Physicochemical characterization and environmental stability of a curcumin-loaded Pickering nanoemulsion using a pea protein isolate-dextran conjugate via the Maillard reaction

This study investigated pea protein isolate (PPI) and dextran (DX) conjugates produced via the Maillard reaction as Pickering stabilizers for various food applications. The results found that as heating time increased (0-5 h), the grafting degree heightened. The PPI-DX conjugate exhibited a rough porous surface in contrast to native PPI, accompanied by changes in molecular weight and secondary structure. Additionally, the aggregation of low-solubility PPI was partially inhibited due to the contribution of increased solubility and reduced surface hydrophobicity by glycation. Curcumin-loaded Pickering nanoemulsions stabilized with PPI-DX had smaller droplets and higher curcumin encapsulation (greater than80 %) than PPI-stabilized nanoemulsions. PPI-DX adsorbed on the interface showed improved physical stability compared to PPI alone, even after various pH conditions and three heat treatments. The nanoemulsion stabilized with PPI-DX demonstrated improved apparent viscosity and dispersion stability. These findings highlight the effectiveness of PPI-DX conjugates as stabilizers for developing stable and functional Pickering nanoemulsions.

Differences in pork myosin solubility and structure with various chloride salts and their property of pork gel

The solubility and structure of myosin and the properties of pork gel with NaCl, KCl, CaCl2, and MgCl2 were investigated. Myofibrillar proteins (MPs) with phosphate were more solubilized with NaCl than with KCl (p < 0.05). CaCl2 and MgCl2 showed lower MP solubilities than those of NaCl and KCl (p < 0.05). The α-helix content of myosin was lower in KCl, CaCl2, and MgCl2 than in NaCl (p < 0.05). The pH of pork batter decreased in the order of KCl, NaCl, MgCl2, and CaCl2 (p < 0.05). The cooking yield of the pork gel manufactured with monovalent salts was higher than that of the pork gel manufactured with divalent salts (p < 0.05). The pork gel manufactured with KCl and MgCl2 showed lower hardness than that of the pork gel manufactured with NaCl. The solubility and structure of myosin were different with the different chloride salts and those led the different quality properties of pork gel. Therefore, the results of this study can be helpful for understanding the quality properties of low-slat meat products manufactured by replacing sodium chloride with different chloride salts.

Characteristics of pork emulsion gel manufactured with hot-boned pork and winter mushroom powder without phosphate

This study investigated the physicochemical characteristics of pork emulsion gels manufactured from hot-boned (HB) pork and winter mushroom powder in the absence of phosphate. It was found that compared to cold-boned (CB) pork, HB pork had a higher pH and exhibited a higher myofibrillar protein solubility with a lower actomyosin content (P < 0.05). Four types of pork gels were prepared, namely CB pork without phosphate, CB pork with phosphate (CBP), HB pork without phosphate, and HB pork with winter mushroom powder but without phosphate (HBW). The total exuded fluid was comparable for the CBP and HBW gels on all storage days. In addition, the HB and HBW gels had similar springiness and cohesiveness properties to the CBP gel (P > 0.05). These results indicate that the quality of pork gels manufactured in the absence of phosphate can be improved by the use of HB pork and with the incorporation of winter mushroom powder.

Higher Protein Digestibility of Chicken Thigh than Breast Muscle in an In Vitro Elderly Digestion Model

This study investigated the protein digestibility of chicken breast and thigh in an in vitro digestion model to determine the better protein sources for the elderly in terms of bioavailability. For this purpose, the biochemical traits of raw muscles and the structural properties of myofibrillar proteins were monitored. The thigh had higher pH, 10% trichloroacetic acid-soluble α-amino groups, and protein carbonyl content than the breast (p<0.05). In the proximate composition, the thigh had higher crude fat and lower crude protein content than the breast (p<0.05). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of myofibrillar proteins showed noticeable differences in the band intensities of tropomyosin α-chain and myosin light chain-3 between the thigh and breast. The intrinsic tryptophan fluorescence intensity of myosin was lower in the thigh than in the breast (p<0.05). Moreover, circular dichroism spectroscopy of myosin revealed that the thigh had higher α-helical and lower β-sheet structures than the breast (p<0.05). The cooked muscles were then chopped and digested in the elderly digestion model. The thigh had more α-amino groups than the breast after both gastric and gastrointestinal digestion (p<0.05). SDS-PAGE analysis of the gastric digesta showed that more bands remained in the digesta of the breast than that of the thigh. The content of proteins less than 3 kDa in the gastrointestinal digesta was also higher in the thigh than in the breast (p<0.05). These results reveal that chicken thigh with higher in vitro protein digestibility is a more appropriate protein source for the elderly than chicken breast.

Improvement of structural, physicochemical, and rheological properties of porcine myofibrillar proteins by high-intensity ultrasound treatment for application as Pickering stabilizers

This study aimed to evaluate the potential of time-dependent (0, 15, 30, 60, 120 min) treatment of porcine-derived myofibrillar proteins (MPs) with high-intensity ultrasound (HIU) for utilizing them as a Pickering stabilizer and decipher the underlying mechanism by which HIU treatment increases the emulsification and dispersion stability of MPs. To accomplish this, we analyzed the structural, physicochemical, and rheological properties of the HIU-treated MPs. Myosin heavy chain and actin were observed to be denatured, and the particle size of MPs decreased from 3,342.7 nm for the control group to 153.9 nm for 120 min HIU-treated MPs. Fourier-transformed infrared spectroscopy and circular dichroism spectroscopy confirmed that as the HIU treatment time increased, α-helical content increased, and β-sheet decreased, indicating that the protein secondary/tertiary structure was modified. In addition, the turbidity, apparent viscosity, and viscoelastic properties of the HIU-treated MP solution were decreased compared to the control, while the surface hydrophobicity was significantly increased. Analyses of the emulsification properties of the Pickering emulsions prepared using time-dependent HIU-treated MPs revealed that the emulsion activity index and emulsion stability index of HIU-treated MP were improved. Confocal laser scanning microscopy images indicated that small spherical droplets adsorbed with MPs were formed by HIU treatment and that dispersion stabilities were improved because the Turbiscan stability index of the HIU-treated group was lower than that of the control group. These findings could be used as supporting data for the utilizing porcine-derived MPs, which have been treated with HIU for appropriate time periods, as Pickering stabilizers.

