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Article Use of /Cellulose Ether Emulsions in Spreadable Creams and the Effect of In Vitro Digestion on Texture and Fat Digestibility

Maria Espert, Teresa Sanz and Ana Salvador * Instituto de Agroquímica y Tecnología de Alimentos (CSIC), Avda. Agustín Escardino 7, 46980 Paterna, Spain; [email protected] (M.E.); [email protected] (T.S.) * Correspondence: [email protected]; Tel.: +34-963900022

 Received: 29 April 2020; Accepted: 15 June 2020; Published: 17 June 2020 

Abstract: This study investigated the texture properties and fat digestibility of new spreadable creams formulated with an emulsion composed of milk fat and a cellulose ether as a fat source. The spreadability was analysed at 20 ◦C and compared with a commercial spreadable cream formulated with palm fat. Structural changes in the creams after the in vitro oral and gastric digestion stages were evaluated; lipid digestibility was determined by titration with NaOH during intestinal digestion. Spreadability tests showed the spreads were similar. After oral digestion, the commercial spread showed an increase in extrusion force because of flocculation induced by saliva, an effect not observed in spreads with cellulose ether. Digestibility determination showed lower values for the reformulated spreads. Therefore, milk fat-cellulose ether based emulsions offer an alternative to achieve reformulated spreadable creams, with physical properties similar to those of commercial products but providing reduced fat content and lower lipid digestibility, without compromising the quality of the final product.

Keywords: hydrocolloids; milk fat; spreadable creams; spreadability; fat release

1. Introduction Solid (fats high in saturated fatty acids) are major components in several food products used daily including spreads, creams, , ice-creams, and various bakery products [1]. These saturated fats have a positive influence on the flavour, taste, texture, and overall acceptability of the food products. However, food safety authorities have pursued the reduction of fat content, leading to multiple reformulation strategies [2] aimed at providing acceptable organoleptic and physical properties of the full-fat counterparts without compromising the eating quality. Chocolate spread is a good candidate for reformulation, as they are high in fat (higher than 40 g/100 g), mostly saturated (, coconut oil, and ), which provides the inherent product texture, mouthfeel, and flavour [3]. However, the partial substitution of with unsaturated oils has not proved suitable, as it compromises the final quality of the confectionary product [4]. An approach to minimize the impact of fat reduction is the use of edible emulsions. Oil-in-water emulsions are common in food products, especially in products considered high in fat [2]. To reduce fat content, the addition of non-fat ingredients (e.g., hydrocolloids), that increase the viscosity of the aqueous phase in a solid fat-water emulsion, achieve fat reduction in a food matrix but maintain the intrinsic fat properties. A possible drawback in the use of containing water emulsions is the moisture they provide; as is well-known, edible spreads containing water are more vulnerable to microbiological deterioration. Notwithstanding, this can be controlled by ensuring a stabilization of the aqueous phase, that can be achieved by increasing the viscosity of the moisture droplets through the use of stabilizers or thickeners [5–7].

Foods 2020, 9, 796; doi:10.3390/foods9060796 www.mdpi.com/journal/foods Foods 2020, 9, 796 2 of 8

A recent study [8] has shown that anhydrous milk fat emulsions with added cellulose ethers proved a viable alternative in reduced fat spreads with improved physicochemical characteristics than conventional butter, resulting in a spreadable product at a wide temperature range (5 ◦C and 20 ◦C). Authors reported that cellulose ethers in a concentrated oil emulsion has a significant impact on lipid digestibility within the digestive tract [9], with only a low percentage of the contained fat being bio-accessible to the body and the rest therefore eliminated without digestion. This hypothesis would be key in solid fat emulsions, although these formulated emulsions would not result in a lipid profile improvement, the decrease in digestibility would represent an interesting approach to fat reduction. The objective of this study was to evaluate the potential fat reduction in chocolate spreads by using anhydrous milk fat-based emulsions, with different cellulose ethers were used as carbohydrate-based stabilizers. The mechanical properties of the chocolate spread matrix before and after in vitro digestion were evaluated, as well as the digestibility of the fat.

