printing.

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NAME OF APPLICANT: ADDRESS OF APPLICANT:.

KEN SAKUMA 793, Hachigasaki, Matstido-shi, Chiba,

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NAME(S) OF INVENTOR(S): ADDRESS FOR SERVICE: Ken SAKUMA DAVIES COLLISON, Patent Attorneys I Little Collins Street, Melbourne, 3000.

*4 COMPLETE SPECIFICATION FOR THE INVENTION ENTITLED: "PROCESS FOR PRODUCING FRIED FOOD AND DEVICE THEREFOR"

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The following statement is a full, description of this invention, including the best method of performing it known to me

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r i-t 1 2 3 4 6 7 8 9 11 t t 13 14 *4 S 16 17 18 19 1 21 S22 23 24 26 27 :28 to 29 31 32 33 34 36 37 BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for producing fried food (or snack foods) from fruits such as apples, and pineapples, vegetables such as pumpkins, sweet potatoes, and onions, and fish such as octopus, cuttlefish, and short-necked clams, and a device therefor.

2. Description of the Related Art In the related art, this kind of fried food has been produced according to a frying process in which a basket containing a starting material in the shape of chips is moved vertically in heated oil in a fryer vessel maintained under a reduced pressure while preventing mutual adhesion of the starting material in the shape of chips, as disclosed in Japanese Unexamined Patent Publication (Kokai) No. 52-3848 and No. 59-210853.

However, since the frying process of the related art as mentioned above merely moves the starting material vertically in the heating oil, the starting raterial is insufficiently dried, resulting in bending or destruction of the material. This gives rise to problems such that not only is the product value lowered, but also the product has an inferior taste and the oil content is markedly increased.

An object of -he present invention is to alleviate one or more of the above-mentioned problems of the prior art and to provide a process and a device for producing fried food which is not only capable of producing homogeneous products evenly and uniformly by frying (or oil cooking) a relatively large amount of the starting material, but can also provide fried food having a good taste and a low oil content by draining the oil quickly therefrom.

According to one aspect of the present invention there is provided a process for producing fried food, which comprises: placing a starting material suitably applied with necessary pretreatment into a vacuum fryer with a given amount of heated oil therein; (ii) moving the material in a substantially vertical 9.

1 i :i i o!i Ia r 2 1 direction so as to thereby repeatedly dip the material into 2 the oil and withdraw the material from the oil surface under 3 vacuum pressure; 4 (iii) thereafter retaining the material to the oil for a period of time under vacuum pressure; and 6 (iv) vibrating the fried material with small amplitudes 7 whilst disposed above the oil under vacuum pressure, 8 followed by retaining the fried material for an appropriate 9 time under vacuum pressure.

In accordance with another aspect of the present 11 invention there is also provided a device for producing S12 fried food including a fryer vessel equipped with a 13 sealing lid at the upper portion on one or both sides, a 14 heater for heating oil, a level gauge for monitoring the oil f I level of the oil, and a drive means such as an air cylinder 16 which drives a waggle frame housed within the fryer vessel 17 vertically to dip the fi'ame into the oil or withdraw the 18 frame above the oil surface, a frying case to be housed 19 within the waggle frame so as to be freely dischargeable by opening the above sealing lid, a pipe for transferring 21 the heated oil to the fryer vessel, an oil reservoir for 22 storing the oil, and a vacuum generating means for 23 producing vacuum inside of the fryer vessel during a frying 24 operation.

According to the present invention, the desired fried 26 food can be obtained especially well, when the frying 27 operation is carried out under a high vacuum pressure such S 28 as 20 Torr or less and also when the distance of the heated 29 oil level and the vertically uppermost position of the material to be fried during 31 32 33 34 36 i T 3 the repeated cycle of the operation, substantially the uppermost position of the bottom of the frying case during the repeated cycle of the frying operation, is 200 mm or more, more preferably 200 mm to 350 mm. This is very important to obtain slices fried food having a good taste without causing agglomeration thereof during the frying operation. The preferable size of the frying case is 100 mm to 250 mm in height (or depth), more preferably about 200 mm.

Other object and advantages of the present invention will be apparent from the following description.

