Dairy Ingredients Research Articles

Safety evaluation of the food enzyme β-galactosidase from the non-genetically modified Aspergillus oryzae strain AE-LA.

The food enzyme β‐galactosidase (β‐d‐galactoside galactohydrolase; EC 3.2.1.23) is produced with the non‐genetically modified Aspergillus oryzae strain AE‐LA by Amano Enzyme Inc. The food enzyme was considered free from viable cells of the production organism. The food enzyme is intended to be used for lactose hydrolysis in milk processing, production of fermented milk products, whey processing and the manufacture of enzyme‐modified dairy ingredients. Dietary exposure to the food enzyme–total organic solids (TOS) was estimated to be up to 1.651 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90‐day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 1,656 mg TOS/kg bw per day, the highest dose tested. This results in a margin of exposure of at least 1,003. A search for similarity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panel considered that, under the intended conditions of use, the risk of allergic reactions by dietary exposure cannot be excluded, but the likelihood is considered to be low. Based on the data provided, the Panel concludes that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Use of micellar casein concentrate and milk protein concentrate treated with transglutaminase in imitation cheese products—Melt and stretch properties

Melt and stretch properties in dairy-based imitation mozzarella cheese (IMC) are affected by the amount of intact casein provided by dairy ingredients in the formulation. Rennet casein (RCN) is the preferred ingredient to provide intact casein in a formulation. Ingredients produced using membrane technology, such as milk protein concentrate (MPC) and micellar casein concentrate (MCC), are unable to provide the required functionality. However, the use of transglutaminase (TGase) has potential to modify the physical properties of MPC or MCC and may improve their functionality in IMC. The objective of this study was to determine the effect of TGase-treated MPC and MCC retentates on melt and stretch properties when they are used in IMC and to compare them with IMC made using RCN. The MCC and MPC retentates were produced using 3 different lots of pasteurized skim milk and treated with 3 levels of TGase enzyme: no TGase (control), low TGase: 0.3 units/g of protein, and high TGase: 3.0 units/g of protein. Each of the MCC and MPC treatments was heated to 72°C for 10 min to inactivate TGase and then spray dried. Each MCC, MPC, and RCN powder was then used in an IMC formulation that was standardized to 48% moisture, 21% fat, 20% protein, and 1% salt. The IMC were manufactured in a twin-screw cooker by blending, mixing, and heating various ingredients (4.0 kg). Due to extensive crosslinking, the IMC formulation with the highest TGase level (MCC or MPC) did not form an emulsion. The IMC made from MCC treatments had significantly higher stretchability on pizza compared with their respective MPC treatments. The IMC made from TGase-treated MCC and MPC had significantly lower melt area and significantly higher transition temperature (TT) and stretchability compared with their respective controls. Comparison of IMC made using TGase-treated MCC and MPC to the RCN IMC indicated no difference in TT or texture profile analysis-stretchability; however, the Schreiber melt test area was significantly lower. Our results demonstrated that TGase treatment modifies the melt and stretch characteristics of MCC and MPC in IMC applications, and TGase-treated MPC and MCC can be used to replace RCN in IMC formulations.

Safety evaluation of the food enzyme β-galactosidase from the non-genetically modified Aspergillus oryzae strain GL470.

The food enzyme β‐galactosidase (β‐d‐galactoside galactohydrolase; EC 3.2.1.23) is produced with the Aspergillus oryzae strain GL 470 by Shin Nihon Chemical Co., Ltd. The food enzyme is free from viable cells of the production organism. It is intended to be used in five food manufacturing processes; lactose hydrolysis in milk processing, production of fermented milk products, whey processing, manufacture of enzyme‐modified dairy ingredients and in the manufacture of galacto‐oligosaccharides. Dietary exposure to the food enzyme–total organic solids (TOS) was estimated to be up to 1.388 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not raise a safety concern. The systemic toxicity was assessed by means of repeated dose 90‐day oral toxicity studies in rats. The Panel identified a no observed adverse effect level of 7,000 mg TOS/kg bw per day, the highest dose tested, which when compared with the estimated dietary exposure, results in a margin of exposure of at least 5,043. A search for similarity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panel concluded that, under the intended conditions of use, the risk of allergic reactions by dietary exposure cannot be excluded, but the likelihood for this to occur is considered to be low. Based on the data provided and considering the most recent complete toxicological data set, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Reduction of multiple reaction monitoring protein target list using correlation analysisa.

