Effects of salting-in/out-assisted extractions on structural, physicochemical and functional properties of Tenebrio molitor larvae protein isolates

Minimizing anti-nutritional factors in wet protein extraction from Swedish faba beans through the application of response surface methodology

Faba beans, rich in protein and ideal for Swedish cultivation, are limited in food industry use due to anti-nutritional factors (ANFs) that hinder nutrient absorption. An extraction method was developed in our study to mitigate ANFs in faba beans, using aqueous alkaline methods and isoelectric precipitation with differential salt concentration. This method yielded 15.8 g of protein per 100 g of flour, with a protein concentration exceeding 83% of the total extract. It reduced ANFs like phytic acid (28.0%), lectins (87.5%), vicine (98.5%), and convicine (99.7%). Extraction conditions were optimized using response surface methodology, identifying pH 6, 2 h, and 20 °C as the most effective parameters, achieving an 86% reduction in phytic acid, closely matched the model's predictions (R2 = 0.945). This method effectively reduced ANFs, offering a sustainable approach for producing proteins suitable for diverse food products, including plant-based alternatives.

Elucidating the formation of the uniform "glass-like" texture in dried-bonito during processing based on microstructure and protein properties

Dried-bonito (Katsuobushi) exhibits a unique uniform "glass-like" texture after traditional smoke-drying. Herein, we developed a novel processing method for dried-bonito and elucidated the mechanism of transformation of loose muscle into a "glass-like" texture in terms of texture, microstructure, and protein properties. Our findings showed that the unfolding and aggregation of proteins after thermal induction was a key factor in shaping the "glass-like" texture in bonito muscle. During processing, myofibrils aggregated, the originally alternating thick and thin filaments contracted laterally and aligned into a straight line, and protein cross-linking increased. Secondary structural analysis revealed a reduction in unstable β-turn content from 26.28% to 15.06%. Additionally, an increase in the content of SS bonds was observed, and the conformation changed from g-g-t to a stable g-g-g conformation, enhanced protein conformational stability. Taken together, our findings provide a theoretical basis for understanding the mechanism of formation of the uniform "glass-like" texture in dried-bonito.

Effects of ultrasonic treatment on the structure and functional characteristics of myofibrillar proteins from black soldier fly

In the process of utilizing black soldier fly larvae (BSFL) lipids to develop biodiesel, many by-products will be produced, especially the underutilized protein components. These proteins can be recycled through appropriate treatment and technology, such as the preparation of feed, biofertilizers or other kinds of bio-products, so as to achieve the efficient use of resources and reduce the generation of waste. Myofibrillar protein (MP), as the most important component of protein, is highly susceptible to environmental influences, leading to oxidation and deterioration, which ultimately affects the overall performance of the protein and product quality. For it to be high-quality and fully exploited, in this study, black soldier fly myofibrillar protein (BMP) was extracted and primarily subjected to ultrasonic treatment to investigate the impact of varying ultrasonic powers (300, 500, 700, 900 W) on the structure and functional properties of BMP. The results indicated that as ultrasonic power increased, the sulfhydryl content and turbidity of BMP decreased, leading to a notable improvement in the stability of the protein emulsion system. SEM images corroborated the changes in the microstructure of BMP. Moreover, the enhancement of ultrasound power induced modifications in the intrinsic fluorescence spectra and FTIR spectra of BMP. Additionally, ultrasonic treatment resulted in an increase in carbonyl content and emulsifying activity of BMP, with both peaking at 500 W. It was noteworthy that BMP treated with ultrasound exhibited stronger digestibility compared to the untreated. In summary, 500 W was determined as the optimal ultrasound parameter for this study. Overall, ultrasound modification of insect MPs emerges as a dependable technique capable of altering the structure and functionality of BMP.

