Variation of volatile compounds and sensory profile for Protaetia brevitarsis larvae fermented with lactic acid bacteria and yeast.

This study aimed to investigate the correlation between the composition of volatile compounds, consumer acceptance, and drivers of (dis)liking of Protaetia brevitarsis larvae fermented using lactic acid bacteria and yeast. Volatile compounds were analyzed using HS-SPME-Arrow-GC-MS, and a sensory evaluation was conducted with 72 consumers. A total of 113 volatile compounds were detected, and principal component analysis indicated that the samples could be divided into three groups. The calculated relative odor activity values (ROAV) revealed the presence of 27 compounds (ROAV >1). Volatile compounds with high ROAV were predominantly found during yeast fermentation. The sensory evaluation results indicated a strong correlation between low levels of off-odor intensity and high odor liking, emphasizing that odor profile had a more direct association with consumer acceptance than odor intensity. These findings suggest that yeast fermentation using volatile compounds, which positively influences consumer acceptance, is appropriate for Protaetia brevitarsis larvae.

The effects of different extraction methods on essential oils from orange and tangor: From the peel to the essential oil.

Citrus fruits are largely consumed due to their unique and pleasant aromas. Citrus hybrids have been developed to enhance their flavors and bioactivities. Citrus aroma depends on the composition of the volatile compounds in citrus essential oils (CEOs), which are mostly located in the peels. During the extraction of CEOs, a specific series of chemical reactions occurred depending on the extraction methods (CP, cold pressing; HD, hydrodistillation), leading to variations in the composition of volatile compounds. In this study, the orange and the tangor which is a hybrid between C. reticulata × C. sinensis were investigated to compare the changes in volatile compounds based on the extraction methods. Results showed that the CP-specific volatile compounds were sesquiterpenes, oxygenated monoterpenes, and fatty acid derivatives, while the HD-specific volatile compounds were terpinyl cation derivatives, limonene, and 4-vinylguaiacol. On the other hand, the contents of some volatile compounds ((E)-ocimene, α-terpinene, and α-terpinolene) were affected by the Citrus species rather than by the extraction methods. In particular, during HD, terpinene-4-ol and 4-vinylguiacol, known as off-flavor compounds in citrus juice, were formed more abundantly in the orange than in the tangor. In conclusion, these results provide comprehensive data on essential oils, especially those derived from oranges and tangors, for selecting the appropriate extraction method for obtaining a higher yield and quality of citrus flavor.

Headspace stir-bar sorptive extraction combined with gas chromatography-mass spectrometry for trace analysis of volatile organic compounds in Schisandra chinensis Baillon (omija).

Analyzing volatile organic compounds (VOCs) in food is crucial but challenging. Schisandra chinensis Baillon (omija) is an herbal plant with various functional health activities. Previous VOC analyses focused on S. chinensis fruit but not its leaves. Therefore, VOCs in S. chinensis fruit and leaves were analyzed using headspace stir-bar sorptive extraction (HS-SBSE)-GC-MS, and optimal conditions were established. Various factors, such as the sample preparation method, twister stir-bar type, sample amount, extraction temperature, and extraction time, expected to affect extraction were carefully optimized. Under the optimal conditions, 35 and 40 VOCs were identified in S. chinensis fruit and leaves, respectively. This HS-SBSE method is capable of rapid analysis and a low contamination rate without requiring organic solvents. These findings provide practical guidelines for HS-SBSE applications in various food matrices by providing analytical methods for VOC detection.

Determination of vitamin K encapsulated into lipid nanocarriers by dispersive liquid-liquid microextraction combined with liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry.

Dispersive liquid-liquid microextraction was used in conjunction with liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry to quantitate vitamins K1 and K2 in vitamin-fortified emulsions, and vital microextraction parameters were optimized using response surface methodology coupled with Box-Behnken design. Under optimal microextraction conditions, highly linear (R 2 > .999) calibration curves were obtained for both vitamins in a broad concentration range (1-1000 µg/L), and vitamin recoveries exceeded 90%. The detection and quantitation limits equaled 1.89 and 5.72 µg/L for vitamin K1, respectively, and 5.00 and 15.15 µg/L for vitamin K2, respectively. When applied to vitamin-K-loaded nanoemulsions and solid lipid nanoparticles, the developed method achieved excellent results, outperforming the currently employed Korean Food Code method, and therefore holding great promise for the quantitation of vitamin K in vitamin-fortified food products.

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.

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.

CRISPR/Cas9-mediated Inactivation of arginase in a yeast strain isolated from Nuruk and its impact on the whole genome.

