Stability and release properties of double-emulsions stabilised by caseinate–dextran conjugates

The subject of the present paper was to investigate the possibility of stabilising water-in-oil-in-water emulsions (W/O/W) by using sodium caseinate (SC)–dextran (Dex) conjugates in order to influence the release of vitamin B₁₂ from the inner water phase (W₁) to the outer aqueous phase (W₂).To prepare the conjugate the SC was combined with Dex (M_r 250,000 or 500,000 g/mol) and incubated at 60 °C and a humidity of 79% for 8 h.The double emulsions, with encapsulated vitamin B₁₂, were prepared using a two-step emulsification technique. Whereas different amounts of polyglycerin polyricinoleate (PGPR, E476) were the hydrophobic emulsifier, the conjugate and the SC alone were used as the hydrophilic emulsifiers. The investigations comprised the determination of the particle size distribution of the W/O/W emulsion and measurement of the amount of vitamin B₁₂ migration from W₁- to the W₂-phase during the second stage of emulsion preparation and after heating or pH changing of emulsion.The water-containing oil droplets of the W/O/W emulsions were smaller and distributed more narrowly using SC–Dex conjugate as emulsifier instead of pure protein. Under acidic conditions, the conjugate-containing emulsions were more coalescence stable than the emulsions with SC, and the vitamin B₁₂ release from the inner W₁-phase was significantly decreased.     

Construction of a water-in-oil-in-water (W/O/W) double emulsion system based on oyster peptides and characterisation of freeze-dried products

In order to broaden the range of applications for oyster peptides in the food field, the amino acid composition of oyster peptide was analysed, after which the peptide sequence was identified using liquid-mass spectrometry technology. A W₁/O/W₂ double emulsion was prepared by the two-step shear emulsification method. The W₁/O/W₂ double emulsion was further freeze-dried after addition of alginate to obtain the final product, and the characteristics of the related product were analysed. The results show that oyster peptides are mainly composed of short peptides with molecular weights between 459.3 Da and 2716.3 Da. Polyglycerol polyrinoleate (PGPR) was selected as the emulsifier and added at 5% of the mass of the oil phase. The mass ratio of the oil phase to the water phase was O:W = 6:4, and optimal stability of the W₁/O emulsion was obtained by shearing and emulsifying for 2 min at 12 000 rpm. A superior W₁/O/W₂ double emulsion can be obtained by secondary emulsification in which the hydrophilic emulsifier Tween 80 was added at 0.8% (w/w) of the mass of the external water phase (W₂). The mass ratio of the emulsion to the external water phase was 5:5. The lyophilised product has good re-solubility, with the reconstituted emulsion maintaining the double-emulsion structure. Electronic nose results showed that the peculiar smell of the reconstituted emulsion was significantly lower than that of the oyster peptide solution. The results of this research provide a reference for the development and application of oyster peptides in the field of functional health foods.     

Lipid and protein structure analysis of frankfurters formulated with olive oil-in-water emulsion as animal fat replacer

Lipid and protein structural characteristics of frankfurter formulated with olive oil-in-water emulsion stabilized with soy protein isolate (SPI) as pork backfat replacer were investigated using Fourier transform infrared spectroscopy (FT-IR). Proximate composition and textural properties were also evaluated. Different frankfurters were reformulated: F/PF with pork backfat, F/SPI with oil-in-water emulsion stabilized with SPI and F/SPI + SC + MTG with emulsion stabilized with a combination of SPI, sodium caseinate (SC) and microbial transglutaminase (MTG). Replacement of pork backfat with these emulsions produced an increase (P < 0.05) of hardness, springiness, cohesiveness and chewiness but a reduction (P < 0.05) of adhesiveness. F/SPI and F/SPI + SC + MTG frankfurters showed the lowest (P < 0.05) half-bandwidth in the 2922 cm⁻¹ band, which could be related to lipid chains were more ordered than in F/PF. Modifications in the amide I band profile revealed a higher concentration of aggregated intermolecular β-sheets in F/SPI + SC + MTG samples. Lipid and protein structural characteristics could be associated with specific textural properties of healthier frankfurters.     

