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1. WO2019053677 - COMPOSITION OF EDIBLE OIL, PARTICULARLY FOR USE IN FRYING AND COOKING OF FOODS

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[ EN ]

COMPOSITION OF EDIBLE OIL, PARTICULARLY FOR USE IN FRYING AND COOKING OF FOODS

Technical Field

The present invention relates to a composition of edible oil, particularly for use in frying and cooking of foods.

Background Art

With reference to the food industry sector the use is known of vegetable oils during the frying processes of food products.

In particular, different types of vegetable oils are known which are obtained by extraction from seeds or fruits of the plant species.

Such vegetable oils have a composition of fatty acids that varies according to the species and the climatic characteristics of the area where the plant is located; the fatty acids themselves, in turn, vary their properties according to their chemical structure.

In this regard it is useful to point out that fatty acids are made up of long carbon chains that may have single carbon-carbon bonds (saturated fatty acids), just one double carbon-carbon bond (monounsaturated fatty acids), or a plurality of double carbon-carbon bonds (polyunsaturated fatty acids).

The presence of single or double carbon-carbon bonds influences the resistance to high temperatures and to the oxidative degradation of vegetable oils, making them more or less suitable for frying food products.

In this regard it is emphasized that, today, use of palm oil is widely used in cooking due to its peculiar characteristics of resistance to high temperatures and oxidative degradation arising from the high concentration of saturated fatty acids.

However, the high presence of saturated fatty acids represents a risk to the health of consumers, as these substances facilitate accumulation of cholesterol, increasing the risk of incurring cardiovascular diseases.

In addition, recent studies have shown that the consumption of saturated fatty acids is strictly implicated in the onset of diseases such as: breast, prostate, ovarian and colon cancer, as well as having harmful effects on the bones.

Added to this is the fact that the prolonged exposure to high temperatures,

reached during the frying process, triggers a series of chain reactions that lead to degradation of fatty acids in polar substances comprising, for example, peroxides, carbonyl derivatives, polymerized fatty acids and others; these substances, besides being detrimental to the health of consumers, give rise to the alteration of vegetable oil organoleptic characteristics, leading to the so-called "rancidity" of the same.

Furthermore, the prolonged use of oil together with the degradation of fatty acids causes the formation of foam, which negatively affects the final quality of the frying and the food taste.

At the end of the cooking or frying process, vegetable oils, in addition to emanating unpleasant odors in the surrounding environment and transferring them to the finished product, have unpleasant tastes that weigh down palatability and flavor thereof.

In fact, the vegetable oils of known type are free of flavoring components intended for compensating any unpleasant tastes arising from oxidative degradation and adapted to increase palatability and pleasantness thereof.

This is particularly felt in the confectionery sector, where the increase of taste and flavor is a fundamental aspect influencing the oil choice by the consumers.

In this regard, in many sectors of industrial and commercial activities, the need is known to be particularly felt to renew products and to steadily search for new ones in order to distinguish such products from those of the competitors.

At the same time, vegetable oils rich in polyunsaturated fatty acids, despite being in themselves less harmful to the health of consumers, do have a reduced resistance to high temperatures and to oxidative degradation; this means that exposure, even for short periods, at high temperatures leads to the formation of substances which are harmful to the health of consumers.

In addition, the reduced resistance to oxidative degradation forces the consumer to frequently change the vegetable oil, not being able to reuse it for several frying cycles, which implies an economic expenditure of a not negligible amount.

Description of the Invention

The main aim of the present invention is to devise a composition of edible oil, particularly for use in frying and cooking of foods, which has high resistance to high temperatures and to oxidative degradation.

Within this aim, one object of the present invention is to devise a composition of edible oil, particularly for use in frying and cooking of foods, which can be used for several frying cycles, leading to significant savings for the consumer and, at the same time, without the risk of incurring substances which are harmful to the health of the same.