2. Materials and Methods

2.1. Emulsion Preparation Different oil-in-water (o/w) emulsions were stabilized using three cellulose ethers with different chemical substitution: methylcellulose Methocel™ A4M (30.0% methoxyl), methylcellulose Methocel™ MX (>30.0% methoxyl), and hydroxypropyl methylcellulose Methocel™ F4M (28% methoxyl, 5% hydroxypropyl, molecular weight of 9500 Da). All of them were provided by The Dow Chemical Company (Midland, MI, USA). Emulsions were prepared using these proportions: 47% (w/w) milk fat (Pure Butter Ghee, East End Foods PLC), 2% (w/w) hydrocolloid, and 51% (w/w) water. Milk fat was melted in a water bath at 65 ◦C and then left to cool to a temperature of 40–45 ◦C. The cellulose ether was dispersed in milk fat using a Heidolph stirrer (Heidolph Instruments GmbH & Co. KG, Schwabach, Germany) at 280 rpm for 5 min. The mixture was hydrated by gradually adding 20 ◦C water with continuous stirring. Finally, the emulsion was homogenised using an Ultra-turrax T18 homogeniser (IKA, Staufen im Breisgau, Germany) at 6500 rpm for 1 min then 17,500 rpm for 1 min.

2.2. Spreadable Creams Preparation Emulsion based cocoa creams comprised water (19%), (Disem, Madrid, Spain) (15%), skimmed milk powder (SMP) (Central Lechera Asturiana, Granda, Asturias, Spain) (5%), cocoa powder (Chocolates Valor S.A., Alicante, Spain) (11%), and cellulose-milk fat based emulsion (50%). A food processor (TM31 Thermomix, Vorwrek, Wuppertal, Germany) was used to mix the ingredients. The sugar, SMP, cocoa powder, and mineral water were mixed at 90 ◦C for 6 min at speed 2. The mixture was cooled at room temperature. The hydrocolloid emulsion was added and mixed in the food processor for 6 min at speed 2 without a temperature selection to obtain the spreadable cream. A commercial cocoa spread (, Ferrero Ibérica, S.A., Barcelona, Spain) was the control. According to the label declaration, the composition of this product is sugar (53%), palm fat (30.9%), (13%), SMP (8.7%), fat-reduced cocoa powder (7.4%), soya lecithin, and vanillin. The total fat content is 30.9% and the saturated fat content is 10.6%. In the formulated spreadable creams, the total fat content was 23.5% and the saturated fat content is 15.6%. All the spreads were stored at 20 ◦C for 24 h before analysis.

2.3. In Vitro Digestion In vitro digestion was performed following the adapted methodology previously used by Espert et al. [10]. This model simulates the different digestion phases (oral, gastric, and small intestine digestion) by applying specific physiologically conditions (digestive fluids, pH, temperature and specific time in each step). Foods 2020, 9, 796 3 of 8

2.4. Fat Digestibility Free fatty acids (FFA) released at the end of in vitro digestion were calculated. The intestinal digestion was carried out over 2 h whilst maintaining the pH at 7.0 by addition of 0.1N NaOH solution (Panreac Química S.L.U., Spain) using a pH-stat automatic titration (Mettler Toledo, Barcelona, Spain). The volume of NaOH added to neutralize the samples was used to calculate the FFA release according to Li and McClements [11].