Low-fat frankfurters formulated with a healthier lipid combination as functional ingredient: microstructure, lipid oxidation, nitrite content, microbiological changes and biogenic amine formation

Oil (healthier lipid combination of olive, linseed and fish oils)-in-water emulsions stabilized with different protein systems (prepared with sodium caseinate (SC), soy protein isolate (SPI), and microbial transglutaminase (MTG)) were used as pork backfat replacers in low-fat frankfurters. Microstructure, lipid oxidation, nitrite content, microbiological changes and biogenic amine formation of frankfurters were analyzed and found to be affected by the type of oil-in-water emulsion and by chilling storage (2° C, 41 days). Although the lipid oxidation levels attained were low, replacement of animal fat by healthier oil combinations in frankfurter formulation did promote a slight increase in lipid oxidation. Residual nitrite was affected (P < 0.05) by formulation and storage. Only 51-61% of the added nitrite was detectable in the product after processing and 17-46% at the end of storage. The microbial population was low in all formulations during chilling storage. Spermine was the most abundant amine (19-20 mg/kg), but similar in level to all samples.     

Characterization of Chemically and Thermally Treated Oil‐in‐Water Heteroaggregates and Comparison to Conventional Emulsions

Heteroaggregated oil‐in‐water (O/W) emulsions formed by targeted combination of oppositely charged emulsion droplets were proposed to be used for the modulation of physical properties of food systems, ideally achieving the formation of a particulate 3‐dimensional network at comparably low‐fat content. In this study, rheological properties of Quillaja saponins (QS), sugar beet pectin (SBP), and whey protein isolate (WPI) stabilized conventional and heteroaggregated O/W emulsions at oil contents of 10% to 60% (w/w) were investigated. Selected systems having an oil content of 30% (w/w) and different particle sizes (d₄₃ ≤ 1.1 or ≥16.7 μm) were additionally subjected to chemical (genipin or glutaraldehyde) and thermal treatments, aiming to increase network stability. Subsequently, their rheological properties and stability were assessed. Yield stresses (τ₀) of both conventional and heteroaggregated O/W emulsions were found to depend on emulsifier type, oil content, and initial droplet size. For conventional emulsions, high yield stresses were only observed for SBP‐based emulsions (τ₀,_SBP approximately 157 Pa). Highest yield stresses of heteroaggregates were observed when using small droplets stabilized by SBP/WPI (approximately 15.4 Pa), being higher than those of QS/WPI (approximately 1.6 Pa). Subsequent treatments led to significant alterations in rheological properties for SBP/WPI systems, with yield stresses increasing 29‐fold (glutaraldehyde) and 2‐fold (thermal treatment) compared to untreated heteroaggregates, thereby surpassing yield stresses of similarly treated conventional SBP emulsions. Genipin‐driven treatments proved to be ineffective. Results should be of interest to food manufacturers wishing to design viscoelastic food emulsion based systems at lower oil droplet contents.     

Stability of Anthocyanin‐Rich W/O/W‐Emulsions Designed for Intestinal Release in Gastrointestinal Environment

