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Microfluidization is a technique commonly used to disrupt and homogenize dispersions such as oil-in-water emulsions or cellular suspensions. In this study, we investigated its ability to alter the physicochemical properties of plant-derived insoluble protein aggregates such as those found in pea protein extracts. Insoluble pea protein dispersions (5% w/w, pH 7) were homogenized at 25–150 MPa for 1–5 cycles. Increasing the homogenization pressure and cycles decreased the particle size (d43) of the unhomogenized insoluble pea proteins from 180 ± 40 μm to 0.2 ± 0.0 μm (at ≥ 125 MPa), leading to more transparent dispersions. Furthermore, the solubility of the insoluble pea proteins increased from 23 ± 1% to 86 ± 4%. Treatments with chaotropic agents, dithiothreitol and urea, revealed that insoluble pea protein aggregates were stabilized not only by disulphide bonds but also by hydrogen bonds and hydrophobic interactions. These molecular interactions were disrupted by microfluidization. The study provides insights into the disruption mechanism of insoluble pea proteins by applying microfluidization and offers a mean to improve their technofunctional properties to facilitate further use in food manufacture.

Plant-based emulsion gels can be used as solid animal fat substitutes for vegan sausages. For this reason, commercially available protein isolates with different amino acid profiles from pea, soy and potato (Pea-1, Pea-2, Soy, Potato) have been tested for their ability to form shape stable emulsions gels at neutral pH and upon heating to 72 °C. In order to obtain emulsion gels that are as solid as possible, the protein concentrations in the continuous phase (CPC, 8.0–11.5% (w/w)) and the oil mass fractions (65–80%) were varied. For leguminous proteins, a positive correlation of both parameters on emulsion rigidity was shown, indicating that both, interfacial and protein–protein interactions, are involved in structure reinforcement. Firmness increased with increasing content in cysteine (Pea-1 PC and oil content. The emulsions showed a much higher degree in crosslinking, and very low charge density. Temperature-sweep analysis and CLSM revealed that Potato protein gelled as consequence to low temperature stability. Hence, the structure reinforcement in Potato emulsions mainly contributed to the protein network, with 70% oil and CPC 11.5% forming a hybrid gel with highest firmness. However, gelling of Potato protein also resulted in interfacial adsorption of protein aggregates and reduced interfacial stability with increasing CPC. This was demonstrated in the amount of extractable fat which was 2.0 and 0.6% for Pea-1 and 2 emulsions, 6.4% for Soy and 34.4% of total fat for Potato emulsions.

Background Oleosomes, widely found in plants, mammals, and microorganisms to act as an energy reservoir for future needs, are a micron- or submicron-sized system of oil droplets surrounded by a specialized membrane of protein-phospholipid mixtures designed through natural evolution. Recently, interest in the plant-derived oleosomes has rapidly increased in food industry, since these unique natural emulsions are a safe alternative to synthetically engineered oil droplets. Scope and approach More and more researches have focused on the plant-based oleosomes due to attractive advantages, such as easy extraction, high yield recovery, and safe use in food products to satisfy consumers' demands for “all natural” products. This review provides the latest information on the structure and composition, and extraction techniques of plant-derived oleosomes. The stability characteristics of oleosomes during storage and processing, and their emerging food applications as well as future perspectives are discussed. Key findings and conclusions Recent studies have reported the alternative extraction techniques (e.g., twin-screw press-, enzyme assisted-, and ultrasound assisted extractions) to obtain native intact oleosomes from oleaginous plant materials, which contain triacylglycerols, phospholipids, distinguished proteins (e.g., oleosin, caleosin, and steroleosin), and some minor bioactive components. By careful control of the stability characteristics such as pH, ionic strength, and temperature, the extracted oleosomes have shown promising applications to inhibit lipid oxidation, encapsulate bioactive compounds (e.g., volatile flavors and hydrophobic nutraceuticals), prepare imitation milk products (e.g., milk, cheese, yogurt, and mayonnaise), and fabricate edible functional films.

In this study, the influence of low (5 °C), intermediate (15 °C) and high (25 °C) storage temperatures on the profile of volatile compounds of North European cured loins fermented with Staphylococcus carnosus strains was investigated. In this context, proteolytic activity, bacterial growth, key volatile compounds and sensory attributes were studied. In conclusion, storage temperature significantly affected the volatile marker compounds. A multiple regression indicated significant effects of seven volatile compounds (acetophenone, benzaldehyde, butanone, 3-methylbutanal, 1-octen-3-ol, nonanal and pentanone) on the overall odor (R2 = 95.9%) and overall flavor (R2 = 81.1%). The sum of the marker volatiles aldehydes, ketones and alcohol increased with rising temperatures and the highest amounts of the odor active 3-methylbutanal up to 155 and 166 ng/g meat were detected in high temperature-stored loins. Moreover, the addition of S. carnosus strain LTH 3838 showed maximum effect at 5 °C-storage temperature in comparison to the control.

In the meat industry, hydrocolloids and phosphates are used to improve the quality attributes of meat products. However, latest research results revealed that the usage of exopolysaccharide (EPS)-forming lactic acid bacteria (LAB), which are able to produce EPS in situ during processing could be an interesting alternative. The current review aims to give a better understanding of bacterial EPS production in food matrices with a special focus on meat products. This includes an introduction to microbial EPS production (homopolysaccharides as well as heteropolysaccharides) and an overview of parameters affecting EPS formation and yield depending on LAB used. This is followed by a summary of methods to detect and characterize EPS to facilitate a rational selection of starter cultures and fermentation conditions based on desired structure-function relationships in different food matrices. The mechanism of action of in situ generated EPS is then highlighted with an emphasis on different meat products. In the process, this review also highlights food additives currently used in meat production that could in the future be replaced by in situ EPS-forming LAB. ispartof: COMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY vol:19 issue:6 pages:2932-2954 ispartof: location:United States status: published

The purpose of the study was to investigate the influence of a heteropolysacchride (HePS)-forming lactic acid bacteria (LAB) on the quality attributes of raw fermented sausages. Therefore, salamis with the HePS-producing strain Lactobacillus plantarum TMW 1.1478 or the non-EPS-producing strain Lactobacillus sakei TMW 1.2037 (control) were manufactured using two different inoculation concentrations: more precisely, 10(7) CFU/g (typical starter culture concentration) or 10(9) CFU/g. Growth behavior, a(w) and pH development were recorded until a weight loss of 31% was reached and in-situ-formed EPS detected using confocal laser scanning microscopy. Moreover, the influence of the HePS formed on texture (texture profile analysis; TPA) and sensory attributes (26 panelists, ranking test) was investigated. The final products containing L. plantarum TMW 1.1478 were found to be significantly softer (p

