BISCUITS AND CRACKERS CONTAINING REDUCED LEVELS OF SATURATED FAT AND METHOD FOR THE MANUFACTURE THEREOF

TECHNICAL FIELD OF THE INVENTION

The present invention relates to biscuits and crackers comprising a fat blend that contains reduced levels of saturated fatty acids and a considerable amount of polyunsaturated fatty acids. The invention also provides a method for the manufacture of such biscuits and crackers.

BACKGROUND OF THE INVENTION

Biscuits and crackers typically contain 10-20 wt.% of fat. Examples of fats that are widely employed in biscuits and crackers include butter oil, palm oil, palm kernel oil, coconut oil, hydrogenated vegetable oils and high melting stearin fractions of vegetable oils. A drawback of these fats is the high amount of saturated fatty acids (SAFA) contained therein. It is generally accepted that fats having a high SAFA content, and consequently a low content of unsaturated fatty acids, do not fit in a healthy diet. In addition, it is a widely held view amongst nutritionists that fats containing high levels of polyunsaturated fatty acids (PUFA) fit well into a healthy diet.

Hence, it would be desirable to replace the high SAFA fats in biscuits and crackers by oils that contain substantially lower amounts of saturated fatty acids and a considerable amount of PUFA. However, the use of low SAFA oils in biscuits and crackers poses serious problems. First of all, the use of low SAFA oils, such as sunflower oil and canola oil, yields a biscuit dough or cracker dough that is very sticky, especially during the first phase of the dough preparation process. This stickiness of the dough causes major problems in the industrial manufacture of biscuits and crackers.

In addition, low SAFA oils, and in particular low SAFA oils containing appreciable levels of PUFA, have the disadvantage that they are easily oxidised,

especially during baking and subsequent storage. Oxidation of unsaturated vegetable oils leads to objectionable off- flavours that are often described as 'cardboard-like'.

EP-A 0 206 850 describes a shelf-stable cookie having a moist, cake-like soft textured crumb structure over an extended period of time and having bloom resistance comprising flavour chips, a humectant, a shortening or fat for promoting softness and for preventing fat bloom on the flavour chips, and a flavouring ingredient, whereby the cookie does not exhibit seepage of shortening or fat at cookie storage temperatures. The examples of the European patent application describe the preparation of a fudge chocolate chip cookie containing partially hydrogenated blend of soybean and palm oil (1 : 1). The melting point of the fat is 98-103 ⁰ F (36.7-39.4 ⁰ C), the solid fat content at 21.1 ⁰ C is 13.0%-18.0% and at 26.7 ⁰ C it is in the range of 7.0%- 11.0%. Due to the partial hydrogenation the PUFA content of this fat is limited.

SUMMARY OF THE INVENTION

The inventors have developed a special fat blend for use in biscuits and crackers that contain substantially reduced levels of SAFA in combination with appreciable levels of PUFA and that can suitably be used in the preparation of biscuits and crackers without giving rise to unacceptable dough stickiness or oil oxidation. The fat blend of the present invention contains at least 30 wt.% of polyunsaturated fatty acids and comprises 50-85 wt.% of a highly unsaturated oil and 15-50 wt.% of a palm oil fraction having a melting point within the range of 27-38 ⁰ C. The fat blend of the present invention is further characterised by a low solid fat content at 25 ⁰ C of less than 10 wt.%. The unsaturated oil employed in the fat blend is selected from the group consisting of sunflower oil, soybean oil, rapeseed oil, cottonseed oil, saffiower oil, marine oil, corn oil, olive oil, linseed oil and combinations thereof.

The inventors have found that despite the low solid fat content at 25 ⁰ C the present fat blend can suitably be used to prepare a biscuit dough or cracker dough that does not suffer from stickiness. Furthermore, despite the high level of polyunsaturated fatty acids in the fat blend the biscuits and crackers made with this fat blend exhibit a surprisingly high oxidative stability.