Another object of the present invention is to devise a composition of edible oil, particularly for use in frying and cooking of foods, which is pleasant and tasty from the point of view of palatability and taste.

A further object of the present invention is to devise a composition of edible oil, particularly for use in frying and cooking of foods, which, even after prolonged exposure to high temperatures, slows down the degradation of fatty acids into substances which are harmful to the consumer's health.

Yet another object of the present invention is to devise a composition of edible oil, particularly for use in frying and cooking of foods which performs a non-covering flavoring function with respect to the finished fried product, thus avoiding the transfer of unpleasant odors and tastes.

A further object of the present invention is to devise a composition of edible oil, particularly for use in frying and cooking of foods, which can be used, specifically but not by way of limitation, in the confectionery sector.

Another object of the present invention is to devise a composition of edible oil, particularly for use in frying and cooking of foods, which allows overcoming the aforementioned drawbacks of the prior art within the scope of a simple, rational, easy, efficient to use and cost-effective solution.

The aforementioned objects are achieved by the present composition of edible oil, particularly for use in frying and cooking of foods, having the characteristics of claim 1.

Brief Description of the Drawings

Other characteristics and advantages of the present invention will become more evident from the description of a preferred, but not exclusive embodiment of a composition of edible oil, particularly for use in frying and cooking of foods, illustrated by way of an indicative, but non-limiting example, in the attached drawings in which:

Figures 1-4 are representative graphs of the oxidative degradation stability study carried out on the composition according to the invention.

Embodiments of the Invention

This description relates to a composition of edible oil, particularly for use in frying and cooking of foods, usable for home and/or industrial frying processes. The composition comprises high oleic sunflower seed oil, at least a first natural extract rich in tocopherols and at least a second natural extract obtained from Rutaceae.

In the context of the present discussion by "high oleic" sunflower seed oil is meant an oil extracted from sunflower seeds of the type known as "high oleic" and from which an oil is obtained which has a higher oleic acid concentration than the percent composition of fatty acids of the "conventional" sunflower seed oil.

In this regard, it is useful to point out that a common sunflower seed oil has an oleic acid concentration of between 14% and 39.4% and is however rich in linoleic acid and for this reason referred to as "high linoleic".

The high oleic sunflower seed oil, on the other hand, comprises oleic acid present in a concentration higher than 70% and on average around 80%.

With reference to a preferred embodiment, the high oleic sunflower seed oil comprises oleic acid in a concentration by weight substantially equal to 75%. In detail, oleic acid (cis-9-octadecenoic acid) is a monounsaturated fatty acid belonging to the category of omega-9, i.e. essential fatty acids of fundamental metabolic importance for the human body, with a carboxylic group and a carbon chain of 18 carbon atoms having a single cis double bond, which is placed, with respect to the methyl group, between the carbon in position 9 and the carbon in position 10.

As is known to the person skilled in the art, high oleic sunflower seed oil has a composition of fatty acids which varies according to the environmental conditions in which the plant grows.

The first natural extract rich in tocopherol comprises natural mixed tocopherols.

According to a preferred embodiment, the natural extract rich in tocopherol is of the E306 type.

Preferably, the first natural extract is present in a concentration by weight comprised between 200 ppm and 1800 ppm.

Advantageously, the first natural extract is present in a concentration by weight comprised between 300 ppm and 1500 ppm. Conveniently, the first natural extract is present in a concentration by weight comprised between 400 ppm and 800 ppm.

As is known to the person skilled in the art, tocopherols are composed of an aromatic ring and a long isoprenoid chain.

In the specific case, tocopherols are biological antioxidants in which the phenolic groups present on the aromatic ring, act as terminators of the radical oxidation reaction thanks to high reactivity thereof; this allows to destroy the most reactive forms of the oxygen radicals and other free radicals, thus protecting the fatty acids from oxidative degradation.