High mass resolution mass spectrometry provides hundreds to thousands of protein identifications per sample, and quantification is typically performed using label-free quantification. However, the gold standard of quantitative proteomics is multiple reaction monitoring (MRM) using triple quadrupole mass spectrometers and stable isotope reference peptides. This raises the question how to reduce a large data set to a small one without losing essential information. Here we present the reduction of such a data set using correlation analysis of bovine dairy ingredients and derived products. We were able to explain the variance in the proteomics data set using only 9 proteins across all major dairy protein classes: caseins, whey, and milk fat globule membrane proteins. We term this method Trinity-MRM. The reproducibility of the protein extraction and Trinity-MRM methods was shown to be below 5% in independent experiments (multi-day single-user and single-day multi-user) using double cream. Further application of this reductionist approach might include screening of large sample cohorts for biologically interesting samples before analysis by high-resolution mass spectrometry or other omics methodologies.

Ceramic membrane filtration of skim milk for the production of a casein-enriched permeate

The protein composition of skim milk was adjusted using a pilot-scale membrane microfiltration system to produce a casein-enriched permeate with a ratio of casein to serum protein close to 1:1. Microfiltration was performed at 50 °C to a volume concentration factor of 3 followed by 2 diafiltration steps. Three different membrane pore sizes (0.10, 0.14 and 0.20 μm) were used to compare the separation effect, then the effect of three different transmembrane pressures (100, 120 and 150 kPa) on protein composition in the permeate was studied. Membranes of 0.10 and 0.14 μm retained most of the casein. The 0.20 μm membrane allowed casein to pass through and made the ratio of casein to serum protein in the permeate close to 50:50 with a mean flux of 128.3 kg m−2 h−1 at 120 kPa, demonstrating the potential application of a 0.20 μm membrane to produce a new dairy ingredient.

Fermented Milk Product Enriched with γ-PGA, Peptides and GABA by Novel Co-Fermentation with Bacillus subtilis and Lactiplantibacillus plantarum

Milk was co-fermented with Bacillus subtilis HA and Lactiplantibacillus plantarum EJ2014 to produce a dairy ingredient enriched with poly-γ-glutamic acid (γ-PGA) and γ-aminobutyric acid (GABA). The first fermentation of milk with B. subtilis HA resulted in a viscous broth with pH 6.56, 0.26% acidity, 1.40 mg/g tyrosine equivalent, and 17.21 U/g protease activity. The viable cell counts of B. subtilis indicated 8.74 log CFU/mL, and the consistency index of the alkaline fermented milk was 1.82 Pa·sn. In addition, 4.65% mucilage was produced with 35.93% γ-PGA content. The milk co-fermented by L. plantarum indicated 1.34% acidity and pH 4.91. The viable bacterial counts of B. subtilis decreased to 4.44 log CFU/mL, whereas those of L. plantarum increased to 9.42 log CFU/mL. Monosodium glutamate (MSG) as a precursor was effectively converted into γ-PGA by B. subtilis, and then residual MSG was completely converted into GABA by L. plantarum with a yield of 26.15 mg/g. Furthermore, the co-fermented milk produced volatiles, including hexanoic acid, 2,3-butanediol, and acetoin, which may be responsible for its aged cheese-like aroma.

Effect of probiotic bacteria on physicochemical, microbiological, textural, sensory properties and fatty acid profile of sour cream.

Sour cream is a dairy product with good potential to act as a food carrier for probiotic bacteria. The effect of probiotic cultures on the quality of sour cream from dry dairy ingredients was assessed during 5 weeks of storage. The treatments design was as follows: Bifidobacterium, Bifidobacterium+ Lactobacillus casei, Lactobacillus acidophilus, Lactobacillus acidophilus+ Lactobacillus casei and Lactobacillus casei. Fatty acids profile, texture, microbial load and sensory characteristics were analyzed. Comparison of fatty acids of different creams produced showed that there is a significant difference between the produced creams. There are a wide range of fatty acids in the structure of sour cream fat. Also, with the addition of these bacteria, the texture of the samples became firmer during storage. The sensory analyses showed that the addition of all three bacteria increased the overall acceptance of this product by the panelists. It is suggested that sour cream fortified with probiotics well orientated functional food had accepted composition and sensory properties.