The impact of extraction processes on the physicochemical, functional properties and structures of bamboo shoot protein

This study aimed to extract bamboo shoot protein (BSP) using different extraction approaches and compare their functional and physicochemical properties with commercial protein ingredients, including whey protein and soy protein isolates. The extraction methods including alkali extraction (AE), salt extraction (SE), and phosphate-aided ethanol precipitation (PE) were used. An enhanced solvent extraction method was utilized in combination, resulting in a significant improvement in the protein purity, which reached 81.59 %, 87.36 %, and 67.08 % respectively. The extraction methods had significant effects on the amino acid composition, molecular weight distribution, and functional properties of the proteins. SE exhibited the best solubility and emulsification properties. Its solubility reached up to 93.38 % under alkaline conditions, and the emulsion stabilized by SE with enhanced solvent extraction retained 60.95 % stability after 120 min, which could be attributed to its higher protein content, higher surface hydrophobicity, and relative more stable and organized protein structure. All three BSP samples demonstrated better oil holding capacity, while the SE sample showed comparable functional properties to soy protein such as foaming and emulsifying properties. These findings indicate the potential of BSP as an alternative plant protein ingredient in the food industry.

A comparative evaluation of the structure, functionality and volatile profiles of Trichosanthes kirilowii seed protein isolates based on different extraction methods

In the present study, we hypothesised that Trichosanthes kirilowii seed protein isolate (TPI) obtained by different extraction methods have distinct structure, functional attributes and volatile profiles. Alkaline-extracted isolate (AE-TPI) exhibited lower protein content and a darker colour than the other two isolates because more polyphenols and pigments were coextracted. Salt-extracted isolate (SE-TPI) and AE-TPI had higher in vitro protein digestibility than reverse micelle-extracted isolate (RME-TPI) due to higher degrees of denaturation, which enabled them to be more susceptible to proteolysis. The SE-TPI gel resulted in a stronger gel network and greater hardness than the other two isolate gels. In the volatile profile, SE-TPI (22) yielded the largest number of volatile compounds, followed by AE-TPI (20) and RME-TPI (15). The current results indicated that the structure, functional properties and volatile profiles of TPI are largely influenced by the extraction technique.

Understanding the mechanism for sodium tripolyphosphate in improving the physicochemical properties of low-moisture extrusion textured protein from rapeseed protein and soybean protein blends

Our previous experiments found that rapeseed protein (RP) has applicability in low-moisture textured proteins. The amount of RP added is limited to <20 %, but the addition of 20 % RP still brings some negative effects. Therefore, in order to improve the quality of 20%RP textured protein, this experiment added different proportions of sodium tripolyphosphate (STPP) to improve the quality of the product, and studied the physical-chemical properties and molecular structure changes of the product to explore the possible modification mechanism. The STPP not only improved the expansion characteristics of extrudates, but also increased the brightness of the extrudates, the rehydration rate. In addition, STPP increased the specific mechanical energy during extrusion, decreased the material mass flow rate. Furthermore, STPP decreased the starch digestibility, increased the content of slow-digesting starch and resistant starch. STPP increased the degree of denaturation of extrudate proteins, the proportion of β-sheets in the secondary structure of proteins, as well as the intermolecular hydrogen bonding interactions. The gelatinization degradation degree of starch molecules also decreased with the addition of STPP. STPP also increased the protein-starch interactions and enhanced the thermal stability of the extrudate. All these indicate that STPP can improve the physical-chemical properties of extrudate.

Protein, lipid, and chitin fractions from insects: Method of extraction, functional properties, and potential applications

Edible insects are accepted as food and feed ingredients in many parts of the world. Insects account for more than 80% of animal kingdom providing rich biodiversity of protein and lipid profiles compared to conventional livestock. Insect biomasses contain an average of 35-62% protein, 3-57% lipid, and 3-12% chitin, and their nutritional values are widely recognized due to their presence, including minerals, and vitamins. While whole insects are consumed as eggs, larvae, pupae, or adults, there has been a recent uptick in interest to use fractions, e.g., protein, lipid, and chitin, as food and feed ingredients. To utilize these fractions in various food and feed preparations, a deeper understanding of the physicochemical as well as functional properties of the ingredients is required, which are generally impacted by extraction and preparation processes. Thus, the methods of extraction/purification are important to preserve the quality and functional properties of these ingredients. This paper discusses the extraction methods for insect protein, lipid, and chitin, their functional properties, and potential applications in food and feed applications.

