Proximate composition and profiles of free amino acids, fatty acids, minerals and aroma compounds in Citrus natsudaidai peel

Untargeted Metabolomics Comparison and Nutrition Evaluation of Geographical Indication Newhall Navel Oranges in China

The untargeted metabolomics of Newhall navel oranges from three areas in China-Ganzhou, Fengjie, and Zigui-with geographical indication (GI) was measured using LC-MS/MS. Orthogonal partial least squares discriminant analysis was performed for sample classification and important metabolite identification. This approach identified the best markers of the geographical origin able to discriminate Fengjie, Ganzhou, and Zigui orange samples. For peeled samples, 2-isopropylmalic acid, succinic acid, citric acid, L-aspartic acid, L-glutamic γ-semialdehyde, D-β-phenylalanine, hesperetin, hydrocinnamic acid, 4-hydroxycinnamic acid, and dehydroascorbate were the markers used to discriminate the geographical origin. All these markers were overexpressed in the peeled samples from the Zigui area, followed by the Ganzhou area. As for unpeeled samples, L-glutamic γ-semialdehyde, isovitexin 2'-O-β-D-glucoside, 2-isopropylmalic acid, isovitexin, diosmetin, trans-2-hydroxycinnamate and trans-cinnamate, L-aspartic acid, hydrocinnamic acid, and β-carotene were used to discriminate their origin. The first seven markers in Zigui-planted whole samples showed the highest levels, and the last three markers were richest in Ganzhou-planted samples. According to the variation in the markers for discriminating the origins of the peeled or unpeeled Newhall navel oranges with GI and the highest value of titratable acidity in those from Zigui, the samples planted in Ganzhou have the best balance between taste and nutrition. This work confirms that the approach of untargeted metabolomics combined with OPLS-DA is an effective way for origin tracing and overall quality evaluation.

Valorization of citrus peel industrial wastes for facile extraction of extractives, pectin, and cellulose nanocrystals through ultrasonication: An in-depth investigation

In this work we developed an eco-friendly valorisation of Citrus wastes (CWs), through a solvent-assisted ultrasonication extraction technique, thus having access to a wide range of bio-active compounds and polysaccharides, extremely useful in different industrial sectors (food, cosmetics, nutraceutical). Water-based low-amplitude ultrasonication was examined as a potential method for pectin extraction as well as polar and non-polar citrus extractives (CEs), among which hesperidin and triglycerides of 18 carbon fatty acids were found to be the most representative ones. In addition, citric acid:glycerol (1:4)-based deep eutectic solvent (DES) in combination with ultrasonic extraction was utilized to extract microcellulose (CMC), from which stable cellulose nanocrystals (CNCs) with glycerol-assisted high amplitude ultrasonication were obtained. The physical and chemical properties of the extracted polysaccharides (pectin, micro and nanocellulose) were analysed through DLS, ζ-potential, XRD, HP-SEC, SEM, AFM, TGA-DSC, FTIR, NMR, and PMP-HPLC analyses. The putative structure of the extracted citrus pectin (CP) was analysed and elucidated through enzyme-assisted hydrolysis in correlation with ESI-MS and monosaccharide composition. The developed extraction methods are expected to influence the industrial process for the valorisation of CWs and implement the circular bio-economy.

Promising future of citrus waste into fermented high-quality bio-feed in the poultry nutrition and safe environment

