Technical field

The invention relates to the food field. In particular, the present invention relates to the field of snacks, for example salted snacks, and to the processes for the production thereof.

Background art

Many types of snacks based on starchy products are known, for example based on potato starch. The known snacks, however, have the problem that for having an appetizing taste they must generally have a relatively high content of salts, fats and sugars.

To date, snacks in which at least one part of the starchy products (for example, potato flour or starch) has been replaced with ingredients deriving from other vegetable ingredients, for example vegetables different from tubers such as, for example, carrot are also known. For producing such snacks, is known the use of vegetables or fruits previously treated and reduced in the form of flour of the vegetable used; thereby it is possible to replace part of the potato flours with vegetable flour and to reduce the amount of starches in the final product. However, the so-obtained products don’t have good taste, unless bringing the content of salt, sugar and fats to an analogous or greater level than that of the snacks based on starchy products only.

In summary, the known snacks have, in general, the problem of high content of salts, fats and sugars. On the other hand, the snacks with reduced content of salts, fats, sugars and, more in general, with reduced caloric intake, are usually poor or lacking in taste, aspect and texture characteristics required by the user.

EP 2117350 describes a process for producing snacks containing“vegetable materials” in the form of small pieces or flour obtained from a pre-gelatinized tapioca starch in the whole or for the most part. Despite this document describes a relatively high theoretical content of vegetable material in small pieces in the final product (i.e. the expanded product), it is sufficiently described only one example with carrot content of about 15%. The final product (snack) obtained from pre-gelatinized flours is anyway very dense, generally about 0.6 - 0.9 g/cc, and thus poorly appetizing. Therefore, there is the need to provide a snack which in its final form contains a significant amount of vegetable material, having at least palatable taste, with natural tastes and being expanded enough to be appetizing.

Summary of the invention

Purpose of the present invention is to solve the problems discussed above and to provide a snack with natural tastes and which is appetizing.

Another purpose of the present invention is to provide a snack having high organoleptic properties and having palatable taste.

Still another purpose of the present invention is to provide a production process allowing to obtain a final product having the above discussed characteristics.

These and other purposes are achieved by a snack according to claim 1. The snack according to the present invention can be obtained through a process according to claim 7.

The present invention further relates to an unexpanded gelatinized product according to claim 11.

Detailed description

In the following description, the characteristics of the present invention will be described with reference to exemplary embodiments; however, each of the characteristics herein described can be combined with one or more other characteristics herein described, providing further embodiments of the present invention. Such embodiments must be considered described by the present description.

As mentioned above, an object of the present invention is a snack comprising at least one starchy material and macroparticles of at least one vegetable material. Preferably, the vegetable material is selected among vegetables and fruits.

According to an aspect of the present invention, at least part of the macroparticles of vegetable material is visible to the naked eye; furthermore, in the snack of the present invention, the macroparticles of vegetable material are dispersed in the starchy material.

As used herein, the term“starchy material” is referring to a material having high starch content, i.e. a content of at least 30 g starch on 100 g material before the beginning of the production process of a snack. Examples of starchy material are tubers, for example potato and Jerusalem artichokes, cereals (for example durum wheat, wheat, kamut, rye, barley, spelled, rice, corn, millet, sorghum and oats) other plants considered pseudo-cereals (i.e. plants which, although not belonging to the Gramineae family, can be used for food use, such as buckwheat, quinoa, amaranth and chia) and the materials derived therefrom such as, for example flours, ground and extracted products. Preferred flour is the potato flour, or potato starch.

In embodiments of the present invention, one or more starchy ingredients can be used, preferably in the form of flour, ground material or their mixtures, to produce a snack according to the present invention.

As used herein, the term“macroparticles of vegetable material” refers to corpuscles or portions with reduced size, but visible to the naked eye, of at least one vegetable material, preferably different from the starchy material discussed above. According to the present description, macroparticles visible to the naked eye can be single corpuscles, i.e. single monolithic or substantially monolithic particles, or else particle agglomerates the size of which are smaller than those of the aggregate, or else colored areas obtained from the disintegration of the vegetable material during the processing to achieve the final snack; such disintegration occurs for example, during the expansion step of the gelatinized product.

In embodiments, the final product, i.e. the snack after expansion by cooking, has a lower number of macroparticles visible to the naked eye than the dried product from which it has been obtained.

