End of Project ReportShortenings (baking fats), microencapsulated using dairy ingredients
and milk protein hydrolysates, were produced for testing in a variety
of baked products. The powders were evaluated for their
functionality as powdered baking fats, as potential replacers of
synthetic emulsifiers, as ingredients capable of improving baking
performance or as potential health-enhancing ingredients.
These studies provide the technology for the dairy industry to enter
the specialised food ingredients sector with a siftable, non-greasy,
free-flowing powdered fat for the baking industry.Department of Agriculture, Food and the Marin

Arendt, Elke

Auty, Mark

Kennedy, R.

Keogh, M.K.

Neville, Denis P.

STANTON, CATHERINE

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DAIRY PRODUCTS RESEARCH CENTREMOOREPARKEND OF PROJECT REPORT 2000  DPRC No. 41Dairy Ingredients for theBaking IndustryM.K. Keogh, D. Neville and C. StantonShortenings (baking fats), microencapsulated using dairy ingredientsand milk protein hydrolysates, were produced for testing in a varietyof baked products.  The powders were evaluated for theirfunctionality as powdered baking fats, as potential replacers ofsynthetic emulsifiers, as ingredients capable of improving bakingperformance or as potential health-enhancing ingredients. These studies provide the technology for the dairy industry to enterthe specialised food ingredients sector with a siftable, non-greasy,free-flowing powdered fat for the baking industry.Functional Additives in Cereal-based Consumer Foods(Dairy Ingredients for the Baking Industry)Armis No. 4518Project Team: Dr. M.K. Keogh (Leader)Mr. D. NevilleDr. C. StantonMr. M. AutyMr. R. KennedyDr. E. Arendt ** Dept. Food Technology, University College CorkThe Dairy Products Research CentreMoorepark, Fermoy, Co. Cork.Teagasc acknowledges with gratitude grant aid under the Food Sub-programme(Sub-Measure 3 (ii) - Institutional R&D) of the Operational Programme forIndustrial Development.  The Programme was managed by the Department ofAgriculture and Food supported by EU and national funds.Teagasc gratefully acknowledges the use of the baking facilities of the FoodTechnology Department, University College Cork in the course of these studies.ISBN  1 84170 181 5DPRC No. 41© Teagasc, August 2001Teagasc 19 Sandymount Avenue EUROPEAN UNIONBallsbridge Dublin 4 European Regional Development Fund2Summary and Conclusions Microencapsulated high fat powders provide a convenient alternative to fatsor shortenings which are usually used in cereal-based baked products.Powdered fats, in common with other baking ingredients, are flowablecompared to block fats and they also increase the overall protein content ofbaked goods, which provides certain functional benefits.  The mainobjective of this project was to evaluate the performance ofmicroencapsulated high fat powders in a range of baked products.Milk protein hydrolysates have well-established nutritional properties, buttheir functional effects in baked goods have not been quantified.  Hence, thefunctional and physicochemical characteristics of some casein hydrolysatesgenerated by a range of food-grade enzymes were evaluated to determinetheir suitability for use in baked products.  Pilot-scale production ofhydrolysates were undertaken and the spray dried products were evaluatedin baked products.Main Conclusions and Achievements*  Microencapsulated fat powders were developed and optimised to suitvarious baking applications.  These powders performed satisfactorily in thebaked goods in which they were assessed in terms of  a) alternatives to blockfats, b) dough conditioners and c) functional substitution of traditionalingredients. *  The influence of microencapsulated high fat powders on the physical,physicochemical and sensory properties of bread, biscuits and cakes wasdetermined.  Whey protein concentrate (WPC-75) was selected asmicroencapsulating agent for its functionality, flavour and cost.  Free fat was found to have the greatest effect on the properties of the bread.The optimum powder gave similar dough rheological properties and loafvolume yield compared to a standard loaf with added shortening.Increasing the scale of production of the powder (using the Niro Tall-Formspray dryer) improved the mechanical and physical properties of thepowder. The powder performed well in pilot-scale baking trials and onassessment by baking end-users. 3A high fat cake powder with WPC-75 was successfully incorporated intoMadeira cake as a complete replacement for margarine and egg.  The cakewith the high fat powder was found to be superior to a commerciallyproduced Madeira cake.