On dry fermented sausages, especially co-extruded with calcium alginate casings, the formation of white crystals on the surface of the product is a common problem. In this study a hurdle system of combinations of different metal complexing chelators (citric acid and polyphosphate) was investigated. The control and the sample produced with 1.1% citric acid in the alginate gel showed strong white efflorescence formation during the storage (∼60% of the surface was covered), whereas the samples with added 0.3% polyphosphate showed no efflorescence formation. The efflorescence-causing substances such as lactate, magnesium, and calcium increased significantly in the samples, which showed the strongest white efflorescence formation. In the control, lactate increased by 45.0%, calcium by 23.9%, and magnesium by 150.8%, whereas in the samples without white efflorescence, the magnesium and lactate content increased only slightly, and the calcium content even decreased during the storage of 8 weeks. The best results were observed on the addition of 0.3% polyphosphates and the citric acid surface treatment directly after the co-extrusion. Moreover, the strong complex formation could be due to the complexation of magnesium and calcium by lactate, whereby they are removed from the diffusion equilibrium leading to an increased diffusion of the efflorescence-causing substances. PRACTICAL APPLICATION: White efflorescence formation on dry fermented sausages is a major problem on dry fermented sausages, which causes food waste and financial loss for the producer. This study investigated different combinations of promising methods and it was possible to inhibit the white efflorescence formation during the storage. The methods are easy to implement during the manufacturing of the products and are therefore quite interesting for the industrial applications.

Microencapsulation of oxidation sensitive oils aims to separate lipids from the environmental oxygen by embedding oil droplets in a solid matrix, which builds a physical barrier. Some oil droplets are not fully incorporated and are in contact with the powder surface generating surface oil. It is proposed that the probability of oil droplets being in contact with the particle surface increases with the oil droplet size. The aim of the study is to investigate the impact of the oil droplet size on the encapsulation efficiency (EE). Two sets of feed emulsions differing in the applied homogenization pressure and in the protein to oil ratio were spray dried using a pilot plant spray dryer. The oil droplet size of the emulsion was determined by static light scattering (SLS). In addition, nuclear magnetic resonance (NMR) was used to measure the d3,2 of oil droplets in the emulsion and in the powder before and after surface oil removal. Encapsulates were analyzed regarding aw, moisture content, particle size, oil load and EE. The oil droplet size in the emulsion decreased with increasing protein to oil ratio as well as with the homogenization pressure. Large oil droplets and in particular droplet clusters resulted in more non-encapsulated oil. The experimentally determined EE was in accordance with the theoretical one, calculated based on the droplet and particle diameter. For emulsions with a diameter > 1 µm, the d3,2 decreased in the powder and further by removing the surface oil, which was related to the deformation of oil droplets contributing to the non-encapsulated oil.

There is an increasing interest in the food industry to use potato protein as an alternative plant protein. However, its bitter taste often limits the utilization in novel foods and beverages. Coacervation is a promising technique to mask bitterness of certain food compounds. In the present study, we aimed to reduce the degree of bitterness of potato protein by generating protein-pectin complexes based on coacervation. Potato protein isolate and pectins derived from various origins having different degree of esterification (DE) were initially mixed under acidic conditions to promote the formation of complexes. Single and complex biopolymers were then characterized in terms of surface charge, solubility, rheological and sensorial properties as a function of protein pectin ratio, pectin source, and the degree of esterification, respectively. The protein-pectin ratio and degree of esterification of pectins substantially influenced the interaction behaviour and phase separation of the protein-pectin mixtures. The bitterness score decreased with increasing surface charge and pectin concentration. Bitterness was strongly reduced for complexes formed with high DE citrus pectin at a protein pectin ratio 0.33. The complexes generated at this ratio were relatively stable based on visual observation and microscopic images. Our results might have significant implications for the utilization of potato proteins in beverage applications.

Microalgae are considered to be a promising alternative protein source after extraction and fractionation. Studies have shown that the insoluble protein fraction possesses interfacial activity and is able to stabilize oil-in-water emulsions after acid hydrolysis. The current work studied the surface pressure and foaming properties of the insoluble microalgae protein fraction obtained from Chlorella protothecoides and two of their hydrolysates. Results showed that the surface pressure of the three used protein fractions increased with increasing protein concentration. Moreover, surface pressure of the insoluble microalgae protein increased after hydrolysis at 65 °C (Hydrolysates 65) or 85 °C (Hydrolysates 85) suggesting an increased foaming capacity of the insoluble microalgae protein fraction after hydrolysis. Hydrolysates 85 had the highest foam capacity, and foams remained stable with a half-life time of over 5 h. Overall, hydrolysis of the insoluble microalgae protein fraction with 0.5 M HCl at 85 °C for 4 h resulted in generation of protein fragments that appear to be very suitable to stabilize air-water interfaces in foam-based foods.

Knowledge of binary emulsifiers' influence on the formation and stability of emulsion-based products is still limited. The aim of this study was to investigate the emulsifying properties of Quillaja saponin-egg lecithin mixtures at different concentration ratios (r = 5:0, 4:1, 3:2, 2:3, 1:4, and 0:5) with total emulsifier concentration set to 0.5% or 1.0% (w/w). For this, oil-in-water emulsions (10% oil, pH 7) were prepared via high-pressure homogenization. Furthermore, emulsion stability against different environmental stresses was tested. All the binary emulsifier mixtures formed submicron sized emulsions upon homogenization. The most stable emulsions among the mixed emulsifiers were obtained at low Quillaja saponin concentration at r = 1:4 that showed similar physical stability over time to emulsions stabilized by Quillaja saponins and egg lecithin alone. The data suggested that the mixtures of Quillaja saponins and egg lecithins built mixed interfacial layers that were prone to changes over time. Emulsions stabilized by the binary mixtures were in general less stable against changes in pH and ionic strength than the emulsions stabilized by the individual emulsifiers. An exception were the emulsions at r = 1:4 that showed improved stability at pH 2 over the phase separated Quillaja saponin-stabilized emulsions at the same pH. Moreover, all the emulsions were heat stable up to 90 °C. On the other hand, none of the emulsions were stable upon freeze-thawing. These results increase our understanding of technofunctionality of binary emulsifier systems. PRACTICAL APPLICATION: Food-grade and natural emulsifier mixtures composed of Quillaja saponins and egg lecithin may be used in selected emulsion-based food or personal care product applications to replace synthetic surfactants due to issues with consumer acceptance and regulatory restrictions.