Abstract: Anthocyanins belong to the most important hydrophilic plant pigments. Outside their natural environment, these molecules are extremely unstable. Encapsulating them in submicron‐sized containers is one possibility to stabilize them for the use in bioactivity studies or functional foods. The containers have to be designed for a target release in the human gastrointestinal system. In this contribution, an anthocyanin‐rich bilberry extract was encapsulated in the inner aqueous phase of water‐in‐oil‐in‐water‐double emulsions. The physical stability as well as the release of free fatty acids and encapsulated, bioactive substances from the emulsions during an in vitro gastrointestinal passage were investigated. The focus was on the influence of emulsion microstructural parameters (for example, inner and outer droplet size, disperse phase content) and required additives (emulsifier systems), respectively. It could be shown that it is possible to stabilize anthocyanins in the inner phase of double emulsions. The release rate of free fatty acids during incubation was independent of the emulsifier used. However, the exterior (O/W)‐emulsifier has an impact on the stability of multiple emulsions in gastrointestinal environment and, thus, the location of release. Long‐chained emulsifiers like whey proteins are most suitable to transport a maximum amount of bioactive substances to the effective location, being the small intestine for anthocyanins. In addition, it was shown that the dominating release mechanism for entrapped matter was coalescence of the interior W₁‐droplets with the surrounding W₂‐phase. Practical Application: Microencapsulation of phytochemicals and bioactives is in the focus of functional food development. Here, the influence of matrix material, formulation, and structural parameters on stabilization and release of the molecules encapsulated has to be known for target product and process design. As the results are representative for hydrophilic active ingredients encapsulated in double emulsion systems a cross‐sectoral use in the pharmaceutical sector is possible.     

酪蛋白酸钠-葵花籽油协同对乳化肠品质特性的影响

以猪后腿肉为原料肉,酪蛋白酸钠、葵花籽油预乳化液替代猪背膘制备乳化肠,研究不同比例（0、25%、50%、75%、100%）预乳化液替代对乳化肠蒸煮损失率、物理化学组成、色泽、质构、脂肪酸组成及硫代巴比妥酸值的影响。结果显示：随着预乳化液替代比例增加,乳化肠中蛋白质、水分的含量显著增加（P＜0.05）,灰分含量变化差异不显著,脂肪含量显著下降（P＜0.05）,从18.58%降低到10.17%;蒸煮损失率降低;乳化肠的亮度值随预乳化液代替猪背膘比例的增加呈上升趋势,红度值和黄度值呈下降趋势;预乳化液替代组乳化肠的质构特性优于对照组;预乳化液替代猪背膘制备乳化肠还可以改变乳化肠的脂肪酸组成,随替代比例的增大,乳化肠中必需脂肪酸亚油酸在总脂肪酸中所占的比例显著增加（P＜0.05）,多不饱和脂肪酸所占的比例增加,高达55.92%,饱和脂肪酸从39.72%降低到13.52%,满足消费者对低脂多不饱和脂肪酸肉制品的需求;随替代比例的增大,乳化肠的TBARS值逐渐减小,用预乳化液替代猪背膘可增强乳化肠的氧化稳定性。因此,酪蛋白酸钠、葵花籽油预乳化液替代猪背膘可显著改善乳化肠的品质及营养特性。     

Double emulsion (W/O/W) gel stabilised by polyglycerol polyricinoleate and calcium caseinate as mangiferin carrier: insights on formulation and stability properties

Mangiferin (MGF) is a phenolic compound isolated from mango, but its poor solubility significantly limits its use. In this study, MGF was embedded into the inner aqueous phase of W₁/O/W₂ emulsions. Firstly, the dissolution method of MGF was determined. MGF remained stable in solution with pH 13 at 30 min, and its solubility reached 10 mg mL⁻¹. When the pH of MGF solutions was adjusted from pH 13 to pH 6, MGF did not immediately crystallise, providing sufficient time to construct the MGF-loaded W₁/O/W₂ emulsions. Subsequently, the MGF-loaded W₁/O/W₂ emulsions were constructed using polyglycerol polyricinoleate (PGPR) and calcium caseinate (CAS). The formation and stability of the W₁/O/W₂ emulsions were investigated. The MGF-loaded W₁/O/W₂ emulsions stabilised with 1% PGPR and 1% – 3% CAS exhibited a low viscosity, limited loading capacity, and poor stability. Conversely, the MGF-loaded W₁/O/W₂ emulsions stabilised by 3%PGPR–3%CAS exhibited optimal loading capacity (encapsulation efficiency = 95.31% and loading efficiency = 0.91%) and stability, which was attributed to the fact that high viscosity and gel state retarded the migration of inner aqueous phase. These results indicated that the W₁/O/W₂ emulsions stabilised by PGPR and CAS may be a potential alternative for encapsulating mangiferin.     