Examples of “vegetable material” according to the present invention are vegetables and fruits. Examples of vegetables suitable to be used in the present invention are carrots, broccoli, cauliflower, celery, bell peppers, tomatoes, zucchini, pumpkin, spinach, beetroot, sugar beet, asparagus, fennel, onion, spring onion, leek, garlic, eggplant, artichokes, aromatic vegetables such as mint, rosemary, sage and their mixtures. Examples of fruits usable in the present invention are apples, pears, lime, lemon and citrus fruits, apricots, peaches, bananas, cherries, grapes, strawberries, blueberries, blackberries, raspberries, melon, watermelon, cocoa and coffee and their mixtures. Advantageously the coffee is added to the starchy material as unroasted coffee beans, i.e. without having been previously toasted. Advantageously, two or more vegetable materials can be combined and used in making the same snack.

For example, a first vegetable material can be used as vegetable base material, i.e. vegetable material adapted to provide a specific flavor and/or aspect and/or nutritional value to the finished product, whereas a second vegetable material can be used to enrich the flavor in the finished product, and/or to provide one or more aromas to the snack.

Examples of combinations of two vegetable materials are carrot and onion, sugar beet and mint, bell pepper and spring onion, pumpkin and rosemary, spinach and garlic.

When two or more vegetable materials are used, the snack comprises macroparticles visible to the naked eye of at least one of the vegetable materials used, for example, of at least the vegetable base material.

According to embodiments, the macroparticles of vegetable material are at least in part macroparticles of a vegetable material used in the process of the invention in the form of untreated vegetable.

In other words, according to embodiments, the macroparticles of vegetable material are at least in part macroparticles deriving from untreated vegetable material.

As used herein, the term“untreated” refers to a vegetable material, for example vegetables or fruits, in which the initial state of the fresh vegetable material has not been substantially altered. In other words, a vegetable or fruit is considered“deriving from untreated vegetable material” if, prior to being used in the process of the invention, it has not been subjected to processes which have altered its original characteristics such as, for example, amount of fibers, water content, protein content, etc.

In particular, the term“untreated” refers to a fresh and/or raw vegetable material, for example fresh and/or raw vegetables or fruits. For example, fresh vegetables can be used in the process of the invention. Advantageously, the vegetable material is added to the matrix after being washed, if necessary cut into coarse pieces. The material is not necessarily treated except, if necessary, having been deprived of the seeds or other parts which give problems during extrusion; the vegetable material is generally still provided with own peel which will provide part of the visible macroparticles in the final product.

For example, carrot macroparticles can be included inside a snack according to the invention by using, in the production process, whole raw carrots. For example, a fresh and raw carrot can be washed, optionally cut into coarse pieces, and directly used in the production process of the snack. At the end of the production process of the snack, a snack will be obtained comprising carrot macroparticles, visible to the naked eye, deriving from an untreated carrot.

According to embodiments, the macroparticles of vegetable material can be at least in part macroparticles of a treated vegetable material.

Examples of treated vegetable materials are lyophilized, dried vegetable materials and their mixtures.

According to embodiments, in addition to the untreated vegetable material described above, in the snack there can be vegetable material in the form of macroparticles of a treated vegetable material, for example by lyophilization.

Advantageously, the snack according to the present invention has high organoleptic and nutritional properties, but also an intense and palatable taste.

In fact, it was surprisingly observed that the inclusion of macroparticles in the snack of at least one vegetable material, for example a vegetable, dispersed in the starchy material, and at least in part visible to the naked eye, allows to obtain a snack with an optimal taste, a particularly appetizing aspect and in which the original flavor of the vegetable material contained therein can be recognized. Such result can allow to reduce the content of salts, fats and sugars of the snack as the product is very much appetizing per se. In embodiments, there can be an extremely low content of salt, fats and sugars, for example in the order of 0.5% by weight salt and 1.5% by weight oil in the semi-finished product (pellet), before toasting or frying.

Typically, the snack according to the invention can have a content of iron (Fe), total phosphorus (P) magnesium (Mg) and potassium (K) in the following ranges: iron (Fe) between 30 and 80 mg/kg, preferably between 40 and 70 mg/kg, measured according to the UNI EN 13805:2014 + UNI EN 15763 :2010 standard regulations; total phosphorus (P) between 700 and 1700 mg/kg, preferably between 800 and 1500 mg/kg, measured according to the UNI EN 13805:2014 + UNI EN 15763 :2010 standard regulations;

magnesium (Mg) between 300 and 900 mg/kg, preferably between 400 and 800 mg/kg, measured according to the UNI EN 13805:2014 + UNI EN 15763 :2010 standard regulations;

potassium (K) between 5000 and 13000 mg/kg, preferably between 7000 and 1200 mg/kg, measured according to the UNI EN 13805:2014 + UNI EN 15763 :2010 standard regulations.