Dairy ingredients replaced with vegan alternatives: valorisation of ice cream

SummaryWith growing concerns of food fortification, dairy ingredient alternatives and waste management have risen the need for food manufacturers to review their recipes. Hence, this study was aimed to extract watermelon seed protein concentrates (WSPC) with ultrasonication and develop vegan ice cream with improved functional properties. Coconut fat and coconut milk were used as fat replacer and total solids source along with extract of WSPC substituting milk solids‐not‐fat (MSNF). Various functional properties of WSPC were assessed. Rheological, structural and sensory quality of vegan ice cream were comparable with standard dairy ice cream formulation. Melting resistance, viscosity and textural hardness were increased with increasing concentration of WSPC and found maximum in IC4 except overrun which was highest (62.02 ± 0.16) in IC0V. Whereas, protein, total solids and total soluble solids were highest in IC4 in contrast to fat and pH which was maximum in IC0D (9.96 ± 0.016) and IC0V (6.82 ± 0.01), respectively. All treatments were found acceptable but highly satisfactory sample, concerning sensory acceptability, was IC2 with 10% WSPC.

Lactose Concentration in Low-Lactose and Lactose-Free Milk, Milk Products, and Products Containing Dairy Ingredients by High Sensitivity Enzymatic Method (K-LOLAC), Collaborative Study: Final Action 2020.08.

The AOAC Stakeholder Panel on Strategic Food Analytical Methods issued a call for methods in 2018 for the measurement of lactose in low-lactose and lactose-free products under Standard Method Performance Requirement (SMPR®) 2018.009. Megazyme's Lactose Assay Kit (K-LOLAC) was reviewed and accepted as a First Action Official MethodSM in 2020 (2020.08). A collaborative study was conducted to evaluate the to evaluate the reproducibility of AOAC Official MethodSM2020.08 for the measurement of lactose concentration in low-lactose and lactose-free milk, milk products, and products containing dairy ingredients. Samples are deproteinated and clarified by treatment with Carrez reagents, and then free glucose is removed using a glucose oxidase and catalase treatment system. Quantification of lactose is based on the hydrolytic activity of β-galactosidase, which hydrolyses lactose to glucose and galactose. Any remaining free D-glucose is first measured using a hexokinase (HK)/glucose 6-phosphate dehydrogenase (G-6PDH)/6-phosphogluconate dehydrogenase (6-PGDH) based assay procedure, and then β-galactosidase is added to hydrolyze the lactose in the same reaction vessel with concurrent measurement of the released D-glucose. The samples analyzed included a number of lactose-free and low-lactose milk samples, lactose-free infant formula, lactose-free milkshake, lactose-free adult nutritional drink, lactose-free cream, and lactose-free cheese. All materials had repeatability relative standard deviations (RSDr) <7%. The reproducibility relative standard deviation (RSDR) varied from 3.8 to 14.9% with seven of the 10 test samples having an RSDR of <10%. The Lactose Assay Kit (K-LOLAC) meets the requirements for reproducibility set out under SMPR 2018.009. The Lactose Assay (K-LOLAC) is a robust, simple, and reproducible method for analysis of lactose in foodstuffs and beverages.

Preliminary sampling of aflatoxin M1 contamination in raw milk from dairy farms using feed ingredients from Rwanda.