Formulation and rheological characterization of reduced-calorie food emulsions

Water-in-oil-in-water (W/O/W) double emulsions are systems where a water-in-oil emulsion (W/O) is dispersed in a second aqueous phase. The W/O emulsion exists in the suspending aqueous medium as oil globules containing smaller water droplets.
In this work, a selection of both materials and procedures has been made in order to obtain an optimal formulation of a W/O/W food emulsion for both yield and rheologica] properties.
The rheological properties of W/O/W emulsions have been studied by means of both steady-shear and oscillatory measurements, and appeared to be similar to those of a simple O/W emulsion having the same volume fraction of dispersed phase, but lower oil content.
This is of great interest to the food industry, since producing double emulsions with the same texture as simple ones, but a lower oil content, helps to formulate reduced-calorie foods.     

Physico chemical,microstructural and sensory characteristics of low‐fat meat emulsion containing aloe gel as potential fat replacer

In this study, a possible use of aloe gel (AG) as a potential fat replacer in the manufacture of low‐fat meat emulsion was investigated. The low‐fat meat emulsions with added AG and vegetable oil (VO) in different proportions [AG7.5 (7.5% AG + 7.5% VO); AG5 (5% AG + 10% VO); AG2.5 (2.5% AG + 12.5% VO)] were compared with full‐fat meat emulsion [Control (15% VO only)]. A substantial fat reduction (P < 0.05) up to 50% as compared to full‐fat control meat emulsion was recorded without compromising other sensory attributes of meat emulsion. Microstructural properties as studied by scanning electron microscopy indicated more homogenous regular emulsion matrix with fewer cracks and more regular shaped oil droplets in AG‐added samples than the control samples.     

Preparation and Characterization of Water/Oil/Water Emulsions Stabilized by Polyglycerol Polyricinoleate and Whey Protein Isolate

ABSTRACT: In this study we tried to prepare stable water-in-oil-in-water (W/O/W) emulsions using polyglycerol polyricinoleate (PGPR) as a hydrophobic emulsifier and whey protein isolate (WPI) as a hydrophilic emulsifier. At first, water-in-oil (W/O) emulsions was prepared, and then 40 wt% of this W/O emulsion was homogenized with 60 wt% aqueous solution of different WPI contents (2, 4, and 6 wt% WPI) using a high-pressure homogenizer (14 and 22 MPa) to produce W/O/W emulsions. The mean size of final W/O/W droplets ranged from 3.3 to 9.9 μm in diameter depending on the concentrations of PGPR and WPI. It was shown that most of the W/O/W droplets were small (<5 μm) in size but a small population of large oil droplets (d > 20 μm) was also occasionally observed. W/O/W emulsions prepared at the homogenization pressure of 22 MPa had a larger mean droplet size than that prepared at 14 MPa, and showed a microstructure consisting of mainly approximately 6 to 7-μm droplets. When a water-soluble dye PTSA as a model ingredient was loaded in the inner water phase, all W/O/W emulsions showed a high encapsulation efficiency of the dye (>90%) in the inner water phase. Even after 2 wk of storage, >90% of the encapsulated dye still remained in the inner water phase; however, severe droplet aggregation was observed at relatively high PGPR and WPI concentrations.     