BRIEF DESCRIPTION OF THE DRAWING The present invention will be better understood from the description set forth below with reference to the accompanying drawings, which illustrate, but are not intended to limit, the preferred embodiments of the present invention, in which: Figure 1 is a schematic illustrating showing an example of the vacuum fryer device for practicing the 20 process of the present invention; Fig. 2 is a graph showing the vertical movement operation in a first preparation example of the process of the present invention; Fig. 3 is a graph showing the drying condition 25 of the starting material; and Fig. 4 is a graph of the vertical movement operation in a second preparation example.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, an example ol the 30 present invention is described.

In Fig. 1, 1 is a lateral type fryer vessel. Three vessel are provided in this example. On one end side of the fryer vesel 1, a sealing lid la is mounted. lb is a level gauge.

35 At the bottom of the fryer vessel 1, a heater 2 is arranged so as to heat oil to a desired temperature. A steam pipe 3, through which steam is supplied, is ft ftt(*..i ft tff ft* ft ft t.

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r tp f ft ft ft ftii f fti ft ftftf*: ft f f*ti ft ft ft ft ftf ftr defffi -4connected to the heater 2.

At the bottom of the fryer vessel 1, an inlet for introducing a pipe 4 for transferring oil is opened so that oil may be fed to each fryer vessel from an oil heater 5. 4a is an oil supply pipe for supplying oil based on the oil level monitored by an oil level gauge lb.

A waggle frame 6 is housed within the above fryer vessel 1, which is movable vertically by an air 1o cylinder 7. Air pipes 8 and 8, which are connected through a change-over valve 9 to an air compressor are connected to the air cylinder 7.

A limit switch 11 detects the respective positions of the ascending end and the descending end of the above waggle frame 6 and performs a change-over operation of the above change-over valve 9. The starting material case 12 can be housed within the above waggle frame 6 so as to be freely dischargeable.

An evacuation pipe 13 i's connected to the upper 1portion of the above fryer vessel 1, which introduces the vapor within the fryer vessel 1, into a mist separator 14. The mist separator 14 is further connected to a first condenser 15. Cooling water is introduced into the first condenser 15 from a cooling water pipe 16, and a second condenser 17 is also connected thereto.

in the figure, 18 is a drain tank, 19 is an auxiliary vacuum pump, 20 a main vacuum pump, 21 an oil reservoir, 24 an oil filter, 22 a vacuum valve, and 23 is a vacuum breaker. The mode of operation of the above %tv 30 device is now described.

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First, the oil in the oil reservoir 21 is introduced into the fryer vessel 1, through the pipe 8 and then itt heated by the oil heater 2.

t Next, the sealing lid la of the fryer vessel is opened and the frying case 12 (or starting material C case) -filled with a starting material is inserted within the waggle frame. 6.

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5 The above sealing lid la is resealed, then the main vacuum pump 20 and the auxiliary vacuum pump 19 are run.

When the auxiliary vacuum pump 19 reaches 50 to 100 Torr, the evacuation system is changed to that of the main vacuum pump 20 by the vacuum valve 22. When the vacuum degree reaches 20 Torr or less, preferably, 10 Torr or less, the solenoid of the change-over valve 9 is turned ON to actuate the air cylinder 7.

The air cylinder 7 causes the waggle frame 6 to descend and dip the frying case 12 into the oil, thereby beginning to fry (or oil cook) the starting material in the starting material case 12.

When the waggle frame 6 reaches the descent limit, the limit switch 11 activates the change-over valve 9 to cause the waggle frame 6 to ascend. When the waggle frame 6 ascends above the oil surface, the limit switch 11 activates the change-over valve 9 to cause the waggle frame 6 to again descend into the oil.

The operation of dipping the waggle frame 6 into and withdrawing it above the oil described above'is repeated for several minutes to cook the starting il" material in the frying case 12. After an elapse of a t4 4, predetermined time, the cooked material is left to rest in the oil, by actuation of a timer, for finishing cooking. Finally, the waggle frame 6 is withdrawn from the oil by the air cylinder 7, and the oil is drained by waggling the frame above the oil surface.

Then the vacuum valve 22 is closed, and the valve 23 is opened to return the pressure in the fryer vessel 1 30 to atmospheric. The frying case 12 within the waggle frame 6 is taken out from within the fryer 1 by opening the sealing lid la, and the product is then taken out.

