Essential oils (EOs) are plant aromas used in the food industry. They have attracted considerable attention due to their diverse properties, i.e., antimicrobial, antifungal, and antioxidant activities, with natural aroma and flavor as beneficial food additives. However, the instability, degradability, and hydrophobicity of EOs have limited their practical use in the food industry. Nanoencapsulation, a process where EOs are enclosed in a protective shell at the nanoscale, promises to enhance the biological properties of EOs. This process empowers EOs with excellent physiochemical stability and solubility, allowing for better distribution in food systems and controlled release for prolonged availability of EOs without rapid evaporation and instability. This review summarizes the recent works on encapsulating EOs to enhance their biological properties, providing a comprehensive overview of various specific nano-carriers and their applications in the food industry.

Essential oils (EOs) are plant aromas used in the food industry. They have attracted considerable attention due to their diverse properties, i.e., antimicrobial, antifungal, and antioxidant activities, with natural aroma and flavor as beneficial food additives. However, the instability, degradability, and hydrophobicity of EOs have limited their practical use in the food industry. Nanoencapsulation, a process where EOs are enclosed in a protective shell at the nanoscale, promises to enhance the biological properties of EOs. This process empowers EOs with excellent physiochemical stability and solubility, allowing for better distribution in food systems and controlled release for prolonged availability of EOs without rapid evaporation and instability. This review summarizes the recent works on encapsulating EOs to enhance their biological properties, providing a comprehensive overview of various specific nano-carriers and their applications in the food industry.

Chlorophyll (Chl), the most widely distributed natural pigment in nature, is limited in use due to its poor stability. This study refers to the aggregation structure of Chl and carotene (Car) in natural photosynthetic systems, hoping to improve the photostability of Chl by constructing Chl/Car aggregates. The stability protection effect of Car on Chl was explored by designing different ratios of Chl and Car aggregation systems. The configuration of Chl/Car aggregates was optimized through ab initio molecular dynamics, and the aggregation mechanism of the aggregates and the photoprotection mechanism of Chl by Car were elucidated through quantum chemical calculations and wave function analysis. Chl/Car had a 27.22% higher Chl retention rate than free Chl after 7 d of illumination, with a Chl to Car ratio of 1.66:1. A configuration of the Chl/Car aggregates which Car's conjugated olefin chain interacts extensively with the porphyrin ring and bent phytyl chain of Chl made them more stable. The photoprotective mechanism of Car on Chl in the Chl/Car aggregates is elucidated. Car's conjugated polyene chain provides HOMO orbitals to the Chl/Car aggregates. It demonstrated that Car supplies electrons in the low-lying excited states S2 and S4, indicating it is more susceptible to damage, protecting Chl. This research will promote the development of natural color formulas and ensure the health of consumers.

Chlorophyll (Chl), the most widely distributed natural pigment in nature, is limited in use due to its poor stability. This study refers to the aggregation structure of Chl and carotene (Car) in natural photosynthetic systems, hoping to improve the photostability of Chl by constructing Chl/Car aggregates. The stability protection effect of Car on Chl was explored by designing different ratios of Chl and Car aggregation systems. The configuration of Chl/Car aggregates was optimized through ab initio molecular dynamics, and the aggregation mechanism of the aggregates and the photoprotection mechanism of Chl by Car were elucidated through quantum chemical calculations and wave function analysis. Chl/Car had a 27.22% higher Chl retention rate than free Chl after 7 d of illumination, with a Chl to Car ratio of 1.66:1. A configuration of the Chl/Car aggregates which Car's conjugated olefin chain interacts extensively with the porphyrin ring and bent phytyl chain of Chl made them more stable. The photoprotective mechanism of Car on Chl in the Chl/Car aggregates is elucidated. Car's conjugated polyene chain provides HOMO orbitals to the Chl/Car aggregates. It demonstrated that Car supplies electrons in the low-lying excited states S2 and S4, indicating it is more susceptible to damage, protecting Chl. This research will promote the development of natural color formulas and ensure the health of consumers.

In this study, static and dynamic desorption methods, infrared spectroscopy and, in vitro antioxidant modeling were used to isolate, purify, and investigate the bioactivity of melanoidins extracted from hypoheat-induced Lycium barbarum L. The results showed that melanoidin fractions with molecular weight in the range of 3−10 kDa were the dominant and most valuable fractions. In the purification phase, the optimal purification conditions were: a loading concentration of 4 mg·mL−1, elution volume of 6 BV, and an elution flow rate of 1 mL·min−1. Purified dominant melanoidin fractions (UF3) exhibited typical Maillard reaction (MR) characteristics in FTIR. The storage stability showed that sunlight and heat treatment exacerbated the instability of the purified UF3. At the same time it was relatively stable under dark conditions and incandescent light, with a retention rate of about 90%. After in vitro digestion, the purified UF3 still exhibited good antioxidant activity, and the DPPH scavenging activity and hydroxyl free radical scavenging ability reached more than 60%.