Milk is susceptible to aflatoxin M1 (AFM1) contamination when dairy cattle consume feed contaminated with aflatoxins and is considered as a public health concern. This pilot study assessed the prevalence and amount of total aflatoxin contamination in commercially available dairy feed and the corresponding AFM1 contamination in raw milk from samples collected at farms using local, commercially available dairy feed across Rwanda's five provinces. The inclusion criteria to select dairy farm participants were (1) to have at least two cows and (2) use of commercially prepared dairy feeds. Importantly, the majority of cattle rearing households in Rwanda rely principally on grazing or other freely available feedstock, rather than on commercially prepared feeds. In total, 170 raw milk samples were collected during one sampling period from dairy farms using commercially prepared dairy feeds. In addition, 154 dairy feed samples were collected simultaneously with the milk samples. These farms were previously targeted in a larger study measuring aflatoxin contamination of Rwandan feeds and feed ingredients. The mean AFM1 concentration in these samples was 0.89 ± 1.64µg/l (median: 0.33µg/l) with a maximum of 14.5µg/l. Maize bran was the principal dairy feed ingredient used by farmers in the sampling, representing more than 65% of the total feed samples collected, with mean aflatoxin concentration of 90.5µg/kg (median 32.3µg/kg). The authors note that this preliminary sampling is not generalizable across Rwandan milk production and consumption; the limited pilot study presented here was not designed with the robustness necessary for broad-scale generalization. Thus, the data presented should not be broadly applied outside of the context of the study.

Highly concentrated micellar casein: Impact of its storage stability on the functional characteristics of process cheese products

Micellar casein is a novel dairy protein ingredient that can be used in process cheese product (PCP). PCP is a dairy food prepared by blending dairy ingredients with nondairy ingredients and then heating the mixture with continuous agitation to produce a homogenized product with an extended shelf-life. The objective of this work was to study the effect of storage of concentrated micellar casein (CMC) on the functionality of PCP. Three treatments of CMC (CMC; CMC + NaCl= CMC + 1% sodium chloride; CMC + NaCl + NaCit = CMC + 1% sodium chloride and 1% trisodium citrate) were prepared and stored for 60 d at 4 °C. The functionality of PCP was determined by measuring the end apparent viscosity, hardness, and melting temperature. This trial was replicated three times. The PCP made with different treatments of CMC during storage had an approximate range of 47.0–48.0% moisture and 5.7–5.8 pH (P < 0.05). The addition of sodium chloride and trisodium citrate to CMC during storage resulted in differences (P < 0.05) in the end apparent viscosity, hardness, and melting temperature of PCP. However, the storage of CMC did not show any differences (P > 0.05) in the functionality of PCP.

Evaluating the in vitro efficacy of bovine lactoferrin products against SARS-CoV-2 variants of concern

Bovine lactoferrin (bLF), a naturally occurring glycoprotein found in milk, has bioactive characteristics against many microbes, viruses, and other pathogens. Bovine lactoferrin strongly inhibits SARS-CoV-2 infection in vitro through direct entry inhibition and immunomodulatory mechanisms. This study reports on the anti-SARS-CoV-2 efficacy of commercially available bLF and common dairy ingredients in the human lung cell line H1437 using a custom high-content imaging and analysis pipeline. We also show for the first time that bLF has potent efficacy across different viral strains including the South African B.1.351, UK B.1.1.7, Brazilian P.1, and Indian Delta variants. Interestingly, we show that bLF is most potent against the B.1.1.7 variant [half-maximal inhibitory concentration (IC50) = 3.7 µg/mL], suggesting that this strain relies on entry mechanisms that are strongly inhibited by bLF. We also show that one of the major proteolysis products of bLF, lactoferricin B 17–41, has a modest anti-SARS-CoV-2 activity that could add to the clinical significance of this protein for SARS-CoV-2 treatment as lactoferricin is released by pepsin during digestion. Finally, we show that custom chewable lactoferrin tablets formulated in dextrose or sorbitol have equivalent potency to unformulated samples and provide an option for future human clinical trials. Lactoferrin's broad inhibition of SARS-CoV-2 variants in conjunction with the low cost and ease of production make this an exciting clinical candidate for treatment or prevention of SARS-CoV-2 in the future.

Assessment of the Microbiological Quality of Ready-to-Eat Salads-Are There Any Reasons for Concern about Public Health?