*t *a In carrying out the frying process by repeating the above operation, the oil is supplemented to a desired 35 oil level by observing the level gauge lb. The fry*ng t4 .,tt or oil cooking process was conducted by repeating the above operations for the three fryer vessels according 1 6 to the following pattern.

Upper stage Middle stage Lower stage No. 1 fryer No. 2 fryer No. 3 fryer 1 Running Preparing Taking out 2 Taking out Running Preparing 3 Preparing Taking out Running Running: the step of frying the starting material.

Preparing: the preparatory steps of charging the starting material, maintaining a predetermined vacuum degree with the auxiliary vacuum pump, controlling oil temperature, etc.

Taking out: the step of taking out the material from within the fryer after completion of the frying process.

After the completion of the frying process, the used oil in each fryer vessel is collected into the oil reservoir 21 and placed under a reduced pressure (vacuum), whereby oxidation of the used oil is prevented, and thus no problems arise concerning reutilization.

Examples The present invention will now be further illustrated by, but is by no means limited to, the following preparation examples.

a 30 Preparation Example 1 Apples were sliced into chips and soaked in a low S sugar thick malt syrup adjusted to a sugar degree of to 45 Bricks at a temperature of 20°C for 5 to 8 hours.

a After draining off the syrup, the chips were placed in a 35 rectangular wire cage case with a height of 200 mm, introduced into the case of a vacuum fryer, and the case S* was moved vertically so that the uppermost position of 1 5 was moved vertically so that the uppermost position of i If I~i~L I-i 7 the bottm of the case was 200 mm. The number of vertical movements of the vacuum fryer may be varied from about 1 to 20 times/minute.

In the vacuum fryer, frying was performed under the conditions of a vacuum degree of 5 to 20 Torr and an oil temperature of 110°C.

As shown in the graph in Fig. 2, of the total frying tim&c of 12 minutes, vertical movement was performed five times/minute at intervals of 30 seconds for 5 minutes after the initiation of frying, then at intervals of one minute for the next 4 minutes. This was followed by standing in oil for the next 3 minutes, followed by vertical movements above the oil level with very small amplitudes (30 to 50 m/m) on recording the final oil temperature (finishing oil temperature) of to 95°C for 30 seconds, followed by standing under vacuum pressure for 5 minutes.

For the drying condition of the starting material during the above operations, the result as shown in Fig. 3 was obtained.

*Therefore, in the first zone, most of the constant rate drying was effected within 10 to 15 seconds from the start-up, followed by the reduced rate drying zone.

'The movement in the first zone was necessary for 25 uniformity of the temperature distribution and the prea, ventioj of adhesion among the chips.

IIn the second zone, where drying proceeded to a considerable extent, the article was handled so as not to be broken. The third zone was the zone for control- 30 ling the final, water content. The final step was the S..t oil draining of the case and the fry box, where the product was moved vertically with an amplitude of to 50 mm, as shown in Fig. 2. When the final oil draining step was conducted, a reduction of the oil content by about 3 to 5% was observed as compared with the case when no such operation was conducted.

Consequently, highly satisfactory results could be a a 11 :i d

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1 4 if I 8 obtained with the fried product of apple 2hips, in that there was no adhesion between the chips or color fading, and there was a good taste and good oil draining.

In the above-mentioned Preparation Example 1, the distance A (mm) between the oil level and the uppermost position of the bottom of the fryi.ng case during the operation and the height B (mm) of the frying case were changed as shown in Table 1. The results are shown in Table 1.

Table 1 Run No. Taste Color Flavor Drying Oil Overall evaluation degree content A 300 4-q 15 18 Very good B 200 2A 150 22 28 Good dryness, but B 200 oily taste 3A 350 20 27 2Q% B 400 and oily taste 4 No 20 25 Much layered vertical product nrvewent Note: very good, common, slightly inferior The elevation was carried out using a panel consisting of 12 members five males and seven females, 30 in three in their teens, five in the 20's, two in the 30's, one in the 40's, and one in the Preparation Example 2 Pineapple cut in round slices was subjected to the same treatment as Preparation Example 1 by using a fine 35 white sugar syrup and under the operational conditions shown below by means of the same device as in Preparation Example 1.