Essential oils (EO), ascorbic acid, sugars, carotenoids, flavonoids, dietary fiber, polyphenols, and trace minerals are found in citrus residue. It gives animals energy and promotes health. On a dry matter basis, the citrus pulp is composed of 7% crude protein, 14% crude fiber, 21.6% nitrogen detergent fiber, 2.5% fat, 24.4% total sugars, and 12.1% ME MJ/kg. It has been reported that the natural antioxidant content of citrus pulp has a beneficial effect on growth and microbial and immunological parameters. The literature indicates that the ultimate weight and weight gain of poultry are significantly (P > 0.05) greater with 7.5% inclusion. Growing knowledge of the health benefits of lactic acid bacteria (LAB) in producing beneficial metabolites has led to interest in developing LAB-containing products for use in biofeed businesses. The consumption of fermented citrus residue significantly decreased blood cholesterol levels. Fermentation results in the production of many compounds (including organic acids, exopolysaccharides, bioactive peptides, phenolic compounds, and gamma-aminobutyric acid), which have many multidimensional functions for maintaining the health and well-being of poultry. During fermentation, the pH may quickly decrease, and harmful bacterial and fungal organisms may be substantially retarded at the early stage of ensiling. The published literature has shown that the fermentation of citrus waste with different probiotic strains, such as Lactobacillus acidophilus, Limosilactobacillus fermentum, Lactiplantibacillus plantarum, Pediococcus pentocaseus, and Lacticaseiobacillus paracasei, in the diet has fantastic effects on the conversion of citrus waste into fermented high-quality feed with extended shelf life and sensory value. Citrus waste lactic acid fermentation may be a viable option for producing nutritional biofeed for poultry, but there is a lack of related research on poultry, so more research on food-grade bacterial fermentation is needed.

Effect of Different Cooking Methods on the Aroma and Taste of Chicken Broth

A single combi oven, known for its versatility, is an excellent choice for a variety of chicken soup preparations. However, the impact of universal steam ovens on the flavor quality of chicken soup remains unclear. This study aimed to explore the impact of different cooking methods on the aroma and taste of chicken soup. Three cooking methods with various stewing times were compared: ceramic pot (CP), electric pressure cooker (EPC), and combi oven (CO). Analyses were conducted using electron-nose, electron-tongue, gas chromatography-ion mobility spectrometry (GC-IMS), automatic amino acid analysis, and chemometric methods. A total of 14 amino acids, including significant umami contributors, were identified. The taste components of CP and CO chicken soups were relatively similar. In total, 39 volatile aroma compounds, predominantly aldehydes, ketones, and alcohols, were identified. Aldehydes were the most abundant compounds, and 23 key aroma compounds were identified. Pearson's correlation analyses revealed distinct correlations between various amino acids (e.g., glutamic acid and serine) and specific volatile compounds. The aroma compounds from the CP and CO samples showed similarities. The results of this study provide a reference for the application of one-touch cooking of chicken soup in versatile steam ovens.

Fruit waste: a current perspective for the sustainable production of pharmacological, nutraceutical, and bioactive resources

Fruits are crucial components of a balanced diet and a good source of natural antioxidants, that have proven efficacy in various chronic illnesses. Various kinds of waste generated from fruit industries are considered a global concern. By utilizing this fruit waste, the international goal of "zero waste" can be achieved by sustainable utilization of these waste materials as a rich source of secondary metabolites. Moreover, to overcome this waste burden, research have focused on recovering the bioactive compounds from fruit industries and obtaining a new strategy to combat certain chronic diseases. The separation of high-value substances from fruit waste, including phytochemicals, dietary fibers, and polysaccharides which can then be used as functional ingredients for long-term health benefits. Several novel extraction technologies like ultrasound-assisted extraction (UAE), pressurized liquid extraction (PLE), and supercritical fluid extraction (SFE) could provide an alternative approach for successful extraction of the valuable bioactives from the fruit waste for their utilization as nutraceuticals, therapeutics, and value-added products. Most of these waste-derived secondary metabolites comprise polyphenols, which have been reported to have anti-inflammatory, insulin resistance-treating, cardiovascular disease-maintaining, probiotics-enhancing, or even anti-microbial and anti-viral capabilities. This review summarizes the current knowledge of fruit waste by-products in pharmacological, biological, and probiotic applications and highlights several methods for identifying efficacious bioactive compounds from fruit wastes.