Ready-to-eat food products can be readily consumed without further preparation and are convenient for busy on-the-go consumers. The objective of the study was to assess the microbiological quality of ready-to-eat salads. Thirty RTE salads were tested for the presence of bacteria, yeasts, and molds using the TEMPO and agar plate method. The study demonstrated that most of the tested products were characterized by varying microbiological quality. The total number of mesophilic microbiotas was about 6 log CFU g−1. The high number of microorganisms was due to yeast and molds or Enterobacteriaceae. Half of the salads were contaminated with E. coli and three salads were contaminated with S. aureus. LAB were also found, which can be explained mainly by a dairy ingredient. In some salads, Salmonella spp. and L. monocytogenes were detected (26.7% and 33.3% of the samples, respectively). Based on the conducted tests, it was found that the microbiological quality was not satisfactory. The results presented in this study indicate that there is a significant problem of the presence of pathogens. Manufacturers should strive to reduce the possibility of microbial contamination through the use of widely understood hygiene of the production process, using hurdle technology, including the modified atmosphere and refrigerated storage.

Effect of alkalinization and ultra-high-pressure homogenization on casein micelles in raw and pasteurized skim milk

Mechanical and physicochemical treatments of milk induce structural modifications of the casein (CN) micelles, affecting their techno-functional properties in dairy processing. Here, we studied the effect of alkalinization and ultra-high-pressure homogenization (UHPH) on CN micelles in raw skim milk (rSM) and pasteurized skim milk (pSM). The pH of both skim milks (approximately 6.7) was adjusted to 8.5 and 10.5 before UHPH at 100, 200, and 300 MPa. The structural changes of the CN micelles during the treatments were assessed using laser diffraction, transmission electron microscopy, and turbidity measurements. Finally, ultracentrifugation (70,000 × g for 1 h at 20°C) was carried out to evaluate the protein's distribution between the supernatant (serum phase) and the pellet (colloidal phase) by gel electrophoresis and protein concentration measurement. Alkalinization of both skim milks induced a significant reduction in turbidity, whereas an increase of the average particle size was observed, the effect being more severe in pSM than rSM. At alkaline pH, more proteins were recovered in the serum phase, which suggested that the CN underwent major rearrangements into nonsedimentable CN forms of various sizes, as confirmed by transmission electron microscopy. The amount of CN found in the serum phase at pH 8.5 also increased with the UHPH pressure. Although UHPH did not influence the average CN micelle size at pH 6.7 and 8.5, a pressure-dependent decrease was observed at pH 10.5 for both skim milks. The structural changes of the CN micelles observed in this study throughout the combination of alkalinization and UHPH could be of interest for developing new dairy ingredients with improved functionality.

Re-authorization of gelatin and collagen of ruminant origin in non-ruminant feed: a new analytical challenge for the control of the feed ban

Description of the subject. A recent revision of the feed ban provisions authorizes the use of ruminant collagen and gelatin in feed for non-ruminant farmed animals. This authorization will promote the use of former foodstuffs (FFS) in poultry and pig feed. Objectives. The study aimed to investigate how these ruminant materials could impact the capacity to detect processed animal proteins (PAP) of ruminant origin in feed using the official PCR method and to evaluate the added value of a mass spectrometry protocol in development. Method. Presence of ruminant DNA in samples of collagen hydrolysate, gelatin and FFS collected from the industry was assessed using the official DNA extraction and PCR method. This allowed to evaluate the PCR inhibition properties of gelatin and collagen. The same samples were also submitted to a mass spectrometry-based proteomics (UHPLC-MS/MS) protocol targeting ruminant proteins, including collagen, to distinguish between ruminant by-products (unauthorized or authorized). Results. The results show the complementarity of PCR and UHPLC-MS/MS approaches in the context of the use of former foodstuffs in animal feed. Their combination has allowed to evidence that the presence of ruminant DNA in samples containing FFS was more linked to the presence of milk than to the presence of gelatin. On contrary, some samples have shown an increase of the cycle threshold value (Ct) that could correspond to an inhibitory effect due to gelatin addition. Conclusions. In the context of the circular economy, FFS is an interesting source of nutriment for animal feed. However, due to the presence of dairy ingredients, interference with official methods giving false suspicion of prohibited materials is to be expected. Furthermore, a masking effect of the presence of PAP due to a PCR inhibitory effect by FFS is also possible.

