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Comprehensive analysis of the lipid content in Cordyceps sinensis samples is essential for optimizing their effective use. Understanding the lipid profile can significantly enhance the application of this valuable fungus across various fields, including nutrition and medicine. However, to date, there is limited knowledge regarding the effects of different drying methods on the quality of lipids present in Cordyceps sinensis. In this study, we employed a broadly targeted lipidomic strategy to conduct a comprehensive analysis of the lipid composition in Cordyceps sinensis subjected to various drying methods. A comprehensive analysis identified a total of 765 distinct lipid species from fresh Cordyceps sinensis (FC), vacuum-freeze-dried Cordyceps sinensis (VG), oven-dried Cordyceps sinensis (OG), and air-dried Cordyceps sinensis (AG). Among these, glycerophospholipids (GP) were the most abundant, followed by glycerides (GL) and sphingolipids (SP). In this study, a total of 659 lipids demonstrated statistically significant differences, as indicated by a p-value (p) < 1. Among these lipids, triglycerides (TG) exhibited the highest concentration, followed by several others, including ceramide-ascorbic acid (Cer-AS), phosphatidylethanolamine (PE), lysophosphatidylcholine (LPC), and phosphatidylserine (PS). OG was the fastest drying method; however, PCA and OPLS-DA analyses indicated that the most significant changes in the lipids of Cordyceps sinensis were observed under the OG method. Specifically, 517 differentially accumulated lipids were significantly down-regulated, while only 10 lipids were significantly up-regulated. This disparity may be attributed to the degradation and oxidation of lipids. The metabolic pathways of glycerolipid, glycerophospholipid, and cholesterol are critical during the drying process of Cordyceps sinensis. This study provides valuable insights that can enhance quality control and offer guidelines for the appropriate storage of this medicinal fungus. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate efficient, cost‐effective, and high‐quality drying technologies for Rosa roxburghii Tratt. Five drying methods—hot air drying (HAD), microwave drying (MD), vacuum drying (VD), microwave vacuum drying (MVD), and freeze vacuum drying (FVD), were employed to dry Rosa roxburghii Tratt. The study focused on evaluating drying characteristics, colors, texture and structure, and microstructure, as well as the content of active ingredients and antioxidant activity of Rosa roxburghii Tratt. The results of drying kinetics indicated that the Wang and Singh model was the most suitable for FVD, while the Page model was optimal for the other four drying methods. Rosa roxburghii Tratt subjected to HAD exhibited the highest energy consumption per unit but the lowest ΔE and the highest TFC. The microstructure of Rosa roxburghii Tratt under different drying methods was analyzed. Rosa roxburghii Tratt dried using MD experienced serious cell rupture, resulting in a large loss of active ingredients and the worst antioxidant ability, but it had the fastest drying rate. On the other hand, Rosa roxburghii Tratt dried under VD had the microstructure with the least pore space, leading to slower drying speed and the highest total polyphenol content. Rosa roxburghii Tratt dried using MVD had the least hardness and chewiness, with slightly better ΔE and active ingredient content compared to MD. FVD Rosa roxburghii Tratt took the longest time to dry, with the greatest ΔE difference, hardness, and chewiness, but it had the highest Vitamin C content and the most powerful antioxidant ability. Principal component analysis (PCA)–entropy weighting method was used to provide comprehensive scores for the different drying methods, with FVD, HAD, VD, MVD, and MD were 0.8107, 0.7037, 0.4499, 0.2746, and 0.0586 respectively. Through comprehensive analysis, we demonstrated that the quality of Rosa roxburghii Tratt obtained via FVD and HAD is satisfactory. Additionally, HAD is characterized by its economic efficiency and convenience, providing valuable insights for the industrial production of Rosa roxburghii Tratt drying. [ABSTRACT FROM AUTHOR]