DETAILED DESCRIPTION OF THE INVENTION

Accordingly, one aspect of the invention relates to a method of preparing biscuits or crackers, said method comprising (i) preparing a dough by combining flour, water, leavening agent, a fat blend and optionally further bakery ingredients; and (ii) baking the dough; wherein the fat blend contains at least 30 wt.% of polyunsaturated fatty acids and comprises:

50-85 wt.% of a highly unsaturated oil selected from the group consisting of sunflower oil, soybean oil, rapeseed oil, cottonseed oil, saffiower oil, marine oil, corn oil, olive oil, linseed oil and combinations thereof; and 15-50 wt.% of a palm oil fraction having a melting point within the range of 27-38 ⁰ C; and wherein said fat blend is further characterised by a solid fat content at 25 ⁰ C of less than 10 wt.%.

The terms "oil" and "fat" are deemed to be synonyms and encompass lipids such as triglycerides, diglycerides, monoglycerides, phosphoglycerides etc. Most preferably, the oil (or fat) employed in accordance with the present invention is a triglyceride fat. The term "fatty acid" as used herein encompasses fatty acid residues contained, for instance, in triglycerides.

The N-value N _t equals the solid fat content of a fat at a temperature of 1 ⁰ C as measured by means of ISO 8292 - Animal and vegetable fats and oils - Determination of solid fat content - Pulsed nuclear magnetic resonance method.

The term "marine oil" as used herein refers to an oil that has been isolated from a marine organism, e.g. fish or algae.

Unless indicated otherwise, fatty acid concentrations are expressed as a percentage of the total weight of fatty acid residues and free fatty acids contained in the fat that is contained in the biscuit dough, the cracker dough or the baked dough product. The fatty acid concentrations are suitably determined by means of ISO 5509 - Animal and vegetable fats and oils - Preparation of methyl esters of fatty acids and ISO 5508 - Animal and vegetable fats and oils - Analysis by gas chromatography of methyl esters of fatty acids.

The triglyceride composition of fats, unless indicated otherwise, is determined by HPLC silver ion chromatography, using the methodology described in "Separation of Triacylglycerol Species from Interesterified Oils by High-Performance Liquid Chromatography", Jeung Hee Lee et al; J Amer Oil Chem Soc (2007) 84:211-217. It is noted that the amount of highly unsaturated oil and the amount of palm oil fraction that is employed in the fat blend according to the present invention can reliably be determined from the triglyceride composition of the fat blend.

Besides the highly unsaturated oil and the palm oil fraction the fat blend employed in accordance with the present invention may contain additional oil components, such as, for instance butter oil. The use of a small quantity of butter offers the advantage that genuine butter flavour can be imparted to the final biscuit or cracker. Typically, the highly unsaturated oil and the palm oil fraction together represent at least 70 wt.%, preferably at least 80 wt.% of the fat blend. Most preferably, the highly unsaturated oil and the palm oil fraction together represent at least 90 wt.% of said fat blend.

The present invention offers the advantage that it enables the preparation of biscuits and crackers containing a low SAFA fat, without using any hydrogenated fats as so called "hardstock". Hence, according to a preferred embodiment, the fat blend employed does not contain hydrogenated fat. Because, partial hydrogenation of unsaturated oils is accompanied by the formation of trans-unsaturated fatty acids and because these trans-unsaturated fatty acids are generally regarded as undesirable, it is preferred that the present fat blend has a trans fatty acid content of less than 2 wt.%, most preferably of less than 1 wt.%.

The total amount of saturated fatty acids in the present fat blend typically does not exceed 35 wt.%. Even more preferably, the SAFA content of the fat blend does not exceed 30 wt.%, most preferably it does not exceed 28 wt.%. In order to achieve the benefits of the present invention, the fat blend must contain a significant amount of saturated fatty acids. Typically, the fat blend contains at least 10 wt.%, preferably at least 15 wt.% of saturated fatty acids. According to a preferred embodiment, the palm oil fraction provides a substantial amount of the saturated fatty acids in the fat blend. The palm oil fraction according to the present invention is rich in palmitic acid residues, whereas the levels of palmitic acid in the highly unsaturated oil are almost negligible. Typically, the fat blend of the

present invention contains more than 10 wt.% of palmitic acid, more preferably more than 12 wt.% of palmitic acid.