Protein extraction from chlorella pyrenoidosa microalgae: Green methodologies, functional assessment, and waste stream valorization for bioenergy production

C. pyrenoidosa, a species of microalgae, has been recognized as a viable protein source for human consumption. The primary challenges in this context are the development of an efficient extraction process and the valorization of the resultant waste streams. This study, situated within the paradigm of circular economy, presents an innovative extraction approach that achieved a protein extraction efficiency of 62 %. The extracted protein exhibited remarkable oil-water emulsifying performances, such as uniform morphology with high creaming stability, suggesting a sustainable alternative to conventional emulsifiers. Additionally, hydrothermal liquefaction technique was employed for converting the residual biomass and waste solution from the extraction process into biocrude. A biocrude yield exceeding 40 wt%, characterized by a carbon content of 73 % and a higher heating value of 36 MJ/kg, were obtained. These findings demonstrate the promising potential of microalgae biorefinery, which is significant for paving toward circular economy and zero-waste society.

Effect of gamma-ray and electron-beam irradiation on the structural changes and functional properties of edible insect proteins from Protaetia brevitarsis larvae

Edible insects are regarded as future food sources to replace traditional livestock proteins. However, insect proteins have poor processing properties owing to various structural limitations. We investigated the structure of Protaetia brevitarsis larvae proteins modified by irradiation, and analyzed their resulting processing abilities. Following irradiation with gamma rays and electron beams, the ratio of parallel β-sheets to β-turns changed significantly, and changes in the tertiary protein structures were also confirmed. The polydispersity indices of the proteins remained relatively constant following irradiation, although the zeta potential and mean diameter changed. Furthermore, the pH, protein solubility, surface hydrophobicity, foaming capacity, and emulsion stability were higher than those of the control, whereas the viscosity and foaming stability were lower. Thus, gamma ray and electron beam irradiation clearly lead to changes in the structures of edible insect proteins and improves their processing properties, promoting the industrial utilization of such proteins in the food industry.

Evaluation of the Emulsifying Property and Oxidative Stability of Myofibrillar Protein-Diacylglycerol Emulsions Containing Catechin Subjected to Different pH Values

Myofibrillar protein-diacylglycerol emulsions containing catechin (MP-DAG-C) possess outstanding emulsifying property and oxidative stability. However, the effect of pH on MP-DAG-C emulsions should be revealed to provide possibilities for their application in practical meat products. Therefore, MP-DAG-C emulsions at different pH values were used in this study, in which lard, unpurified glycerolytic lard (UGL), and purified glycerolytic lard (PGL) were used as the oil phases. The results indicated that the emulsifying property of the UGL- and PGL-based emulsions increased compared to those of the lard-based emulsions (p < 0.05). The emulsifying activity and stability indices, absolute value of ζ-potential, and rheological characteristics increased with the increase in pH values (p < 0.05), with the droplets were smallest and distributed most uniformly at a pH of 6.5 compared to the other acidic environment (p < 0.05). The thiobarbituric acid substance and carbonyl content increased (p < 0.05), while the total sulfydryl content decreased (p < 0.05) during storage. However, there was no statistical difference between the oxidative stability of the MP-DAG-C emulsions with different pH values (p > 0.05). The results implied that the emulsifying property of MP-DAG-C emulsions increased with an increase in pH values. The oxidative stability of the MP-DAG-C emulsions at high pH values was improved by catechin.

Influence of heat treatment before and/or after high-pressure homogenization on the structure and emulsification properties of soybean protein isolate

This study investigates the effects of heat treatment before high-pressure homogenization (HHPH) and heat treatment after high-pressure homogenization (HPHH) at different pressures (20, 60, and 100 MPa) on the structural and emulsification properties of soy protein isolate (SPI). The results indicate that HHPH treatment increases the surface hydrophobicity (H0) of the SPI, reduces β-fold and irregular curls, leading to the formation of soluble aggregates, increased adsorbed protein content, and subsequent improvements in emulsification activity index (EAI) and emulsion stability index (ESI). In contrast, the HPHH treatment promoted the exchange of SH/SS bonds between protein molecules and facilitated the interaction of basic peptides and β-subunits, leading to larger particle sizes of the soluble aggregates compared to the HHPH-treated samples. However, excessive aggregation in HPHH-treated aggregates leads to decreased H0 and adsorbed protein content, and increased interfacial tension, negatively affecting the emulsification properties. Compared to the HPHH treatment, HHPH treatment at homogenization pressures of 20 to 100 MPa increases EAI and ESI by 5.81-29.6 % and 5.31-25.9 %, respectively. These findings provide a fundamental basis for soybean protein manufacturers to employ appropriate processing procedures aimed at improving emulsification properties.