In this regard it is useful to point out that the term "tocopherol" is used in its collective meaning to indicate four forms of tocopherols, different from each other by the number and position of the methyl groups on the aromatic ring, listed in Table 1 : a-toco herol, β-tocopherol, γ-tocopherol, δ-tocopherol.



Table 1

With reference to the second natural extract, the Rutaceae comprise three

genera: Citrus, Fortunella and Poncirus trifoliata.

Preferably, the second natural extract is obtained from at least one of: orange, lemon, grapefruit, mandarin, pomelo, cedar, Clementine, bergamot, chinotto, kaffir lime, lime and bitter orange.

In other words, the second natural extract is obtained from the genus Citrus. Alternative embodiments cannot however be ruled out, wherein the second natural extract is obtained from Fortunella or Poncirus trifoliata.

Specifically, the genus Fortunella comprises: Fortunella crassifolia, Fortunella hindsii, Fortunella japonica, Fortunella margarita, Fortunella obovata, Fortunella polyandra.

Alternative embodiments cannot however be ruled out, wherein the composition also comprises a third, a quarter, etc. natural extracts obtained from Rutaceae and combined with each other.

For example, the making cannot be ruled out of a composition also comprising a third and a fourth natural extract obtained respectively from one of orange, lemon, grapefruit, mandarin, pomelo, cedar, Clementine, bergamot, chinotto, kaffir lime, lime and bitter orange.

In detail, the second natural extract comprises at least one of: citric acid, limonene and linalyl acetate.

It cannot also be ruled out that the composition also comprises a third natural extract obtained from Vanilla planifolia.

Preferably, the second natural extract is present in a concentration by weight comprised between 0.1 ppm and 40 ppm.

Advantageously, the second natural extract is present in a concentration by weight comprised between 1 ppm and 20 ppm.

Conveniently, the second natural extract is present in a concentration by weight comprised between 2 ppm and 5 ppm.

With special reference to a preferred embodiment, the second natural extract is obtained from bergamot.

Furthermore, the composition is palm oil free.

EXAMPLE 1

A composition of edible oil was made, particularly for use in frying and

cooking of foods, comprising high oleic sunflower seed oil mixed with the first natural extract rich in tocopherols, and the second natural extract obtained from Rutaceae.

Specifically, the second natural extract is obtained from bergamot.

The aforesaid composition comprises 1 1. of high oleic sunflower seed oil, the first natural extract rich in tocopherols and the second natural extract obtained from bergamot in the following concentrations by weight:

first natural extract rich in tocopherols 550 ppm

second natural extract obtained from bergamot 3 ppm

As will be better described below, the composition thus obtained has a very high resistance to oxidation expressed by the so-called "OSI time" (oxidative stability index) expressed in hours, also known as induction time; in other words, this parameter expresses the resistance to oxidation and, therefore, to oil rancidity.

In this regard it is useful to point out that by the term "OSI time" is meant the time interval between the beginning of the oxidative degradation process and the occurrence of the products arising from this reaction.

In detail, to assess the oxidative stability of the composition, different samples of oil were compared to each other, having different characteristics:

- sample no. 1 (high oleic sunflower seed oil);

sample no. 2 (high oleic sunflower seed oil, natural extract rich in tocopherols and rosemary extract); and

sample no. 3 (high oleic sunflower seed oil, natural extract rich in tocopherols);

- sample no. 4 (high oleic sunflower seed oil, natural extract rich in tocopherols, bergamot essential oil in the percentage of 0.3%);

sample no. 5 (high oleic sunflower seed oil, natural extract rich in tocopherols, bergamot essential oil in the percentage of 0.1%);

- sample no. 6 (high oleic sunflower seed oil, natural extract rich in tocopherols, bergamot essential oil in the percentage of 0.03%);

sample no. 7 (high oleic sunflower seed oil, natural extract rich in tocopherols, citrus mix essential oil in the percentage of 0.03%);

sample no. 8 (high oleic sunflower seed oil, natural extract rich in tocopherols, citrus mix essential oil in the percentage of 0.3%).

