GB2430862A - Cooking oil filtration assembly and method - Google Patents

Abstract

A cooking oil filtration assembly for use in high-volume deep frying applications. The assembly comprises a submersible frying basket for retaining foodstuff to be fried and a removable mesh filter structure positioned below or around the frying basket. The filter includes a metal frame 12 and mesh panels 10. The mesh is provided with openings which are smaller than those of the frying basket and sized to trap the majority of food particulates which break away from the foodstuff. Filtering of the cooking oil involves removing the frying basket from the frying vessel and simultaneously (or subsequently) removing the mesh filter structure. The mesh filter structure is then suspended over the cooking oil to allow excess oil to drain through the mesh before the food particulates are removed and the mesh filter structure is cleaned for re-use.

Description

1 Cooking Oil Filtration Assembly and Associated 2 Method 4 This invention

relates to a cooking oil filtration assembly, and particularly, but not exclusively, to 6 a filtration assembly for use in high-volume deep 7 frying applications and a method of filtering 8 cooking oil using said assembly.

Infrequent and incomplete filtering of cooking oil 11 means that small food particles tend to remain in 12 the fryer for long periods at high temperatures.

13 Once they lose their moisture content, the particles 14 sink to the base of the fryer where they are overcooked and impart a burnt taste and colour to 16 the cooking oil causing it to break down more 17 rapidly than it would otherwise do so. Frying uses 18 cooking oil as a heat transfer medium with the 19 intention of forming a crust on a food product to seal in its moisture content. The formation of a 21 crust inevitably causes food particles to form.

22 This problem is particularly evident when frying 1 food products which are coated with batter or 2 breadcrumbs which are easily detached. It will be 3 appreciated that the term cooking oil' used 4 throughout the specification should be interpreted as including any suitable liquid for use in frying 6 such as vegetable or animal based oils.

8 It is widely accepted that regular filtering of 9 cooking oil used in high-volume deep frying applications yields benefits in terms of prolonging 11 the useful life of the oil and therefore reducing 12 the costs associated with premature replacement and 13 disposing of used oil. Moreover, it is known that 14 regular filtering of cooking oil helps to maintain the desired flavour, texture and aesthetics of fried 16 food, minimises the breakdown of the oil and reduces 17 the formation of by-products and compounds that are 18 potentially harmful to health.

Various methods of filtering cooking oil are 21 currently used ranging from merely skimming the 22 surface of the oil with a sieve to remove obvious 23 floating particulates to more comprehensive multi- 24 stage filtration processes that involve passing the oil through a series of progressively finer filters.

27 Whilst the manual skimming method can be performed 28 quickly and easily, it fails to remove smaller 29 particulates and those which have sunk to the bottom of the fryer or are suspended well below the surface 31 of the oil. On the other hand, whilst multi-stage 32 filtration processes are more effective at removing 1 a wider range of particulate sizes from the oil, 2 they require complicated, time consuming and costly 3 drainage, storage and pumping mechanisms to enable 4 the oil to be removed, filtered and subsequently returned to the fryer. Despite the benefits to be 6 had from such multi-stage processes, the significant 7 investment in time required to perform this 8 unpleasant task means that it is often carried out 9 only occasionally, for example, after closing time.

This is particularly so when only one fryer is 11 available.

13 In an effort to overcome the aforementioned 14 problems, some high-volume food fryers have been adapted to provide a "cool-zone" at their base where 16 the temperature of the oil can be maintained at a 17 relatively cooler temperature. The function of the 18 "cool-zone" is to allow food particulates to 19 accumulate therein so as to minimize the effect they have in prematurely breaking down the cooking oil.

21 However, this approach means that the overall volume 22 of the fryer is increased, as is the volume of oil 23 required to fill the fryer.

According to a first aspect of the present 26 invention, there is provided a cooking oil 27 filtration assembly for use in a frying vessel, said 28 assembly comprising: 29 a submersible frying basket for holding a food product to be fried, said basket having 31 openings formed therein; and 1 a filter structure adapted to have openings 2 which are smaller than those of the frying 3 basket and sized to trap food particulates, 4 wherein the frying basket is receivable over, or within, the filter structure.

7 Preferably, the filter structure is formed from a 8 wire mesh.

Preferably, the filter structure is provided with a 11 base and side walls the internal surfaces of which 12 define a first notional volume within which said 13 food particulates are retained, a second notional 14 volume being defined by the inner surface of a frying vessel and the outer surfaces of the mesh 16 filter structure.

18 Preferably, the filter structure is shaped and 19 dimensioned to correspond with the inner surface profile of a frying vessel and said second notional 21 volume is minimised when the filter structure is 22 positioned fully within a frying vessel.