In this study, static and dynamic desorption methods, infrared spectroscopy and, in vitro antioxidant modeling were used to isolate, purify, and investigate the bioactivity of melanoidins extracted from hypoheat-induced Lycium barbarum L. The results showed that melanoidin fractions with molecular weight in the range of 3−10 kDa were the dominant and most valuable fractions. In the purification phase, the optimal purification conditions were: a loading concentration of 4 mg·mL−1, elution volume of 6 BV, and an elution flow rate of 1 mL·min−1. Purified dominant melanoidin fractions (UF3) exhibited typical Maillard reaction (MR) characteristics in FTIR. The storage stability showed that sunlight and heat treatment exacerbated the instability of the purified UF3. At the same time it was relatively stable under dark conditions and incandescent light, with a retention rate of about 90%. After in vitro digestion, the purified UF3 still exhibited good antioxidant activity, and the DPPH scavenging activity and hydroxyl free radical scavenging ability reached more than 60%.

The colonic mucosal barrier is an important component of the intestinal barrier, and its integrity is crucial for maintaining digestive tract homeostasis and normal metabolism in the body. This study aimed to elucidate the mechanisms by which malvidin-3-O-galactoside (M3G) might ameliorate colonic mucosal barrier function, from the perspective of physical barrier function and immune barrier function. Male C57BL/6J mice were given dextran sulfate sodium (DSS) to establish a mice model for colitis and then administrated with or without M3G for one week. The results showed that M3G supplementation significantly improved the disease activity index (DAI) score and colon tissue injury in mice with DSS-induced colitis. M3G improved the colonic physical barrier function by modulating the expression of mucin2 (MUC2), claudin-1, occludin, zona occludens 1 (ZO-1), and intestinal fatty acid binding protein (iFABP) in the colonic mucosa. Additionally, M3G also relieved the colonic immune barrier of mice by increasing the level of secretory immunoglobulin A (SIgA) in colon tissue and the percentages of CD4+T (CD3+CD4+) and CD8+T (CD3+CD8+) cells in colon lamina propria monocytes in mice. Furthermore, M3G down-regulated Notch signaling pathway-related proteins such as Notch1, notch intracellular domain (NICD), delta-like ligand 4 (DLL4), delta-like ligand 1 (DLL1), and hairy/enhancer of split 1 (Hes1) of colon tissue. The present results demonstrated that M3G can improve colonic mucosal barrier function by inhibiting the Notch signaling pathway.

The colonic mucosal barrier is an important component of the intestinal barrier, and its integrity is crucial for maintaining digestive tract homeostasis and normal metabolism in the body. This study aimed to elucidate the mechanisms by which malvidin-3-O-galactoside (M3G) might ameliorate colonic mucosal barrier function, from the perspective of physical barrier function and immune barrier function. Male C57BL/6J mice were given dextran sulfate sodium (DSS) to establish a mice model for colitis and then administrated with or without M3G for one week. The results showed that M3G supplementation significantly improved the disease activity index (DAI) score and colon tissue injury in mice with DSS-induced colitis. M3G improved the colonic physical barrier function by modulating the expression of mucin2 (MUC2), claudin-1, occludin, zona occludens 1 (ZO-1), and intestinal fatty acid binding protein (iFABP) in the colonic mucosa. Additionally, M3G also relieved the colonic immune barrier of mice by increasing the level of secretory immunoglobulin A (SIgA) in colon tissue and the percentages of CD4+T (CD3+CD4+) and CD8+T (CD3+CD8+) cells in colon lamina propria monocytes in mice. Furthermore, M3G down-regulated Notch signaling pathway-related proteins such as Notch1, notch intracellular domain (NICD), delta-like ligand 4 (DLL4), delta-like ligand 1 (DLL1), and hairy/enhancer of split 1 (Hes1) of colon tissue. The present results demonstrated that M3G can improve colonic mucosal barrier function by inhibiting the Notch signaling pathway.