*  Caseinate hydrolysates were prepared in spray-dried powder form andwere evaluated as suitable protein-rich ingredients in bread makingapplications.A sodium caseinate hydrolysate of limited degree of hydrolysis (DH) whichexhibited superior in-vitro functional properties, and an extensivelyhydrolysed hydrolysate prepared from acid casein, with inferior in-vitrofunctional properties to unhydrolysed sodium caseinate were prepared inspray-dried powder form.Results of these studies showed that there was no correlation between thepositive in-vitro functional properties observed for the sodium caseinatehydrolysate and performance in bread making applications.  The bread made using the sodium casein hydrolysate  (at 1 and 4% w/w)was generally of inferior quality to the control.  However, the bread madeusing the extensively hydrolysed acid casein hydrolysate was equivalent orof superior quality to the control.  Therefore, this ingredient may haveapplications in the development of protein-enriched bread.*  The project was very successful in understanding the effects of theselected milk components (milk fat, milk protein type/level and lactose) andhomogenisation conditions on the functional properties of spray-driedpowders (free fat and whey protein denaturation) relevant for bakedproducts.This provides the  technology for the dairy industry to enter the specialisedfood ingredients sector with a siftable, non-greasy, free-flowing powdered fatsuitable for the baking industry.Fundamental knowledge was gained on the influence of proteinhydrolysates on the quality of baked products, and processing procedureswere modified with a view to enhancing quality.  4Research and Results Microencapsulated High Fat PowdersMicroencapsulated high fat powders (70% fat) ranging in free fat contentfrom 2 to 60 g /100 g fat were produced. The free fat content decreased significantly as the homogenisation pressureand added sucrose level in the powders increased. Fat type (milk fat orhydrogenated vegetable fat), protein type (whey protein concentrate orsodium caseinate) and protein level (5 to 20%) did not significantly affectfree fat. Wettability, which is a measure of the reconstitution properties of thepowders ranged from 30 to 133 seconds.  Wettability was poorer at thehigher protein level (20%), which increased the wetting time by 17 seconds. Microencapsulated fat powders made with whey protein concentrate (WPC-75) rather than sodium caseinate were selected for further study because offunctionality, flavour and cost reasons, based on their evaluation in bakedproducts. In a second stage, microencapsulated powders were produced using WPC-75 or WPI (90% protein) at levels of 5 - 20% w/w of powder protein and atvarying levels of homogenisation pressure (40 - 400 MPa).  Hydrogenatedvegetable shortening was used as the fat source.Increasing the homogenisation pressure significantly decreased the fatglobule size of the concentrate prior to drying. The particle size of the spray-dried powders was also significantly decreased. The free fat of themicroencapsulated fat powders ranged from 8 to 80 g fat/100 g fat.Increasing the homogenisation pressure decreased free fat significantly whileincreasing the protein level from 5 to 20% increased the free fat significantlyin the powders (Fig.1).One of the primary objectives at this stage was to producemicroencapsulated powders with a wide range of free fat contents, as it wasfound in stage one that free fat had the greatest effect on the properties ofbaked bread and dough. The processing and compositional variables thataffected the properties of the microencapsulated powders also affected thebaked bread properties. 5Increasing the homogenisation pressure, which decreased the free fat of the powders,resulted in a significant decrease in loaf volume (Fig 2). Increasing the protein levelin the powders significantly increased the hardness and chewiness of the breads.Increasing the homogenisation pressure significantly increased the dough rheologicalproperties related to stiffness of the dough (tan δ and complex viscosity), making itmore difficult to process and expand during baking.A hydrogenated vegetable fat powder (70% fat) was produced usinghomogenisation at high pressure with 10% WPC as the emulsifying agent and 20%lactose as the filler. A hydrogenated vegetable fat powder (39% fat) was alsoproduced with 38% WPC-75 and 22% sucrose at the same homogenisationpressure. The powders were spray dried using an Anhydro pilot-scale dryer andstored at 16ºC. The 70% WPC-based microencapsulated powder was used as a complete replacerfor egg, synthetic emulsifier and fat in English cake, while the 39% fat powder wasused as a similar replacer in sponge cake. The expected benefit was to replaceexpensive egg proteins, synthetic emulsifiers and bulk fats normally used in cakeswith one microencapsulated dairy ingredient. The powders produced were in the61009080706050403020100 ❉❉❉   5                                 12.5                            20Protein Content (%)Free Fat (g/100g fat)Fig. 1: Effect of protein content and homogenisation pressure on powderfree fat at 4 MPa (), 13 MPa ( ), 22 MPa (), 31 MPa (❏) and40MPa (❉).7500490480470460450440 ❉❉❉  