Fortification of Chlorella vulgaris with citrus peel amino acid for improvement biomass and protein quality

The amino acid extract (protein hydrolysate) from various citrus peels was employed as an organic nutrition source for the culture of Chlorella to investigate their effects on the biomass and protein quality of the microalgae. The major amino acids in citrus peels included proline, asparagine, aspartate, alanine, serine, and arginine. The most plentiful amino acids in the Chlorella were alanine, glutamic acid, aspartic acid, glycine, serine, threonine, leucine, proline, lysine, and arginine. Adding the citrus peel amino acid extracts to the Chlorella medium enhanced overall microalgal biomass (more than two folds p < 0.05) and protein content (more than 1.25 fold, p < 0.05). Citrus peel amino acids increase essential amino acids and decrease the non-protein amino acid of Chlorella (p > 0.05). The present research shows that citrus peels have good nutritional quality and could be used for the inexpensive cultivation of Chlorella biomass with potential utility for food application.

Evaluation of nutritional profile, phytochemical potential, functional properties and anti-nutritional studies of Citrus limetta peels

The aim of this work was to determine the proximate, mineral, amino acid composition, antioxidant activity, anti-nutritional factors, total dietary fiber, total phenolic content and technological properties of C. limetta peels. Moreover, analytical techniques including FT-IR and SEM were also conducted to study the morphological and structural properties of C. limetta peels. Considering the proximate, mineral, and amino acid composition, C. limetta peels was found to be a good source of ash (3.06 ± 0.20%), crude fiber (10.13 ± 0.30%), carbohydrate (64.08 ± 0.55%), protein (7.56 ± 0.25%), potassium (125.9671 mg/100 g), calcium (112.5861 mg/100 g), magnesium (16.43 mg/100 g), asparagine (2111.06 nmol/mg), glutamic acid (1331.96 nmol/g), and aspartic acid (1162.19 nmol/mg). Furthermore, they contain an appreciable amount of total dietary fiber (48.73 ± 0.45%), total phenolic content (14.30 ± 0.03 mg GAE/g), and antioxidant activity (52.65 ± 0.10%). Moreover, the antinutritional factors present in C. limetta peels were observed to be within the threshold limit. The results of technological properties of peels suggested that they can be potentially utilized as good emulsifying, gelling, foaming, and bulking agents in food industries. Therefore, C. limetta peels can be successfully re-utilized as natural food additive with numerous nutritive and bioactive properties in food sector, thereby achieving zero waste generation.

Transcriptome and UPLC-MS/MS reveal mechanisms of amino acid biosynthesis in sweet orange 'Newhall' after different rootstocks grafting

Sweet orange 'Newhall' (C. sinensis) is a popular fruit in high demand all over the world. Its peel and pulp are rich in a variety of nutrients and are widely used in catering, medicine, food and other industries. Grafting is commonly practiced in citrus production. Different rootstock types directly affect the fruit quality and nutritional flavor of citrus. However, the studies on citrus metabolites by grafting with different rootstocks are very limited, especially for amino acids (AAs). The preliminary test showed that there were significant differences in total amino acid content of two rootstocks (Poncirus trifoliata (CT) and C. junos Siebold ex Tanaka (CJ)) after grafting, and total amino acid content in the peel was higher than flesh. However, the molecular mechanism affecting amino acid differential accumulation remains unclear. Therefore, this study selected peel as the experimental material to reveal the amino acid components and differential accumulation mechanism of sweet orange 'Newhall' grafted with different rootstocks through combined transcriptome and metabolome analysis. Metabolome analysis identified 110 amino acids (AAs) and their derivatives in sweet orange 'Newhall' peels, with L-valine being the most abundant. L-asparagine was observed to be affected by both developmental periods and rootstock grafting. Weighted gene co-expression network analysis (WGCNA) combined with Redundancy Analysis (RDA) revealed eight hub structural genes and 41 transcription factors (TFs) that significantly influenced amino acid biosynthesis in sweet orange 'Newhall' peels. Our findings further highlight the significance of rootstock selection in enhancing the nutritional value of citrus fruits and might contribute to the development of functional citrus foods and nutritional amino acid supplements.