2.5. Textural Properties TA-XT plus Texture Analyser equipped with the Texture Exponent software (Stable Microsystems, Godalming, UK) was used to determinate the texture properties of the samples. Spreadability of samples was measured using a TTC spreadability rig (HDP/SR) (Stable Microsystems, Godalming, UK) attachment. Samples were filled into a female cone (90◦) with special attention to avoid bubbles formation. Samples were penetrated to 22 mm using a corresponding male cone (90◦) attachment at a speed of 1 mm/s. Force expressed in Newtons and area under the curve (AUC; N s), as a measure of spreadability, were recorded. Measurements were performed in triplicate. · A back extrusion test was conducted using a bucket of 50 mm diameter and 75 mm height with a compression probe of 49 mm diameter. The samples were extruded by 15 mm, at a speed of 1 mm/s. From the force time profiles, the AUC (N s), a measure of consistency, was recorded. Measurements · were performed in triplicate.

2.6. Statistical Analysis Levene’s test was used to assess homogeneity of variances across groups. Analysis of variance (ANOVA) was performed on the data using XLSTAT statistical software (version 5 May 2014, Microsoft Excel®, Barcelona, Spain). The means were compared using the Tukey test and the statistical significance was determined at p < 0.05.

3. Results and Discussion

3.1. Appearance of Cocoa Spreads with Milk Fat Emulsion Cocoa spreads designed using milk fat/cellulose ether emulsions as a fat source contain 23.5% total fat, a significant decrease from other fat sources such as palm fat, vegetable shortenings and butter which containing 80% fat. In this case, milk fat was used instead of olive or sunflower oil (low in saturated fatty acids), because the texture of fat spreads formulated with liquid oils do not have the plastic properties of solid fats, and their texture is fluid. In addition, during preliminary tests, milk fat was found to be the most effective (compared to liquid oil) in minimizing the gummy taste provided by cellulose ethers. The visual appearance of the cocoa spreads with milk fat/cellulose ether emulsions is presented in Figure1. The three spreads presented a spreadable texture like the commercial control cream. The MX spread was the least similar to the control, presenting a lumpy and aerated texture, similar to that of a mousse. Foods 2020, 9, 796 4 of 8 Foods 2020, 9, x FOR PEER REVIEW 4 of 9 Foods 2020, 9, x FOR PEER REVIEW 4 of 9

Figure 1. Appearance of formulated cellulose ethers spreads compared to a commercial control (A4M: Figure 1. AppearanceAppearance of of formulated formulated cellulose cellulose ethers ethers sp spreadsreads compared compared to to a a commercial commercial control control (A4M: (A4M: methycellulose Methocel A4M; MX: methycellulose Methocel MX; F4M: methycellulose MethocelMethocel A4M; MX:A4M; methycellulose MX: Methocelmethycellulose MX; F4M: hydroxypropylmethycelluloseMethocel MX; F4M: hydroxypropylmethycellulose Methocel F4M; C: commercial cocoa spread). Methocelhydroxypropylmethycellulose F4M; C: commercial cocoaMethocel spread). F4M; C: commercial cocoa spread). 3.2. Texture 3.2. Texture 3.2.1.3.2.1. Spreadability Test 3.2.1. Spreadability Test TheThe chocolatechocolate spreadsspreads onon thethe market are characterised by their plastic and spreadable character; The chocolate spreads on the market are characterised by their plastic and spreadable character; here,here, reduced-fatreduced-fat formulated formulated spreads spreads were were compared compared with with the commercial the commercial control control cream, cream, with respect with here, reduced-fat formulated spreads were compared with the commercial control cream, with torespect the spreading to the spreading capacity. capacity. Figure2 shows Figure the 2 shows spreadability the spreadability profiles of theprofiles samples of the at 20 samplesC. The at control 20 °C. respect to the spreading capacity. Figure 2 shows the spreadability profiles of the samples◦ at 20 °C. creamThe control showed cream a higher showed maximum a higher force maximum than the creamsforce than with the emulsion, creams althoughwith emulsion, the cream although with F4M the The control cream showed a higher maximum force than the creams with emulsion, although the exhibitedcream with a similarF4M exhibited profile. a similar profile. cream with F4M exhibited a similar profile.