Effects of Defatting Methods on the Physicochemical Properties of Proteins Extracted from Hermetia illucens Larvae

In this study, we investigated the effects of various defatting methods, including organic solvent (aqueous, acetone, ethanol, and hexane) extraction and physical (cold pressure) extraction, on the nutritional, physicochemical, and functional properties of proteins extracted from Hermetia illucens larvae. The total essential amino acid contents were higher with cold pressure protein extraction than other treatments. The surface hydrophobicity with cold pressure treatment was the lowest, and there were no significant differences among the other treatments. The protein solubility after defatting with organic solvent was higher than for other treatments. The nonreduced protein band at 50 kDa of the defatted protein prepared using organic solvent was fainter than in the cold pressure treatment. The cold pressure-defatted protein showed the highest emulsifying capacity, and the water extracted protein showed the lowest emulsifying capacity. Although organic solvents may be efficient for defatting proteins extracted from insects, organic solvents have detrimental effects on the human body. In addition, the organic solvent extraction method requires a considerable amount of time for lipid extraction. Based on our results, using cold pressure protein extraction on edible insect proteins is ecofriendly and economical due to the reduced degreasing time and its potential industrial applications.

How to Develop Strategies to Use Insects as Animal Feed: Digestibility, Functionality, Safety, and Regulation

Various insects have emerged as novel feed resources due to their economical, eco-friendly, and nutritive characteristics. Fish, poultry, and pigs are livestock that can feed on insects. The digestibility of insect-containing meals were presented by the species, life stage, nutritional component, and processing methods. Several studies have shown a reduced apparent digestibility coefficient (ADC) when insects were supplied as a replacement for commercial meals related to chitin. Although the expression of chitinase mRNA was present in several livestock, indigestible components in insects, such as chitin or fiber, could be a reason for the reduced ADC. However, various components can positively affect livestock health. Although the bio-functional properties of these components have been verified in vitro, they show positive health-promoting effects owing to their functional expression when directly applied to animal diets. Changes in the intestinal microbiota of animals, enhancement of immunity, and enhancement of antibacterial activity were confirmed as positive effects that can be obtained through insect diets. However, there are some issues with the safety of insects as feed. To increase the utility of insects as feed, microbial hazards, chemical hazards, and allergens should be regulated. The European Union, North America, East Asia, Australia, and Nigeria have established regulations regarding insect feed, which could enhance the utility of insects as novel feed resources for the future.

Effects of loquat (Eriobotrya japonica Lindl.) leaf extract with or without ascorbic acid on the quality characteristics of semi-dried restructured jerky during storage

Deterioration of jerky during storage is a major concern; this is usually combated with natural or synthetic antioxidants. This study aimed to evaluate the quality characteristics of semi-dried restructured jerky with and without loquat leaf extract (LE) powder and ascorbic acid (AA) during storage for 180 days. The jerkies were formulated with 0%, 0.15%, and 0.3% LE and/or 0.05% AA (Control, no antioxidant; AA, 0.05% AA; LE 0.15, 0.15% loquat LE; LE 0.15-AA, 0.15% loquat LE+0.05% AA; LE 0.3, 0.3% loquat LE; LE0.3-AA, 0.3% loquat LE+0.05% AA). LE is a phenolic compound, whose 1,1-diphenyl-2-picrylhydarzyl radical scavenging activity and metal chelating activity were found to be higher than AA. All antioxidant combinations having higher LE concentration and containing AA were effective in delaying protein and lipid oxidation compared to the control or AA. At the end of storage period, LE 0.15-AA and AA had higher CIE a* and lower shear force than the control. Therefore, the combination of 0.15% LE and 0.05% AA can result in reduced protein and lipid oxidation without any negative effect on the quality characteristics of semi-dried restructured jerky.

Combined Effects of Pressure cooking and Enzyme Treatment to Enhance The Digestibility and Physicochemical Properties of Spreadable Liver Sausage

This study aimed to determine the effect of enzyme, guar gum, and pressure processing on the digestibility and physicochemical properties of age-friendly liver sausages. Liver sausages were manufactured by adding proteolytic enzyme (Bromelain) and guar gum, and pressure-cooking (0.06 MPa), with the following treatments: control, without proteolytic enzyme; T1, proteolytic enzyme; T2, proteolytic enzyme and guar gum; T3, pressure-cooking; T4, proteolytic enzyme and pressure-cooking; T5, proteolytic enzyme, guar gum, and pressure-cooking. The pH was high in the enzyme- and pressure-processed groups. The pressure-processed groups had lower apparent viscosity than other cooking groups, and it decreased during enzyme treatment. Hardness was lower in the enzyme- and pressure-processed groups than in the control, and the T4 was the lowest. Digestibility was the highest in T4 at 82.58%, and there was no significant difference with that in T5. The general cooking group with enzyme and guar gum also showed higher digestibility than the control (77.50%). As a result of the sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the enzyme- and pressure-treated groups (T4, T5) were degraded more into low-molecular-weight peptides (≤37 kDa) than the control and other treatments. Viscoelasticity showed similar trends for viscous and elastic moduli. Similarly, combined pressure processing and enzymatic treatment decreased viscoelasticity, while guar gum increased elasticity but decreased viscosity. Therefore, the tenderized physical properties and improved digestibility by enzyme and pressurization treatment could be used to produce age-friendly spreadable liver sausages.