The values of iron (Fe), total phosphorus (P) magnesium (Mg) and potassium (K) mentioned above have to be considered independent of each other.

For example, a snack according to the invention, for example comprising spinach macroparticles, after the expansion by toasting (baking), can have a content of iron (Fe) between 50 mg/kg and 75 mg/kg, total phosphorus (P) between 1000 mg/kg and 1700 mg/kg, magnesium (Mg) between 500 mg/kg and 800 mg/kg, and potassium (K) between 8000 mg/kg and 13000 mg/kg, measured as mentioned above.

In another example, a snack according to the invention, for example comprising spinach macroparticles, after an expansion by frying, can have a content of iron (Fe) between 30 mg/kg and 50 mg/kg, total phosphorus (P) between 700 mg/kg and 1200 mg/kg, magnesium (Mg) between 300 mg/kg and 600 mg/kg, and potassium (K) between 5000 mg/kg and 9000 mg/kg, measured as mentioned above. According to embodiments, the amount by weight of the vegetable material in the snack is between 20% and 50%, preferably between 30% and 50%, more preferably between 35% and 45%. For example, in embodiments, the snack of the present invention can contain about 38% and up to 44% by weight of vegetable material, with respect to the total weight of the snack.

As mentioned above, according to an aspect of the present invention, at least part of the macroparticles of vegetable material of the snack is visible to the naked eye.

In other words, looking at the snack, even intact, from the outside, it is possible to see, to the naked eye, at least part of the macroparticles of vegetable material comprised in the snack. For that purpose, the product has macroparticles made of vegetable material and/or colored areas obtained by the destruction of the vegetable material whose size is at least 0.1 mm, preferably at least 0.5 mm, more preferably at least 1 mm; in other words, the size of at least part of the macroparticles in the final product is at least 0.1 mm, preferably at least 0.5 mm, more preferably at least 1 mm.

Advantageously, this allows the consumer to immediately recognize the actual presence of at least one vegetable material which is not deriving from flours (for example, carrot or sugar beet corpuscles), and to be able to appreciate the high content of such vegetable material inside the snack.

According to the present invention, the macroparticles of vegetable material are dispersed in the starchy material. In other words, the macroparticles are kneaded with the starchy material, i.e., are included inside the dough used to make the snack.

According to embodiments, at least part of the macroparticles of vegetable material in the snack has dimensions, in general a length, between 5 mm and 0.1 mm, preferably between 4 mm and 0.5 mm, more preferably between 3 mm and 1 mm. In embodiments, in the snack according to the present invention (in particular, in a single piece) there are at least 3, preferably at least 4, macroparticles visible to the naked eye of size at least of 0.5 mm, preferably at least 1 mm, more preferably at least 2 mm, even more preferably at least 3 mm. In embodiments, in the snack according to the present invention (in particular, in a single piece,) there are at least 10 macroparticles visible to the naked eye, of which at least 4 macroparticles have size of at least 1 mm, preferably at least 2 mm, more preferably at least 3 mm.

As mentioned above, macroparticles visible to the naked eye can be single corpuscles, i.e. single particles, or else particle agglomerates having smaller size, or else colored areas obtained by the destruction of the vegetable material, for example, during the expansion step. The original flavor of the vegetable material, for example a vegetable, inside the snack, is particularly intense and recognizable.

As mentioned above, according to an embodiment of the present invention, at least part of the macroparticles inside the snack derives from a fresh, i.e. untreated, vegetable material, contrary to the known technique which provides the use of flours. The matrix of starchy material is pre-gelatinized during the extruding step, forming a structure able to expand during the cooking step (e.g. in the oven or by frying). Advantageously, the use of fresh vegetable materials, for example fresh vegetables or fruits, allows to obtain a snack having high nutrient content, intense and palatable taste also with low content of salts, fats and sugars. Advantageously, the snack according to the invention turns out to be particularly crunchy, however without presenting an unpleasant level of hardness to chewing.