Background: Chrysanthemi Flos is a traditional Chinese medicine with a long history of medicinal use. Prior research suggests that the intrinsic composition of Chrysanthemi Flos is affected by shade-drying and oven-drying methods. Nevertheless, the effects of these methods on the proteins and metabolites of Chrysanthemi Flos have not been extensively studied. Methods: The TMT (tandem mass tag) quantitative proteomics method and the LC–MS/MS (liquid chromatography-tandem mass spectrometry) non-targeted metabolomics method were used to systematically study the differences in the proteins and metabolites during the process of drying Chrysanthemi Flos in the shade and an oven. Results: Differentially accumulated metabolites and abundant proteins were primarily enriched in the purine metabolism, pyrimidine metabolism, cyanogenic amino acid metabolism, phenylpropanoid biosynthesis, and starch and sucrose metabolism pathways. Primary metabolites, such as guanine, xanthine, cytidine 5'-diphosphate serine, L-isoleucine, stearidonic acid, alginate, and inulin, play a crucial role in providing energy for Chrysanthemi Flos to withstand desiccation stress. The upregulation of ferulate-5- hydroxylase (F5H), shikimate O hydroxycinnamoyltransferase (HCT), caffeoyl-CoA O-methyltransferase (CCoAOMT), and chalcone isomerase (CHI) enzymes promotes the synthesis of flavonoids, including sinapic acid, caffeoyl shikimic acid, and naringenin chalcone, which possess antioxidant properties. Despite the notable improvements in energy metabolism and antioxidant capacity, these enhancements proved insufficient in halting the senescence and ultimate demise of Chrysanthemi Flos. Moreover, the shade-drying method can inhibit protein expression and promote the accumulation of bioactive components, but the drying efficiency is low, while the oven-drying method exhibits rapid drying efficiency, it does not effectively preserve the components. Conclusion: Our study offers a comprehensive explanation for the changes in protein expression and metabolite conversion observed in shade-dried and oven-dried Chrysanthemi Flos, also providing a foundation for optimizing the drying process of Chrysanthemi Flos. [ABSTRACT FROM AUTHOR]

This study analyzed the effects of thermal pre-treatments such as convective drying (P-CD), water (BL_W), and microwave blanching (M_BL) and osmotic enrichment pre-treatments with juices from pomegranate (PG), chokeberry (CH), and sea buckthorn (SB) on microwave-vacuum-dried (MVD) carrot properties. Convective drying (CD) and freeze-drying (FD) were used as a comparative method. The dry matter content and water activity of MVD carrots were varied, but in many cases, the values were comparable to those of FD-dried carrots. Pre-enrichment in CH juice significantly reduced the values of the color parameters L*, a*, and b*, regardless of the drying method. The smallest changes were observed in microwave pre-blanching (M_BL). The lowest loss in carotenoid content was observed in CD-dried carrots (14–34 mg/100 g d.m.). Blanching and enrichment in SB juice allowed significant retention of these compounds. As a result of drying carrots, the total phenolic content (TPC) increased. Compared to the raw material, the TPC content in dried carrots increased 3–9 times. Drying using the FD and MVD methods gave a similar effect of increasing the TPC content, including a greater effect after enrichment in CH juice. The highest average antioxidant activity against the DPPH• and ABTS•+ radicals was recorded for FD-dried carrots (6.9 and 30.0 mg Trolox/g d.m.). SB juice contributed to a significant increase in the total vitamin C content, even by 89.1%, compared to raw carrots. Applying osmotic pre-enrichment in PG juice increased the sugar content in dried FD and CD samples by 37.4–49.9%, and in MVD by 21–59%. [ABSTRACT FROM AUTHOR]