5                                 12.5                            20Protein Content (%)(a)Volume Yield (ml/100g flour)500490480470460450440 ❉❉❉  5                                 12.5                            20Protein Content (%)(b)Fig. 2: Effect of protein content and homogenisation pressure on thevolume yield of baked bread with added powders (5% w/w of flour) using(a) WPC-75 and (b) WPI at 4 MPa (), 13 MPa ( ), 22 MPa (),31 MPa (❏) and 40 MPa (❉).Volume Yield (ml/100g flour)low free fat range, and the free fat of the 70% fat powder was greater than the 39%fat powder (7.0 v. 3.7 g free fat/100 g fat). The properties of the cakes produced with egg and synthetic emulsifier were betterthan cakes produced with the microencapsulated fat powders and syntheticemulsifiers. However, the microencapsulated fat powders performed as well as eggin cakes produced without synthetic emulsifier in the recipes. A further series of powders was produced with and without added syntheticemulsifier and substituted for egg and/or emulsifier in English cake.It was found that the recipe used for cake manufacture did not produce a goodcontrol cake, but the cakes manufactured with the microencapsulated powderingredient performed adequately in this recipe. Commercial Scale Assessment of Dairy Ingredients for Baking A whey protein-based high fat microencapsulated powder with optimumfunctionality in baked bread was manufactured on a commercial scale using a NiroTall-Form spray dryer in Moorepark Technology Ltd.The powder performed well in terms of its handling and flow properties duringdrying and the recovery of the powder was high. Increasing the scale of productionof the powder improved the mechanical and physical properties of the powder. Thepowder performed well in baking trials and the powder and process were assessedby commercial milk powder manufacturers and baking end-users.Puff pastry products are the primary outlets for hard milk fat fractions. Puff pastrywas produced using hard milk fat fraction, winter milk fat and microencapsulatedpowders containing each of the fats.Hard milk fat fraction performed better than winter milk fat when added as bulk fator in microencapsulated powder form. The microencapsulated fat powdersperformed poorly in these trials. When the fat content in the powders was increasedfrom 70 to 80%, puff pastry quality improved. The improvement could be attributedto the greater availability of fat during baking, as the free fat values increased 3-foldin the higher fat powder.A Madeira cake (high ratio) formulation was used, into which a series of high fatcake powders was incorporated. The formulation and process for manufacture ofcake powders was further modified by the inclusion of specific small molecularweight emulsifiers. The interaction between the whey protein/emulsifier system was8assessed and optimised. An optimum powder was produced in terms of itsperformance in Madeira cake.  A commercial milk powder manufacturer assessedthe powder and process.The powder produced a cake superior to a commercially produced Madeira cakeproduct. This powder was manufactured on a commercial scale using the Niro Tall-Form spray dryer. The powder performed well in terms of its handling and flowproperties during drying and the recovery of the powder was high. Casein HydrolysatesAn evaluation of the functional and physicochemical characteristics of five caseinhydrolysates, which were generated by a range of food-grade enzymes, wasundertaken to determine their suitability for use in baked bread products.  In allcases, sodium caseinate was hydrolysed to a limited degree (1% DH) by food-gradecommercial enzyme preparations. This typically involved the use of 0.1 - 0.001%enzyme:substrate ratio for 2 - 4 hours at conditions of optimum temperature and pHfor the particular enzyme. The peptide size distribution of the five hydrolysates varied depending on theproteolytic enzyme used.  Protamex, a Bacillus protease complex (Novo Nordisk),was the most proteolytic enzyme studied, generating a hydrolysate which consistedof 25% of total peptides of less than 5 kDa, while the other hydrolysates hadbetween 14 - 21% of total peptides less than 5 kDa.The emulsification, foaming/whipping and water-binding capacity of these caseinhydrolysates were evaluated and compared to unhydrolysed sodium caseinate.Emulsification activity (EA), an indicator of the ability of the hydrolysate to form anemulsion, was measured at pH values ranging from 2.0 to 10.0. For all hydrolysates, EA was higher at alkaline pH than at acid pH values.Emulsion stability (ES) over 30 min was recorded from pH 2.0 - 10.0 and comparedwith unhydrolysed sodium caseinate. ES was reduced at acidic pH values, and emulsions were most stable in the alkalinepH range, with the most stable emulsion being generated at pH 10.0 by the caseinhydrolysate made using Alcalase.Whipping and foaming properties of the hydrolysates and sodium caseinate weremeasured at pH 2.0, 7.5 and 10.0.  