An instrumental evaluation of the texture has been carried out, in order to evaluate the crunchiness and the hardness of the snack of the invention. The same analyses have been carried out on an analogous snack, free from macroparticles of vegetable material. The instrumental evaluation of the texture is a consolidated analytical practice which allows to express sensorially perceived properties (to the touch, palatability) in a quantitative way, and to investigate the structure properties of the food materials (TEXTURE IN FOODS (2004). B. M. McKenna, David Kilcast (eds), Woodhead Publishing).

The analysis has been carried out by TEXTURE ANALYZER (TAXTplus, Stable Micro System).

Herein below are the test conditions:

PROBE: Ottawa Cell with wire plate code A/wir

TEST MODE: Compression

PRE-TEST SPEED: 2 mm/s

TEST SPEED: 2 mm/s

POST-TEST SPEED: 10 mm/s

TRIGGER FORCE: 250 g

DATA ACQUISITION: 200 PPS

The Ottawa cell is a parallelepiped with a grate at the bottom. In the Ottawa cell a sample mass having constant weight (10 g) is loaded. The material is then compressed by a piston. The end-of-test criterion was: 33% deformation of the pre compressed mass to uniform the loading surface.

For each sample 5 replicas of the test were carried out.

The test allowed to determine the following parameters:

- compression work (g x mm), which expresses the sensory characteristic of crunchiness; - apparent elasticity index (g/mm), which expresses the sensory characteristic of hardness perceived by chewing/breaking.

The results obtained showed that the snack according to the invention is crunchier and, at the same time, less hard than the analogous products free from vegetables, i.e. free from macroparticles of vegetable material.

Furthermore, the use of fresh vegetable materials, for example fresh vegetables or fruits, allows to reduce the amount of water needed for the production process. In addition, since the vegetable material is not subjected to preliminary treatments (for example, drying) the energy consumption of the production process is reduced.

Another object of the present invention is a production process of a snack according to the present invention, comprising the following steps:

a. preparing a mixture comprising at least one starchy material and macroparticles of at least one vegetable material, in which at least part of said macroparticles is visible to the naked eye,

b. gelatinizing the starchy material present in said mixture in the presence of said macroparticles, to obtain a gelatinized product;

c. drying the gelatinized product, to obtain a dried product; and d. expanding the dried product, preferably by frying or toasting.

The toasting generally occurs in oven. Advantageously, the process of the present invention allows to avoid a step of pre-gelatinizing the starch in the starchy material, thus reducing the energy consumption with respect to known processes.

In fact, as mentioned above, according to an aspect of the present invention, the step of gelatinizing the starchy material is directly carried out on the mixture of starchy material and macroparticles of vegetable material. In other words, advantageously, the step of gelatinizing the starch is carried out in the presence of the macroparticles of vegetable material, to obtain a gelatinized product. Advantageously, such gelatinized product will include macroparticles of a vegetable material, preferably at least part deriving from an untreated vegetable material, i.e. a fresh vegetable material before the step of gelatinizing.

According to embodiments, the macroparticles are at least in part macroparticles of an untreated vegetable material. Advantageously, the use of untreated vegetable material, allows to reduce the production time, with respect to known processes. In fact, the use of fresh vegetable material allows to avoid the pre-treatment of the vegetable material, for example the addition of water to a lyophilized material before mixing it with a starchy material.

According to embodiments, the mixture of at least one starchy material and macroparticles of at least one vegetable material can be obtained and heated by techniques known per se.

According to embodiments, the macroparticles are at least in part macroparticles of an untreated vegetable material. In addition or in alternative to the macroparticles of untreated vegetable material, the mixture can comprise macroparticles of treated vegetable material.

For example, the mixture can comprise one or more lyophilized, dried vegetable materials, or their mixtures.

For example, an untreated vegetable material, for example a fresh vegetable, can be chopped and mixed to a flour, for example potato flour, optionally by adding water, to obtain a mixture comprising a starchy material (i.e. the potato flour) and macroparticles of the vegetable material. The so-obtained mixture is gelatinized according to known techniques, for example by boiling or extrusion. This way, a gelatinized product containing macroparticles of at least one vegetable material can be obtained. A suitable gelatinizing technique is to extrude the mixture described above, possibly by heating it, until obtaining the required gelatinization of the starch.

According to embodiments, the vegetable material in said mixture is present in an amount between 25% and 65% by weight, preferably between 30% and 55% by weight, more preferably between 32% and 48% by weight with respect to the weight of the mixture.