Sodium caseinate–maltodextrin conjugate stabilized double emulsions: Encapsulation and stability

The potential food applications of water-in-oil-in-water (W₁/O/W₂) double emulsions are great, including the encapsulation of flavours or active ingredients. However, the stability of these emulsions restricts their applications in food systems. Sodium caseinate (NaCN)–maltodextrin (Md40 or Md100) conjugates were investigated for their potential to improve the stability of W₁/O/W₂ double emulsions compared to NaCN. NaCN–Md40 and NaCN–Md100 conjugates were prepared by a Maillard-type reaction by dry heat treatment of mixtures of NaCN–Md40 or NaCN–Md100 at 60 °C and 79% relative humidity for 4 days. Water-in-oil-in-water (W₁/O/W₂) double emulsions with NaCN, NaCN–Md40 or NaCN–Md100 as outer aqueous phase containing emulsifier were prepared using a two-step emulsification process. General emulsion stability was characterised by determining the droplet size distribution, viscosity characteristics and by confocal microscopy of the W₁/O/W₂ double emulsions on formation and after their storage under accelerated shelf life testing conditions at 45 °C for up to 7 days. Inner phase encapsulation and stability were characterised by monitoring the level of entrapped Vitamin B₁₂ in the inner aqueous phase on formation of the double emulsions and after storage at 45 °C for up to 7 days. Conjugate stabilized emulsions were more generally stable than NaCN stabilized emulsions. In comparison to NaCN stabilized emulsions, conjugate stabilized emulsions showed improved Vitamin B₁₂ encapsulation efficiency in the inner aqueous phase on emulsion formation and improved encapsulation stability following storage of the emulsions.     

Olive oil-in-water emulsions stabilized with caseinate: Elucidation of protein–lipid interactions by infrared spectroscopy

This paper reports a FT-IR study for probing lipid and protein structural changes and their interactions in various oil-in-water emulsions. Two different emulsions were prepared using sodium caseinate, as stabilizer system, without and with microbial transglutaminase (MTG), denominated E/SC and E/SC + MTG respectively. Proximate composition, fat and water binding properties and textural characteristics were also evaluated in the emulsions. Penetration force and gel strength values were used to distinguish different (P < 0.05) textural behaviours depending on the formulation of emulsifying system. E/SC + MTG emulsion showed gel textural behaviour while E/SC lack of this property. The spectral results showed frequency upshifting of the amide I band in going from protein stabilizer systems isolate (the solution used as reference) to their corresponding emulsions, what is attributable to greater protein structural order upon emulsion formation. Enzymatic action of MTG in the sodium caseinate stabilizing system induces structural changes, in terms of lipid chain disorder or lipid–protein interactions and protein secondary modifications, which may reflect the formation of a gel structure in the emulsion. These results could help to choose the stabilizing system that is most suitable and effective for its use in the formulation of food products.     

Effect of a new emulsifier containing sodium stearoyl-2-lactylate and carrageenan on the functionality of meat emulsion systems

The emulsion capacity and stability of a new emulsifier containing sodium stearoyl lactylate plus iota carrageenan (SSL/iC) in comparison to caseinate and soy isolate was analysed. The emulsion capacity and stability of SSL/iC in oil/water (O/W) model system emulsions was higher than shown by caseinate and soy isolate. However, the O/W emulsion stability was negatively affected by sodium chloride addition, but positively affected by an increase in temperature. Meat batters were made with caseinate, soy isolate, and SSL/iC at the minimum concentration that showed a good performance (>75% stability) in the O/W emulsions. The emulsifier SSL/iC produced high cook yields and good stability when used in meat batters. However, the cooked meat batters containing SSL/iC showed texture characteristics highly detrimental to the sensory analysis. On the other hand, the addition of 2% potato starch reduced the differences in texture parameters among the samples made with the different emulsifiers.     