The study aims to investigate the impact of various drying techniques on the quality of sulfated polysaccharides (SP) extracted from Skipjack tuna (Katsuwonus pelamis) skin. Three drying methods, namely microwave drying (M‐KPP), freeze‐drying (F‐KPP), and hot air drying (HA‐KPP), are examined. The chemical and monosaccharide compositions of SP are significantly affected by the drying methods. The extraction yields for M‐KPP, F‐KPP, and HA‐KPP are 3.30%, 3.11%, and 2.50%, respectively (P < 0.05). Additionally, HA‐KPP, with 10.67% moisture content, exhibits the lowest moisture level among the dried samples (P < 0.05). Furthermore, the structural properties of SP remain consistent across different drying methods, as indicated by FTIR, XRD, and DSC analyses. F‐KPP demonstrates the highest antioxidant properties. The functional and antimicrobial activities of SP are significantly influenced by the drying technique, with hot air drying resulting in increased foaming capacity and microwave drying showing enhanced antimicrobial activity. In conclusion, the findings demonstrate that the functionality and bioactivity of SP from tuna skin are greatly influenced by the drying technique employed, suggesting that the selection of the optimal method should be tailored to the desired properties of the SPs and given careful consideration. [ABSTRACT FROM AUTHOR]

The mulberry fruit is edible and medicinal, and it is commonly referred to as the "best health product of the 21st century". The purpose of this study was to find out whether different drying methods affect the quality of mulberry fruits and the main nature of the volatile organic compounds (VOCs) they contain. This study used vacuum freeze-drying (VFD), vacuum drying (VD), sun drying (SD), hot-air drying (HAD), and microwave drying (MD) to treat fresh mulberry fruits. Gas-phase ion mobility spectrometry (GC-IMS) was used to detect and analyze the VOCs in mulberry fruit samples treated with the different drying methods. There were 47 VOCs detected, with aldehydes and alcohols dominating. The obtained data were subjected to principal component analysis (PCA), cluster analysis (CA), nearest neighbor fingerprint analysis, and partial least-squares regression analysis (PLS-DA). The conclusion was drawn that fresh mulberry fruits contain abundant VOCs, and mulberry fruits after VD contain many aldehydes; thus, VD promoted the synthesis of phellandrene and other compounds widely used in the preparation of cosmetics such as perfume and soap. HAD promoted the synthesis of esters commonly used in the preparation of fruit flavor and wine essence. The higher (E)-2-heptenal content with SD was conducive to the Maillard reaction. MD promoted the synthesis of heptanal and valeraldehyde with aroma characteristics such as fatty, green, fruity, grassy, and floral. According to the VIP results, VOCs (E)-2-heptenal, pentanal D, cyclohexanone, and 2-hexanone D influenced the VOCs in most of the mulberry fruit samples. The findings of this study provide an important reference for drying mulberry fruits, which, in turn, will help to ensure the safety and effectiveness of processed mulberry fruit products. [ABSTRACT FROM AUTHOR]

Abstract Background Chrysanthemi Flos is a traditional Chinese medicine with a long history of medicinal use. Prior research suggests that the intrinsic composition of Chrysanthemi Flos is affected by shade-drying and oven-drying methods. Nevertheless, the effects of these methods on the proteins and metabolites of Chrysanthemi Flos have not been extensively studied. Methods The TMT (tandem mass tag) quantitative proteomics method and the LC–MS/MS (liquid chromatography-tandem mass spectrometry) non-targeted metabolomics method were used to systematically study the differences in the proteins and metabolites during the process of drying Chrysanthemi Flos in the shade and an oven. Results Differentially accumulated metabolites and abundant proteins were primarily enriched in the purine metabolism, pyrimidine metabolism, cyanogenic amino acid metabolism, phenylpropanoid biosynthesis, and starch and sucrose metabolism pathways. Primary metabolites, such as guanine, xanthine, cytidine 5'-diphosphate serine, L-isoleucine, stearidonic acid, alginate, and inulin, play a crucial role in providing energy for Chrysanthemi Flos to withstand desiccation stress. The upregulation of ferulate-5- hydroxylase (F5H), shikimate O hydroxycinnamoyltransferase (HCT), caffeoyl-CoA O-methyltransferase (CCoAOMT), and chalcone isomerase (CHI) enzymes promotes the synthesis of flavonoids, including sinapic acid, caffeoyl shikimic acid, and naringenin chalcone, which possess antioxidant properties. Despite the notable improvements in energy metabolism and antioxidant capacity, these enhancements proved insufficient in halting the senescence and ultimate demise of Chrysanthemi Flos. Moreover, the shade-drying method can inhibit protein expression and promote the accumulation of bioactive components, but the drying efficiency is low, while the oven-drying method exhibits rapid drying efficiency, it does not effectively preserve the components. Conclusion Our study offers a comprehensive explanation for the changes in protein expression and metabolite conversion observed in shade-dried and oven-dried Chrysanthemi Flos, also providing a foundation for optimizing the drying process of Chrysanthemi Flos.