The purpose of the study was to investigate the effect of a reduced pH value (5.1 instead of 5.5 to 5.6) on the properties of highly perishable, spreadable raw fermented sausages (onion mettwurst) with or without the addition of homopolysaccharide (HoPS)-producing lactic acid bacteria (LAB). Hence, sausages with HoPS-producing LAB and a pH value of 5.1 were produced and compared to sausages (pH 5.1) produced with a non-exopolysaccharide (EPS)-forming strain (Lactobacillus sakei TMW 1.2037). Microbial growth and pH values were monitored during processing (24 °C for 48 hr, 10 °C for 24 hr) and storage (14 days at 0 to 2 °C). Furthermore, fat (Weibull-Stoldt) and EPS contents were determined in the final products. Sausages were characterized using texture profile and sensory analysis. The fat contents ranged from 16% to 19% and the determined EPS concentrations ranged from 0.17 to 0.59 g/kg for L. sakei TMW 1.411 and Lactobacillus curvatus TMW 1.1928 and from 0.67 to 1.58 g/kg for L. curvatus TMW 1.51. The strains L. sakei TMW 1.411 and L. curvatus TMW 1.51 reduced the hardness of the samples significantly (P

Animal fat tissue (that is, pork or beef fat) is composed of liquid and solid fat incorporated in a network of connective tissue. Hence, their rheological and thermal properties may differ significantly from plant-derived fats. Specifically, animal fats have elastic and melting properties that give rise to not only a certain comminution behavior during processing, but also provide meat products such as sausages with certain organoleptic properties. To mimic key properties of animal fat tissue with plant-derived materials, a new structuring approach was used. Canola oil was mixed with

Solid lipid nanoparticles (SLN) have emerged as a potential delivery system for bioactive ingredients, as they are associated with improving the stability of incorporated bioactive components by preventing their diffusion to the particle surface. The aim of this study was to investigate the impact of carrier lipid composition and surfactant type on the physical stability and thermal behavior of SLN containing β-carotene. As carrier lipids we used cocoa butter and/or tristearin and as surfactants we used Quillaja saponin extract in a combination with high- or low-melting lecithin. All the ingredients were food-grade. The results showed that all the SLN were physically stable and had a particle diameter Quillaja saponins and low-melting lecithin as emulsifier, which showed slightly increased particle sizes during storage due to polymorphic transition. In general, this study indicated that the introduction of heterogenous lipids can improve the physical stability of the SLN due to the more random crystal structures formed. Moreover, the polymorphic stability is dependent on the surfactants applied. These results are of interest for manufacturers in food, pharmaceutical, cosmetic and personal care industries using cocoa butter or any lipid blend to enrich their products with bioactive components.

Background Acid-induced hydrolysis of proteins has been used to improve the solubility and functional properties of various proteins, and could be a promising tool to facilitate the use of currently underutilized insoluble microalgae protein-rich fractions in food applications. However, the results of a prior study showed an unusual resistance of an insoluble microalgae protein-rich fraction to acid hydrolysis at room temperature. Results In the present study, the insoluble protein-rich fraction extracted from microalgae Chlorella prothothecoides was treated with 0.5 mol L-1 hydrochloric acid at 25, 45, 65 or 85 °C for 0-4 h. The results showed that hydrolysis of the fraction at 85 °C for 4 h led to decreases in the amount of insoluble protein-rich aggregates and the formation of fragments with a lower molecular weight, as well as an increase in protein solubility by approximately 40%. Nevertheless, some aggregated insoluble protein-rich particles remained, even after hydrolysis at 85 °C for 4 h. Conclusion The higher temperature improved the efficiency of the acid hydrolysis of the insoluble protein fraction from microalgae Chlorella prothothecoides, which is highly acid-resistant. Overall, an erosion-based mechanism was suggested for the acid hydrolysis of insoluble microalgae protein fraction. © 2019 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

The effect of a phosphate surface treatment on dry-fermented sausages with co-extruded alginate casings was investigated to reduce or inhibit the formation of white efflorescences on the surface of the sausages. Furthermore, with the co-extrusion process a continuous sausage production is possible with increased product volume compared to batch processing. Moreover, the production of meat snack products with very small diameters are possible. Solutions (5%) of different commercially available phosphates, mixture of di- and polyphosphates and two polyphosphates, were applied to the surfaces of the sausages after drying. The area amount of efflorescence was reduced from ∼65% on the control to 4–7%, depending on the phosphates used. The migration of magnesium and lactate to the surface of the sausage was inhibited by the diffusion of free phosphates and calcium phosphate complexes from the surface layer into the sausage. This study illustrated an easy application to prevent efflorescence formation.

Background Water-soluble proteins extracted from the heterotrophically cultivated microalga Chlorella protothecoides have been shown to have a good solubility over a broad pH range, which makes them a promising candidate for beverage formulations. This study investigated the sensory properties of dispersions of a protein-rich extract from C. protothecoides at neutral and pH 3. Results Sensory acceptance tests of the pure extract revealed an overall low acceptance at pH 7 without sucrose addition. Sensory acceptance was significantly (P ≤ 0.05) increased by lowering the pH to 3 with citric acid, and the addition of 50 g kg-1 sucrose. Here, overall positive sensory acceptance ratings were achieved up to a protein extract concentration of 40 g kg-1 . Basic taste evaluations showed only low bitterness scores and no significant (P > 0.05) increase in bitterness with decreasing pH. Conclusion It is suggested that protein-rich extracts from C. protothecoides have promising sensory properties in beverage formulations. © 2019 The Authors. Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

This study aims to reduce the high fat content of spreadable raw fermented sausages (Teewurst) through the application of in–situ exopolysaccharide (EPS)-forming lactic acid bacteria (LAB). For this reason, sausages with EPS-forming LAB and different fat contents (20–40% added belly fat) were produced and compared to control products without an EPS-forming culture (L. sakei TMW 1.2037). Microbial growth and pH were monitored during processing, the fat (Weibull-Stoldt method) and EPS content (HPLC) of the final products determined, and the products characterized using rheological and texture profile analysis. The fat content of the final products ranged between 17–20%, 25–27%, and 30–33%, respectively. The EPS content of the spreadable raw sausages ranged between 0.08 and 0.30 g/kg for the heteropolysaccharides-producing strain L. plantarum TMW 1.1478, and between 0.46 and 1.03 g/kg for the homopolysaccharide (HoPS)-producing strains L. sakei TMW 1.411 and L. curvatus TMW 1.1928. The latter ones significantly (p This study clearly demonstrated that the application of HoPS-producing LAB is a promising approach to reduce the fat content of spreadable raw fermented sausages.