In scientific literature, many health benefits have been attributed to polyunsaturated fatty acids. For this reason, it is preferred that the present fat blend contains at least 35 wt.% of polyunsaturated fatty acids. Surprisingly, even if the present fat blend contains substantial quantities of easily oxidised polyunsaturated acids, no serious problems with oxidation off-flavours are observed.

The fat blend of the present invention advantageously contains 60-80 wt.% of the highly unsaturated oil. The palm oil fraction is advantageously incorporated in the fat blend in an amount of 20-40 wt.%.

The highly unsaturated oil that is employed in accordance with the present invention preferably is a vegetable oil. More preferably, said oil is selected from the group consisting of sunflower oil, soybean oil, rapeseed oil, cottonseed oil, safflower oil, corn oil, olive oil and combinations thereof. Whenever the term sunflower oil is used in here, this term is meant to encompass any type of sunflower oil including, for instance, high oleic sunflower oil. The same holds for other vegetable oils, such as for instance rapeseed oil, which includes high erucic rapeseed oil.

The palm oil fraction employed in accordance with the present invention preferably is a palm mid fraction. Palm mid fractions are rich in PPO-triglycerides, POP triglycerides and PPP-triglycerides. Here, P represents a palmitic acid residue and O represents an oleic acid residue. According to a particularly preferred embodiment, the fat blend employed in accordance with the present invention contains in total 12-30 wt.%, preferably 13-25 wt.% of triglycerides belonging to the group consisting of PPO-triglycerides, POP triglycerides and PPP-triglycerides. Palm mid fractions are further characterised in that the weight ratio of HUH- triglycerides to HHU-triglycerides is very high. Here H represents a saturated C10-C22 fatty acid residue and U represents an unsaturated C10-C22 fatty acid residue. The fat blend employed in accordance with the present invention advantageously contains HUH triglycerides and HHU triglycerides in a weight ratio of at least 7:1, most preferably o f at least 7.2:1.

Unlike the fats normally employed in biscuits and crackers, the fat blend employed in accordance with the present invention contains very little solid fat at 30 ⁰ C. According to a preferred embodiment, the fat blend has a solid fat content at

30 ⁰ C of less than 3 wt.%. Most preferably, the fat blend has a solid fat content at 30 ⁰ C of less than 1 wt.%

Unlike highly unsaturated oils, the present fat blend preferably contains some solid fat at 15 ⁰ C. Preferably, the fat blend has a solid fat content at 15 ⁰ C (N ₁₅ )of at least 3 wt.%, more preferably of at least 5 wt.%. Typically, the solid fat content at at 15 ⁰ C does not exceed 20%.

According to a particularly preferred embodiment, the fat blend of the present invention is characterised by the following solid fat profile: 0% < N ₂₀ < 15%, preferably 1 % < N ₂₀ < 10%; and 0% < N ₃₀ < 8%, preferably 0% < N ₃₀ < 5%.

The fat blend of the present invention typically exhibits a steep melting curve between 1O ⁰ C and 2O ⁰ C. Preferably, the fat blend difference in solid fat content at these two temperatures exceed 10%, more preferably it exceeds 30%. Biscuits and crackers are advantageously prepared by using baking soda as a leavening agent. Hence, in a preferred embodiment, the leavening agent employed is baking soda. Here the term "baking soda" encompasses any leavening agent that is capable of generating carbon dioxide as a result of reaction between a leavening acid and a leavening base. Another embodiment of the present invention relates to a biscuit dough or a cracker dough containing 15-50% of fat by weight of flour, 10-20% water by weight of flour and baking soda, said fat being a fat blend as defined herein before. The total fat content of the dough or cracker dough typically is in the range of 10-40 wt.%.

According to a particularly preferred embodiment, the biscuit or cracker dough contains not more than 10 wt.%, even more preferably not more than 8 wt.% of saturated fat. Here the weigh percentage saturated fat is calculated by multiplying the total fat content (wt.%) with the weight ratio of saturated fatty acids to total fatty acids.

Expressed differently, saturated fat preferably represents less than 15%, even more preferably less than 13% of the total caloric content of the biscuit or cracker dough. Here the percentage of total caloric content contributed by saturated fat is calculated by multiplying the percentage of the total caloric content that is derived from fat with the weight ratio of saturated fatty acids to total fatty acids.