24 Alternatively, the filter structure is shaped and dimensioned to correspond with the outer surface 26 profile of the frying basket and said first notional 27 volume is minimised when the frying basket is 28 positioned fully within the mesh filter structure.

optionally, a plurality of filter structures are 31 receivable within a frying vessel in a side-by-side 32 arrangement.

2 Preferably, the filter structure is provided with a 3 supporting framework.

Preferably, a handle means extends from the 6 supporting framework to facilitate the removal of 7 the filter structure from a frying vessel.

9 Optionally, the handle means is detachable.

11 Preferably, an engagement member extends from the 12 supporting framework to facilitate the engagement of 13 the filter structure with a frying vessel to 14 facilitate its suspension above the surface of cooking oil.

17 According to a second aspect of the present 18 invention, there is provided a method of filtering 19 cooking oil from a frying vessel after frying using the apparatus of the first aspect, the method 21 comprising the steps of: 22 (i) removing the frying basket from the 23 frying vessel; and 24 (ii) simultaneously or subsequently removing the mesh filter structure, and 26 therefore the food particulates trapped 27 therein, from within the frying vessel.

29 Preferably, the method includes the additional step of suspending the filter structure above the surface 31 of the cooking oil to allow excess cooking oil 32 trapped between the food particulates to drain 1 through the mesh under the influence of gravity and 2 into the frying vessel.

4 Preferably, the method includes the additional step of providing a further identical clean filter 6 structure and positioning it within the frying 7 vessel whilst the other filter structure is 8 suspended above the surface of the cooking oil and 9 before re-submersing the frying basket.

11 Preferably, the method includes the additional step 12 of cleaning the suspended filter structure such that 13 the cycle can be repeated.

An embodiment of the invention will now be 16 described, by way of example only, with reference to 17 the following drawings, in which: 19 Figs. la-c show side, front and plan views respectively a mesh filter structure; and 22 Fig. 2 shows a cross-sectional side view of a mesh 23 filter structure suspended above the surface of the 24 oil within a frying vessel.

26 Figs. la-c show a filter structure formed from five 27 substantially rectangular panels 10 of food approved 28 mesh material. The structure includes a supporting 29 metal framework 12 to which the panels 10 are connected whilst leaving an upper opening 14. A 31 handle 16 is connected to, or formed integrally 32 with, an upper portion of the supporting framework 1 12. A hanging fork 18 is connected to, or formed 2 integrally with, an upper portion of the supporting 3 framework 12 opposite the handle 16.

The mesh material used in the panels 10 is food 6 grade stainless steel.

8 In use, the filter structure forms part of a cooking 9 oil filtration assembly comprising a fryer vessel and a frying basket. The openings in the filter 11 structure are smaller than those in the frying 12 basket, their size being selected to trap the 13 majority of food particulates. The filter structure 14 is positioned within the frying vessel such that its mesh separates the inner surface of the frying 16 vessel from the, or each, frying basket by enclosing 17 the frying basket within its five panels 10.

19 Once a batch of food within the frying basket is cooked, the fryer operator may wish to perform a 21 rapid removal of food particulates from the cooking 22 oil in order to prolong the useful life of the oil, 23 reduce the formation of by-products and compounds 24 that are potentially harmful to health and maintain the desired characteristics of the food product 26 being fried.

28 This is achieved by removing the frying basket(s) 29 from the frying vessel and immediately removing the filter structure from the frying vessel by means of 31 its handle 16. The filter structure is then 32 suspended above the surface of the cooking oil (as 1 illustrated in Fig. 2) by means of its hanging fork 2 18 which engages with a complementary formation on 3 the fryer. Accordingly, all food particulates of a 4 size which is larger than the mesh size will be removed from the cooking oil. By suspending the 6 filter structure above the surface of the cooking 7 oil, any residual oil within the structure (i.e. oil 8 trapped between food particulates) can drain through 9 the mesh under the influence of gravity and fall back into the frying vessel. It will be appreciated 11 that the rate at which the oil drains through the 12 mesh will be dictated by the technical 13 characteristics of the mesh, i.e. weave-type, 14 aperture size, open area percentage etc. 16 Meanwhile, it is preferable that a further filter 17 structure is ready to be introduced into the frying 18 vessel to allow the frying baskets to be re- 19 submerged and a further batch of food products to be cooked. Once the oil from the suspended filter 21 structure has drained back into the frying vessel, 22 the hanging fork 18 can be disengaged and the 23 structure can be removed for cleaning ready to 24 replace the structure now in the frying vessel to thus repeat the process.

27 It will be appreciated that the filter structure 28 facilitates rapid removal of small food particulates 29 from the oil in a matter of seconds as compared to known multi-stage processes which take several 31 minutes. Accordingly, in view of the speed and ease 32 with which filtering can be achieved using the 1 assembly and method of the present invention, a 2 fryer operator is able to perform this operation 3 multiple times each day, most preferably between 4 each batch of frying whilst increasing the productivity of the frying apparatus.