Microalgae are a new source of proteins, with yet unknown technofunctionalities. The aim of this work was to study protein solubility – a key technofunctionality - in water in the pH-range of 2–12 of proteins from water-soluble (WSPE) and water-insoluble protein extracts (WISPE) obtained from Chlorella sorokiniana, Phaeodactylum tricornutum, and Nannochloropsis oceanica. Proteins in the WSPEs exhibited an unusual solubility pattern with a solubility ≥39.5 g/100 mL and no complete precipitation in the pH-range 2-12, which was attributed to protein glycosylation and a high amount of hydrophilic amino acids. However, slight aggregation was evident at all pH-values and no transparent solutions were formed. The highest protein solubility was observed for proteins of Nannochloropsis oceanica, followed by Chlorella sorokiniana, and Phaeodactylum tricornutum. In the WISPEs, strong aggregation and a low solubility (≤22.6 g/100 mL) were observed in the pH-range of 2–11, with an increase at pH 12. Overall, the studied proteins exhibited solubility patterns in the pH-range 2-12 that were different to conventional food proteins, and especially the proteins in the WSPE of Nannochloropsis oceanica exhibited a high solubility (≥58.8 g/100 mL) at pH ≤ 5. Thus, this fraction is quite promising for food applications (e.g. protein-rich acidic beverages) and is of interest for further studies.

This study investigated thermally stabilised whey protein-pectin complexes (WPPC) regarding their potential as fat-replacer. Sensory and rheological characteristics of WPPC in dairy based desserts were studied using generic descriptive analysis and rotative and oscillatory rheometry. The aroma profile of WPPC was dominated by dairy associated attributes, whereas textural attributes similar to high-fat products were achieved. Attribute intensities increased proportionally with WPPC concentration, enabling a tailoring of sensory parameters. Addition in suspensions and vanilla sauces revealed that WPPC acted as non-interactive fat-replacers, reaching apparent viscosities similar to products rich in fat. In solid gelled puddings, a slight softening of the gel was found which was attributed to thermodynamic incompatibility between unbound pectin and the embedding starch matrix. Based on this, a model for the modes of action of WPPC depending on the matrix – requirements was postulated stressing the role of pectins as thickeners in liquid and semi-solid systems and of excluded volume effects in solid gels.

Fat-replacers can be applied to enhance creaminess as they often possess a high ability to bind water. Especially for mixed biopolymer complexes, such as whey protein–pectin complexes (WPPC), the viscosity measurement can show non-linear behaviour, impairing exact calculations of bound water or elucidating the structure from the intrinsic viscosity. By means of mass balance based on ultra-centrifugation and capillary viscosimetry, an alteration in biopolymer ratio during thermal stabilisation was determined. The initial ratio of 5:1 (w/w) shifted in favour of the protein component in the complex. 98% of the pectin were not incorporated in the complex but remained in the outer phase increasing its viscosity. By considering this alteration, the voluminosity of WPPC was calculated to be 18.3 ±0.5 mL g−1. Supplementary scanning electron micrographs showed a porous complex structure dominated by denatured whey proteins, which were linked by few pectin molecules. A model of the thermally induced complex formation from whey protein isolate and low-methoxyl pectin was postulated in which the unbound pectin plays a catalyst-like role.

Consumer concerns about synthetically derived food additives have increased current research efforts to find naturally occurring alternatives. This review focuses on a group of natural surfactants, the Quillaja saponins, that can be extracted from the Quillaja saponaria Molina tree. Quillaja saponins are triterpenoid saponins comprising a hydrophobic quillaic acid backbone and hydrophilic sugar moieties. Commercially available Quillaja saponin products and their composition and properties are described, and the technofunctionality of Quillaja saponins in a variety of food, cosmetic, and pharmaceutical product applications is discussed. These applications make use of the biological and interfacial activities of Quillaja saponins and their ability to form and stabilize colloidal structures such as emulsions, foams, crystallized lipid particles, heteroaggregates, and micelles. Further emphasis is given to the complexation and functional properties of Quillaja saponins with other cosurfactants to create mixed surfactant systems, an approach that has the potential to facilitate new interfacial structures and novel functionalities.

The stabilization of interfaces with mixed emulsifiers composed of natural ingredients is of increasing interest in order to modulate stability of food colloids. To this purpose, we first investigated the emulsifying properties of binary emulsifier mixtures composed of natural and food-grade ingredients. We prepared oil-in-water emulsions (10% oil) stabilized by Quillaja saponin-sodium caseinate mixtures at different concentration ratios (r = 5:0, 4:1, 3:2, 2:3, 1:4, 0:5) with the total concentration set to 0.5% and pH set to 7 or 3. Second, we tested the emulsion stability against environmental stresses. The emulsions produced with binary emulsifier mixtures at low Quillaja saponin ratios (r = 2:3 and 1:4, pH 7) showed the best overall performance in terms of generating small and physically stable emulsion droplets similarly to the emulsions stabilized with Na-caseinate or Quillaja saponins alone, whereas at higher Quillaja saponin ratios (r = 4:1, 3:2) the emulsions were unstable. At r = 2:3 and 1:4, the emulsions were also stable at ≤90 °C and ≤200 mM NaCl. Furthermore, they were also stable upon pH change to 2, whereas emulsions stabilized with Quillaja saponins alone (r = 5:0) flocculated. These results demonstrated that the emulsifying properties of mixed binary emulsifiers comprising natural components and subsequent stability of the emulsions is highly dependent on the applied concentration ratio. This study provides valuable insights into the techno-functionality of binary emulsifier systems.

The stability of black carrot extract-loaded liposomes (0.1% and 0.2% extract) was presented as additional data related to the research article entitled “Physical and Chemical Stability of Anthocyanin-rich Black Carrot Extract Loaded Liposomes During Storage” (Guldiken et al., 2018) [1]. This article provides further information and data on physical and chemical stability considering lower extract concentrations during storage of extract-loaded liposomes. The lower the amount of extract and higher the lecithin concentration the faster the loss of the red color is visible.