Cricket Protein Isolate Extraction: Effect of Ammonium Sulfate on Physicochemical and Functional Properties of Proteins

Crickets are known to be a promising alternative protein source. However, a negative consumer bias and an off-flavor have become obstacles to the use of these insects in the food industry. In this study, we extracted the protein from commercial cricket powder by employing alkaline extraction-acid precipitation and including ammonium sulfate. The physicochemical and functional properties of the proteins were determined. It was found that, upon including 60% ammonium sulfate, the cricket protein isolate (CPI) had the highest protein content (~94%, w/w). The circular dichroism results indicated that a higher amount of ammonium sulfate drastically changed the secondary structure of the CPI by decreasing its α-helix content and enhancing its surface hydrophobicity. The lowest solubility of CPI was observed at pH 5. The CPI also showed better foaming properties and oil-holding capacity (OHC) compared with the cricket powder. In conclusion, adding ammonium sulfate affected the physicochemical and functional properties of the CPI, allowing it to be used as an alternative protein in protein-enriched foods and beverages.

Construction of a Collagen-like Protein Based on Elastin-like Polypeptide Fusion and Evaluation of Its Performance in Promoting Wound Healing

In the healing of wounds, human-like collagen (hCol) is essential. However, collagen-based composite dressings have poor stability in vivo, which severely limits their current therapeutic potential. Based on the above, we have developed a recombinant fusion protein named hCol-ELP, which consists of hCol and an elastin-like peptide (ELP). Then, we examined the physicochemical and biological properties of hCol-ELP. The results indicated that the stability of the hCol-ELP fusion protein exhibited a more compact and homogeneous lamellar microstructure along with collagen properties, it was found to be significantly superior to the stability of free hCol. The compound hCol-ELP demonstrated a remarkable capacity to induce the proliferation and migration of mouse embryo fibroblast cells (NIH/3T3), as well as enhance collagen synthesis in human skin fibroblasts (HSF) when tested in vitro. In vivo, hCol-ELP demonstrated significant enhancements in healing rate and a reduction in the time required for scab removal, thereby exhibiting a scar-free healing effect. The findings provide a crucial theoretical foundation for the implementation of an hCol-ELP protein dressing in fields associated with the healing of traumatic injuries.

Edible insects as emerging food products-processing and product development perspective

Edible insects (EI) are also becoming as a part of the diet due to their nutritional value and health benefits in many regions of the world. These EI are inexhaustible sources accessible by garnering from the wild with high feed conversion efficiency. Appreciating the budding of EI in justifiable food production, enlightening food security and biodiversity conversion, is promising a sufficient supply of the insect resource for future food to the world. These insects are processed to develop new products, improve organoleptic and nutritional parameters as well as the extension of shelf life. In this review, we discuss the edible insect characteristics, the potential application of EI in food industry, processing, pretreatments, drying, extraction of edible compounds like protein, lipid and chitin various food products formulation, safety regulation. Availability of broad nutritional spectrum of EI includes protein, mono and poly unsaturaturated fatty acids, amino acids, vitamins, amino aids and minerals has been used as an ingredient in development of various forms of food products such as flours in the form of whole insect powder, protein isolate, canned products, extruded products, hard candies, spreads, liquor infusion, cookies and other products.

Structural, physicochemical, and immune-enhancing properties of edible insect protein isolates from Protaetia brevitarsis larvae

Edible insects are promising future food resources globally. Herein, the structural, physicochemical, and bio-functional properties of edible insect protein isolates (EPIs) extracted from Protaetia brevitarsis larvae were investigated. The results showed that EPIs have a high total essential amino acid content; moreover, β-sheet is the major secondary protein structure. The EPI protein solution was highly soluble and electrically stable and did not aggregate easily. In addition, EPIs exhibited immune-enhancing properties; EPI treatment of macrophages induced the activation of macrophages and consequently promoted the production of pro-inflammatory mediators (NO, TNF-α, and IL-1β). Moreover, macrophage activation of EPIs was confirmed to occur through the MAPK and NF-κB pathways. In conclusion, our results suggest that the isolated P. brevitarsis protein can be fully utilized as a functional food material and alternative protein source in the future food industry.