Effects of added cereal fibers on the quality characteristics of black pudding prepared with duck blood

We investigated the physicochemical and rheological properties of black pudding prepared with duck blood using various combinations of cereal fiber sources: oat, buckwheat, quinoa, amaranth, and sorghum. The processing yield of black pudding made with duck blood and the cereals was higher than that of the control (without cereals) in all cases (P < 0.05). The moisture content of the black pudding was the highest in the buckwheat and amaranth groups (P < 0.05). The water activity, pH, and yellowness of the black pudding combined with duck blood and cereals were lower than that of the control (P < 0.05). The hardness of the black pudding with duck blood and cereals was higher than that of the control (P < 0.05), except for the amaranth group. The cohesiveness, gumminess, and chewiness of the black pudding with duck blood and cereals were higher than that of the control (P < 0.05). Differential scanning colorimetry showed distinct peak points according to treatment at the same temperature, and all treatments exhibited 2 peak temperatures, except for sorghum. The viscosities of all samples, including the control, decreased as the shear rate increased, and the viscosity of the black pudding with oat was slightly lower than that of the other samples. Thus, black pudding prepared with duck blood and cereal fibers showed excellent physicochemical and rheological properties, suggesting an improved processing method. These findings can further the development of products using duck blood as a valuable nutritional source rather than being lost as a by-product during slaughter.

Application of edible insects as novel protein sources and strategies for improving their processing

Insects have long been consumed by humans as a supplemental protein source, and interest in entomophagy has rapidly increased in recent years as a potential sustainable resource in the face of environmental challenges and global food shortages. However, food neophobia inhibits the widespread consumption of edible insects, despite their high nutritional and functional value. The own characteristics of edible insect protein such as foaming properties, emulsifying properties, gelling properties and essential amino acid ratio can be improved by drying, defatting, and extraction. Although nutritional value of some protein-enriched bread, pasta, and meat products, especially essential amino acid components was increased, replacement of conventional food with edible insects as a novel food source has been hindered owing to the poor cross-linking properties of edible insect protein. This deterioration in physicochemical properties may further limit the applicability of edible insects as food. Therefore, strategies must be developed to improve the quality of edible insect enriched food with physical, chemical, and biological methods. It was presented that an overview of the recent advancements in these approaches and highlight the challenges and prospects for this field. Applying these strategies to develop insect food in a more familiar form can help to make insect-enriched foods more appealing to consumers, facilitating their widespread consumption as a sustainable and nutritious protein source.

Effect of hydrocolloids on functionality of Protaetia brevitarsis proteins

In this study, the effects of various hydrocolloids on the functionality of extracted proteins from Protaetia brevitarsis were investigated. Gel solubility, apparent viscosity, thermal properties, microstructure, textural properties, foaming properties, and emulsion properties were estimated and compared among treatments. Although all hydrocolloids enhanced the protein gelling properties compared with those of the control protein, the protein-polysaccharide complex in samples treated with a hydrocolloid with a lower solubility of hydrophobic bonds and disulfide bonds showed a more compact microstructure with high textural properties, apparent viscosity, and emulsion stability. By contrast, hydrocolloids with a high solubility of hydrophobic bonds increased the foaming properties and showed high thermal stability of the insect proteins. These results indicate that hydrocolloids should be carefully selected when in complex with edible insect proteins according to their purpose as gelling or foaming agents.

Natural Extracts as Inhibitors of Microorganisms and Lipid Oxidation in Emulsion Sausage during Storage

Food additives are required to maintain the freshness and quality of foods, particularly meats. However, chemical additives may not be preferred by consumers, and natural materials with antimicrobial and antioxidant effects may be used as replacements for common chemical additives. Accordingly, in this study, we compared the antimicrobial and antioxidant activities of natural compounds extracted with ethanol and hot water, and emulsion sausage prepared with natural ethanol extracts was analyzed for pH, color, thiobarbituric acid reactive substances (TBARS), and Clostridium perfringens growth during storage. The antimicrobial activities of 49 natural extract candidates against Listeria monocytogenes, C. perfringens, Salmonella spp., and Escherichia coli were analyzed, and six natural materials with excellent antibacterial activities, i.e., Elaeagnus umbellata Thunb. f. nakaiana (Araki) H. Ohba, Punica granatum L., Ecklonia cava, Nelumbo nucifera Gaertner, and Schisandra chinensis (Turcz.) Baill., and Rubus coreanus Miq. were evaluated to determine their total polyphenol contents and DPPH radical scavenging activities. The total polyphenol contents of ethanol extracts were higher than those of hot water extracts, whereas DPPH radical scavenging activity was found to be higher in hot water extracts. The TBARS values of emulsion sausages were significantly increased as storage time increased, and the TBARS values of emulsion sausages prepared with natural extracts were lower than those of control sausages. Natural extract-treated emulsion sausages showed a 99% reduction in bacterial contents compared with untreated sausages on day 2, with greater than 99.9% reduction after day 3. Thus, these results demonstrated that natural extracts could have applications as natural preservatives in meat products.

Processing Characteristics of Freeze-Dried Pork Powder for Meat Emulsion Gel

The processing characteristics of freeze-dried pork powder as raw meat for comminuted meat products were compared with those of freeze-thawed pork. The tertiary structural properties, oxidation, and solubility of proteins in the freeze-dried pork powder were investigated. In addition, the properties of the emulsion gels manufactured with freeze-dried pork powder (GFD) and freeze-thawed pork (GFT) at 1.5% and 2.0% NaCl were evaluated. The surface hydrophobicity and intrinsic tryptophan fluorescence intensity of myofibrillar proteins between the freeze-dried pork powder and freeze-thawed pork were similar. However, freeze-dried pork powder had higher carbonyl compounds and lower solubility of sarcoplasmic and myofibrillar proteins than freeze-thawed pork (p<0.05). GFD had higher cooking loss than GFT in 2.0% NaCl, and lower hardness and a* value of GFD were observed regardless of NaCl level (p<0.05). Moreover, GFD had higher malondialdehyde content than GFT at the two NaCl concentrations (p<0.05). Therefore, our study demonstrated that freeze-dried pork powder has lower functional properties than freeze-thawed pork as raw meat for comminuted meat products.