According to embodiments, the step of gelatinizing the starch present in the mixture comprises an extruding step, optionally an extruding and heating step. The heating can be obtained by friction of the mixture in a suitable extrusion cylinder. The extrusion and extrusion-heating (i.e. the cooking by extrusion) are processes known per se. In this case, advantageously, the vegetable material, preferably fresh, i.e. preferably untreated, can be added with at least one starchy material (for example, one or more tubers and/or cereals flours), and optionally water, inside the extruder.

Advantageously, when the vegetable material is at least in part a fresh vegetable material, i.e. untreated, such fresh vegetable material will be able to be added inside the extruder after being washed and possibly cut into coarse pieces, without the need of being preliminary treated and/or preliminary chopped. In fact, advantageously, the reduction of the vegetable material to macroparticles can occur inside the extruder, i.e. during the extruding step.

For example, a carrot will be able to be added raw, intact, or else, optionally, cut into pieces in the extruder. Advantageously, the size of such pieces is reduced during the extrusion process, for example during the cooking-extrusion process.

According to embodiments of the process of the present invention, the step of extruding comprises a step of reducing the size of said macroparticles made of vegetable material .

For example, in embodiments, the extruding step allows to obtain macroparticles made of vegetable material whose size is at least 3 mm, preferably at least 4 mm, more preferably at least 5 mm.

According to embodiments, the step of gelatinizing is carried out at a temperature between 80°C and l50°C, preferably between H0°C and l40°C, more preferably between l20°C and l30°C.

According to embodiments, the step of gelatinizing is carried out for a time between 15 minutes and 75 minutes, preferably between 30 minutes and 60 minutes, more preferably between 40 minutes and 50 minutes.

Advantageously, when the gelatinizing step comprises an extruding step, the gelatinizing step can be carried out for a time between 30 seconds and 120 seconds, at a suitable temperature to obtain the starch gelatinization. When the gelatinizing step comprises an extruding step, the production times of the snack are significantly reduced. Times and temperatures of the gelatinizing step (for example, of the hot extrusion step) will be able to be adjusted according to the components used in the mixture and/or the technique used to carry out such gelatinizing step.

For example, times and temperatures will be able to be adjusted in relation to the amount of untreated vegetable material (i.e. fresh) in the mixture, and/or the type of starchy material used.

At the end of the gelatinizing step, preferably the extruding step, more preferably the cooking-extruding step, a gelatinized product is obtained. Such gelatinized product is an unexpanded gelatinized product, i.e. which has not been subjected to expansion (for example has not been fried or toasted). The starch gelatinization is a process known per se.

According to an aspect of the present invention, the gelatinized product comprises macroparticles of at least one vegetable material, in which at least part of the macroparticles of vegetable material is visible to the naked eye, and such macroparticles are dispersed in the starchy material. Preferably, at least part of the macroparticles is deriving from at least one untreated vegetable material, i.e. derives from at least one vegetable material which has been subjected to the gelatinizing step in the untreated form, i.e. fresh.

The gelatinized product can be subsequently dried and expanded, for example through frying or toasting, to give a finished product, i.e. a snack.

The gelatinized product, optionally dried at least in part, can be subsequently preserved and expanded. For example, the gelatinized product, optionally dried at least in part, can be packed and delivered to whom will carry out the final processing, until obtaining the final product, i.e. a snack.

According to embodiments, the process of the present invention further comprises a step of reducing the thickness of said gelatinized product. Optionally, such gelatinized product can be dried in part before the step of reducing the thickness.

The gelatinized product, which comprises macroparticles of at least one vegetable material, can be treated with techniques known per se with the purpose of obtaining a thickness reduction of such gelatinized product. The thickness of the gelatinized product can be reduced through techniques known per se. Known techniques are for example those described in the Italian Paten Application ITPD20090371, herein incorporated for reference. In particular, the Italian Paten Application ITPD20090371 describes a hot calendering process of a gelatinized product, allowing to obtain a thickness reduction of such gelatinized product. The calendering step is described in detail, for example, in the steps herein incorporated for reference from page 8 raw 21 to page 10 raw 4 of the mentioned Italian Paten Application.

For example, the preferably extruded gelatinized product can have a thickness between 0.8 mm and 1.5 mm, preferably between 0.9 mm and 1.3 mm, more preferably between 1 mm and 1.2 mm.

For example, the thickness of gelatinized product can be reduced to a size between 0.4 and 0.9 mm, preferably between 0.5 mm and 0.8 mm, more preferably between 0.6 mm and 0.8 mm.