The peel of pitaya fruit is a promising source of pectin, and non- or low-methylesterified pectin has multiple bioactivities and application scenarios. In this study, non-methylated pectin was prepared from pitaya peel and the structure was characterized. Single factor experiment and response surface methodology were conducted to optimize the procedure of ultrasonic-assisted extraction for pectin. Under the optimal conditions (solid-liquid ratio of 1:40 g·mL−1, extraction temperature at 56 °C, extraction time of 25 min and ultrasonic power of 200 W), the pectin yield was up to 9.93% ± 0.97%. Degree of methylesterification and FTIR analysis confirmed that the extracted pectin was almost non-methylesterified. The pectin possessed less linear homogalacturonan (HG) but more rhamnogalacturonan (RG) regions according to the molar ratios of monosaccharides. Meanwhile, the molecular weight of the pectin was 33.52 kDa and the crystalline index was only 0.60%. Furthermore, the nanoscale structure observed by atomic force microscopy showed that the pectin was rich in highly branched polymers. Generally, pitaya peel pectin extracted by ultrasonic-assisted extraction showed a wide range of potential use as a non-or low- methylesterified pectic substance to reach the efficient utilization of fruit waste.

The peel of pitaya fruit is a promising source of pectin, and non- or low-methylesterified pectin has multiple bioactivities and application scenarios. In this study, non-methylated pectin was prepared from pitaya peel and the structure was characterized. Single factor experiment and response surface methodology were conducted to optimize the procedure of ultrasonic-assisted extraction for pectin. Under the optimal conditions (solid-liquid ratio of 1:40 g·mL−1, extraction temperature at 56 °C, extraction time of 25 min and ultrasonic power of 200 W), the pectin yield was up to 9.93% ± 0.97%. Degree of methylesterification and FTIR analysis confirmed that the extracted pectin was almost non-methylesterified. The pectin possessed less linear homogalacturonan (HG) but more rhamnogalacturonan (RG) regions according to the molar ratios of monosaccharides. Meanwhile, the molecular weight of the pectin was 33.52 kDa and the crystalline index was only 0.60%. Furthermore, the nanoscale structure observed by atomic force microscopy showed that the pectin was rich in highly branched polymers. Generally, pitaya peel pectin extracted by ultrasonic-assisted extraction showed a wide range of potential use as a non-or low- methylesterified pectic substance to reach the efficient utilization of fruit waste.

Alternaria alternata and Botrytis cinerea are among the primary fungal pathogens of fruits, causing black spot and gray mold disease, respectively. They cause serious losses in yield as well as affect fruit quality. Controlling fruit postharvest diseases largely relies on the use of chemical fungicides. However, the overuse of fungicides makes the produce unsafe due to their residual effects on the environment and human health. Therefore, significant advancements are necessary to investigate and find sustainable ways to prevent postharvest disease of fruits and minimize postharvest losses. This review summarizes the recent developments in the application of biological control and other sustainable approaches in managing fruit postharvest diseases, with an emphasis on A. alternata and B. cinerea, respectively. Furthermore, several action mechanisms, challenges, and prospects for the application of biological control agents (BCAs) are also discussed. Biological control application has been proven to successfully reduce postharvest disease of fruits caused by A. alternata and B. cinerea. In recent years, it has gradually changed from being primarily an independent field to a more crucial part of integrated pest management. Due to their characteristics that are safe, eco-friendly, and non-toxic, several BCAs have also been developed and commercialized. Therefore, biological control has the potential to be a promising approach to replace the use of chemical fungicides in controlling postharvest disease of fruits.

Alternaria alternata and Botrytis cinerea are among the primary fungal pathogens of fruits, causing black spot and gray mold disease, respectively. They cause serious losses in yield as well as affect fruit quality. Controlling fruit postharvest diseases largely relies on the use of chemical fungicides. However, the overuse of fungicides makes the produce unsafe due to their residual effects on the environment and human health. Therefore, significant advancements are necessary to investigate and find sustainable ways to prevent postharvest disease of fruits and minimize postharvest losses. This review summarizes the recent developments in the application of biological control and other sustainable approaches in managing fruit postharvest diseases, with an emphasis on A. alternata and B. cinerea, respectively. Furthermore, several action mechanisms, challenges, and prospects for the application of biological control agents (BCAs) are also discussed. Biological control application has been proven to successfully reduce postharvest disease of fruits caused by A. alternata and B. cinerea. In recent years, it has gradually changed from being primarily an independent field to a more crucial part of integrated pest management. Due to their characteristics that are safe, eco-friendly, and non-toxic, several BCAs have also been developed and commercialized. Therefore, biological control has the potential to be a promising approach to replace the use of chemical fungicides in controlling postharvest disease of fruits.