Comparative Analysis of the Impact of Three Drying Methods on the Properties of Citrus reticulata Blanco cv. Dahongpao Powder and Solid Drinks

Citrus reticulata Blanco cv. Dahongpao is a traditional Chinese citrus variety. Due to the high investment in storage and transport of Citrus reticulata Blanco cv. Dahongpao and the lack of market demand, the fresh fruit is wasted. The processing of fresh fruit into fruit drinks can solve the problem of storage and transport difficulties and open up new markets. Investigating the effects of different drying processes (hot air, freeze, and spray drying) on fruit powders is a crucial step in identifying a suitable production process. The experiment measured the effects of different drying methods (hot air drying, freeze drying, and spray drying) on the nutrient, bioactive substance, and physical characteristics of fruit powder. This study measured the influence of three different drying methods (hot air, freeze, and spray drying) on the nutritional, bioactive substance, and physical characteristics of fruit powder. The results showed that compared to vacuum freeze-drying at low temperature (-60 °C) and spray-drying at high temperatures (150 °C), hot air drying at 50 °C produced fruit powder with superior nutritional quality, higher levels of active substances, and better physical properties. Hot air drying produced fruit powder that had the highest content of amino acids (11.48 ± 0.08 mg/g DW), vitamin C (112.09 ± 2.86 μg/g DW), total phenols (14.78 ± 0.30 mg/g GAE DW), total flavonoids (6.45 ± 0.11 mg/g RE DW), organic acids, and antioxidant activity capacity. Additionally, this method yielded the highest amounts of zinc (8.88 ± 0.03 mg/Kg DW) and soluble sugars, low water content, high solubility, and brown coloration of the fruit powder and juice. Therefore, hot air drying is one of the best production methods for producing high-quality fruit powder in factory production.

Comparison of Phenolic and Volatile Compounds in MD2 Pineapple Peel and Core

The peel and core discarded from the processing of MD2 pineapple have the potential to be valorized. This study evaluated the functional and volatile compounds in the extracts of MD pineapple peel and core (MD2-PPC). The total soluble solids, pH, titratable acidity, sweetness index, and astringency index were 9.34 °Brix, 4.00, 0.74%, 12.84, and 0.08, respectively, for the peel and 12.00 °Brix, 3.96, 0.32%, 37.66, and 0.03, respectively, for the core. The fat and protein contents of the peel and core were found to be significantly different (p < 0.05). The total phenolic (TPC) and flavonoid contents (TFC) were significantly higher in the peel. The peel also showed better antioxidant activity, with a half-maximal inhibitory concentration (IC₅₀) of 0.63 mg/mL for DPPH free radical activity compared with the core. The TPC of different phenolic fractions from peel extract was highest in the glycosylated fraction, followed by the esterified, insoluble-bound, and free phenolic fractions. GC-MS analysis identified 38 compounds in the peel and 23 in the core. The primary volatile compounds were 2-furan carboxaldehyde, 5-(hydroxymethyl), and 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP). The identification of phenolics and volatile compounds provides important insights into the valorization of (MD2-PPC) waste.

Comparison of the volatile organic compounds in Citrus reticulata 'Chachi' peel with different drying methods using E-nose, GC-IMS and HS-SPME-GC-MS

Introduction

Citrus reticulata 'Chachi' peel (CRCP), which is named "Guangchenpi" in China, is a geographical indication product with unique flavor properties. CRCP has been used for centuries as a traditional genuine herb because of its excellent therapeutic effects. In addition, owing to its unique odor and high nutrition, it is widely used in various food preparations. Volatile organic compounds (VOCs) are regarded as an important quality marker for CRCP and are highly susceptible to effects in the drying process due to their thermal instability.

Methods

In the current study, the main VOCs in CRCP were processed using different drying methods, including sun-drying, hot air drying, and vacuum-freeze drying. The VOCs were identified by the electronic nose (E-nose), gas chromatography-ion mobility spectrometry (GC-IMS), and headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS).