7 Currently, the fryer operator accepts that there 8 will be a significant build up of food particulates 9 and residue at the end of the day making the cleaning of the frying vessel a very unpleasant 11 task. By using the apparatus and implementing the 12 method of the present invention, the frying vessel 13 requires only light cleaning as the amount of 14 surface residue is significantly reduced. Moreover, if any further filtering of the oil is required, 16 this can be performed much more easily since all but 17 the smallest food particulates will already have 18 been removed.

A further advantage of the present invention is that 21 the "cool zone" used in many commercial fryers can 22 be eliminated with the advantage that the fryer 23 requires less space and less cooking oil.

Modifications and improvements can be made without 26 departing from the scope of the present invention.

27 For example, the mesh size of the filter structure 28 can be selected depending on the type of food being 29 fried and the anticipated size of the food particulates (i.e. breadcrumbs etc.).

1 Although the filter structure has been described and 2 illustrated in the form of a three-dimensional 3 basket, it will be appreciated that any structure 4 which serves to separate the frying basket from the base of the frying vessel will be sufficient. For 6 example, the filter structure could be in the form 7 of a planar mesh (i.e. without side walls) which 8 rests on the base of the frying vessel and extends 9 across its full length and width.

Claims (1)

1 CLAIMS 3 1. A cooking oil filtration assembly for use in a 4 frying

vessel, said assembly comprising: a submersible frying basket for holding a food 6 product to be fried, said basket having 7 openings formed therein; and 8 a filter structure adapted to have openings 9 which are smaller than those of the frying basket and sized to trap food particulates, 11 wherein the frying basket is receivable over, or 12 within, the filter structure.

14 2. A cooking oil filtration assembly as claimed in claim 1, wherein the filter structure is formed from 16 a wire mesh.

18 3. A cooking oil filtration assembly as claimed in 19 claim 1 or 2, wherein the filter structure is provided with a base and side walls the internal 21 surfaces of which define a first notional volume 22 within which said food particulates are retained, a 23 second notional volume being defined by the inner 24 surface of a frying vessel and the outer surfaces of the mesh filter structure.

27 4. A cooking oil filtration assembly as claimed in 28 claim 3, wherein the filter structure is shaped and 29 dimensioned to correspond with the inner surface profile of a frying vessel and said second notional 31 volume is minimised when the filter structure is 32 positioned fully within a frying vessel.

2 5. A cooking oil filtration assembly as claimed in 3 claim 3, wherein the filter structure is shaped and 4 dimensioned to correspond with the outer surface profile of the frying basket and said first notional 6 volume is minimised when the frying basket is 7 positioned fully within the mesh filter structure.

9 6. A cooking oil filtration assembly as claimed in any preceding claim, wherein a plurality of filter 11 structures are receivable within a frying vessel in 12 a side-by-side arrangement.

14 7. A cooking oil filtration assembly as claimed in any preceding claim, wherein the filter structure is 16 provided with a supporting framework.

18 8. A cooking oil filtration assembly as claimed in 19 claim 7, wherein a handle means extends from the supporting framework to facilitate the removal of 21 the filter structure from a frying vessel.

23 9. A cooking oil filtration assembly as claimed in 24 claim 8, wherein the handle means is detachable.

26 10. A cooking oil filtration assembly as claimed in 27 any of claims 7 to 9, wherein an engagement member 28 extends from the supporting framework to facilitate 29 the engagement of the filter structure with a frying vessel to facilitate its suspension above the 31 surface of cooking oil.

1 11. A cooking oil filtration assembly substantially 2 as hereinbefore described with reference to the 3 accompanying drawings.

12. A method of filtering cooking oil from a frying 6 vessel after frying using the apparatus of the first 7 aspect, the method comprising the steps of: 8 (i) removing the frying basket from the 9 frying vessel; and (ii) simultaneously or subsequently removing 11 the mesh filter structure, and 12 therefore the food particulates trapped 13 therein, from within the frying vessel.

13. A method of filtering cooking oil as claimed 16 in claim 12, the method including the additional 17 step of suspending the filter structure above the 18 surface of the cooking oil to allow excess cooking 19 oil trapped between the food particulates to drain through the mesh under the influence of gravity and 21 into the frying vessel.

23 14. A method of filtering cooking oil as claimed 24 in claim 13, the method including the additional step of providing a further identical clean filter 26 structure and positioning it within the frying 27 vessel whilst the other filter structure is 28 suspended above the surface of the cooking oil and 29 before re-submersing the frying basket.

31 15. A method of filtering cooking oil as claimed 32 in claim 14, the method including the additional 1 step of cleaning the suspended filter structure such 2 that the cycle can be repeated.