Edible insect as an alternative protein source: a review on the chemistry and functionalities of proteins under different processing methods

The consumption of edible insects can be anadvantageous alternative to the conventional food supply chain, which involves global water waste, land deficit, undernutrition, and starvation. Besides the nutritional aspects, insect proteins have demonstrated a wide range of functional properties such as foamability, emulsifying and gelling abilities. The protein content and amino acid profile of some insects have revealed a good nutritional value and interesting functional properties. However, it is crucial to comprehend how the protein quality is affected by insect feeding, drying, and defatting. There is a knowledge gap about the impact of industrial treatment, such as pH, ionic strength, and heat treatment, on insect proteins' functional properties. In this review, we have aimed to highlight the potential application of insect proteins as a nutritional source and their promising technological applications. The study reported the principal insect protein characterization methodologies that have been investigated in the literature aiming to correlate the physicochemical parameters to possible protein functionalities. The research on the functional properties of insect proteins is at the exploratory level. Further detailed studies are needed to clarify the structure-function relation of insect proteins and how these functionalities and insect processing can increase consumer acceptance.

Ultrafiltration of Black Soldier Fly (Hermetia illucens) and Mealworm (Tenebrio molitor) Protein Concentrates to Enhance Emulsifying and Foaming Properties

Mealworm, TM (Tenebrio molitor), and black soldier fly, BSF (Hermetia illucens) are of special interest for food and feed applications due to their environmental benefits such as low water and land requirements, low greenhouse gas emissions, and high feed-conversion efficiency. This study assesses the use of ultrafiltration (UF) to fractionate protein concentrates from TM and BSF (TMPC, BSFPC) in order to enhance emulsifying and foaming properties. A 30 kDa regenerated cellulose acetate membrane enabled the separation of concentrate and permeate fractions for both insect proteins from two different initial feed concentrations (10 and 7.5 g/L). Permeate flux and protein transmission behave differently depending on the insect type and the initial concentration; while for TMPC permeate flux increases with a decrease in the initial protein concentration, it is not affected for BSFPC. The existing membrane cleaning protocols are suitable for recovering water flux after UF of insect proteins, enabling membrane re-use. Emulsifying activity is maintained for all the TMPC fractions, but it is significantly lower for the permeate fractions of BSFPC. Foaming properties are maintained for all the UF fractions of BSFPC and the ones from 7.5 g/L TMPC. Acidic solubilization leads to a fraction with enhanced emulsifying capacity and one with higher foaming capacity than the original for BSFPC. This study opens the door to membrane technology for insect protein fractionation, which has not been studied so far and has already provided useful solutions for other animal and plant proteins.

Characterization of Tenebrio molitor Larvae Protein Preparations Obtained by Different Extraction Approaches

Edible insects have recently attracted research attention due to their nutritional value and low environmental footprint. Tenebrio molitor larva was the first insect species to be classified by European Food Safety Authority (EFSA) as safe for human consumption. However, it is thought that the incorporation of edible insect as an ingredient in a food product would be more appealing to consumers than being visible. The aim of the present study was to determine the physicochemical properties of the larvae meal and protein concentrates. Different methods to extract and recover proteins from defatted (DF) Tenebrio molitor larvae were applied; i.e., alkaline extraction (DF-ASP); isoelectric precipitation after alkaline extraction (DF-AIP); and NaCl treatment (DF-SSP), and the obtained protein fractions were characterized. The DF-ASP exhibited the highest protein extraction/recovery efficiency (>60%), while it was the most effective in decreasing the interfacial tension at the oil/water (o/w) interface. The DF-AIP had the highest protein content (75.1%) and absolute values of ζ-potential and the best ability to retain water (10.54 g/g) and stabilize emulsions at pH 3.0. The DF-SSP protein preparation had the highest oil binding capacity (8.62%) and solubility (~88%) at acidic pHs and the highest emulsifying activity (~86 m2/g). Electrophoresis of the protein preparations revealed proteins with different molecular weights, while the protein secondary structure was dominated by β-structures and α-helix. Protein concentrates with different properties were able to be recovered from Tenebrio molitor larvae, that could affect their interactions with other food ingredients and their behavior during processing or storage. These findings would be valuable guidance for the technological exploitation of larvae protein preparations in the development of food formulations.