Results

The results showed that the CRCP dried by vacuum-freeze exhibited the highest VOCs contents and retained the richest compounds compared to those dried by other methods, which indicated that vacuum-freeze drying is the most suitable for CRCP production. Furthermore, the chemometrics analysis revealed that the primary differential metabolites of the samples generated using different drying methods were terpenes and esters.

Discussion

Overall, our study would help better understand the VOCs present in CRCP with different drying methods. The outcomes of the current study would guide the drying and processing of CRCP, which is beneficial for large-scale storage and industrial production of CRCP.

Recent Advances in Health Benefits of Bioactive Compounds from Food Wastes and By-Products: Biochemical Aspects

Bioactive compounds, including terpenoids, polyphenols, alkaloids and other nitrogen-containing constituents, exert various beneficial effects arising from their antioxidant and anti-inflammatory properties. These compounds can be found in vegetables, fruits, grains, spices and their derived foods and beverages such as tea, olive oil, fruit juices, wine, chocolate and beer. Agricultural production and the food supply chain are major sources of food wastes, which can become resources, as they are rich in bioactive compounds. The aim of this review is to highlight recent articles demonstrating the numerous potential uses of products and by-products of the agro-food supply chain, which can have various applications.

Review of phytochemical and nutritional characteristics and food applications of Citrus L. fruits

Since the dietary regimen rich in fruits is being widely recognized and encouraged, Citrus L. fruits have been growing in popularity worldwide due to their high amounts of health-promoting phytonutrients and bioactive compounds, such as flavonoids, phenolic acids, vitamins, carotenoids, pectins, and fatty acids. The diverse physicochemical properties and multiple utilization of citrus fruits in food industry are associated with their unique chemical compositions. Throughout the world, citrus has been used for producing various value-added and nutritionally enhanced products, including juices, wines, jams, canned citrus, and dried citrus. However, the current studies regarding the phytochemical and nutritional characteristics and food applications of citrus are scattered. This review systematically summarizes the existing bibliography on the chemical characteristics, functional and nutraceutical benefits, processing, and potential applications of citrus. A thorough understanding of this information may provide scientific guidance for better utilizing citrus as a functional fruit and benefit the extension of citrus value chain.

Manipulation of fatty acid profile and nutritional quality of Chlorella vulgaris by supplementing with citrus peel fatty acid

Microalgae could be an excellent resource of functional and essential fatty acids. To achieve viable microalgal biomass production, mass cultivation of microalgae is required; however, the high cost of nutrients is the obstacle. An inexpensive and nutritious material is required to feed Chlorella vulgaris in the pharmaceutical and food sectors. Citrus peel waste with a valuable nutritional quality could be one of the promising and inexpensive candidates. In this study, the fatty acid extract from different citrus peels was used as the organic nutrient source for the cultivation of Chlorella. The proximate composition of bitter orange, sweet orange, grapefruit, and mandarin peels were determined, and their nutritional quality was evaluated. Total fatty acids from the citrus peel were prepared by acidic methanol hydrolysis and hexane extraction. Fourier transforms infrared (FT-IR) and gas chromatography–mass spectrometry (GC–MS) was used to analyze the fatty acid composition and nutrient composition. Fatty acids from the citrus peels were added to the Chlorella culture medium to study their influences on biomass, lipid production, fatty acid profile, and nutritional quality of Chlorella. The most predominant citrus peel fatty acids were linoleic, palmitic, oleic, linolenic, and stearic acids. The citrus peels contain polyunsaturated, saturated, and monounsaturated fatty acids. The most unsaturated fatty acids were omega-6, omega-3, omega-9, and omega-7. The citrus peel had acceptable atherogenicity, thrombogenicity, omega-6/omega-3, peroxidizability, hypocholesterolemic, and nutritive value indices. The major fatty acids of Chlorella were palmitic, linoleic, oleic, alpha-linolenic, gamma-linolenic, 4,7,10,13-hexadecatetraenoic, palmitoleic, 7,10-hexadecadienoic, 7,10,13-hexadecatrienoic, lauric and 5,8,11,14,17-eicosapentaenoic acids. Chlorella contains polyunsaturated, saturated, and monounsaturated fatty acids. The most unsaturated fatty acids contain omega-6, omega-3, omega-9, and omega-7. Chlorella had acceptable atherogenicity, thrombogenicity, omega-6/omega-3, hypocholesterolemic, peroxidizability, and nutritive value indices. Supplementation of Chlorella with citrus peels fatty acid increases total biomass, lipid content, and nutritional quality of Chlorella. The present research shows that citrus peels have good nutritional quality and could be used for the inexpensive cultivation of Chlorella biomass with potential utility for food application.