The biscuit dough or cracker dough typically contains 40-85 wt.% of flour.

According to a preferred embodiment, the dough is a plastic non-pourable dough, i.e. not a pourable batter.

The biscuit dough of the present invention typically contains 40-70 wt.%, preferably 45-65 wt.% of flour. Besides flour, water, fat and baking soda, the biscuit dough preferably contains an appreciable amount of mono- and/or disaccharides, notably sucrose, glucose, fructose and combinations thereof. Advantageously, the biscuit dough contains 20-40% by weight of flour of saccharides selected from the group consisting of monosaccharides, disaccharides and combinations thereof. The combination of flour, water, fat, baking soda and saccharides typically represents at least 80 wt.%, most preferably at least 90 wt.% of the biscuit dough.

The cracker dough of the present invention typically contains 60-85wt.%, preferably 65-80 wt.% of flour. The combination of flour, water, fat and baking soda typically represents at least 80 wt.%, most preferably at least 90 wt.% of the cracker dough. Yet another aspect of the present invention relates to a biscuit or a cracker containing 15-50% of fat by weight of flour, said fat being a fat blend as defined herein before.

The total fat content of the biscuit or cracker typically is in the range of 12-45 wt.%. Furthermore, the biscuit or cracker advantageously contains not more than 10 wt.%, even more preferably not more than 8 wt.% of saturated fat. In terms of caloric content, saturated fat preferably represents less than 15%, even more preferably less than 13% of the total caloric content of the biscuit or cracker.

The invention is further illustrated by means of the following non-limiting examples.

EXAMPLES

Example 1

Biscuits were prepared on the basis of the following dough recipe:

First, a premix was prepared by thoroughly blending sugar, water, salt, sodium bicarbonate, ammonium bicarbonate, tartaric acid and malt extract. Subsequently, the oil was admixed to the premix. In a high speed kneader, the wheat flour was added to the premix and mixing was continued until a strong elastic dough was obtained.

The dough was removed from the kneader and a dough sheet with a thickness of about 2-2.5 mm was produced by passing the dough through a sheeting roll. Next, round dough pieces (diameter 4-7 cm) were cut from the dough sheet and baked in an oven to yield the biscuits.

Biscuits were produced as described above, using the following oil components:

palm fraction used is a soft stearin fraction with an iodine value of 43 (obtained as the stearin fraction of palm olein with a iodine value of 56).

The properties of the oil components used in products A, B and C are summarised in the following table:

During preparation of the biscuit dough it was observed that the dough prepared with sunflower oil (product A) was much more sticky than the other doughs, making it difficult to handle this particular dough as it tended to stick to equipment. The dough prepared with a fat blend according to the present invention (product C) was found to be very elastic and supple, whereas the dough made with palm oil (product B) was found to be a bit "short".

The biscuits obtained after baking were stored at 36 ⁰ C at a relative humidity of 55% for 63 days. During this storage period every 7 days the products were evaluated by an expert panel. The expert panel found that the taste of freshly baked products A, B and C was comparable. However, the panel also observed that the taste of product A deteriorated rapidly during storage. During storage, product A developed clearly perceptible off-notes that the panelists associated with oil oxidation. In contrast, products B and C did not exhibit significant taste deterioration during the evaluation period.

The fact that products B and C performed equally well is quite unexpected given that product C contains a high level of polyunsaturated fatty acids (PUFA). Oils containing appreciable levels of PUFA are usually rapidly oxidised during baking and

storage, resulting in the development of an undesirable oxidation off- flavour (see findings for product A).

Example 2

Example 1 was repeated, except that in product C the oil component was replaced by an oil blend of the following composition:

soft stearin fraction with an iodine value of 43 (see Example 1) palm stearin having an iodine value of 35

The properties of the oil components used in product C is summarised below:

The performance of product C was very similar to that of product C of Example 1.

Example 3

Example 1 was repeated, except that in product C the oil component was replaced by an oil blend of the following composition:

# interesterified blend of palm stearine having an iodine value of 35 (70 wt.%) and palm kernel oil (30 wt.%) stearin fraction of palm stearin having an iodine value of 12

The properties of the oil components used in product C is summarised below:

Again, the performance of product C was very similar to that of product C of

Example 1.