Studying the metabolic patterns underlying the key quality traits during the growth and development of melon is very important for the quality improvement and breeding of melon fruit. In this study, we employed transcriptomics and metabolomics to analyze the primary metabolic changes occurring in melon ('Xizhoumi 25') across five growth and development stages. We identified a total of 666 metabolites and their co-expressed genes, which were categorized into five different metabolic and gene modules. Through the analysis of these modules, the main metabolic pathways during the growth and development of melon were demonstrated from a global perspective. We also discussed the contribution of sucrose accumulation, the TCA cycle, and amino acid metabolism to the quality and flavor of melon. Enzymes related to amino acid metabolism were proposed, including Amine oxidase (AOC), aldehyde dehydrogenase (ALDH), tryptophan synthase (TRPB), etc. These results and data can provide new insights for further study on the metabolic regulation of melon quality and improve fruit quality.

Studying the metabolic patterns underlying the key quality traits during the growth and development of melon is very important for the quality improvement and breeding of melon fruit. In this study, we employed transcriptomics and metabolomics to analyze the primary metabolic changes occurring in melon ('Xizhoumi 25') across five growth and development stages. We identified a total of 666 metabolites and their co-expressed genes, which were categorized into five different metabolic and gene modules. Through the analysis of these modules, the main metabolic pathways during the growth and development of melon were demonstrated from a global perspective. We also discussed the contribution of sucrose accumulation, the TCA cycle, and amino acid metabolism to the quality and flavor of melon. Enzymes related to amino acid metabolism were proposed, including Amine oxidase (AOC), aldehyde dehydrogenase (ALDH), tryptophan synthase (TRPB), etc. These results and data can provide new insights for further study on the metabolic regulation of melon quality and improve fruit quality.

In this work, the gastrointestinal digestive outcome of Tremella fuciformis polysaccharide (TFP) was examined using in vitro simulated experiments, together with its effect on the intestinal microbiota. TFP did not significantly alter during the stage of oral digestion, according to an in vitro digestion investigation. Nevertheless, glycosidic connections of TFP were broken throughout the intestinal and stomach digesting phases, which resulted in the dissociation of macromolecular aggregates, a marked rise in decreasing sugar content (CR), as well as a drop in molecular weight (Mw). Additionally, microbial community analysis following fecal fermentation in vitro indicated that TFP might control the alpha and beta diversity of gut microbiota and change the genus- and phylum-level community composition. It increased the abundance of beneficial bacteria including Megasphaera, Phascolarctobacterium, and Bacteroides, and suppressed the growth of harmful bacteria like Escherichia-shigella and Fusobacterium, thus contributing to maintaining gut homeostasis. These results suggested that TFP could have a positive impact on health through enhancing the gut microbiota environment, giving a theoretical basis for its use as a prebiotic.

In this work, the gastrointestinal digestive outcome of Tremella fuciformis polysaccharide (TFP) was examined using in vitro simulated experiments, together with its effect on the intestinal microbiota. TFP did not significantly alter during the stage of oral digestion, according to an in vitro digestion investigation. Nevertheless, glycosidic connections of TFP were broken throughout the intestinal and stomach digesting phases, which resulted in the dissociation of macromolecular aggregates, a marked rise in decreasing sugar content (CR), as well as a drop in molecular weight (Mw). Additionally, microbial community analysis following fecal fermentation in vitro indicated that TFP might control the alpha and beta diversity of gut microbiota and change the genus- and phylum-level community composition. It increased the abundance of beneficial bacteria including Megasphaera, Phascolarctobacterium, and Bacteroides, and suppressed the growth of harmful bacteria like Escherichia-shigella and Fusobacterium, thus contributing to maintaining gut homeostasis. These results suggested that TFP could have a positive impact on health through enhancing the gut microbiota environment, giving a theoretical basis for its use as a prebiotic.

β-ionone has various biological activities, such as anti-inflammatory, antimicrobial, and anticancer effects. The pathogenesis of ulcerative colitis is correlated with immune dysfunction, intestinal barrier damage, and gut microbiota imbalance. However, whether β-ionone has preventive efficacy against ulcerative colitis is unknown. This study investigated the effect of β-ionone on dextran sulfate sodium-induced ulcerative colitis and the underlying molecular mechanisms involved. The ulcerative colitis mouse model was induced by 1.5% dextran sulfate sodium for 10 d. Meanwhile, 200 mg/kg β-ionone was administrated to the mice. Body weight, colon length, colon tissue pathology, colon tissue inflammatory cytokines, colonic oxidative stress, and barrier function were assessed. The composition and structure of gut microbiota were profiled using 16S rRNA sequencing. The results showed that β-ionone supplementation effectively prevented ulcerative colitis by ameliorating colonic tissue damage, reducing inflammatory phenomena, and protecting the colonic epithelial mucosal barrier. β-ionone also protected mice from dextran sulfate sodium-induced gut microbiota disturbance by modifying the overall structure and function of the gut microbiota community and increasing the relative abundance of beneficial gut microbiota. The Spearman correlation analysis revealed that the changes in abundance of the gut microbiota were correlated with ulcerative colitis-related indicators. Overall, this study demonstrated that β-ionone has a preventive effect on ulcerative colitis in mice, and the underlying mechanism may be associated with the protection of the gut barrier and regulation of the gut microbiota. These results are conducive to promoting clinical trials and product development of β-ionone for the prevention and treatment of ulcerative colitis.