Quantification of Lactose in Lactose-Freeand Low-Lactose Milk and Milk Products by BIOMILK 300 Lac Biosensor: First Action 2020.09.

In 2018, the AOAC Stakeholder Panel on Strategic Food Analytical Methods approved Standard Method Performance Requirement (SMPR®) 2018.009, for lactose in low-lactose or lactose-free milk, milk products, and products containing dairy ingredients, establishing the minimum recommended performance characteristics to be addressed during the evaluation of methods. Subsequently, AOAC INTERNATIONAL opened a call for methods under the Official Method of AnalysisSM program with the aim of finding a candidate method for confirming compliance with regulatory standards and dispute resolution. A biosensor-based analytical method, BIOMILK 300 LAC, was developed by BIOLAN Microbiosensores S.L. (www.biolanmb.com) to rapidly, easily, and accurately quantify lactose in free or low-lactose dairy products. In response to the AOAC call for methods, BIOLAN performed a single laboratory validation of this method against SMPR 2018.009. Several different matrixes were tested, including: milk, sugary plain yogurt, fruit plain yogurt, flavored liquid yogurt, Greek yogurt, cream, soft cheese, infant formula, café latte, chocolate milk, and high-protein milk shake. Evaluated method parameters included: linearity, selectivity, matrix effect, recovery, accuracy, repeatability, intermediate reproducibility, robustness, reagent lot-to-lot consistency, and stability. The method is based on the use of the Biotest gold electrode together with the BIOMILK 300 biosensor reader, for the quantification of residual levels of lactose in dairy samples via an enzymatic recognition/electrochemical transduction system. Assay linearity, applicability to different matrixes, recovery, and precision demonstrated that the method is fit for purpose. The method proved to be robust, consistent, and stable, under conditions detailed in the Instructions For Use guide. The overall results were within requirements stated by SMPR 2018.009 for low-lactose and lactose-free milk, milk products and products containing dairy ingredients. The BIOMILK 300 LAC method enables the quantification of reduced levels of lactose in less than 5 min, without the requirement for expert technicians, toxic solvents or intricate procedures, maintaining a high degree of precision and accuracy in the results. BIOMILK 300 LAC was adopted as a First Action Official MethodSM by the Expert Review Panel of Low-lactose Methods in April 2020 after rigorous review.

Principles of lactose crystallization and rheology of milk protein concentrate

Milk protein concentrate (MPC) is a commercial designation for dairy ingredients with higher protein and lower lactose content than conventional skim milk powder. Lactose in its amorphous form is found in several spray-dried dairy powders. Amorphous lactose is thermodynamically unstable and can mobilize and crystallize over time under adequate temperature and moisture content. Moisture sorption from the air precedes crystallization, enhancing MPC cohesiveness and caking. This increased humidity results in poor rehydration and dispersibility, lower yield during drying, operation problems, difficulties in handling and storage. Moreover, lactose crystallization in MPC can cause Maillard browning reaction and fat oxidation. To avoid this problem, it is necessary to pre-crystallize lactose as alpha-lactose monohydrate, which is non-hygroscopic, before spray drying. Such a procedure is essential in preventing deterioration of MPC resulting from lactose crystallization or chemical reactions. Additionally, the control of this step is important to obtain specified and reproducible powder, in terms of size and crystallization level. There are various reports on the rheology of milk-based products; however, there is a lack of investigation on concentrated systems. Consequently, the objective of the present work is to review basic concepts of lactose crystallization and rheology of milk protein concentrate.