Drying-induced restructured jerky analog developed using a combination of edible insect protein and textured vegetable protein

With an increasing consumer interest in meat analog products, various imitation products have been developed. Among conventional meat products, jerky-type foods are rich in proteins and exhibit a long shelf-life owing to their low water activity (<0.90). Restructured jerky is advantageous because it can be easily processed into uniform products. This study investigated the physicochemical and thermal properties of drying-induced restructured jerky analogs prepared by combining textured vegetable protein (TVP) and edible insect protein (EIP) in the following ratios: 100/0, 80/20, 60/40, 40/60, 20/80, and 0/100% (w/w), as well as the interactions between EIP and TVP. Furthermore, qualitative characteristics, color, pH, moisture content, water activity, shear force, and rehydration capacity of the analogs were investigated. In conclusion, restructured jerky analogs developed by combining TVP and EIP may provide a tender dried food with high nutritional value.

Biological activity and processing technologies of edible insects: a review

The burgeoning global population growth has raised concerns regarding the expected increase in the demand for food, which could be partially tackled by identifying novel food sources. To this end, edible insects have recently attracted research interest. Several technologies for utilizing edible insect-derived proteins have been introduced; however, research into their functional utilization is insufficient. Herein, we reviewed the relevant literature on the importance of insects as food sources, extraction of edible insects, the nutritional value of insects, biological activities of components, and their applications in food industries. We summarized the studies primarily focused on the functional utilization of edible insects, suggesting that for successful incorporation and growth of edible insects in food and pharmaceutical industries, strategies to improve the extraction methods are required to explore the biological activity of edible insects. Furthermore, the awareness of edible insects with a focus on their allergens warrants consideration.

Understanding protein digestion in infants and the elderly: Current in vitro digestion models

The last decades have witnessed a surge of interest in the fate of dietary proteins during gastrointestinal (GI) digestion. Although several in vitro digestion models are available as alternatives to clinical experiments, most of them focus on the digestive conditions of healthy young adults. This study investigates the static/dynamic models used to simulate digestion in infants and the elderly and considers the related in vivo conditions. The in vitro digestive protocols targeting these two groups are summarized, and the challenges associated with the further development of in vitro digestion models are discussed. Static models rely on several factors (e.g., enzyme concentration, pH, reaction time, and rotation speed) to differentiate digestive conditions depending on age. Dynamic models can more accurately simulate the complex digestion process and allow the inclusion of further parameters (sequential secretion of digestive fluids, gradual changes in pH, peristaltic mixing, GI emptying, and the inoculation of luminal microbiota). In the case of infants, age or growth stage clarification and the differentiation of digestive protocols between full-term and preterm infants are required, whereas protocols dealing with various health statuses are required in the case of the elderly, as this group is prone to oral cavity and GI function deterioration.

Effect of reducing sodium chloride based on the sensory properties of meat products and the improvement strategies employed: a review

Many consumers are concerned about the high levels of salt intake owing to the accompanied risk of chronic diseases. Due to this dietary concern, the food industry has recommended the reduction of salt content in many products. However, the addition of salt to meat products improves their quality and sensory properties, including saltiness, color, juiciness, and texture. Because quality deteriorations could induce decreased sensory scores owing to salt reductions, the challenges involved in improving the quality of reduced-salt meat products have been addressed. During the development of low-salt meat products, it is important to reduce sodium content and address the problems that arise with this reduction. Modified salt, organic acids, amino acids, nucleotides, hydrocolloids, high-pressure, ultrasound, electric pulsed field, and irradiation have been suggested as strategies to replace or reduce sodium content, and sensory scores could be improved by these strategies. Therefore, when developing a low-salt meat product, several perspectives must be considered and the latest technologies that could resolve this problem should be adopted.

Alternative of Phosphate by Freeze- or Oven-Dried Winter Mushroom Powder in Beef Patty

This study investigated freeze- or oven-dried winter mushroom powder (FDP or ODP, respectively) as an alternative to phosphate in beef patties. The beef patties were prepared with four treatments: no addition of phosphate and winter mushroom (control), addition of 0.3% sodium pyrophosphate (BP), addition of 1% FDP (BFW), and addition of 1% ODP (BOW). The pH of FDP and ODP was 6.73, and 7.00, respectively. FDP and ODP contained phenolic compound at a level of 3.50 and 5.45 g gallic acid equivalent/kg, respectively. The cooking loss of beef patties was the highest in the control and lowest in BP (p<0.05). BFW had lower cooking loss than the control (p<0.05), and BOW showed similar cooking loss as that of the control (p>0.05). Inhibition of lipid oxidation was found in BP and BOW as compared with control (p<0.05). BFW was similar to the control in terms of the degree of lipid oxidation (p>0.05). BOW showed lower L* and higher a* values than those of the control, BP and BFW (p<0.05). Texture properties such as hardness, springiness, cohesiveness, gumminess, and chewiness were the highest in BP (p<0.05). A slight increase in hardness and springiness was observed in BOW compared to those of the control (p<0.05). The results showed that FDP and ODP did not exhibit all the properties of phosphate in beef patties. Therefore, FDP and ODP can be used for partial substitution of phosphate in beef patties.