The rising cultivation of edible insects at an industrial level highlights the importance of employing appropriate post-harvest methods for processing safe and fine-quality insect-based products. The study investigated the impact of different drying and extraction methods on the quality of Tenebrio molitor larvae powder. Two drying treatments, microwave and oven drying, were evaluated followed by total lipid extraction using various methods. Soxhlet extraction with an n-hexane–EtOH (3:1) mixture was effective, yielding 37.85% (microwave) and 38.85% (oven). The highest fatty acid (FA) content was 9-octadecenoic acid, methyl ester (E)-(C18:1). The Schlechtriem and Bligh and Dyer (BD) methods resulted in higher total lipid yields, with BD yielding 56.66% in oven-dried samples. FA profiles were consistent, with monounsaturated FAs predominant. Oven-dried samples had higher saturated FAs. Phenolic content was greater in oven-dried samples, with the n-hexane–EtOH extraction showing the highest total phenolic content (0.09 ± 0.02 mg GAE/100 mg). BD extract from oven-dried samples was the most cytotoxic, significantly reducing cell survival against A549 cells (IC50 = 458.6 µg/mL) and inducing apoptosis at 250 µg/mL. This study underscores the importance of post-harvest methods in producing high-quality insect-based products, revealing that oven drying and specific solvent extractions can enhance total lipid yield, phenolic content, and cytotoxic effects on cancer cells.

This research investigated the impacts of various drying methods, including hot-air drying, hot-air-microwave drying, heat-pump drying, vacuum-freeze drying, microwave-vacuum drying, and multi-stage hot-air drying, on the physicochemical properties, antioxidant capacity and flavor profile of Lentinus edodes powder (LEP). The results demonstrated that vacuum-freeze-dried LEP was superior to LEP produced using the other drying methods in terms of physicochemical properties such as water absorption index, expansion ratio, and color. Moreover, vacuum-freeze-dried LEP had the highest total phenolic content (1.345 mg/g) and strongest antioxidant capacity in terms of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radical scavenging capacity. In contrast, microwave-dried LEP showed the lowest antioxidant capacity. Analysis by electronic nose and gas chromatography-ion mobility spectrometry (GC-IMS) revealed that the major volatile compounds in the six LEPs included sulfur-containing compounds, aldehydes, alcohols, ketones, and esters, and there were significant differences in the aroma profiles of these LEPs. Notably, heat-pump-dried LEP exhibited the highest levels of alcohols and esters. Hot-air-dried LEP exhibited the highest levels of aldehydes. Vacuum-freeze drying was conducive to retaining aroma compounds. The results of electronic tongue analysis indicated that hot-air-microwave dried LEP had high umami and low bitterness. These findings could provide a theoretical foundation for the development and application of LEP as a food ingredient.