100 A4M 100 A4M 80 80 MX 60 MX 60 F4M 40 F4M 40 20 CONTROL 20 CONTROL 0

Force (N) 0

Force (N) -20 0 5 10 15 20 25 30 -20 0 5 10 15 20 25 30 -40 -40 -60 -60 -80 Time (s) -80 Time (s) (displacement (mm)) (displacement (mm)) Figure 2. Spreadability curves of the didifferentfferent studiedstudied spreads.spreads. Figure 2. Spreadability curves of the different studied spreads. ToTo betterbetter appreciateappreciate thethe significantsignificant didifferencesfferences betweenbetween thethe samples,samples, Table1 1 shows shows the the values values To better appreciate the significant differences between the samples, Table 1 shows the values ofof maximummaximum forceforce andand AUCAUC calculatedcalculated fromfrom thethe curvescurves data.data. The maximummaximum force andand AUCAUC werewere of maximum force and AUC calculated from the curves data. The maximum force and AUC were significantlysignificantly higherhigher inin thethe controlcontrol cream,cream, whilewhile F4MF4M spreadspread showsshows significantlysignificantly higherhigher forceforce valuesvalues significantly higher in the control cream, while F4M spread shows significantly higher force values thanthan thethe MXMX andand A4MA4M spreads.spreads. MXMX creamcream waswas thethe oneone withwith thethe lowestlowest peakpeak forceforce andand AUC.AUC. than the MX and A4M spreads. MX cream was the one with the lowest peak force and AUC. ThisThis didifferencefference couldcould bebe associatedassociated withwith thethe presencepresence ofof lumpslumps andand thethe aeratedaerated texturetexture ofof thisthis This difference could be associated with the presence of lumps and the aerated texture of this sample.sample. The didifferentfferent texture providedprovided byby thethe MXMX spreadspread could be explained because of the didifferentfferent sample. The different texture provided by the MX spread could be explained because of the different texturetexture alsoalso shown shown by by the the initial initial MX emulsionMX emulsion in a previous in a previous study [ 8study]. This [8]. study This showed study that showed compared that texture also shown by the initial MX emulsion in a previous study [8]. This study showed that tocompared other cellulose to other ether cellulose emulsions, ether MX emulsions, showed lowerMX showed firmness lower and lowerfirmness viscoelastic and lower functions, viscoelastic fact compared to other cellulose ether emulsions, MX showed lower firmness and lower viscoelastic thatfunctions, was attributed fact that was to the attributed lowest level to the of lowest crystallization level of crystallization observed in the observed microstructure, in the microstructure, smaller than functions, fact that was attributed to the lowest level of crystallization observed in the microstructure, thesmaller other than methylcellulose the other methylcellul cellulose (A4M)ose cellulose ether spreads. (A4M) ether The presencespreads. ofThe smaller presence crystals of smaller forms crystals weaker smaller than the other methylcellulose cellulose (A4M) ether spreads. The presence of smaller crystals linksforms and weaker these links result and in a these decrease result of viscoelasticityin a decrease [of12 viscoelasticity]. The F4M emulsion [12]. The showed F4M theemulsion highest showed values forms weaker links and these result in a decrease of viscoelasticity [12]. The F4M emulsion showed the highest values of G’ and the closest behavior to butter, while MX emulsion showed the lowest the highest values of G’ and the closest behavior to butter, while MX emulsion showed the lowest