Effects of High Hydrostatic Pressure on Technical Functional Properties of Edible Insect Protein

The objective of this study was to determine the effects of high pressure to investigate the technical functional properties of the protein solution extracted from an edible insect, Protaetia brevitarsis seulensis. High pressure processing was performed at 0 (control), 100, 200, 300, 400, and 500 MPa at 35°C. The essential amino acid index of the control was lower (p<0.05) than that of the P. brevitarsis seulensis extract treated with 100 MPa. The SDS-PAGE patterns tended to become faint at approximately 75 kDa and thicker at approximately 37 KDa after high pressure treatment. The protein solubility and pH of the protein tended to increase as the hydrostatic pressure levels increased. The instrument color values (redness and yellowness) of the P. brevitarsis seulensis protein treated with high pressure were lower (p<0.05) than those of the control. The forming capacity of the protein solution with P. brevitarsis seulensis treated with high pressure was higher (p<0.05) than that of the control. In conclusion, we confirmed that the technical functional properties of edible insect proteins extracted under high pressure of 200 MPa are improved. Our results indicate that high pressure can improve the technical functional properties of proteins from edible insects.

Quality Characteristics of Semi-Dried Restructured Jerky Processed Using Super-Heated Steam

Moisture content and water activity play important roles in extending the shelf life of dried meat products, such as jerky. However, the commonly used hot air drying process is time-consuming, costly, and adversely affects the quality of dried meat products, warranting the development of an advanced and economical drying method. This study investigated the effect of super-heated steam (SHS) drying on the quality characteristics of semi-dried restructured jerky as a measure to prevent the excessive quality deterioration of meat products during drying. The control sample was dried using hot air, and the treatment samples were dried using SHS at different temperatures (200, 250, and 300 °C) and for different durations (90, 105, and 120 min). With increasing SHS temperature and duration, the moisture content, water activity, and residual nitrite content of the jerky were reduced. The shear force values for treatments at 200 and 250 °C were lower than those for the control. With a non-significant difference in lipid oxidation compared with the control, the overall acceptability score was the highest for the treatment at 250 °C for 120 min. In conclusion, SHS (250 °C for 120 min) drying has a potential industrial value to replace the hot air drying method.

Physicochemical and textural properties of emulsions prepared from the larvae of the edible insects Tenebrio molitor, Allomyrina dichotoma, and Protaetia brevitarsis seulensis

The use of edible insects to replace meat protein is important to ensure future global food security. However, processed foods using edible insects require development to enhance consumer perception. Here, we examined the physicochemical characteristics and rheological properties of emulsions prepared from different edible insect larvae. Three edible insect species (Tenebrio molitor, Allomyrina dichotoma and Protaetia brevitarsis seulensis) were used to prepare larval emulsions that were formulated with 65% of insect larvae, 20% of pork back fat, and 15% ice. The A. dichotoma emulsion had the highest pH and lightness, redness, and yellowness values, while the T. molitor emulsion had the lowest pH and lightness, redness, and yellowness values. The T. molitor emulsion had the highest hardness, gumminess, chewiness, and apparent viscosity values but the lowest springiness and cohesiveness values. According to the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis, T. molitor had the thickest bands, followed by P. brevitarsis seulensis . The differential scanning calorimetry distributions for the T. molitor and A. dichotoma emulsions showed one peak, while that of the P. brevitarsis seulensis emulsion had two peaks. The collective results suggest that T. molitor was the most suitable candidate (of the three tested species) for use as a meat replacement in terms of its physicochemical and rheological properties. It is important that such properties of insect-based emulsions are maintained using various technologies.

Improvement of meat protein digestibility in infants and the elderly

Meat is a valuable protein source with a balanced composition of essential amino acids and various nutrients. This review aims to identify methods to improve digestion of meat proteins, as well as evaluate the digestive characteristics of infants and the elderly. Immature digestive conditions in infants, including a high gastric pH and low protease concentration, can hinder protein digestion, thus resulting in inhibited growth and development. Likewise, gastrointestinal (GI) tract aging and chronic health problems, including tooth loss and atrophic gastritis, can lead to reduction in protein digestion and absorption in the elderly compared with those in young adults. Moderate heating and several non-thermal technologies, such as aging, enzymatic hydrolysis, ultrasound, high-pressure processing, and pulsed electric field can alter protein structure and improve protein digestion in individuals with low digestive capacity.

Clean Label Meat Technology: Pre-Converted Nitrite as a Natural Curing

Clean labeling is emerging as an important issue in the food industry, particularly for meat products that contain many food additives. Among synthetic additives, nitrite is the most important additive in the meat processing industry and is related to the development of cured color and flavor, inhibition of oxidation, and control of microbial growth in processed meat products. As an alternative to synthetic nitrite, pre-converted nitrite from natural microorganisms has been investigated, and the applications of pre-converted nitrite have been reported. Natural nitrate sources mainly include fruits and vegetables with high nitrate content. Celery juice or powder form have been used widely in various studies. Many types of commercial starter cultures have been developed. S. carnosus is used as a critical nitrate reducing microorganism and lactic acid bacteria or other Staphylococcus species also were used. Pre-converted nitrite has also been compared with synthetic nitrite and studies have been aimed at improving utilization by exploiting the strengths (positive consumer attitude and decreased residual nitrite content) and limiting the weaknesses (remained carcinogenic risk) of pre-converted nitrite. Moreover, as concerns regarding the use of synthetic nitrites increased, research was conducted to meet consumer demands for the use of natural nitrite from raw materials. In this report, we review and discuss various studies in which synthetic nitrite was replaced with natural materials and evaluate pre-converted nitrite technology as a natural curing approach from a clean label perspective in the manufacturing of processed meat products.

No mutagenicity and oral toxicity of winter mushroom powder treated with atmospheric non-thermal plasma

This study aimed to evaluate the mutagenicity and oral acute toxicity of winter mushroom powder (PW) treated by atmospheric non-thermal plasma (ANP). Winter mushroom powder without plasma treatment (CW) containing an equivalent amount of sodium nitrite as PW was used as a control. The Ames test revealed that the number of revertant colonies did not significantly increase compared to that in the control. Acute toxicity was assessed in rats that were fed a single dose of winter mushroom powder (5000 mg/kg body weight). Results of the acute toxicity test revealed no remarkable clinical symptoms in any of the rats. No significant difference was observed in of the serum biochemical parameters between the treatments. Regardless of the ANP treatment, mild histological changes were observed in few rats in all groups. Therefore, it is concluded that ANP treatment did not cause any mutagenicity or acute toxicity in the winter mushroom.