The objective of the present research was to determine the nutrient utilization of full-fat black soldier fly larvae (Hermetia illucens; BSFL), which were processed by various drying methods, using in vitro procedures for pigs. Four sources of BSFL were prepared using various drying methods: (1) hot-air drying at 65 °C for 24 h; (2) microwave drying at 700 W for 5 min, three times; (3) freeze drying at −40 °C for 72 h; (4) infrared drying at medium infrared region (ranged from 2.0 to 6.0 μm) and at 95 °C for 12 min. In vitro ileal disappearance (IVID) of nutrients in the BSFL was measured using a procedure simulating the nutrient digestion and absorption in the stomach and small intestine of pigs. In vitro total tract disappearance (IVTTD) of nutrients in the BSFL was also measured using a procedure that simulated the total intestine of pigs. The contents of dry matter, ether extract, and crude protein in the dried-BSFL ranged from 94.6 to 96.8%, 49.2 to 52.8%, and 30.0 to 36.8%, respectively, on an as-is basis. Microwave drying resulted in a greater (p < 0.05) IVID of dry matter in BSFL, compared with the freeze drying or infrared drying method, which caused the least IVID of dry matter. Hot air-dried BSFL, microwave-dried BSFL, and freeze-dried BSFL had a greater (p < 0.05) IVID of crude protein and a greater (p < 0.05) IVTTD of dry matter and organic matter, compared with infrared-dried BSFL. In conclusion, the hot-air drying, microwave drying, and freeze drying of full-fat black soldier fly larvae resulted in fairly comparable and relatively high nutrient digestibility based on the present in vitro study for pigs. However, the infrared drying method impaired nutrient utilization of full-fat black soldier fly larvae for pigs. [ABSTRACT FROM AUTHOR]

This study examined the effects of hot air drying (HAD), infrared radiation drying (IRD), microwave vacuum drying (MVD), freeze drying (FD), and freeze drying combined with microwave vacuum drying (FD-MVD) on the drying kinetics, color, rehydration ratio, titratable acidity, and vitamin C content of small white apricots (Prunus armeniaca L.). Results showed drying times of 12.5 h (IRD), 14.1 h (FD), 16 h (HAD), 0.53 h (MVD), and 6.15 h (FD-MVD). FD-MVD significantly outperformed MVD, HAD, and IRD in color, vitamin C, titratable acidity, and rehydration, though was slightly inferior to FD. Microstructural analysis revealed that FD-MVD preserved the most uniform pore structure, better maintaining apricots' original appearance. In contrast, IRD and HAD caused severe surface shriveling, compromising quality. In conclusion, FD-MVD emerges as a promising drying method to enhance apricot quality and market competitiveness in food processing. [ABSTRACT FROM AUTHOR]

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Cauliflower (Brassica oleraceae L. var. Botrytis Linnaeus) has various health benefits due to its rich bioactive compound content. However, this fresh vegetable faces challenges related to its perishability and short shelf life. This study explores the effect of five drying methods, namely vacuum drying (VD), convective drying (CD), infrared drying (IRD), low-temperature vacuum drying (LTVD) and vacuum freeze-drying (VFD), on the bioactive compounds and health-promoting properties of cauliflower. Analyses of amino acids, hydroxycinnamic acid and its derivatives, glucosinolates, and isothiocyanates, as well as evaluations of their anti-inflammatory, antiproliferative, and neuroprotective properties, were conducted based on these five drying methods. The results revealed that samples treated with VFD and IRD had a higher content of amino acids involved in GSL anabolism. Moreover, VFD samples retained hydroxycinnamic acid derivatives and glucosinolates to a greater extent than other methods. Nonetheless, the CD and VD samples exhibited higher antiproliferative and neuroprotective effects, which were correlated with their high sulforaphane content. Overall, considering the retention of most bioactive compounds from cauliflower and the topical inflammation amelioration induced in mice, VFD emerges as a more satisfactory option. [ABSTRACT FROM AUTHOR]