β-ionone has various biological activities, such as anti-inflammatory, antimicrobial, and anticancer effects. The pathogenesis of ulcerative colitis is correlated with immune dysfunction, intestinal barrier damage, and gut microbiota imbalance. However, whether β-ionone has preventive efficacy against ulcerative colitis is unknown. This study investigated the effect of β-ionone on dextran sulfate sodium-induced ulcerative colitis and the underlying molecular mechanisms involved. The ulcerative colitis mouse model was induced by 1.5% dextran sulfate sodium for 10 d. Meanwhile, 200 mg/kg β-ionone was administrated to the mice. Body weight, colon length, colon tissue pathology, colon tissue inflammatory cytokines, colonic oxidative stress, and barrier function were assessed. The composition and structure of gut microbiota were profiled using 16S rRNA sequencing. The results showed that β-ionone supplementation effectively prevented ulcerative colitis by ameliorating colonic tissue damage, reducing inflammatory phenomena, and protecting the colonic epithelial mucosal barrier. β-ionone also protected mice from dextran sulfate sodium-induced gut microbiota disturbance by modifying the overall structure and function of the gut microbiota community and increasing the relative abundance of beneficial gut microbiota. The Spearman correlation analysis revealed that the changes in abundance of the gut microbiota were correlated with ulcerative colitis-related indicators. Overall, this study demonstrated that β-ionone has a preventive effect on ulcerative colitis in mice, and the underlying mechanism may be associated with the protection of the gut barrier and regulation of the gut microbiota. These results are conducive to promoting clinical trials and product development of β-ionone for the prevention and treatment of ulcerative colitis.

Baijiu Daqu, a traditional component in the Baijiu brewing process, serves as both a 'saccharifying fermenting agent' and an 'aroma-producing catalyst', embodying a rich historical legacy. Daqu offers a diverse microorganism environment that is crucial for the fermentation of Baijiu. The distinctive flavor profile, a key attribute of Baijiu, is intricately linked to the microflora present in Daqu. To date, research on Daqu has primarily concentrated on the diversity of microbial communities, microbial interactions, flavor characteristics, and biochemical properties. The functional enzyme system in Daqu serves as a crucial link connecting the flavor of Baijiu with the microbial community of Daqu. However, reviews that particularly focus on the role of enzymes in determining the quality of Daqu have not yet been reported. Thus, here the types and production processes of Daqu are initially summarized. Then, the pathways involved in the production of the major flavor substances in Daqu are elucidated, as well as the role and contribution of different functional enzymes in the formation of Daqu flavor. Finally, the current technologies for improving Daqu flavor through microbial inoculation aree discussed, including the advantages, shortcomings, and bottlenecks of microbial inoculation. The findings gained in this study provide valuable information for the efficient production of high-quality Daqu for the brewing of Baijiu.

Baijiu Daqu, a traditional component in the Baijiu brewing process, serves as both a 'saccharifying fermenting agent' and an 'aroma-producing catalyst', embodying a rich historical legacy. Daqu offers a diverse microorganism environment that is crucial for the fermentation of Baijiu. The distinctive flavor profile, a key attribute of Baijiu, is intricately linked to the microflora present in Daqu. To date, research on Daqu has primarily concentrated on the diversity of microbial communities, microbial interactions, flavor characteristics, and biochemical properties. The functional enzyme system in Daqu serves as a crucial link connecting the flavor of Baijiu with the microbial community of Daqu. However, reviews that particularly focus on the role of enzymes in determining the quality of Daqu have not yet been reported. Thus, here the types and production processes of Daqu are initially summarized. Then, the pathways involved in the production of the major flavor substances in Daqu are elucidated, as well as the role and contribution of different functional enzymes in the formation of Daqu flavor. Finally, the current technologies for improving Daqu flavor through microbial inoculation aree discussed, including the advantages, shortcomings, and bottlenecks of microbial inoculation. The findings gained in this study provide valuable information for the efficient production of high-quality Daqu for the brewing of Baijiu.