Nutritional Value and Physicochemical Characteristics of Alternative Protein for Meat and Dairy-A Review

In order to alleviate the pressure on environmental resources faced by meat and dairy production and to satisfy the increasing demands of consumers for food safety and health, alternative proteins have drawn considerable attention in the food industry. However, despite the successive reports of alternative protein food, the processing and application foundation of alternative proteins for meat and dairy is still weak. This paper summarizes the nutritional composition and physicochemical characteristics of meat and dairy alternative proteins from four sources: plant proteins, fungal proteins, algal proteins and insect proteins. The difference between these alternative proteins to animal proteins, the effects of their structural features and environmental conditions on their properties, as well as the corresponding mechanism are compared and discussed. Though fungal proteins, algal proteins and insect proteins have shown some advantages over traditional plant proteins, such as the comparable protein content of insect proteins to meat, the better digestibility of fungal proteins and the better foaming properties of algal proteins, there is still a big gap between alternative proteins and meat and dairy proteins. In addition to needing to provide amino acid composition and digestibility similar to animal proteins, alternative proteins also face challenges such as maintaining good solubility and emulsion properties. Their nutritional and physicochemical properties still need thorough investigation, and for commercial application, it is important to develop and optimize industrial technology in alternative protein separation and modification.

Recent Insight on Edible Insect Protein: Extraction, Functional Properties, Allergenicity, Bioactivity, and Applications

Due to the recent increase in the human population and the associated shortage of protein resources, it is necessary to find new, sustainable, and natural protein resources from invertebrates (such as insects) and underutilized plants. In most cases, compared to plants (e.g., grains and legumes) and animals (e.g., fish, beef, chicken, lamb, and pork), insect proteins are high in quality in terms of their nutritional value, total protein content, and essential amino acid composition. This review evaluates the recent state of insects as an alternative protein source from production to application; more specifically, it introduces in detail the latest advances in the protein extraction process. As an alternative source of protein in food formulations, the functional characteristics of edible insect protein are comprehensively presented, and the risk of allergy associated with insect protein is also discussed. The biological activity of protein hydrolyzates from different species of insects (Bombyx mori, Hermetia illucens, Acheta domesticus, Tenebrio molitor) are also reviewed, and the hydrolysates (bioactive peptides) are found to have either antihypertensive, antioxidant, antidiabetic, and antimicrobial activity. Finally, the use of edible insect protein in various food applications is presented.

Effects of the Temperature and Salt Concentration on the Structural Characteristics of the Protein (PDB Code 1BBL)

The effect of the temperature and salt solution on the structural characteristics of the protein 1BBL was investigated by molecular dynamics simulations. The paper presents simulation results regarding the non-bonded energy and the structural stability of the protein immersed in salt solutions with different concentrations and temperatures. Our work demonstrates that the electrostatic potential energy and van der Waals energy of the system show the opposite changes with the influence of the external environment. Since the electrostatic potential energy changes more obviously, it is dominated in the non-bonding interactions. The structural parameters, such as the root mean square deviation and the radius of gyration, increased initially and decreased afterward with the increase of the salt concentration. The protein presented the loose structure with a relative low stability when it was immersed in a monovalent solution with a salt concentration of 0.8 mol/L. The salt concentration corresponding to the maximum value of structural parameters in the monovalent salt solution was double that in the divalent salt solution. It was also concluded that the protein presented a compact and stable structure when immersed in salt solutions with a high concentration of 2.3 mol/L. The analysis of the root mean square deviation and root mean square fluctuation of the protein sample also exhibited that the structural stability and chain flexibility are strongly guided by the effect of the temperature. These conclusions help us to understand the structural characteristics of the protein immersed in the salt solutions with different concentrations and temperatures.