The eryngo plant is an herb related to the Apiaceae family with the greatest diversity of species, has a gorgeous taste when eaten as a vegetable, and is traditionally used in folk medicine for its health benefits. The present study was to assess the effects of different drying methods and storage times on the quality and appearance of Eryngium caeruleum. The treatments of this study were drying methods (room temperature (25°C) with proper ventilation, oven temperature 55°C, vacuum oven temperature 55°C, and a microwave with a power of 500 W) and storage times (1, 75, and 150 days). The lowest brightness index and the highest browning index were found in the shade‐dried samples kept in the refrigerator for 150 days. In these samples, the numerical values of chlorophyll were lower than others. After 75 days, in the vacuum oven‐dried samples, the maximum levels of total phenolics and flavonoids and antioxidant activity were calculated. The colorimetric test showed that the oven‐dried samples maintained their green color well. However, the storage decreased the quality of plant samples due to the degradation of chlorophyll. Overall, this study showed that the highest greenness and appearance qualities were found in the samples dried in a vacuum oven at 55°C. It seems that appearance indices can be introduced as an initial and quick step in the qualitative assessment of dried leafy products. [ABSTRACT FROM AUTHOR]

Summary: Boiling, centrifuging and various drying techniques (vacuum freeze‐drying (VFD), vacuum drying (VD), hot‐air drying (HAD) and microwave drying (MWD)) were assessed for their impact on bioactive compounds in Antarctic krill meal. A comparison between the raw and boiling groups revealed a significant degradation and isomerisation of astaxanthin, accompanied by a 1.25‐fold and 1.32‐fold increase in saturated (SFAs) and monounsaturated fatty acids (MUFAs), respectively. Drying was the primary factor responsible for the reduction in phospholipids, α‐tocopherol and polyunsaturated fatty acid (PUFAs), in combination with the increase in thiobarbituric acid‐reactive substances. For different drying methods, it was found that HAD induced severe lipid oxidation. In contrast, the VFD, VD and MWD improved lipid quality, reducing thiobarbituric acid‐reactive substances (TBARS) by 13–22% and increasing phospholipids by 1.08–1.11 times compared to HAD. VD preserved higher levels of bioactive compounds. PLS‐DA analysis identified 13‐cis‐astaxanthin, α‐tocopherol and eleven fatty acids as key indicators for Antarctic krill meal. [ABSTRACT FROM AUTHOR]

Bulbine inflata is one of the species in the genus Bulbine that are yet to be documented for potential medicinal uses. Hence, we carried out its preliminary phytochemical profiling and investigated its antioxidant potential. The leaves were dried using air- and freeze-drying techniques and were extracted by water, methanol, ethyl acetate and hexane. Various common colour tests were used for the presence of phytochemicals. Some of the phytochemicals were further quantified. Phosphomolybdate, 2, 2 diphenyl-1-picryhydrazyl, hydrogen peroxide and metal chelating assays were used to assess the antioxidant potential of B. inflata. Tannin, flavonoids, phenols, glycosides, steroids, coumarins, quinones, saponins and terpenoids were detected phytochemicals in B. inflata leaves. The highest total phenolic, flavonoid and tannin contents, as well as total antioxidant capacity, were recorded for water extract. B. inflata showed moderate to high antioxidant activities against DPPH, H2O2 and metal chelating. Freeze-dried samples presented with higher results than air-dried samples in most assays. The results showed the potential of B. inflata for medicinal uses and could expand the ethnomedicinal resources in the communities where it is prevalent and beyond. [ABSTRACT FROM AUTHOR]

Mulberry perishes easily due to its high water content and thin skin. It is important to extend the shelf life of mulberry by proper processing methods. In the present study, the influence of three drying techniques, including hot air drying (HAD), vacuum drying (VD), and vacuum freeze-drying (VFD) on the quality maintenance of mulberry was comprehensively evaluated. Bioactive compounds, antioxidant activity, and the sensory and volatile flavor compounds of mulberry have been researched. The results showed that VFD treatment maintained the highest anthocyanins (6.99 mg/g), total flavones (3.18 mg/g), and soluble sugars (2.94 mg/g), and exhibited the best DPPH· (81.2%) and ABTS+· (79.9%) scavenging ability. Mulberry also presented the lowest hardness and the greatest brittleness after VFD. Additionally, VFD maintained the optimal color and presented the best sensory attributes. Furthermore, 30, 20, and 32 kinds of volatile flavor compounds were detected in HAD, VD, and VFD, respectively, among which aldehydes, esters, and ketones were the most abundant compounds. This study indicated the potential application value of VFD for the drying of fruit and vegetable foodstuffs. [ABSTRACT FROM AUTHOR]