Freezing-then-aging treatment improved the protein digestibility of beef in an in vitro infant digestion model

In vitro protein digestibility of freezing-then-aged beef was investigated in an infant digestion model. The treatments were divided into freezing-then-aging (FA) and aging-only (AO) groups. Carbonyl and total free sulfhydryl contents were the same between both groups for 14-day aging. Freezing had no effect on beef myofibrillar protein tertiary structure. Although caspase-3 activity did not differ, the FA group showed higher cathepsin B activity than the AO group (p < 0.05). The 10% trichloroacetic acid-soluble α-amino content was higher in FA than AO group, on aging day 14 (p < 0.05). Post in vitro digestion of beef aged for 14 days, the FA group had a higher content, than the AO group, of α-amino groups and proteins digested under 3 kDa (p < 0.05). An electrophoretogram of the digesta showed improved digestion of actin in the FA group. Collectively, the freezing-then-aging process enhanced the protein digestibility of beef in this in vitro infant digestion model.

Physiochemical properties of reduced-fat duck meat emulsion systems: effects of preemulsification with vegetable oils and duck skin

The effects of commercial vegetable oils and duck skin on quality characteristics of a reduced-fat duck meat emulsion were examined. The cooking loss, emulsion stability, and hardness were lower for emulsions preemulsified with vegetable oils and duck skin (P < 0.05) than for the control. Storage modulus (G') and loss modulus (G″) of reduced-fat duck meat emulsions treated with corn, grape seed, soy, and olive oils were similar to the values of control; the highest G' and G″ values were reported for the reduced-fat duck meat emulsion treated with coconut oil. Myofibril protein solubility was the highest for the reduced-fat duck meat emulsion treated with coconut oil and duck skin (P < 0.05). Replacing of pork back fat with different vegetable oils for emulsification may impart superior quality to reduced-fat duck meat emulsion. We recommend preemulsion with vegetable oils and duck skin to enhance the quality characteristics of reduced-fat duck meat emulsion.

Effect of Interaction between Mealworm Protein and Myofibrillar Protein on the Rheological Properties and Thermal Stability of the Prepared Emulsion Systems

In this study, we investigated the effect of replacing myofibrillar protein (pork ham) with edible insect proteins (Tenebrio molitor L.) in meat emulsion systems and examined the interaction between the two types of proteins. We also evaluated the rheological properties and thermal stability of these meat emulsions. The replacement ratios of myofibrillar protein and edible insect protein were as follows: 100:0 (EI0), 80:20 (EI20), 60:40 (EI40), 40:60 (EI60), 20:80 (EI80), and 0:100 (EI100). The pH, redness, and yellowness of the emulsion systems, after replacing myofibrillar protein with T. molitor protein, significantly increased with T. molitor protein concentrations. In contrast, the lightness, hardness, cohesiveness, gumminess, chewiness, apparent viscosity, and differential scanning calorimetry (DSC) of the emulsion systems decreased significantly with increasing T. molitor protein concentrations. The backscattering values of EI0, EI20, and EI40 decreased evenly in all spots of the dispersions as the storage time increased. Thus, up to 40% of pork myofibrillar protein could be replaced with T. molitor protein in meat emulsion systems. The results also suggest that the interaction between edible insect protein and myofibrillar protein degrades the rheological properties and thermal stability of the meat emulsion systems.

Status of meat alternatives and their potential role in the future meat market - A review

Plant-based meat analogues, edible insects, and cultured meat are promising major meat alternatives that can be used as protein sources in the future. It is also believed that the importance of meat alternatives will continue to increase because of concerns on limited sustainability of the traditional meat production system. The meat alternatives are expected to have different roles based on their different benefits and limitations. Plant-based meat analogues and edible insects can replace traditional meat as a good protein source from the perspective of nutritional value. Furthermore, plant-based meat can be made available to a wide range of consumers (e.g., as vegetarian or halal food products). However, despite ongoing technical developments, their palatability, including appearance, flavor, and texture, is still different from the consumers' standard established from livestock-based traditional meat. Meanwhile, cultured meat is the only method to produce actual animal muscle-based meat; therefore, the final product is more meat-like compared to other meat analogues. However, technical difficulties, especially in mass production and cost, remain before it can be commercialized. Nevertheless, these meat alternatives can be a part of our future protein sources while maintaining a complementary relationship with traditional meat.

Quality characteristics and protein digestibility of Protaetia brevitarsis larvae

Herein, the in vitro protein digestibility of lyophilized Protaetia brevitarsis larvae flour with and without defatting using 70% ethanol was compared with beef loin. Proximate analysis showed that the defatted larvae contained the highest protein content (p < 0.05). The viable counts of total aerobic bacteria, Escherichia coli, and coliform bacteria decreased significantly after defatting the larval samples with 70% ethanol (p < 0.05). Measurement of α-amino group content and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed higher amounts of low molecular weight proteins in the larvae compared to beef loin (p < 0.05). After in vitro digestion, the degree of protein hydrolysis of the digesta was higher for both larvae samples compared to beef loin (p < 0.05). No change was observed in the in vitro larval protein digestibility after defatting. These results highlight the excellent protein digestibility of P. brevitarsis larvae with high protein content. Defatting insect flour with 70% ethanol could enhance microbial safety while maintaining excellent protein digestibility.