Foods 2020, 9, 796 5 of 8 of G’Foods and 2020 the, 9, closestx FOR PEER behavior REVIEW to butter, while MX emulsion showed the lowest viscoelasticity.5 In of the9 F4M emulsion a more dense crystalline structure is observed [8]. These results explain that the texture viscoelasticity. In the F4M emulsion a more dense crystalline structure is observed [8]. These results of the F4M spread at 20 ◦C is also harder and close to control spread, so this spread has an optimal explain that the texture of the F4M spread at 20 °C is also harder and close to control spread, so this behavior and could be an alternative to commercial full-fat spread. spread has an optimal behavior and could be an alternative to commercial full-fat spread. Table 1. Textural parameters (mean standard deviation) from penetration curves of the different Table 1. Textural parameters (mean± ± standard deviation) from penetration curves of the different spreads at 20 ◦C. spreads at 20 °C. Spreads Max. Force (N) AUC (N s) Spreads Max. Force (N) AUC· (N·s) ControlControl 85.3885.38 a ± 2.042.04 109.55109.55a 13.00 a ± 13.00 c ± ± b A4MA4M 19.8419.84 c ± 1.761.76 56.7356.73b 1.64 ± 1.64 F4M 66.61 b ±± 0.95 57.41± b ± 0.84 F4M 66.61 b 0.95 57.41 b 0.84 MX 23.26 c ±± 4.27 37.54± c ± 5.40 MX 23.26 c 4.27 37.54 c 5.40 AUC: Area under the curve. abc Values with the± same letter for each ±parameter are not statistically AUC: Area under the curve. abc Values with the same letter for each parameter are not statistically different (p < 0.05). different (p < 0.05).

3.2.2.3.2.2. Back Back Extrusion Extrusion Test Test ToTo evaluate evaluate changes changes in in sample sample texture texture caused caused byby inin vitrovitro digestion,digestion, a a back back extrusion extrusion test test was was conductedconducted at 37at 37◦C °C (simulating (simulating body body temperature). temperature). RepresentativeRepresentative extrusion extrusion curves curves of of the the different different creamscreams before before and and after after oral oral and and gastric gastric in in vitro vitro digestion digestion areare presentedpresented in Figure 33..

FigureFigure 3. 3.Extrusion Extrusion profilesprofiles of the the studied studied spread spread and and after after oral oral and andgastric gastric in vitroin vitrodigestion.digestion. (A, ((A)control; control; B, ( BA4M;) A4M; C, F4M; (C) F4M; D, MX). (D) MX).

FormulatedFormulated spreads spreads showed showed similar similar behavior behavior during during digestion. digestion. A decreaseA decrease in extrusionin extrusion force force was observedwas observed after in after vitro in digestion vitro digestion in the in mouth the mout buth was but much was much greater greater after af stomachter stomach digestion. digestion. TheThe behavior behavior of theof the control control sample sample after after oral oral digestion digestion diff ereddiffered completely completely from from the the spreads spreads with emulsion.with emulsion. The control The samplecontrol showedsample showed a notable a increasenotable increase in extrusion in extrusion force after force oral after digestion. oral digestion. In contact withIn saliva,contact the with commercial saliva, the spread commercial became consistent,spread became heterogeneous, consistent, andhete sticky;rogeneous, associated and sticky; with a saliva-inducedassociated with flocculation a saliva-induced effect. flocculation As is known, effect. saliva As is induces known, almost saliva induces instantaneous almost instantaneous flocculation of emulsionsflocculation [13,14 of]. emulsions Droplet aggregation [13,14]. Droplet in contact aggregation with saliva in contact was also with found saliva in fishwas oilsalso emulsified found in fish with lecithin,oils emulsified attributed with to depletion lecithin, attributed flocculation to induceddepletion by flocculation non-adsorbed induced mucin, by non-adsorbed or electrostatic mucin, screening or causedelectrostatic by inorganic screening salts [15caused]. This by di ffinorganicerence between salts [15]. commercial This difference and cellulose-based between commercial spreads wouldand cellulose-based spreads would explain the barrier effect exerted by the cellulose against the action of