Stability and release properties of double emulsions for food applications

Water-in-oil-in-water (W₁/O/W₂) double emulsions (DEs) containing gelatin and sodium chloride (NaCl) in the inner aqueous phase were developed for controlled release applications. Emulsions were prepared with water and canola oil, as well as with polyglycerol polyricinoleate and polysorbate 80 as emulsifiers for the primary water-in-oil (W₁/O) emulsion and secondary W₁/O/W₂ emulsions, respectively. All DEs containing both NaCl and gelatin were stable against sedimentation for the month-long study whereas control emulsions (with either no NaCl or gelatin) showed visual phase separation. The average oil globule size in freshly-prepared DEs grew from ∼45 to 70 μm with an increase in salt load from 2 to 8% (w/w), and changed little after 1 month. Besides its role in stabilization, NaCl was also used as a marker to evaluate DE release behaviour. The salt diffusion coefficient obtained using Fujita’s model rose from 4.7 to 6.0 × 10⁻¹¹ cm²/s with increasing NaCl concentration in the DEs from 2 to 8% (w/w). All stable DEs showed a high salt retention in the inner aqueous phase (>94%) after 1 month of storage at 4 °C. These results demonstrated the synergistic action of a gelling agent and electrolyte in stabilizing and modulating the release behaviour of NaCl from W₁/O/W₂ DEs.     

Synergistic effects of polyglycerol ester of polyricinoleic acid and sodium caseinate on the stabilisation of water–oil–water emulsions

The inherent thermodynamic instability of water–oil–water (W/O/W) emulsions has restrictions for their application in food systems. The objective of this study was to develop a food grade W/O/W emulsions with high yield and stability using minimal concentrations of surfactants. Emulsions were prepared using soybean oil, polyglycerol ester of polyricinoleic acid (PGPR) alone or in combination with sodium caseinate (NaCN) as emulsifier(s) for primary water-in-oil (W/O) emulsions and NaCN as the sole emulsifier for secondary W/O/W emulsions. Increasing the concentration of PGPR (0.5–8%w/v) had no effect on the droplet sizes of the resulting W/O/W emulsions. However, significant increases in droplet sizes of W/O/W emulsions were observed when the concentration of NaCN in external phase was reduced from 0.5 to 0.03% (w/v) (p<0.05). Percentage yields of emulsions (using a water-soluble dye) improved when PGPR concentration in the inner phase was increased from 0.5 to 8% (w/v). A stable W/O/W emulsion with a yield >90% could be prepared with 4% (w/v) PGPR alone as primary hydrophobic emulsifier and 0.5% (w/v) NaCN as external hydrophilic emulsifier. The concentration of PGPR in the inner phase could be reduced to 2% (w/v) without affecting the yield and stability of the W/O/W emulsion by partially replacing PGPR with 0.5% (w/v) NaCN, which was added to the aqueous phase of the primary W/O emulsion. The results indicate that a possible synergistic effect may exist between PGPR and NaCN, thus allowing formulation of double emulsions with reduced surfactant concentration.     

鹰嘴豆分离蛋白对减盐猪肉糜凝胶品质的影响

为探究鹰嘴豆分离蛋白(chickpea protein isolate, CPI)不同添加量对2种盐含量(质量分数1.4%和2%)猪肉糜凝胶品质的影响,将猪瘦肉与猪背膘斩拌成肉糜,分别设置不同盐含量和鹰嘴豆分离蛋白的处理组并加热制成凝胶。测定猪肉糜凝胶的色泽、乳化稳定性、质构、水分分布和流变特性。结果表明,在不添加鹰嘴豆分离蛋白的条件下,1.4%食盐质量分数的猪肉糜凝胶的汁液流失和硬度值显著高于2%食盐浓度的猪肉糜凝胶;相同食盐浓度条件下,随着CPI添加量的增加,猪肉糜凝胶的a^*值、b^*值、硬度、弹性、咀嚼性以及不易流动水比例均显著增加(P<0.05),动态流变储能模量G′值升高,汁液流失率显著降低(P<0.05),并在CPI添加量为1.2%时达到最大值或最小值;在相同CPI添加量条件下,1.4%食盐1.2%CPI的猪肉糜凝胶的储能模量G′值高于2%食盐1.2%CPI的猪肉糜凝胶,且2组凝胶的不易流动水比例、乳化稳定性、质构特性无显著差异(P>0.05)。综上,鹰嘴豆分离蛋白的添加能够在降低食盐用量的同时提升猪肉糜的凝胶品质...     