The present study was aimed to determine the effect of ultrasound pretreatment and different drying methods viz sun drying, solar drying, cabinet drying, vacuum drying, microwave assisted drying and freeze drying on physicochemical, phytochemical activity, rehydration ratio and drying time of the purslane. The purslane was ultrasonicated for 15, 30, 45 and 60 min following by drying. The ultrasound pretreatment (60 min) combined with freeze drying retained the highest antioxidants (95.59 %), phenolic content (7.85 mgGAE/100 g), total carotenoid content (99.74 mg/100 g), ascorbic acid (399.94 mg/100 g) and rehydration ratio (6.80). Moreover, the same combination revealed higher L and a* values when compared with other drying methods. However, the purslane pretreated with ultrasonication for 60 min and then dried via microwave took less time for drying. This study suggests that Ultrasound pretreatment (60 min) followed by freeze drying is recommended for preserving the nutritional and functional properties of purslane. It could be scaled up for commercial applications in the functional food and nutraceutical industries, where high-quality preservation is crucial.

Avocados are among the most well-known nutrient-rich fruits worldwide. However, there is a high production of by-product waste, mainly avocado seeds. Avocado seeds can be used in many functional food and non-food applications, due to their nutritional and health-promoting properties. However, preservation technologies such as drying are essential to increase shelf life and preserve bioactive compounds. It has been anticipated that pre-drying techniques could improve the quality of dried products. This study investigates the drying kinetics of avocado seed slices that have been subjected to different pre-treatments (ascorbic acid, blanching, roasting) and drying methods (fluidized bed dryer, hot air dryer, and solar dryer) using freeze-dried samples as a control. In addition, the interaction effect of pretreatment and drying methods on the thermodynamic properties, physicochemical quality, and bioactive compounds of dried avocado seeds were also evaluated. Results indicate that the logarithmic model provides the best fit for the experimental data on drying kinetics. Thermal profile coefficients for avocado seeds activation energy and effective moisture diffusivity were predicted to range from 80.91 to 97.02 kJmol-1, and 4.8 to 5.8 × 10−10 m2s−1, respectively. Moreover, the study showed that the sample treated with roasting and dried using hot air drying (HAD) achieved the maximum desirability value of 0.9256 for thermal profile coefficients. In terms of nutritional and bioactive compound retention, samples treated with ascorbic acid and dried using a fluidized bed dryer (FBD) exhibited maximum values of phenols (106.6 mg GAE/100 g) and vitamin C (77 %), along with a total colour difference recovery of 86 %. In summary, dried avocado seeds are a valuable source of macronutrients and bioactive compounds, highlighting their potential as functional ingredients in the food industry. Furthermore, the implications of this research finding is to produce stable products with better quality from plant by-products using the proper drying methods and promoting a circular economy.