Foods 2020, 9, 796 6 of 8 explain the barrier effect exerted by the cellulose against the action of saliva. A lack of effect of saliva on the structure of sunflower oil/cellulose emulsions was also observed; the microstructure, particle size distribution and viscoelastic properties were not affected [9,16]. Custard desserts prepared with HPMC or CMC were also not affected by mixing with saliva [12,17]. This difference in the saliva effect between control and cellulose-based spreads would lead to a different sensory perception in the mouth. The control cream would show an increase in hardness/consistency perceived during mixing with saliva, not perceptible in the reformulated spreads. After the gastric phase all the samples, including the control, were more fluid, showing a decrease in the extrusion force as their structure was altered due to the presence of enzymes, the change in pH and temperature and the dilution that occurs at this stage. The AUC gives an objective evaluation of the spreads’ consistency. Table2 shows the mean values of this parameter for each sample at each digestion stage. A significant increase (p < 0.05) was observed in the control sample after incubation with saliva, which confirms the aforementioned hypothesis.

Table 2. Extrusion parameter (AUC) (mean standard deviation) of the fresh spreads and after ± in vitro digestion.

Creams Digestion Step AUC (N s) · Fresh 27.42 a 4.22 ± Control Saliva 151.93 b 36.25 ± Stomach 3.78 a 0.26 ± Fresh 38.24 a 1.73 ± A4M Saliva 25.37 b 2.81 ± Stomach 9.63 c 1.09 ± Fresh 23.27 a 2.25 ± F4M Saliva 13.95 b 1.45 ± Stomach 4.18 c 0.24 ± Fresh 3.57 a 0.15 ± MX Saliva 2.87 b 0.16 ± Stomach 2.30 c 0.13 ± AUC: Area under the curve. abc Values with the same letter for each spread are not statistically different (p < 0.05).

3.3. Determination of FFA after In Vitro Digestion Figure4 shows the volume of NaOH consumed by each spread sample as a function of time, during incubation with intestinal fluids. A higher consumption of NaOH indicates an increased production of FFA during incubation, which would result in greater fat digestibility. During the first 30 min of incubation, a rapid increase in the consumption of NaOH is observed, neutralizing the FFA generated during the fat digestion, with no differences were between samples. However, this increase was followed by a more gradual release for the last digestion phase. This phenomenon may be due to the fact that the lipolysis products accumulated at the droplet interface, which restricted the access of the enzym complex to the triacylglycerides. After 30 min of intestinal incubation differences were observed between the samples, with a decrease of the curves’ gradients for the cellulose ether spreads. The F4M spread had the lowest NaOH consumption when the trial ended, followed by the MX and A4M spreads. This lower NaOH consumption indicates a lower digestibility in the emulsion-based spreads than the control spread. Therefore, cellulose ethers reduce the effectiveness of bile salts and digestive enzymes in fat digestion. To compare the differences between samples, Table3 shows the release of FFA (%) after in vitro digestion of each spread. Foods 2020, 9, 796 7 of 8 Foods 2020, 9, x FOR PEER REVIEW 7 of 9

12 A4M

10 MX

8 F4M

CONTROL 6

Volume (mL) 4

2

0 0 2000 4000 6000 8000 Time (s)

Figure 4.FigureVolume 4. Volume of NaOH of NaOH consumed consumed during during intestinal intestinal digestion digestion of the ofstudied the studied spreads. spreads.