This study investigated the preparation of protein-rich extracts from different microalgae by purification and minimal processing approaches (less-refinement) by studying separately the effects of (i) (nonaqueous) solvent-precipitation, (ii) lyophilization, and (iii) (nonaqueous) solvent-washing of lyophilized fractions. Cells were disrupted by high pressure homogenization (180 MPa, 25 °C) and increasing number of passes. Cells were resistant to cell disruption in following order: Phaeodactylum tricornutum

High levels of meat consumption are increasingly being criticised for ethical, environmental, and social reasons. Plant-based meat substitutes have been with reservations identified as healthy sources of protein in comparison to meat. This alternative offers several social, environmental, and probably health benefits, and it may play a role in reducing meat consumption. However, there has been a lack of research on how specific meat substitute attributes can influence consumers to replace or partially replace meat in their diets. Research has demonstrated that, in many countries, consumers are highly attached to meat. They consider it to be an essential and integral element of their daily diet. For the consumers that are not interested in vegan or vegetarian alternatives to meat, so-called meathybrids could be a low-threshold option for a more sustainable food consumption behaviour. In meathybrids, only a fraction of the meat product (e.g., 20% to 50%) is replaced with plant-based proteins. In this paper, the results of an online survey with 500 German consumers are presented with a focus on preferences and attitudes relating to meathyrids. The results show that more than fifty percent of consumers substitute meat at least occasionally. Thus, approximately half of the respondents reveal an eligible consumption behaviour with respect to sustainability and healthiness to a certain degree. Regarding the determinants of choosing either meathybrid or meat, it becomes evident that the highest effect is exerted by the health perception. The healthier meathybrids are perceived, the higher is the choice probability. Thus, this egoistic motive seems to outperform altruistic motives, like animal welfare or environmental concerns, when it comes to choice for this new product category.

Meat protein gels are present in a variety of foods and are frequently filled with fat particles. This study set out to elucidate the effect of replacing hydrophobic fat-based particles with hydrophilic inert glass particles on thermal and structural properties during heating. Meat protein gels were prepared with different diameters (60 to 90 mm) according to a typical emulsified sausage recipe and fat-based particles as well as inert glass particles were incorporated at concentrations from 10 to 40% and heated to 85 °C, while thermal as well as structural properties were monitored. The results revealed two main effects. First, due to the higher thermal conductivity, the lower heat capacity and the absence of extensive phase transitions, the time to reach the final temperature was reduced with increasing glass particle content (e.g. from 118 ± 2 min with 40% fat particles to 86 ± 1 min for gels with 40% glass particles at a depth of 40 mm). Second, volume change and temperature sweep measurements revealed that glass particles fostered the protein gel formation and enhanced the resilience against structural breakdown during heating. This was evident during small-amplitude shear experiments that showed an almost twofold increase in the storage modulus when 10% fat-based particles were replaced with 10% glass particles from G′85 °C = 223.4 ± 14.8 kPa to G′85 °C = 431.0 ± 16.6 kPa, respectively. Overall, these findings might be of interest to meat-product manufacturers that seek to lower heating times to reach the core temperature necessary for protein denaturation and ensure microbial safety with additional holding times and modify the structural properties of foods while replacing fat particles.

The modern food system is seeing a change in consumption patterns provoked by several drivers—including ethical, health, and environmental concerns—that are increasing the sales of meat analog foods. This change is accompanied by increased research and development activities in the area of plant-based meats. The aim of the present review is to describe methods that are being employed by scientists to analyze and characterize the properties of meat alternatives and to propose standardized methods that could be utilized in the future. In particular, methods to determine the proximate composition, microstructure, appearance, textural properties, water-holding properties, cooking resilience, and sensory attributes, of plant-based meat are given. The principles behind these methods are presented, their utility is critically assessed, and practical examples will be discussed. This article will help to guide further studies and to choose appropriate methods to assess raw materials, processes, products, and consumption behavior of meat analogs.

Plant proteins are being considered to become the most important protein source of the future, and to do so, they must be able to replace the animal-derived proteins currently in use as techno-functional food ingredients. This poses challenges because plant proteins are oftentimes storage proteins with a high molecular weight and low water solubility. One promising approach to overcome these limitations is the glycation of plant proteins. The covalent bonding between the proteins and different carbohydrates created via the initial stage of the Maillard reaction can improve the techno-functional characteristics of these proteins without the involvement of potentially toxic chemicals. However, compared to studies with animal-derived proteins, glycation studies on plant proteins are currently still underrepresented in literature. This review provides an overview of the existing studies on the glycation of the major groups of plant proteins with different carbohydrates using different preparation methods. Emphasis is put on the reaction conditions used for glycation as well as the modifications to physicochemical properties and techno-functionality. Different applications of these glycated plant proteins in emulsions, foams, films, and encapsulation systems are introduced. Another focus lies on the reaction chemistry of the Maillard reaction and ways to harness it for controlled glycation and to limit the formation of undesired advanced glycation products. Finally, challenges related to the controlled glycation of plant proteins to improve their properties are discussed., Foods, 10 (2), ISSN:2304-8158

Recently an approach has been developed to structure plant-based lipids with the intention to mimic animal fat tissue in processed meat products or analogues. This study investigated the comminution behavior in a bowl chopper of such structured lipids with varying mechanical properties. For products like salami-type sausages these systems need to withstand comminution to yield particles for inclusion in product matrices. Therefore, samples were prepared from protein suspensions with 6%, 8%, 10%, and 12% soy protein isolate (SPI) and 70% (w/w) total fat with varying solid fat contents (0–30%, w/w). The hardness of samples prepared with 6% and 8% SPI varied between 4.5 and 35.9 N. When comminuted in a bowl chopper, these structures had insufficient mechanical strengths to facilitate the formation of small particles and yielded a coarse paste. Higher concentrations of protein increased hardness (15.9–76.2 N and 15.6–96.1 N, for 10% and 12% SPI, respectively). These samples retained their structural integrity upon comminution yielding individual intact particles. The size of these particles increased with sample firmness, i.e. with increasing amount of protein. The shape of the particles was more elongated the higher the solid fat content as indicated by a higher aspect ratio. Taken together, results show that structural characteristics of the gelled emulsions can be tuned to yield desired fat particles after comminution.