Despite the advantages of CRISPR/Cas9 technology in the food industry, controversy over its off-target effects exists. We engineered an industrial Saccharomyces cerevisiae strain isolated from a Korean rice wine starter, Nuruk, using CRISPR/Cas9 to decrease ethyl carbamate (EC) formation. We disrupted the CAR1 gene encoding arginase, which plays a key role in EC formation. Subsequently, we compared the whole genome of the engineered strain to that of the wild type by analyzing heterozygous and homozygous mutations through variant calling. Homozygous mutations in the genome of the engineered strains were identified as the target mutations in CAR1 induced by CRISPR/Cas9, and no other off-target effects were observed. Our findings have critical implications for the use of CRISRP/Cas9 technology in yeasts in the food industry.

Chemical Composition, Antioxidant, and Anti-Inflammatory Activity of Essential Oil from Omija (Schisandra chinensis (Turcz.) Baill.) Produced by Supercritical Fluid Extraction Using CO2.

Schisandra chinensis (Turcz.) Baill., which is known as omija in South Korea, is mainly cultivated in East Asia. The present study aimed to investigate the chemical composition of essential oil from the omija (OMEO) fruit obtained by supercritical fluid extraction using CO2 and to confirm the antioxidant and anti-inflammatory activity of OMEO using HaCaT human keratinocyte and RAW 264.7 murine macrophages. As a result of the chemical composition analysis of OMEO using gas chromatography-mass spectrometry, a total of 41 compounds were identified. The detailed analysis results are sesquiterpenoids (16), monoterpenoids (14), ketones (4), alcohols (3), aldehydes (2), acids (1), and aromatic hydrocarbons (1). OMEO significantly reduced the increased ROS levels in HaCaT keratinocytes induced by UV-B irradiation (p < 0.05). It was confirmed that 5 compounds (α-pinene, camphene, ß-myrcene, 2-nonanone, and nerolidol) present in OMEO exhibited inhibitory activity on ROS production. Furthermore, OMEO showed excellent anti-inflammatory activity in RAW 264.7 macrophages induced by lipopolysaccharide. OMEO effectively inhibited NO production (p < 0.05) by suppressing the expression of the iNOS protein. Finally, OMEO was investigated for exhibition of anti-inflammatory activity by inhibiting the activation of NF-κB pathway. Taken together, OMEO could be used as a functional food ingredient with excellent antioxidant and anti-inflammatory activity.

Analysis of in vitro digestion using human gut microbiota in adult and elderly individuals.

In vitro human digestion models are widely used to determine the digestibility of bioactive substances and to perform drug delivery analyses. To develop the most accurate in vitro human digestion model reported to date, we simulated all digestion conditions, including pH and digestion time, with changes in the amount of digestive enzymes, motility, and proportion of human gut microbiota in adult and elderly individuals. Using this newly developed model, the digestibility of vitamin E emulsified by lard was found to be significantly different between adults and the elderly. Therefore, this model can accurately simulate oral, gastric, and intestinal (with gut microbiota effects) digestion of bioactive substances and can aid in analyzing drug delivery in adults and elderly individuals.

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.

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.

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.

Analysis of volatile compounds in rooibos tea (Aspalathus linearis) using different extraction methods and their relationship with human sensory perception.

This study aimed to comparatively analyze the volatile flavor of rooibos tea (Aspalathus linearis) obtained by two commonly used flavor extraction methods, simultaneous distillation-extraction (SDE) and steam distillation under reduced pressure (DRP). The tea obtained by the two extraction methods, were analyzed by gas chromatography-mass spectrometry to identify volatile aroma-related compounds. Descriptive sensory analysis of the extracted rooibos tea flavor was carried out by a trained panel (n = 7). Fifty volatile compounds were identified, including 26 and 25 aroma-active compounds by SDE (45.9 µg/g) and DRP (37.5 µg/g), respectively. SDE recovered larger quantities of alcohols, acids, and esters, whereas DRP was useful for analyzing thermally unstable volatile compounds, including various alcohols, aldehydes, and hydrocarbons. Descriptive sensory analysis revealed that ketones and phenolic compounds may be responsible for the sensory attributes woody and grassy green, whereas the aldehydes and acidic compounds may contribute to floral and fruity.

Differences in the gut microbiota between young and elderly persons in Korea.