Utilization and evaluation of Citrus natsudaidai peel waste as a source of natural food additives

This study aims to obtain beneficial ingredients from Citrus natsudaidai (CN) peel waste. The yields of ingredients were 26.2-31.6 mg/g dried material (DM) in pectin, 466-581 mg/g DM in insoluble dietary fiber, 5.56-7.15 g/kg fresh material (FM) in the hexane extracts obtained from CN peels, 23.8-27.0 mg/g DM in naringin, and 8.30-10.2 mg/g DM in neohesperidin. A sensory evaluation and instrumental assays using an Electronic nose and Electronic tongue were performed to evaluate aqueous solutions flavored with 0.02% hexane extracts obtained from CN peels. CN-flavored solutions had a preferred smell over commercial citrus-flavored drinks and were classified into the same group as commercial citrus juices in the Electronic nose assay. In addition, CN-flavored solutions showed sourness, bitterness, and orange-like taste, and the overall acceptance of CN-flavored solutions did not significantly differ from commercial citrus-flavored drinks. CN peel waste can be industrially utilized as a source of natural food additives.

Citrus Genus and Its Waste Utilization: A Review on Health-Promoting Activities and Industrial Application

Citrus fruits such as oranges, grapefruits, lemons, limes, tangerines, and mandarins, whose production is increasing every year with the rise of consumer demand, are among the most popular fruits cultivated throughout the globe. Citrus genus belongs to the Rutaceae family and is known for its beneficial effects on health for centuries. These plant groups contain many beneficial nutrients and bioactive compounds. These compounds have antimicrobial, anticancer, antidiabetic, antiplatelet aggregation, and anti-inflammatory activities. Citrus waste, generated by citrus-processing industries in large amounts every year, has an important economic value due to richness of bioactive compounds. The present review paper has summarized the application and properties of Citrus and its waste in some fields such as food and drinks, traditional medicine practices, and recent advances in modern approaches towards pharmaceutical and nutraceutical formulations.

Nutrients and bioactives in citrus fruits: Different citrus varieties, fruit parts, and growth stages

Citrus fruits are consumed in large quantities worldwide due to their attractive aromas and taste, as well as their high nutritional values and various health-promoting effects, which are due to their abundance of nutrients and bioactives. In addition to water, carbohydrates, vitamins, minerals, and dietary fibers are important nutrients in citrus, providing them with high nutritional values. Citrus fruits are also rich in various bioactives such as flavonoids, essential oils, carotenoids, limonoids, and synephrines, which protect from various ailments, including cancer and inflammatory, digestive, and cardiovascular diseases. The composition and content of nutrients and bioactives differ significantly among citrus varieties, fruit parts, and growth stages. To better understand the nutrient and bioactive profiles of citrus fruits and provide guidance for the utilization of high-value citrus resources, this review systematically summarizes the nutrients and bioactives in citrus fruit, including their contents, structural characteristics, and potential health benefits. We also explore the composition variation in different citrus varieties, fruits parts, and growth stages, as well as their health-promoting effects and applications.