Quality characteristics of semi-dried restructured jerky: combined effects of duck skin gelatin and carrageenan

The present study investigated the effects of duck skin gelatin and carrageenan on the quality of semi-dried restructured jerky. Restructured jerky was prepared as follows: G0 (control, without duck skin gelatin and carrageenan), G0C (0.3% carrageenan), G0.5 (0.5% duck skin gelatin), G0.5C (0.5% duck skin gelatin and 0.3% carrageenan), G1 (1.0% duck skin gelatin), and G1C (1.0% duck skin gelatin and 0.3% carrageenan). The moisture content was the highest for the semi-dried restructured jerky from G0.5C and G1C groups, which showed the lowest for shear force value (p < 0.05). The processing yield of semi-dried restructured jerky with carrageenan was higher compared to that of the control group (p < 0.05). The rehydration capacities of G0.5, G0.5C, and G1C groups were significantly higher than the rehydration capacity of the control group (p < 0.05). Water activity, lightness, yellowness, flavor score, texture score, and overall acceptability were the highest (p < 0.05) for the semi-dried restructured jerky from the G1C group. No significant (p > 0.05) difference was observed in appearance score among restructured jerky prepared from duck skin gelatin and carrageenan. Thus, the addition of 1.0% duck skin gelatin and 0.3% carrageenan to semi-dried restructured jerky formulations results in the optimization of quality characteristics.

Synergistic bactericidal effect of clove oil and encapsulated atmospheric pressure plasma against Escherichia coli O157:H7 and Staphylococcus aureus and its mechanism of action

We investigated the bactericidal effect of clove oil and encapsulated atmospheric pressure plasma (EAP), individually or in combination, against Escherichia coli O157:H7 and Staphylococcus aureus. The bactericidal effect of the combined treatment was also investigated in inoculated beef jerky. For both pathogens, clove oil and EAP single treatments resulted in less than 3.0-log reductions, whereas the combined treatment resulted in more than 7.5-log reductions. The disc-diffusion assay and gas chromatography-mass spectrometry showed no changes in both the clear zone diameter and chemical composition of clove oil before and after the EAP treatment. Significant changes in cell membrane permeability and cell morphology resulting from the combined treatment of clove oil and EAP were evidenced by increased in UV absorption of cell supernatants, increased cell staining with propidium iodide, and changes in cell structure revealed by transmission electron microscopy. The synergistic bactericidal effects of clove oil and EAP against both pathogens were also observed in inoculated beef jerky, but the treatments were less effective against S. aureus, presumably due to thicker peptidoglycan layer. Experiments also demonstrated that the synergistic bactericidal effects between clove oil and EAP are due to clove oil increasing the susceptibility of the bacteria to subsequent EAP treatment, and does not involve alteration of the antibacterial activity of clove oil by EAP.

Effects of hydrocolloids on the quality characteristics of cold-cut duck meat jelly

In this study, we examined the effects of various hydrocolloid (alginate, carrageenan, and konjac) treatments on the quality characteristics of cold-cut duck meat jelly. Seven different types of cold-cut duck meat jelly were prepared: control, without hydrocolloids; T1, 0.5% alginate; T2, 0.5% carrageenan; T3, 0.5% konjac; T4, 0.25% alginate + 0.25% carrageenan; T5, 0.25% carrageen + 0.25% konjac; and T6, 0.25% alginate + 0.25% konjac. The pH and moisture content of the cold-cut duck meat jelly with hydrocolloids was higher (p < 0.05) than that of the control. The highest lightness value was recorded for T4 and T6 (p < 0.05), and the hardness was lower (p < 0.05) in the meat jelly with hydrocolloids than in the control, except for T2 and T5. The springiness of the meat jelly was the highest (p < 0.05) in T1 and T4. The onset, peak, and end temperatures were the lowest (p < 0.05) in the control. The highest appearance score of the meat jelly was observed in T6, and its overall acceptability was higher (p < 0.05) than that of the control, indicating that, of all the treatments, 0.25% alginate + 0.25% konjac yielded the most desirable results. Thus, the combined use of duck skin and gelatin with alginate and konjac is potentially applicable for the development of new cold-cut duck meat products.

Effects of organic solvent on functional properties of defatted proteins extracted from Protaetia brevitarsis larvae

This study investigated the effect of aqueous fat separation and defatting using organic solvents (99% methanol, ethanol, and n-hexane) on the characteristics and functionality of proteins extracted from Protaetia brevitarsis. The defatting efficiency, amino acid composition, protein solubility, and technical properties were the highest when proteins were defatted using n-hexane. Proteins defatted using ethanol were similar in foam capacity and emulsifying capacity. Surface hydrophobicity decreased when using organic solvents, and excessive fat content disrupted the functional properties of the extracted proteins. Proteins extracted using the different solvents displayed different pH values. The pH of the aqueous extract was the lowest. CIE L* a* b* color values also differed using the different extraction methods. Although n-hexane might be the most efficient solvent for defatting the proteins extracted from edible insects, ethanol could also be used to obtain similar foam and emulsifying capacities.

Quality characteristics of the enhanced beef using winter mushroom juice

This study investigated the quality properties of enhanced beef, manufactured by injecting the beef with a brine containing winter mushroom juice powder (WMJP). The enhanced beef was manufactured by injecting the eye of round with brine (15% by green weight). Four treatments consisted of control (no injection of brine) and three enhanced beef, EBS (brine containing 5 g sodium chloride per kg beef), EBW 0.2 (brine containing 5 g sodium chloride and 2 g WMJP per kg beef), and EBW 0.5 (brine containing 5 g sodium chloride and 5 g WMJP per kg beef), were tested. The effect of enhancement or WMJP on the quality properties of beef was evaluated during storage at 4°C for 1, 5, and 10 days. Total aerobic bacteria counts between the control and the enhanced beef, and among EBS, EBW 0.2, and EBW 0.5 were not significantly different after any storage period (p > 0.05). The pH of beef was not different between the control and the enhanced beef, and among enhanced beef at 1 and 5 days of storage (p > 0.05). However, it was higher in the enhanced beef than control, and EBW 0.2 and EBW 0.5 had higher pH than EBS after 10 days of storage (p < 0.05). The enhanced beef showed a high total loss at all storage days (p < 0.05). There were no differences in total loss among enhanced beef after any storage period (p > 0.05). The enhanced beef had no consistent differences in L*, a*, and b* values with control during storage, however, EBW 0.5 showed high color stability. The hardness of the enhanced beef was significantly lower than that of the control after 10 days of storage, although the values were lower at all storage stages. EBS 0.5 had the lowest thiobarbituric acid reactive substance (TBARS) value among cooked beef of all treatments at all storage days. The enhanced beef received higher scores in all sensory properties than control, and no negative effect of WMJP was found in the sensory quality of the enhanced beef. The use of winter mushroom juice can result in quality improvement in enhanced beef.