In order to make a comparison on the oxidative stability, the different samples were subjected to forced oxidation, using a heat flow and an air flow under standardized and controlled conditions.

To perform this analytical determination, the 8-channel Oxidative Stability Instrument (OSI) was used (Omnion, Decatur, Illinois, USA).

This instrument comprises an aluminum alloy heating block, provided with 8 housings for the introduction of glass tubes containing the sample, and other 8 housings for the respective housing of as many polycarbonate tubes filled with de-ionized water and containing an electrode.

Inside the sample an air flow is bubbling, the latter leads the volatile organic acids (especially formic acid), formed as terminal products of the oxidative process, to solubilize in the de-ionized water, where variation of conductivity over time is measured by the electrodes (Bendini et al., 2001).

The assessment of oxidative stability is expressed based on a time interval (hour and hundredths of an hour); it indicates the end time of the induction step of the oxidation process, under analysis conditions, and is referred to as OSI time. All of the samples were subjected to forced oxidation at 110 °C with a constant air flow of 150 ml/min.

The table below (Table 2) shows the data related to the OSI analysis on oil samples.


Table 2

Based on the data obtained it is possible to observe how different oil samples show different sensitivity to oxidative stress.

Broadly speaking, significant differences are noted between OSI times recorded on samples of high oleic sunflower seed oil (SAMPLE No. 1) compared to those formulated with different content of substances with an antioxidant and aromatic effect (SAMPLES No. 2-8).

It is pointed out how the combination of the first natural extract rich in tocopherols and the second natural extract obtained from bergamot shows an unexpected effect.

Indeed, sample no. 4 shows an unexpected improvement in OSI time compared to samples no. 5, 6, 7 and 8.

It should be noted that in samples no. 7 and 8, in addition to the aromatic component characteristic of the genus Citrus, there is a greater amount of tocopherol compared to samples 2, 3, 4, 5 and 6.

Specifically, the aromatic component of the genus Citrus has an amount of tocopherol belonging to different classes for a total tocopherol and squalene titer equal to 40,000 mg of tocopherol and 40,000 mg of squalene per kilo (Kg) of product respectively.

This means that the synergistic combination of the first natural extract rich in tocopherol with the second natural extract obtained from bergamot has an unexpected antioxidant effect even compared to samples having higher antioxidant titer.

Furthermore, oxidative stability was assessed using the Oxidative Stability Instrument (OSI) of frying oils.

In detail, a comparison was made between the composition of Example 1 (hereinafter referred to as 1A) and a composition of frying oil (hereinafter referred to as IB) comprising high oleic sunflower seed oil, natural extract rich in tocopherol (E306) in a concentration by weight substantially equal to 275 ppm, and rosemary extract (E392) in a concentration by weight substantially equal to 325 ppm.

The OSI Time values were then measured on the aforementioned samples before a frying cycle, and at the end of the frying cycle.

This frying cycle was repeated continuously for 5 days and comprises the following operating steps:

a pre-heating step having a duration of 60 min;

a first frying step having a duration of 4 min;

- a first interval having a duration of 15 min;

a second frying step having a duration of 4 min;

a second interval having a duration of 15 min;

a third frying step having a duration of 4 min;

a final heating step having a duration of 60 min.

Table 3 and Figure 1 show the values measured on each oil sample before frying (TQ) and at the end of the three frying cycles on days 1-3-5 (Tl, T3, T5).


Table 3

The OSI analysis conducted on oil as such, i.e. TQ, has found a higher OSI time for the sample IB compared to the sample 1A, from a time of 29.53 OSI hours to 24.28 hours as found on the product as such.

After that, upon increasing the heat- oxidation time, a progressive decrease in the OSI time occurs.

Surprisingly, there is a passage from 21.43 hours to 1.18 hours for the sample IB and from 22.38 hours to 1.73 hours for the sample 1A.