Table 3. FFATable release 3. FFA release at the at end the ofend the of the in in vitro vitro digestion digestion expressed expressed as a asmean a mean ± standardstandard deviation. deviation. ± Spreads FFA (%) Spreads FFA (%) Control 62.61 a ± 0.82 A4MControl 62.6161.40 aa,b ± 0.820.26 ± MX A4M 61.4052.10a,b a,b ± 0.270.26 b ± F4M MX 52.1046.25a,b ± 0.200.27 abc ± Values with the sameF4M letter are not statistically46.25 b different0.20 (p < 0.05). ± ab The F4M spreadValues presented with the significantly same letter lower are not values statistically than the di controlfferent (spread,p < 0.05). and no significant differences with the other cellulose ether spreads. Although no significant differences were observed The F4Mbetween spread the cellulose presented ether significantlyspreads, the fat lowerrelease valuesprofile during than theintestinal control digestion spread, was and lower no in significant differencescase with of F4M the cream. other This cellulose finding ethercan be spreads.attributed to Although its greater hardness no significant and the different differences fat crystals were observed morphology in the initial emulsion, which consists of a dense crystalline structure with larger crystals between thecompared cellulose to A4M ether and spreads, MX emulsions the fat release[8]. Previous profile studies during confirm intestinal that the digestion polymorphic was lower in case of F4Morganization cream. This of the finding lipids in cancrystals be attributedmay result less to itsaccessible greater to hardnessthe enzymes and than the the diliquidfferent state fat crystals morphology[18]. in At the the same initial time, emulsion, larger fat crystals which may consists have greater of a dense spatial crystalline resistance to structureprevent the withadsorption larger crystals comparedof to the A4M enzymatic and MX complex emulsions [19]. [8]. Previous studies confirm that the polymorphic organization of the lipids4. Conclusions in crystals may result less accessible to the enzymes than the liquid state [18]. At the same time, larger fatMilk crystals fat-cellulose may haveether based greater em spatialulsions represent resistance a feasible to prevent alternative the adsorptionfor the elaboration of the of enzymatic complex [19reformulated]. spreads with reduced fat content which maintain their plastic properties. In this study, hydroxypropyl methylcellulose (F4M) provided the most consistent textured spread, very similar to 4. Conclusionscommercial spreads. Besides, these emulsion-based creams present a lower digestibility, which is associated with the barrier effect provided by cellulose of the emulsion against fat digestion. The Milkpresence fat-cellulose of cellulose ether ethers based reduces emulsions the effectiv representeness of saliva, a feasible bile salts alternative and digestive for enzymes the elaboration of reformulatedduring in spreads vitro digestion, with so reduced the bioavailability fat content of fat which is lower maintainthan in commercial their plastic spreads. properties. Although In this study, hydroxypropylfrom a nutritional methylcellulose point of view the (F4M)milk fat providedused has a high the mostpercentage consistent of saturated textured fatty acids, spread, very cellulose based emulsions contribute to the spreads nutritional improvement, since the emulsion has similar toa commercial lower initial fat spreads. content and Besides, reduces digestibility these emulsion-based in the final product. creams Furthermore, present cellulose a lower ether digestibility, which is associatedemulsion formulated with the with barrier milk fat eff ecthelps provided to accompli bysh cellulosethe characteristic of the plasticity emulsion of saturated against fats fat digestion. The presencethat cannot of cellulose be achieved ethers with reduces liquid oils, the thus eff ectivenessproviding consistency of saliva, and bile spreading salts and properties digestive like enzymes during in vitrothose ofdigestion, a commercial sothe spread. bioavailability of fat is lower than in commercial spreads. Although from a nutritional point of view the milk fat used has a high percentage of saturated fatty acids, cellulose based emulsions contribute to the spreads nutritional improvement, since the emulsion has a lower initial fat content and reduces digestibility in the final product. Furthermore, cellulose ether emulsion formulated with milk fat helps to accomplish the characteristic plasticity of saturated fats that cannot be achieved with liquid oils, thus providing consistency and spreading properties like those of a commercial spread.

Author Contributions: Conceptualization, A.S. and T.S.; methodology, A.S., T.S. and M.E.; formal analysis, A.S. and M.E.; investigation, A.S., T.S. and M.E.; writing: original draft preparation, M.E.; writing: revision and editing, A.S., T.S. and M.E. All authors have read and agreed to the published version of the manuscript. Foods 2020, 9, 796 8 of 8

Funding: This work was funded by grant RTI-2018-099738-B-C21 from the Spanish Ministry of Economy, Industry and Competitiveness. Conflicts of Interest: The authors declare that there are no conflict of interest.

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