Heat-treated electrospun pea protein isolate (PPI)–maltodextrin fibers containing glycated PPI were analyzed for their interfacial tension and emulsifying properties compared to unheated electrospun PPI–maltodextrin fibers. Interfacial tension at the oil–water-interface of the heated fibers was higher (19.2 ± 0.1 mN m−1) compared to the unheated fibers (16.3 ± 1.4 mN m−1) due to the covalently bound hydrophilic maltodextrin in the glycoconjugates. Applied in oil-in-water emulsions (10% w/w oil, 0.7% protein, 103.4 MPa, 3 passes), unheated PPI–maltodextrin fibers produced large droplets (72–259 μm) with multimodal distributions in the pH range of 2–7. The largest droplet size was at pH 4, which was around the pI of PPI. Emulsions were also prone to flocculation, which was most probably caused by a depletion flocculation mechanism due to an excess of maltodextrin in the aqueous phase. In contrast, emulsions made with heated PPI–maltodextrin fibers were monomodal (36–55 μm) at pH 2–7 and only showed a minor increase in droplet size close to the pI of PPI. The improved properties of heated PPI–maltodextrin fibers were ascribed to the enhanced steric repulsion caused by the covalently bound maltodextrin. The results indicate that Maillard-induced glycation of PPI with maltodextrin in electrospun fibers can be used as a novel method to improve the properties of PPI as a plant-based emulsifier.

The effect of the oil load on the oxidation of microencapsulated fish oil powders was investigated. The oil load was varied between 4.95 and 20.33%(w/w) by spray drying O/W emulsions with different oil to matrix ratios (0.05, 0.1, 0.15 and 0.2(w/w)), whereas solid content (45%(w/w)) and soy protein isolate to oil ratio (0.15(w/w)) were kept constant. A standardized size fraction of particles (50–80 µm) was stored for 82 days and hydroperoxides and anisidine value measured in the total- and encapsulated oil. Oxidation was limited by the oxygen amount rather than by the oil load. The absolute amount of oxidation products (per powder mass) increased with the oil load, which was explained by oxygen diffusion. Calculating oxidation products per oil mass resulted in a faster oxidation of the powder with 5% oil, whereas the oxidation rate for oil loads ≥10%(w/w) was similar, due to a scavenging effect of oil droplets.

Protein/polysaccharide complexes can be formed by electrostatic interactions and may be useful for enhancing the stability of nanoemulsions containing short-chain alkanes, which are highly prone to destabilization by Ostwald ripening. The study aimed to assess the capacity of biopolymer complexes composed of whey protein isolate (WPI) and sugar beet pectin (SBP) to form and stabilize interfacially structured nanoemulsions. Nanoemulsions were stored for 21 days at room temperature to assess their stability against Ostwald ripening over time. Complexes showed higher emulsifying capacity than biopolymers alone since particle size of complex-stabilized nanoemulsions remained stable (d(4;3)similar to 0.26 mu m) for at least 48 h after preparation, whereas WPI- or SBP-stabilized nanoemulsions were prone to destabilization during the first 24 h reaching values around 1 mu m. Moreover, while the final particle size observed for the latter during the 21 days of storage was around 8 mu m, complex-stabilized nanoemulsions exhibited particle sizes up to 2.34 mu m, which had a direct impact in delaying creaming. Moreover, complex-stabilized nanoemulsions exhibited negative zeta-potential with similar values to those stabilized by SBP (-20.4 and - 22.1 mV, respectively) while the interfacial rheology behavior of complex-stabilized systems was more similar to those stabilized by WPI. This evidences that the protein fraction may be adsorbed at the oil interface thus dominating the interface rheology, whereas pectin chains located on the periphery of the complex and oriented towards the water phase may confer negative interfacial charge to oil droplets. These results indicated that WPI/SBP complexes were more effective than the biopolymers alone in preventing Ostwald ripening in decane-in-water nanoemulsions. This study was funded by the Ministry of Economy, Industry and Competitiveness (MINECO/FEDER, UE) throughout project AGL2015-65975-R. Author María Artiga-Artigas thanks the University of Lleida for their pre-doctoral fellowship. Author Laura Salvia-Trujillo thanks the “Secretaria d’Universitats i Recerca del Departament d’Empresa i Coneixement de la Generalitat de Catalunya” for the Beatriu de Pinós post-doctoral grant BdP2016 00336.

BACKGROUND Chlorella protothecoides is one of the most widely commercialized and studied microalgae species. Recent research reported improved emulsifying properties of the insoluble protein fraction from C. protothecoides after thermal-acid treatment. RESULTS In this research, we studied the influence of ionic strength (sodium chloride 50-500 mmol L-1 or calcium chloride 5-50 m mol L-1 ) and pH (2-9) on the stability of oil-in-water emulsions prepared by 3% (w/w) of the untreated insoluble microalgae protein fraction or hydrolysates obtained after treatment with hydrochloric acid at 65 °C (Hydrolysates 65) or 85 °C (Hydrolysates 85) for 4 h. The emulsions were prepared by mixing 10% (w/w) oil and homogenized at 68.9 MPa. The ionic strength and pH were, subsequently, adjusted. The mean particle diameter of emulsions remained constant despite extensive variations in ionic strength or pH. Emulsion droplets stabilized by Hydrolysates 85 were stable against coalescence at all ionic strengths or pH values tested. CONCLUSION The results indicate a high potential to use acid-hydrolyzed insoluble microalgae protein fractions for the formulation of various emulsion-based food systems. © 2020 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Additive layer manufacturing (ALM) is an emerging technology for production of complex three-dimensional objects in the food sector. In this study, semi-hard model cheeses with different calcium levels (15.8 ± 0.9 to 31 ± 2 mg Ca g−1 protein) were produced to investigate thermo-rheological properties and shear behavior at large strain to set up process parameters for hot-melt extrusion based ALM. The gel-sol transition temperature (51.7 ± 0.2 to 60 ± 2 °C) significantly (P

Natural emulsifiers have become of increasing interest within the food and beverage industry. Oat bran is a natural side-stream product produced during oat refinement that may be used to obtain amphiphilic extracts. Our hypothesis was that the oat bran extract is rich in surface-active and amphiphilic oat saponins and proteins that can form and stabilize emulsions. For this, we examined the surface activity of oat bran extract at oil-water and air-water interfaces, its ability to form oil-in-water emulsions and their stability against various stress tests. The highly surface-active oat bran extract acted as an ionic emulsifier, forming highly negatively charged submicron-sized emulsion droplets. These emulsions were stable over a wide range of pH (4–9), heat treatment (≤50 °C), and during storage at ≤25 °C up to 42 days. However, the emulsions showed instability at pH 2–3, at high ionic strengths, and during freeze-thawing. The formation and stability of the emulsions is related to interfaces containing oat saponins or oat saponin-protein complexes rather than a protein layer. These findings show that oat bran extract is a highly promising natural emulsifier, providing the food and beverage industry with a viable substitute to traditional emulsifiers.