According to embodiments, in the step of reducing the thickness of the gelatinized product, the thickness of such gelatinized product is reduced so as to obtain a thickness reduction between 10% and 80%, preferably between 40% and 60% with respect to the initial thickness.

A further object of the present invention is an unexpanded gelatinized product comprising at least one starchy material and macroparticles of a vegetable material. In particular, in the unexpanded gelatinized product, the macroparticles of vegetable material are dispersed in the starchy material and at least part of said macroparticles is visible to the naked eye.

In embodiments, a portion of unexpanded gelatinized product whose size is 4.8 cm ² comprises at least 10 macroparticles of vegetable material, or colored areas obtained from vegetable material, visible to the naked eye.

Depending on the vegetable material used, a portion size of unexpanded gelatinized product of 4.8 cm ² comprises up to 40 macroparticles of vegetable material, or colored areas obtained from vegetable material, visible to the naked eye, the size of which at least 3 or 4 macroparticles is bigger or equal to 2 mm, even more preferably bigger or equal to 3 mm. In embodiments, the weight of the snack, i.e. the weight of a single piece (i.e. the final product ready for consumption) is between 0.7 g and 1.5 g. In embodiments, the size of at least part of the macroparticles of the vegetable material inside the unexpanded gelatinized product changes during the expansion step.

However, in general a piece having the aforementioned weight preferably contains macroparticles visible to the naked eye, of which at least 2 or 3 macroparticles have size bigger or equal to 2 mm, even more preferably bigger or equal to 3 mm.

According to the present description, by“unexpanded gelatinized product” we refer to a semi-finished product, for example a pellet.

According to embodiments, the macroparticles of unexpanded vegetable material are at least in part macroparticles of an untreated vegetable material, i.e. are at least in part deriving from a fresh vegetable material. According to embodiments, the unexpanded gelatinized product is dried at least in part.

As mentioned above, the gelatinized product obtained at the end of the step of gelatinizing the starch of the mixture comprising at least one starchy material and macroparticles of a vegetable material is dried to obtain a dried product. The drying can be carried out by known techniques.

In the following step of the process of the invention, the dried product is thus expanded so as to obtain the finished product, i.e. a snack. The expansion can be carried out by known techniques, for example by frying or toasting. The expansion is preferably carried out at a temperature between 200°C and l80°C, preferably at a temperature of about l90°C.

We want to point out that the process of the present invention allows to obtain an expanded final product, which comprises high amounts of vegetable material as macroparticles, having density dramatically lower than the density of the products known in the art.

According to embodiments, the apparent density of the finished product is generally lower than 0.14 g/cc (140 grams/liter), preferably is between 0.04 and 0.08 g/cc (40 and 80 g/liter), and more preferably is between 0.04 and 0.065 g/cc (40 and 65 g/liter). The apparent density of the finished product can be measured by methods known in the art. In particular, the apparent density of the product can be measured, for example, as follows:

A cylinder with an internal volume of three liters is provided, having a diameter of 150 mm and having a reference mark indicating the level corresponding to the volume of three liters.

Such cylinder is filled with still hot finished product (preferably at a temperature of about l85°C). The cylinder containing the finished product is vibrated for at least 30 seconds. This way the snacks contained in the cylinder settle at the reference mark level of the three liters on the cylinder. Furthermore, this way, the interstitial spaces remaining between a snack and the other are substantially negligible, and do not substantially affect the measurement. The possible excess product, i.e. exceeding the reference mark level, is discarded. The product inside the cylinder is thus weighed and its apparent density is calculated by dividing the weight of the finished product by the volume it occupies.

Another known method which can be used for determining the apparent density according to the invention is that described in the scientific paper“Sandra Segnini, Franco Pedreschi & Petr Dejmek (2004) Volume

Measurement Method of Potato Chips, International Journal of Food Properties, 7: 1, 37-44, DOF 10.1081/JFP-120022494”. In particular, the measurement method of the apparent density is described on page 39 of the mentioned publication.

Note that different methods can provide different point results, which are however substantially equivalent and, in any case, comprised in the ranges herein described.

For example, the apparent density of the finished product is generally lower than about 0.14 g/cc (140 grams/liter), preferably can be between about 0.04 and about 0.08 g/cc (about 40 and about 80 g/liter), and more preferably can be between about 0.04 and about 0.065 g/cc (about 40 and about 65 g/liter).