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1) Operational conditions Oil temperature: 120 0

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Frying times: 15 minutes Operational vacuum degree: 10 Torr or lower Final temperature: 940C 2) Vertical movement condition As shown in Fig. 4, vertical movement was performed 5 to 6 times/minute at intervals of 30 seconds for 5 minutes after the initiation of frying, 4 to 6 times/minutes at intervals of 1 minute for the next minutes, and 3 to 6 times/minute after 2 minutes for the next 3 minutes. After the elapse of 15 minutes, vertical movement with an amplitude of 30 50 m/m was performed above the oil level 5 to 10 times, followed by standing in vacuum for 3 minutes. The product was then taken out by breaking the vacuum and cooled.

3) Results The results of a comparison among the products obtained by frying while performing vertical movement S 20 with the various dimensions of A and B as deuCribed in SPreparation Example 1 are given in table 2.

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10 Table 2 Run No. Taste Color Flavor Drying Oil Overall evaluation degree content 1 A 300 17 20% Very good B 200 2 A 150 20 28% Good, but oily B 200 taste 3 A 350 21 26% 10 15% stickness B 400 and oily taste 4 When fried -4 18 25% Much layered without and dried product vertical movement Note: very good, camon As is clear from the results shown in Tables 1 and 2, the vertical movement of the frying case and the distance between the oil level and the uppermost position of the bottom of the frying case and the height of the frying case are essential factors for producing the desired fried food having the excellent characteristics.

25 As explained above, according to the present invention, the following advantageous results can be obtained.

By placing the starting material in a fryer filled with heated oil to an intermediate level and repeating the operation cf dipping into oil and withdrawing above the oil surface by vertical movement a.

of the fryer, not only can mutual adhesion between the starting material be prevented, but also even and S* uniform frying can be performed to produce homogeneous 35 products.

a Since the starting material is left to stand for a necessary time under a high vacuum pressure 11 after the above vertical movement operation, the fried product has an improved taste, color, flavor, and dryness.

By performing final oil draining by vibration with small amplitudes above the oil, the flavor is increased with a reduced oil content without drying irregularities.

The selection of the distance between the oil level and the uppermost position of the material to be fried during the vertical movement operation and also of the height or depth of the frying case is especially important for obtaining a fried product having excellent taste, color, flavor, and dryness.

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Claims (1)

12- THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS: 1. A process for producing fried food, which comprises: placing a starting material suitably applied with necessary pretreatment into a vacuum fryer with a given amount of heated oil therein; (ii) moving the material in a substantially vertical direction so as to thereby repeatedly dip the material into the oil and withdraw the material from the oil surface under vacuum pressure; (iii) thereafter retaining the material to the oil for a period of time under vacuum pressure; and (iv) vibrating the fried material with small amplitudes whilst disposed above the oil under vacuum pressure, followed by retaining the fried material for an appropriate time under vacuum pressure. 2. A process as claimed in claim 1, wherein the distance between the oil level and the vertically uppermost position of the material at the outside of the oil is 200 mm or more. 3. A process as claimed in claim 1, wherein the vacuum pressure is 20 Torr or less. 4. A device for producing fried food, comprising a fryer vessel equipped with a sealing lid at the upper portion on one or both sides, a heater for heating oil, a level gauge for monitoring the oil, level of the oil, and a drive means such as an air cylinder which drives a waggle 7" frame housed vidthin the fryer vessel vertically to dip the 1 frame into the oil or withdraw the frame above the oil surface, a frying case to be housed within the waggle 14 frame so as to be freely dischargeable by opening the above i :sealing lid, a pipe for transferring the heated oil to the fryer vessel, an oil reservoir for storing the oil, and a vacuum generating means for producing vacuum in the inside of the fryer vessel during a frying operation 9 036#7174icl I T 4P :r 13 A device as claimed in claim 4, wherein the distance between the oil level and the vertically uppermost position of the bottom of the frying case is set to 200 mm or more. 6. A device as claimed in claim 4, wherein the vacuum pressure is set to 20 Torr or less during the operation. 7. A process for producing fried food, substantially as hereinbefore described with reference to the drawings. 8. A device for producing fried food, substantially as hereinbefore described with reference to the drawings. 9 a tapc or fcataurc di oocd hr-oia. or Dated this 13th day of November 1987 KEN SAKUMA By His Patent Attorneys DAVIES COLLISON t C ft .4" t f aa~e ft a ft. r, 1