Oil bulking agents based on polysaccharide gels in meat batters: A Raman spectroscopic study

A Raman spectroscopic study was performed to determine protein and lipid structural properties in meat batter containing oil bulking agents as pork backfat replacers. Meat batters were prepared with pork backfat (MB-PF) or with a combination of olive oil, sodium alginate, CaSO₄, sodium pyrophosphate and dextrin (MB-A/D) or inulin (MB-A/I) as a fat replacer. Proximate composition, pH, cooking loss (CL), colour and texture were evaluated. MB-A/D and MB-A/I both showed lower (P < 0.05) CL and a^∗ values, higher (P < 0.05) L^∗ and b^∗ values, and higher (P < 0.05) hardness and chewiness. MB-A/I showed the highest hardness and chewiness. Enhancement of the β-sheet structure was observed in MB-A/D and MB-A/I, more so in MB-A/I. There was increased disorder in the oil acyl chains, which involve lipid–protein interactions, in both MB-A/D and MB-A/I. Structural characteristics in proteins and lipids may be associated with specific water and fat binding properties and textural characteristics of meat batters.     

A healthier oil combination and konjac gel as functional ingredients in low-fat pork liver pâté

Healthier lipid patés were formulated by reducing the fat content and/or replacing the pork backfat by a healthier oil combination (olive, linseed and fish oils) and konjac gel (0-15%). The reformulation results were evaluated by composition (proximate analysis and fatty acid profile), technological properties (emulsion stability, colour, and texture), microbiological and sensory parameters of the patés. Patés with partial or total replacement of pork backfat had lower levels of saturated fatty acids (SFA) (27.4% and 21.3%) and monounsaturated fatty acids (MUFA) (49.8% and 42.5%), and higher levels of polyunsaturated fatty acids (PUFA) (22.4% and 35.6%) compared with control patés (32.2%, 58.2% and 9.04% respectively). The n-6/n-3 PUFA ratio was decreased from 6.78 (in control patés) to 0.79 and 0.48 when partial and total pork backfat respectively was replaced by a healthier oil combination. Although emulsion stability was affected by the formulation, in general all patés had good fat and water binding properties. The fat reduction produced a softer and more spreadable paté, although no effect on penetration parameters was observed after by pork fat replacement by a healthier oil combination. The addition of 15% of konjac gel produced stiffer structures (as compared with 0 and 7%) which are very close to those of the control samples. No microbiological limitations were produced by the reformulation process, obtaining patés with acceptable sensory characteristics, similar to the control sample.     

Impact of amylose from maize starch on the microstructure,rheology and lipolysis of W/O emulsions during simulated semi-dynamic gastrointestinal digestion

This study aims to examine the microstructure, rheology and lipolysis of water-in-oil (W/O) emulsions (40 wt.%) prepared with or without (Control) the addition of normal (NAM) and high amylose (HAM) maize starch during simulated digestion in a semi-dynamic gastrointestinal tract (GIT) model. Microstructural examinations showed modification in initial W/O emulsion droplets to multiple W₁/O/W₂ droplets during in vitro digestion. This is in line with the rheological results, where the shear viscosity and moduli in the oral phase were remarkably reduced after entering the intestinal phase. In comparison to control and NAM emulsions, HAM emulsions showed a more compact and continuous network structure and greater viscosity and elastic modulus throughout GIT digestion. These results support lipolysis, where fewer free fatty acids were released in the HAM emulsion (70%) than in the control (86%) and NAM (78%) emulsions. This work has provided an in-depth understanding of the digestion of W/O emulsions as influenced by amylose content, which is meaningful for the development of low-fat products with reduced lipid digestibility.