The gut microbiota differs among countries owing to the prevailing diet composition. For the characterization of the gut microbiota of Koreans at different ages in future studies, e.g., in an in vitro human digestion model, we tried to investigate whether the gut microbiota differs between the young and elderly in Korea. Two hundred fecal samples were collected: 100 from elderly people (over 65 years old) at geriatric nursing hospitals and 100 from young people (university students, 20-25 years old) in Gyeonggi province, Korea. The composition of the gut microbiota in these fecal samples was analyzed by next-generation sequencing methods. There were significant differences in the taxonomic composition of the microbiota (the top 10 most abundant taxa) between the young and elderly people in Korea, especially in terms of relative abundance levels of bacteria in phyla Firmicutes, Proteobacteria, Tenericutes, and Fusobacteria (P < 001). The gut microbiota of young people contained higher relative abundance of Lactobacillus than did the microbiota of elderly people, while the microbiota of elderly people manifested higher relative abundance of Escherichia. Even though the sample size may not be large enough for this study to be representative of the entire population of Korea, the study still provides data that are suggestive of differences in the gut microbiota between young and elderly people in Korea. Furthermore, our findings may be applied to develop an improved age-based in vitro model of digestion of Koreans for future research.

Physical and turbidimetric properties of cholecalciferol- and menaquinone-loaded lipid nanocarriers emulsified with polysorbate 80 and soy lecithin.

The present study aimed to investigate the physical and turbidimetric properties of cholecalciferol- and menaquinone-loaded lipid nanocarriers emulsified with different ratios of polysorbate 80 and soy lecithin. The lipid nanocarriers were subjected to three different heat treatments, LTLT (low temperature long time), HTST (high temperature short time), and autoclave treatments. Both cholecalciferol and menaquinone were successfully encapsulated in lipid nanocarriers and there was little loss of them during preparation. The droplet size of lipid nanocarriers emulsified with only polysorbate 80 increased and its PDI became larger than 0.3 after autoclave treatment. Moreover, 30.9% and 49.4% of cholecalciferol and menaquinone, respectively, were lost. In turbidimetric analysis, the destabilization by creaming formation in the upper layer of the lipid nanocarriers emulsified with a high polysorbate ratio was observed. However, the use of combination of both emulsifiers inhibited destabilization by flocculation as well as retained the cholecalciferol and menaquinone after all heat treatments.

Analyzing Gluten Content in Various Food Products Using Different Types of ELISA Test Kits.

Gluten is an insoluble protein produced when glutelins and prolamins, which are found in grains such as wheat, barley, and oats, combine to form an elastic thin film. This dietary gluten can cause severe contraction of the intestinal mucous membrane in some people, preventing nutrient absorption. This condition, called celiac disease (CD), affects approximately 1% of the world's population. The only current treatment for patients with CD and similar diseases is lifelong avoidance of gluten. To analyze the gluten content in food, various enzyme-linked immunosorbent assay (ELISA) tests are currently used. In this study, the gluten content in various food products was analyzed using different kinds of ELISA test kits. For gluten-free food, three different ELISA test kits mostly yielded values below the limit of detection. However, gluten was detected at 24.0-40.2 g/kg in bread, 6.5-72.6 g/kg in noodles, and 23.0-86.9 g/kg in different powder food samples. A significant difference (p < 0.05) in gluten content was observed for these gluten-containing food products. Reproducibility issues suggest that it is necessary to use several ELISA kits for the accurate detection and quantification of gluten in various food products rather than using one ELISA kit.

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.

Analysis of Volatile Compounds in Soju, a Korean Distilled Spirit, by SPME-Arrow-GC/MS.

The SPME Arrow technology-a novel solid phase micro-extraction technique-was used to analyze Soju, a traditional Korean distilled liquor, in barrels made of Quercus spp. The volatile compounds detected when the barrels were toasted were analyzed. Five types of sorbents-carbon wide range/polydimethylsiloxane, divinylbenzene/carbon wide range/polydimethylsiloxane, divinylbenzene/polydimethylsiloxane, polydimethylsiloxane, and polyacrylate-were used for this investigation. Fifty-four volatile compounds were detected in Soju using gas chromatography/mass spectrometry. A high extraction efficiency was obtained using carbon wide range/polydimethylsiloxane. Nineteen samples were analyzed using barrels made of six species of carbonated oak (Q. aliena, Q. variabilis, Q. dentate, Q. acutissima, Q. mongolica, and Q. serrata) and control groups in three ways: noncharring, medium charring, and heavy charring. Ethanol, 1-propanol, isoamyl acetate, and isoamyl alcohol can be used as indicator volatile components for Soju and other such traditional Korean distilled liquors. We believe our study results can be used to design better analysis methods for Soju and other distilled liquors.

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.