Sodium caseinate was hydrolyzed with the commercial enzyme preparation Sternzym BP 25201, containing a thermolysin-like peptidase from Geobacillus stearothermophilus as the only peptidase. The hydrolysis was carried out at 65 °C with an enzyme activity of 1 nkat mL−1 or 15 nkat mL−1, leading to various degrees of hydrolysis (DH) ranging between 0.1 and 8.5%. The hydrolysates obtained were analyzed in a multi-scale approach, covering the hydrolysate properties (viscosity, hydrophobicity, peptide composition) and their interaction at oil–water (emulsion) and air–water (foam) interphases. The viscosity and surface hydrophobicity generally decreased with an increasing DH. Longer, more hydrophobic peptides, which self-assembled into network-like supramolecular particles, were detected up to a DH of 2.2%. Compared to untreated sodium caseinate, these structures could increase the half-life of emulsions (+400%) and foams (+31%). This was most probably caused by an increase in particle size (45.2-fold). By contrast, a higher DH led to a less hydrophobic product and smaller, spherical-shaped supramolecular structures. Foams and emulsions prepared with those hydrolysates were not stable and phase separated within minutes (for example, emulsion half-life = 5 min; foam half-life = 4.6 min at DH of 8.5%).

Replacement of synthetically derived food additives and increase of sustainability are two major trends within the food industry, and usage of by‐products may represent a potential solution. We characterised an extract obtained from red beet that could also be obtained from red beet peels, that are typical industrial by‐products, and examined its interfacial and emulsion forming properties. Results showed that red beet extract contained considerable amounts of surface‐active saponins. The smallest negatively charged droplets (~1.36 μm, −40 mV) were obtained at low emulsifier‐to‐oil ratio and were fairly stable over a wide range of environmental stresses such as a wide pH range and temperature (

The occurrence of efflorescences on the surface of dry fermented sausages represents a current issue for the meat processing industry. Preventing the efflorescence formation by the addition of sodium hexametaphosphate (SHMP) was shown to be promising in a previous study. The optimum SHMP addition was studied by adding SHMP (0.0, 1.0, 3.0, and 5.0g/kg) directly to the sausage batter. Visual and chemical analyses were conducted during 8weeks of storage under modified atmosphere. Visual analyses revealed significant lower amounts of efflorescences on the sausage surface after 8weeks when 1.0 (27.1%), 3.0 (9.0%), and 5.0g/kg SHMP (3.4%) were added, compared to the control with 38.0% efflorescences. SHMP significantly affected the occurrence (8weeks) of magnesium on the surface: +85.5%, +23.7%, +3.5%, and -28.2% for 0.0, 1.0, 3.0, and 5.0g/kg, respectively. The addition of 4.785g/kg was calculated to fully inhibit the formation of efflorescences by complexing magnesium ions.

We studied the impact of lactose impurities (0, 130, 150 m m ) on micro- and macro-structural characteristics of thermally stabilised whey protein–pectin complexes (WPPC) by varying biopolymer concentration [c high = 5.0% whey protein isolate (WPI) + 1.0% pectin; c med = 2.75% WPI + 0.55% pectin; c low = 0.5% WPI + 0.1% pectin], shear rate (0, 150, 500 s −1 ) and scale (lab/pilot plant). We demonstrated that ≤150 m m lactose had no significant effect on the microstructure of WPPC, as investigated by fluorescence spectroscopy and browning measurements. Unfolding of β-lactoglobulin within WPPC depended on the biopolymer concentration, being strongest at c high . Measured browning was attributed to reactions between whey proteins and neutral sugars in pectin side chains. Particle size was unaffected by lactose, but showed an increase with biopolymer concentration and a decrease with shear rate. Thus, WPPC can likely be generated using whey powders with lactose impurities or other protein sources of lower purity.

Various casing types can be used to produce dry fermented sausages. Within the group of dry fermented sausages, efflorescence formation represents a current issue for the meat processing industry. Therefore, this study aims to investigate the coherence between the casing type and the efflorescence amount. Different casing materials (co-extruded alginate, collagen, and natural casing) were used for the sausage production. The sausages were stored under modified atmosphere packaging at 4 °C and visual and chemical analyses were conducted regularly during 8 wk of storage. Image analyses revealed different amounts of efflorescences for the sausages with alginate (72.2%), collagen (48.3%), and natural casings (25.0%). The magnesium content increased in different amounts on the surface of the sausages produced with alginate (88%), collagen (83%), and natural (59%) casing. The calcium content significantly increased on the alginate casings by 32% but the other casing types showed no enrichment of calcium on the surface. It seems likely that the differences regarding the efflorescence formation occur due to differences in the average pore size of the casings.

Ultrasonic spectrometry was used to monitor the changes in polymorphism of palm kernel fat present in two tempered non-dairy emulsions with different globule sizes. Laser diffraction and differential scanning calorimetry (DSC) were performed to characterize the emulsions. X-ray diffraction (XRD) and nuclear magnetic resonance (NMR) were used to determine the polymorphic state and solid fat content (SFC) of fully hydrogenated palm kernel oil during tempering of the emulsions. The ultrasonic instrument generated a “chirp” signal, which is characterized by its bandwidth. The ultrasonic measurements were carried out using two different pairs of transducers with different center frequencies, 2.25 and 0.5 MHz, and bandwidths. 3D plots were generated disputing time, frequency, and signal strength. The whole tempering process, from start to finish, was better characterized with the 2.25-MHz center frequency transducers. The ultrasonic velocity through the emulsions was always higher for the more stable β′ polymorph than for the α polymorph (p 0.05) on the ultrasound velocities obtained for the two globule sizes. Monitoring of polymorphic changes in emulsions using ultrasonic spectrometry could be used for an online measurement system for industrial manufacturing.

An unusual growth behaviour of biopolymer complexes composed of whey protein isolate (WPI) and pectin with various degrees of esterification (DE) was investigated. The formation and stability of complexes was studied at the isoelectric point (p I ) of the protein since most likely hydrophobic rather than electrostatic interaction forces dominate the complexation process. As such, biopolymer particles were generated under slightly acidic conditions (pH 4.6) which had been subjected to various heat treatments ( ϑ = 25–80 °C). Dynamic light scattering and ζ-potential measurements were utilized to examine the formation and stability of pectin-protein complexes. The results revealed that the initial size and surface charge of biopolymer particles depended on the pectins DE. Use of low-methoxylated pectins (DE 10%) led to the formation of small-sized complexes with narrow particle size distributions and a higher magnitude of surface charge. All biopolymer samples showed a time-dependent increase in size. A linear regression analysis revealed that the particle volume ( r 3 ) increased linearly with time. It was demonstrated that the growth rates increased with decreasing temperatures, increasing DE, and decreasing pectin concentrations, respectively. However, the ζ-potential remained unchanged over the entire storage time tested. These results suggest that the control over processing conditions, biopolymer characteristics, and physicochemical interactions might lead to the fabrication of particles with specific particle sizes and surface charges.