Functional Properties of Extracted Protein from Edible Insect Larvae and Their Interaction with Transglutaminase

Global concern about food supply shortage has increased interest on novel food sources. Among them, edible insects have been studied as a potential major food source. This study aimed to improve the functional properties of protein solutions extracted from Protaetia brevitarsis (PB) by use of transglutaminase (TG) as a cross-linking agent. After various incubation times (10, 20, 30, 60, and 90 min) with TG, the protein solutions were assessed with regard to their amino acid composition, protein nutritional quality, pH, color (yellowness), molecular weight distribution, thermal stability, foam ability (capacity and stability), and emulsion ability (capacity and stability). Incubation with TG changed the amino acid composition of the proteins and shifted the molecular weight distribution towards higher values, while improving the rest of the aforementioned properties. Since the incubation time for 90 min decreased the protein functionality, the optimum incubation time for cross-linking PB-derived protein with TG is 60 min. The application of TG to edible insect proteins ultimately increases its functionality and allows for the development of novel insect processing technology.

Plasma-Polymerized Phlorotannins and Their Enhanced Biological Activities

Here, we investigated the effect of cold plasma (CP) on the biological activities of phloroglucinol. Phloroglucinol (7.92 and 15.84 mM in methanol) was treated with air dielectric barrier discharge plasma at 250 W. In vitro, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and ferrous-reducing antioxidant power (FRAP) values of phloroglucinol increased in plasma treatment in a time-dependent manner. CP treatment of phloroglucinol decreased the lipid oxidation of oil emulsion during storage and increased the antimicrobial activity against Bacillus cereus, Escherichia coli O157:H7, and Staphylococcus aureus. Angiotensin-converting enzyme (ACE) inhibitory activity of phloroglucinol increased and total phenolic content decreased based on CP treatment. The CP-induced polymerization of phloroglocinol to phlorotannin derivatives was identified using high-performance liquid chromatography with UV detector and electrospray ionization/mass spectrometry (HPLC-UV-ESI/MS) method. Consequently, the polymer structure of phloroglucinol was found in the CP-treated phloroglucinol. In addition, CP enhances the biological activity of phloroglucinol and could be applied to bioactive materials in food and related industries.

Effects of Searing Cooking on Sensory and Physicochemical Properties of Beef Steak

The purpose of the present study was to evaluate the sensory and instrumental quality of thawed beef steak prepared by searing and oven cooking. Beef purchased in the local market was divided into two groups; one group was cooked in a 180°C oven until the internal temperature reached 60°C, and the other group was oven cooked until 35°C, then cooked in a 250°C pan until the internal temperature reached 60°C. Despite a noticeable change in appearance due to the high temperature of the searing, there was no significant difference in juiciness, water content, and cooking loss between the searing-cooked and the oven-cooked steaks. However, in searing cooking, both scores of overall flavor and roast meat flavor were significantly higher than those of oven cooking. In the searing-cooked steak, the reducing sugar, which is a reactant of the Maillard reaction, was lower and Maillard-reaction products were higher than oven-cooked steak. From our results, it can be concluded that searing does not improve juiciness of the steak, but improves the flavor of beef steak due to higher levels of Maillard reaction products.

Edible Insects as a Protein Source: A Review of Public Perception, Processing Technology, and Research Trends

This review summarizes the current trends related to insect as food resources among consumers, industry, and academia. In Western societies, edible insects have a greater potential as animal feed than as human food because of cultural biases associated with harmful insects, although the abundant characteristics of edible insects should benefit human health. Nevertheless, many countries in Asia, Oceania, Africa, and Latin America utilize insects as a major protein source. Using insects can potentially solve problems related to the conventional food-supply chain, including global water, land, and energy deficits. Academic, industry, and government-led efforts have attempted to reduce negative perceptions of insects through developing palatable processing methods, as well as providing descriptions of health benefits and explaining the necessity of reducing reliance on other food sources. Our overview reveals that entomophagy is experiencing a steady increase worldwide, despite its unfamiliarity to the consumers influenced by Western eating habits.

Technical Functional Properties of Water- and Salt-soluble Proteins Extracted from Edible Insects

The amino acid composition, protein quality, and protein functionality of protein solution extracted from three edible insect species were investigated. We used 0.02% ascorbic acid and 0.58 M saline solution to extract water-soluble and salt-soluble proteins from the three insect species. Extracted protein solutions of Tenebrio molitor (TM), Allomyrina dichotoma (AD), and Protaetia brevitarsis seulensis (PB) were divided into six groups, according to species and solubility: WTM, WAD, WPB (water-soluble), and STM, SAD, and SPB (salt-soluble). Defatted TM had the highest protein content, but its protein solubility was the lowest, for both water and saline solutions. Amino acid composition differed by edible insect species and buffer type; SPB had the highest protein quality, followed by WPB. PB had a higher pH than the other species. Color values also differed among species. SPB had abundant high molecular weight proteins, compared with other treatments; and also had the highest foaming capacity, foam stability, and emulsifying capacity. In conclusion, PB is a good source of functional protein compared with the other studied species. Additionally, protein extraction using saline solution is promising as a useful method for improving edible insect protein functionality.