Specifically, as shown in Figure 1, the sample 1A at T3 has an oxidative stability twice higher than the sample IB.

Furthermore, at the end of the frying cycle, the sample 1A shows an oxidative stability higher than the sample IB by a value substantially equal to 47%.

Sample 1A and sample IB were subjected to an analysis aimed at assessing hydrolytic stability by determining free acidity (FFA) of frying oils.

Free acidity is an important indicator of the hydrolysis level of a fatty substance during each stage of the transformation processes, i.e. of the frying steps.

Table 4 and Figure 2 show the percentages of free fatty acids (FFA) measured in percentage of oleic acid before the frying cycle (TQ) and at the end of the three frying cycles (Tl, T3 and T5) respectively on days 1, 3 and 5.

Table 4

Also in this case, the synergistic combination of the extract rich in tocopherols with the bergamot extract causes an unexpected decrease in the percentage of fatty acids present at the end of the frying cycle.

Sample 1A and sample IB were subjected to an assessment regarding the formation of polar compounds during the frying cycles.

The aforementioned type of analysis represents a further indicator of oil deterioration state.

Table 5 and Figure 3 show the amount of polar compounds (TPM) measured in percentages (%) on the sample as such (TQ) and at the end of the fifth day of the frying cycle (T5).

Table 5

It is possible to notice how the percentage value of TPM, which was found for frying oil mixtures, is subjected to a progressive increase during the days on which trials are being performed.

Also in this case, the synergistic combination of the first extract rich in tocopherols with the second natural extract obtained from Bergamot causes an unexpected decrease in the formation of polar compounds during the frying cycles.

Specifically, it is noticed how the percentage value of TPM, which was found for frying oil mixtures, is subjected to a progressive increase during the days on which trials are being performed.

In fact, there is a passage from 3.0% detected on the first day (TQ), to 18.63% found during the last day of the frying cycle (T5) for sample 1A respectively, and from 3.0% to 22.34% on the first day (TQ) and on the fifth day of the frying cycle (T5) respectively.

Finally, the sample 1A and the sample IB were subjected to a test for the determination of the smoke point using the Cleveland instrument.

The determination of the smoke point of a fatty substance relates to the identification of the lowest temperature at which the fatty substance must be heated to emit smoke in a continuous way.

This determination is aimed at assessing the degradation state of an oil subjected to heating which is hydrolysed in glycerol and fatty acids due to temperature action.

In detail, oil degradation occurs then by transformation of glycerol (with loss of water) into acrolein (acrylic aldehyde).

This last formation is greater the more the oil is rich in unsaturated fatty acids

(more sensitive to heat) and determines the point of smoke in question.

Table 6 and Figure 4 show the smoke points found on the sample 1 A and sample IB.

Table 6

Based on data analysis a higher smoke point value may be noticed for the sample 1A compared to the sample IB, thus being shown a valid protective effect which is higher with respect to heat- degradation processes.

It has in practice been found that the described invention achieves the intended objects.

The particular precaution of providing for the combination of a natural extract rich in tocopherols with a natural extract obtained from Rutacee, and according to a preferred embodiment obtained from bergamot, allows fully preventing the formation of foam and rancidity of the finished cooked or fried product in the composition itself.

To this must be added that, thanks to the high stability during frying and resistance to oxidative degradation arising from high temperatures, the aforementioned combination of components considerably reduces the total oil absorption by the finished product.

By way of a non-limiting example, the composition according to the invention when used for frying pastry products allows obtaining crispy and dry products, which are light in appearance and extremely light in taste and palatability.

In addition, the aforementioned composition, even in consideration of long use times, overcomes the drawback of odorous emissions in the environment and transferring thereof to the finished product, thus preventing flavors from being transferred and product color from being altered.

Finally, the synergistic combination of the first natural extract, resulting rich in tocopherols, along with the second natural extract obtained from bergamot, determines a considerably lower smoke point than eligible oil compositions of the known type.