3D printing: Development of animal products and special foods

The present review examines the printing properties of different animal protein-based food inks/materials used in the production of 3D printed constructs. The review examines their microstructural, colorimetric, printability, rheological and textural properties and investigates how these properties correlate to or are reflected in the characteristics of the printed constructs. These characteristics include their shape and dimensional stability, textural, nutritional, microstructural and sensorial properties. The review also examines the potential for development of animal protein-based special diets for people with special requirements such as for dysphagia patients and geriatrics. A special focus has been given to the application of transglutaminase for the development of 3D fish-based products and the possibility of developing cultured meat-based products. The properties of different food inks and 3D printed constructs based on animal proteins such as beef, poultry, fish, egg, seafood, milk, cheese and dairy ingredients were analysed with emphasis on the studies that were published in the last three years. Studies on the development of special animal protein-based diets and the possibility of 3D printed products based on cultured meat were critically reviewed. 3D food printing offers numerous possibilities for development of tailored animal protein-based structures and products which includes, but is not limited to, extraordinary flexibility in geometries, textures and flavours and customised nutrition. Technology for production of 3D printed meat products necessitates the reduction of particle size of meat and dilution of meaty and savoury flavour and this is generally expected to reduce the value of premium meat products. However, the technology might be a good option for utilization of lower value and tougher cuts and trimmings. Production of 3D printed cultured meat-based products is still at a conceptual stage and a little or no research has been done in this area. Consumer acceptance of 3D printed cultured meat products seems to be less favourable in Western countries like Australia. Technology for the production of several animal protein-based 3D printed products for special dietary requirements such as for dysphagia patients has been optimized and is currently feasible with good success. Fancy shaped 3D printed cheese and egg products may evolve as a new segment of foods with a focus on children, festive occasions and the personal gift market. This review expands our understanding of how the composition of food inks affects the properties of the printed constructs and generates knowledge that will be crucial for optimizing the 3D printed animal products for maximum nutritional and sensory benefits. Extensive research is required to develop unique animal-based products with functional and nutraceutical value to attract consumers. Scientific knowledge is required to decipher the underlying mechanisms of how 3D printing process affects the food microstructure and sensory characteristics and its impact on consumer acceptance that will expand the use of the technology within the food industry. • 3D food printing offers numerous possibilities for development of tailored animal protein-based products. • This technology might be a good option for utilization of lower value and tougher cuts of meat. • Production of 3D printed cultured meat-based products is still at a conceptual stage. • Production of the products for special dietary requirements is feasible with good success. • Fancy shaped 3D printed cheese and egg products may evolve as a new segment of foods.

Effect of Different Temperature-Controlled Ultrasound on the Physical and Functional Properties of Micellar Casein Concentrate.

Micellar casein concentrate (MCC) is a novel dairy ingredient with high protein content. However, its poor functional properties impair its potential for further application, highlighting the importance of using innovative processing methods to produce modified MCC, such as ultrasound (US). This work investigated the impact of US on the physical and functional properties of MCC under temperature-controlled and -uncontrolled conditions for different time intervals. Under temperature-controlled ultrasound (TC-US) treatment, a reduction was found in the supernatant particle size of casein micelles. Soluble calcium content and hydrophobicity increased following ultrasound treatment at 20 °C, resulting in a remarkable improvement in emulsification. However, long-time ultrasonication led to an unstable state, causing the MCC solutions to show shear thinning behavior (pseudoplastic fluid). Compared with 50 °C temperature-controlled ultrasonication, ultrasonication at 20 °C had a greater influence on particle size, viscosity and hydrophobicity. These findings indicate that 20 °C TC-US could be a promising technology for the modification of MCC.

Improving rehydration properties of spray-dried milk protein isolates by supplementing soluble caseins

Spray-dried milk protein isolates (MPIs) are important dairy ingredients but may not have desirable rehydration properties for industrial applications. In the present study, rehydration properties of MPIs were improved by spray-drying MPI dispersions containing different amounts of soluble caseins in the form of derivatized MPI (dMPI). dMPI was prepared by alkalizing MPI dispersions to pH 11.0 and subsequently acidifying to pH 6.8 (the pH-cycle). All the spray-dried MPIs had the similar bulk density (around 0.33 g/cm−3), composition, size distribution (1–100 µm), and SEM morphology. However, the decrease of hydrodynamic diameter, dissolution of total solids and proteins, and disruption of particles during the dynamic rehydration were accelerated as the dMPI content increased, indicating the improved rehydration properties. The improvement in rehydration properties was not due to the wettability that decreased as the dMPI:MPI mass ratio changed from 0:8 to 8:0, but resulted from the reduced cross-linking of casein micelles on powder surface and the increased surface porosity during the hydration as observed for partially hydrated samples. The present work may assist industrial applications of spray-dried MPIs.