Process-stable complexes composed of whey protein isolate (WPI) and sugar beet pectin have great potential as structuring agents or fat replacers in foods. The current study investigates the compatibility of heated WPI : pectin complexes in different meat matrices. Spreadable raw-fermented sausages and sliceable emulsion-type sausages were therefore manufactured containing biopolymer complexes with various WPI : pectin ratios r (2 : 1, 8 : 1). Macro- and microstructural properties of the meat dispersions were analyzed in terms of colour, texture, rheometry, sensory, and confocal laser scanning microscopy (CLSM) measurements. Textural and sensorial results demonstrated that the meat products became increasingly soft and yellowish as the biopolymer ratio r was increased regardless of the meat matrix, whereas pH and water activity values were not affected. CLSM images revealed that the meat protein network became disrupted and loose in the presence of pectin, which was attributed to a thermodynamic incompatibility effect. The results obtained from this study highlight that biopolymer complexes might be suitable fat mimetics, particularly for spreadable meat products.

The conjugation reaction of electrospun fibers of a mixture of whey protein isolate (WPI) and dextran using different molecular weights (40, 70, and 100 kDa) and mixing ratios was studied. This study includes the electrospinnability of a mixture of WPI and dextran, and the conjugation reaction between them via the initial stage of the Maillard reaction. The WPI-dextran fibers were characterized using optical and transmission electron microscopy. The covalent attachment of dextran to WPI was confirmed using sodium-dodecyl-sulfate-polyacrylamide gel-electrophoresis with protein and glycoprotein staining. Both 70 and 100 kDa of dextran and WPI at mixing ratios of 2 : 1 and 3 : 1 in phosphate buffer (30 mM, pH 6.5) were electrospun using needleless electrospinning. The solution concentration of the mixture was 50 wt% (33.3/37.5 wt% for dextran/16.5/12.5 wt% for WPI). The optimal conjugation conditions chosen from the experiments were a mixture of dextran (70 kDa)-WPI at 3 : 1 (75% relative humidity, 60 °C, 48 h).

By lowering the pH of a dispersion prepared with a water-soluble protein extract from the microalga Chlorella protothecoides, a minor insoluble protein fraction is formed. The aim of this study was to reveal what kind of insoluble structure is formed at pH 3. For that purpose, the spatial fractionation of proteins and carbohydrates, and the effect of urea addition was studied. Results showed that mainly proteins precipitate from solution at pH 3, whereas no significant change (p > 0.05) was found in carbohydrate concentration during the shift in pH. Moreover, urea dissolved aggregates, showing that mainly hydrophobic interactions were causing the aggregate formation. Taken together, the results imply that the formed insoluble structures at pH 3 are composed of protein aggregates and not electrostatically stabilized protein-polysaccharide complexes.

One of the major trends within the food industry is the replacement of synthetically-derived food additives (e.g. emulsifiers) by natural alternatives. A promising approach is the utilization of saponins that have attracted attention due to their effective emulsifying properties and their natural origin from plants. Panax ginseng is well known in Asian countries for its health benefits that are mainly attributed to amphiphilic triterpene saponins, namely ginsenosides. In this study, we characterized two food-grade ginseng extracts (Finzelberg: FB; CheilJedang: CJ) regarding their chemical composition, surface activity, and effectiveness as emulsifier. Both ginseng extracts reduced the interfacial tension appreciably by up to 80%, and formed negatively charged oil-in-water emulsions at a low emulsifier-to-oil ratio. Ginseng FB formed small submicron-sized emulsions, whereas the mean particle sizes with ginseng CJ were much larger (up to 25 μm). Both ginseng extract-stabilized emulsions were stable towards a range of stresses (pH 4–9, ≤100 mM NaCl) or when stored at ≤25 °C for four weeks. However, the emulsions showed instability at highly acidic conditions (pH 2–3), during the 4-week storage at an elevated temperature (55 °C), and at high ionic strengths (≥250 mM NaCl, >10 mM CaCl2), which was mainly attributed to the reduction or screening of electrostatic repulsion. Emulsion formation and stabilization was proposed to occur via formation of a saponin or biogenic saponin-protein complex layer leading to a stronger interfacial network. In conclusion, both ginseng extracts were able to form emulsions, although ginseng FB extract showed especially remarkable emulsifying properties, similar to the highly effective Quillaja saponaria extract. The results may therefore be helpful in replacing other emulsifiers and formulating emulsion products with varying particle size ranges.

Core-shell nanofibers were electrospun from bilayer gelatin/gum arabic corn oil-in-water emulsions crosslinked by genipin. The crosslinking increased the apparent viscosity and induced a predominantly elastic behavior of the emulsions, which favored the formation of a more stable emulsion system and then electrospun fibers with larger diameters. These fibers had improved surface hydrophobic and mechanical properties, and did not thermally decompose until heated to 250 °C, which might be associated with the chemical bonds formed between primary amines on the protein chains. The encapsulation efficiency of corn oil in the fibers at different crosslinking time was higher than 86% without any significant change during 7 days of storage at room temperature. Thus, this work provides a genipin crosslinking strategy to the development of emulsion-based fibrous mats with desired mechanical and surface hydrophobic properties for food applications of bioactive encapsulation and controlled release.

This study investigated the interfacial shear rheology of mixed Quillaja saponin - pea protein systems to better understand their interactions and adsorption behaviors over time (5–720 min). The interfacial storage (Gi′) and loss (Gi″) moduli of the individual and mixed surfactants were recorded as amplitude sweeps (0.05 Hz, strain 1–100%) using a rheometer equipped with a biconical disk. Quillaja saponins formed highly viscoelastic interfaces within 5 min. Pea proteins formed less viscoelastic interfacial layers within 5–240 min, and led viscoelasticities increase greatly after 720 min of aging. This is indicative of much slower rearrangement processes compared to a rapid establishment of Quillaja saponin interfacial layers. Quillaja saponin - pea protein mixtures had lower Gi′- than Gi″-values than either of the individual. This mixed interface weakened upon aging which was suggested to be indicative of the development of particulates unable to interlink thereby decreasing the interfacial cohesion.