Bioactive Substances, Heavy Metals, and Antioxidant Activity in Whole Fruit, Peel, and Pulp of Citrus Fruits

The use of whole citrus fruits in the food industry means that the valuable peel is used, but this may raise palatability or health concerns among consumers. The content of sugars, dietary fibre, redox compounds, lead, and cadmium was compared in citrus fruits (orange; pomelo; mandarin; lemon; key lime; and red, yellow, and green grapefruit). The pulp of all fruits contained significantly less fibre, tannins, and phenolic compounds than the peel. Whole citrus fruits had significantly lower content of sugars and higher content of dietary fibre and phenolic compounds, including ferulic acid, than their pulps. Whole grapefruits had higher concentrations of ascorbic acid. Whole lemons, limes, and mandarins had higher antioxidant potential than their pulp, due to their higher content of ascorbic acid, tannins, and phenolic compounds. Lead and cadmium content in whole fruits, while higher than in the pulps, was well below the acceptable daily intake.

Effects of "nine steaming nine sun-drying" on proximate composition, oil properties and volatile compounds of black sesame seeds

Black sesame seeds (BSS) were processed by nine cycles of steaming and sun-drying, and the chemistry of their resulting products studied. That is, the shell color and structure, proximate composition, oil properties and volatile compounds of raw BSS were determined and compared with processed BSS. Various levels of shell color change and structure damage were observed. The proximate composition also differed, whereas the relative proportion of fatty acids and oil properties were unchanged. SPME-GCMS analysis revealed that aldehydes, hydrocarbons and alcohols were the main volatile compounds. And compared with raw BSS, four volatile substances were newly detected in the processed BSS. Principal component analysis (PCA) displayed the overall difference between samples and showed that repeated steaming and sun-drying process had a significant impact on the chemical composition of BSS.

Encapsulation of tangeretin in PVA/PAA crosslinking electrospun fibers by emulsion-electrospinning: Morphology characterization, slow-release, and antioxidant activity assessment

In this work, water-resistant poly (vinyl alcohol) (PVA)/poly (acrylic acid) (PAA) electrospun fibers encapsulating tangeretin (Tan) were fabricated by emulsion-electrospinning. To optimize the electrospinning condition, the size and morphology of electrospun fibers were characterized by dynamic light scattering (DLS), optical light microscope, fluorescence microscopy, and scanning electron microscopy (SEM), respectively. The optimized initial concentration of PVA/PAA was 10% (w/w) with a mass ratio of 3:7. The time and temperature of optimized thermal crosslinking treatment were 2 h and 145 °C, respectively. The results of XRD and SEM showed that the Tan was successfully incorporated into smooth PVA/PAA electrospun fibers and those fibers possessed nano-diameter size and high porosity. The encapsulation of Tan had no significant impact on the antioxidant activity of PVA/PAA/Tan crosslinking electrospun fibers. The in vitro release test showed the PVA/PAA/Tan crosslinking electrospun fibers achieved durable release profiles and lower burst release rates than that from the pure Tan emulsion. Based on these results, it is concluded that PVA/PAA/Tan crosslinking electrospun fibers prepared by emulsion-electrospinning serve as a promising technique in the fields of water-insoluble drug delivery and slow-release.

Evaluation of the physiochemical and aromatic qualities of pickled Chinese pepper (Paojiao) and their influence on consumer acceptability by using targeted and untargeted multivariate approaches

Paojiao, which is traditionally pickled Chinese chili peppers (Capsicum frutescens Linn.), possesses unique flavors. This study was conducted to investigate the flavor, mouthfeel, and consumer acceptability of Paojiao. The quality of six homemade and two industrial Paojiao samples were evaluated by integrating untargeted (to fingerprint volatile fraction) and targeted (to analyze free amino acids or FAAs, capsaicinoids, and texture) approaches. Furthermore, multivariate data analysis (MVDA) was applied to identify the quality characteristics that drive the consumer acceptability for Paojiao. As for the targeted quality, hardness (1.30-10.52 N) and capsaicin (2.22-3.84 mg/g) varied with different samples. The main taste-active FAAs in Paojiao were detected. A total of 127 volatiles were observed, and esters were the major components. Based on sensory analysis, the homemade samples received higher acceptability than the industrial samples. MVDA demonstrated that some key volatiles, taste-active FAAs, and chewiness were the discriminant quality attributes affecting consumer acceptability.