Foams were prepared at 4% protein and foamexpansion and percentage drainage quantified.9All hydrolysates exhibited superior foam expansion compared to unhydrolysedsodium caseinate at all pH values tested.  Furthermore, there were no differencesbetween the levels of foam expansion obtained between the five hydrolysates. Unhydrolysed sodium caseinate had low drainage at pH 2.0, whereas at pH valuesof 7.5 and 10.0, greater than 95% drainage was observed.  Interestingly, thehydrolysate made using Neutrase had low drainage at all pH values investigated,whereas all other hydrolysates exhibited high drainage (> 90%) at pH 2.0.  Of thefive casein hydrolysates, that made using Neutrase exhibited the lowest drainage atpH 7.5.Water-binding capacity of sodium caseinate and the five casein hydrolysates (3%w/v) was measured and compared with commercial bakers flour, which yielded avalue of 0.80 ml/g. Unhydrolysed sodium caseinate exhibited higher water-binding capacity (0.88 ml/g)than the casein hydrolysates (0.76 - 0.87 ml/g). The hydrolysate made using Neutrase exhibited improved foaming and whippingproperties and had similar water binding capacity to unhydrolysed sodium caseinate,and was subsequently selected for incorporation into baked goods.The performance of this hydrolysate was compared to an extensively hydrolysedacid casein hydrolysate, prepared with the enzyme Flavourzyme, in  bakingapplications.  The functional properties (e.g. emulsification and foaming/whipping)of the extensively hydrolysed acid casein hydrolysate were very poor.Bread was produced to a standard procedure and the casein hydrolysates wereincorporated at 1% and 4% (flour basis).  Batches were also prepared withouthydrolysate and with unhydrolysed material (also at 1% and 4% w/w).  All breadbatches were evaluated using standard balling tests, crumb firmness testing andcrumb grain image analysis. Bread made using the sodium casein hydrolysate was generally inferior in qualitycompared with the control, while the incorporation of the extensively hydrolysedacid casein hydrolysate resulted in bread of equivalent or superior quality to thecontrol.  Therefore, the results indicated that there was no correlation between suchfunctional properties as foaming/whipping and bread making potential.For further information please contact:Dr. Kieran Keogh or Dr. Catherine Stanton10PublicationsO’Brien, C.M., Grau, H., Neville, D.P.,  Keogh, M.K. and Arendt, E.K. (1998).  Use ofmicroencapsulated high fat powders in bread.  Proceedings of 28th Annual Food Science andTechnology Conference, September, Cork, Ireland.Neville, D.P. and Keogh, M.K. (1998). Microencapsulated high fat milk powders spray dried usingsodium caseinate. Proceedings of 28th Annual Food Science and Technology Conference, September,Cork, Ireland.Neville, D.P. (1998). Development of a natural bacon fat flavoured ingredient using microencapsulationtechnology. Presentation for The 1998 Food Ingredients Europe Research Award, November, Frankfurt,Germany.Neville, D.P. (1998). Microencapsulation technology for ingredient and flavour delivery in consumerfoods. Dissemination Project Workshop on Ingredients for Consumer Foods, December, UniversityCollege, Dublin.Kenny, S., Wehrle, K.,  Stanton, C. and Arendt, E.K. (1998). Use of dairy powders as functionalingredients in wheat bread. International Dairy Journal 8, (5-6) (A), 576.O’Brien, C.M., Grau, H., Neville, D.P., Keogh, M.K. and Arendt, E.K. (1998).  Rheology of wheat breaddoughs containing microencapsulated high fat powders.  Proceedings of the 1998 Annual AACCMeeting, Minneapolis, MN, USA.O’Brien, C.M., Grau, H., Neville, D.P.,  Keogh, M.K. and Arendt, E.K. (1998).  Functionality ofmicroencapsulated high fat powders in wheat bread.  Journal of Cereal Science. Submitted.Neville, D.P.,  Kelly, P.M. and Keogh, M.K. (1999). A natural bacon fat flavoured ingredient developedby microencapsulation technology.  Farm & Food, Winter 1998/99.Kenny, S., Wehrle,  K., Stanton, C. and Arendt, E.K.  (2000).   Incorporation of dairy ingredients intowheat bread: effects on dough rheology and bread quality. Eur. Food Research Technol. 210, 391-316.Crowley, P., Slattery, H.,  Arendt, E.K. and Stanton, C. (2000).  Evaluation and Application of CaseinHydrolysates in Wheat Bread.  Irish J. Agricultural Food Research 39, 1, 149.Neville, D.P.,  Keogh, M.K. and  Auty, M.A. (2001). Spray dried high fat powders. J. Food Science.Submitted.Neville, D.P., Keogh, M.K., Auty, M.A., O’Brien, C.M. and Arendt, E.K. (2001). Whey proteinencapsulated high fat powders for application in wheat bread. J. Food Science. In Preparation.11Dr. Kieran KeoghDAIRY PRODUCTS RESEARCH CENTREMoorepark, Fermoy, Co. Cork, IrelandTel: +353 (0) 25 42222 - Fax: +353 (0) 25 42340E-Mail: reception@moorepark.teagasc.ie

Dairy Ingredients for the Baking Industry.

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