Application of Aqueous Saline Process to Extract Silkworm Pupae Oil (Bombyx mori): Process Optimization and Composition Analysis

Silkworm pupae, a waste product from the silk production industry, can be an alternative source of edible oil, thus reducing the industry's waste. In the present work, frozen silkworm pupae were used as raw material to extract oil via an aqueous saline process. The Box-Behnken design (BBD) and response surface methodology (RSM) were used to optimize the extraction process. The extraction conditions with the highest oil yield and a low peroxide value were obtained when using a saline solution concentration of 1.7% w/v, a ratio of aqueous liquid to silkworm pupae of 3.3 mL/g, and a 119 min stirring time at the stirring speed of 100 rpm. Under these conditions, silkworm oil with a yield of 3.32%, peroxide values of approximately 1.55 mM, and an acid value of 0.67 mg KOH/g oil was obtained. The extracted oil contained omega-3 acids (α-linolenic acid), which constituted around 25% of the total fatty acids, with approximate cholesterol levels of 109 mg/100 g oil. The amounts of β-carotene and α-tocopherol were approximately 785 and 9434 μg/100 g oil, respectively. Overall, the results demonstrated that oil extracted from silkworm pupae has good quality parameters and thus can be used as a new valuable source of edible lipids.

Polyphenol Loaded W1/O/W2 Emulsions Stabilized with Lesser Mealworm (Alphitobius diaperinus) Protein Concentrate Produced by Membrane Emulsification: Stability under Simulated Storage, Process, and Digestion Conditions

Water-in-oil-in-water (W1/O/W2) emulsions are complex delivery systems for polyphenols amongst other bio-actives. To stabilize the oil-water interphase, dairy proteins are commonly employed, which are ideally replaced by other, more sustainable sources, such as insect proteins. In this study, lesser mealworm (Alphitobius diaperinus) protein concentrate (LMPC) is assessed and compared to whey protein (WPI) and pea protein (PPI), to stabilize W1/O/W2 emulsions and encapsulate a commercial polyphenol. The results show that LMPC is able to stabilize W1/O/W2 emulsions comparably to whey protein and pea protein when using a low-energy membrane emulsification system. The final droplet size (d4,3) is 7.4 μm and encapsulation efficiency is between 72 and 74%, regardless of the protein used. Under acidic conditions, the LMPC shows a similar performance to whey protein and outperforms pea protein. Under alkaline conditions, the three proteins perform similarly, while the LMPC-stabilized emulsions are less able to withstand osmotic pressure differences. The LMPC stabilized emulsions are also more prone to droplet coalescence after a freeze-thaw cycle than the WPI-stabilized ones, but they are the most stable when exposed to the highest temperatures tested (90 °C). The results show LMPC's ability to stabilize multiple emulsions and encapsulate a polyphenol, which opens the door for application in foods.

Tenebrio molitor as a source of interesting natural compounds, their recovery processes, biological effects, and safety aspects

Nowadays, it is urgent to produce in larger quantities and more sustainably to reduce the gap between food supply and demand. In a circular bioeconomy vision, insects receive great attention as a sustainable alternative to satisfy food and nutritional needs. Among all insects, Tenebrio molitor (TM) is the first insect approved by the European Food Safety Authority as a novel food in specific conditions and uses, testifying its growing relevance and potential. This review holistically presents the possible role of TM in the sustainable and circular solution to the growing needs for food and nutrients. We analyze all high value-added products obtained from TM (powders and extracts, oils and fatty acids, proteins and peptides, and chitin and chitosan), their recovery processes (evaluating the best ones in technical and environmental terms), their nutritional and economical values, and their biological effects. Safety aspects are also mentioned. TM potential is undoubted, but some aspects still need to be discussed, including the health effects of substances and microorganisms in its body, the optimal production conditions (that affect product quality and safety), and TM capacity to convert by-products into new products. Environmental, economic, social, and market feasibility studies are also required to analyze the new value chains. Finally, to unlock the enormous potential of edible insects as a source of nutritious and sustainable food, it will be necessary to overcome the cultural, psychological, and regulatory barriers still present in Western countries.