Sargassum sp., a brown seaweed abundant in Semau Island, East Nusa Tenggara, Indonesia, has potential as an alternative feed source in animal nutrition due to its rich chemical composition. This study aimed to determine Sargassum sp.'s chemical and carbohydrate composition using different drying methods to evaluate its suitability as livestock feed. A Completely Randomized Design (CRD) with three treatments—sun drying, oven drying at 60°C, and air drying—and five replications were employed. Using standard proximate analysis, fresh seaweed samples were dried according to the treatments and analyzed for dry matter, organic matter, crude protein, crude fat, crude fiber, and carbohydrate content. The results showed that the drying method significantly affected (P 0.05) on crude fiber and carbohydrate content. Air-dried samples exhibited the highest crude protein content (6.38%) compared to sun-dried (4.71%) and oven-dried (4.94%) samples, indicating better preservation of protein at lower temperatures. Crude fat content was highest in sun-dried samples (0.56%) and lowest in air-dried samples (0.24%). Carbohydrate content ranged from 52.83% to 54.00% across all treatments without significant differences. These findings suggest that air drying is the most effective method for retaining the nutritional components of Sargassum sp., enhancing its potential as a valuable ingredient in animal feed formulations. The drying method significantly influences Sargassum sp. seaweed's chemical composition. Air drying preserves key nutritional components, making it the recommended method for processing Sargassum sp. for use in animal nutrition.

This study investigated the effects of hot air drying (HAD), microwave vacuum drying (MVD), and vacuum frying drying (VFD) on the quality of yuba and utilized mathematical models (Peleg model, Weibull model, first-order kinetic model, and exponential association model) to explore the rehydration kinetics of yuba. The results indicated that, compared to HAD, MVD significantly increased yuba's L* value and sensory score, while VFD notably reduced the cooking loss and enhanced moisture retention. Significant changes were observed in the texture of yuba before and after cooking, with distinct differences noted under microscopic observation, and a pronounced change in protein secondary structure. The Peleg model can effectively fit the rehydration processes of HAD and VFD yuba, while the first-order kinetic model can effectively fit the rehydration processes of MVD yuba. This study provides a valuable reference for yuba's drying methods and rehydration kinetics model.

Abstract The study aims to investigate the impact of various drying techniques on the quality of sulfated polysaccharides (SP) extracted from Skipjack tuna (Katsuwonus pelamis) skin. Three drying methods, namely microwave drying (M‐KPP), freeze‐drying (F‐KPP), and hot air drying (HA‐KPP), are examined. The chemical and monosaccharide compositions of SP are significantly affected by the drying methods. The extraction yields for M‐KPP, F‐KPP, and HA‐KPP are 3.30%, 3.11%, and 2.50%, respectively (P

This study investigated the effects of drying methods on the yield, bioactive compounds, and antibacterial activity of amla extract. Fresh amla was oven-dried and sun-dried at different temperatures and ground into powder. Bioactive compounds were extracted from amla using maceration with ethanol as a solvent. The amla extract was used for the antibacterial susceptibility test using the agar disc diffusion method. The yield of amla extract increased with increasing drying temperature. The highest yield (53.47%) was obtained at a drying temperature of 70o C. Fourier Transform Infrared (FTIR) analysis confirmed that sun-drying and oven-drying exhibited no qualitative effect on the bioactive compound in amla extract. FTIR analysis also indicated that amla extract contains bioactive compounds, validated by phytochemical analysis. The antibacterial activity of oven-dried samples at 40 oC produced the largest inhibition zone (24.57 mm) compared to sun-drying and oven-drying at other temperatures. It can be concluded that drying temperature, especially higher temperatures, had a significant impact on the antibacterial activity of amla as its active components degraded.

This study analyzed and compared the effects of different drying methods on the volatile composition and aroma characteristics of Osmanthus fragrans extract and absolute oil. The volatile composition was determined by gas chromatography-mass spectrometry (GC-MS) and partial least squares-discriminant analysis (PLS-DA), relative odor activity value (ROAV), aroma profile radar and principal component analysis (PCA) were employed to determine the effect of different drying methods on the volatile aroma components of O. fragrans extract and absolute oil. The results showed that a total of 113 volatile components were identified. The types and concentrations of volatile components were significantly different among samples (P < 0.05). Through PLS-DA analysis, 36 volatile marker substances were selected using the cut-off of variable importance in the projection (VIP) score greater than 1, and the accuracy of predictive discrimination of O. fragrans extract and absolute oil prepared by different drying methods was 99.6%. The ROAV and aroma radar plots showed that dihydro-β-ionone, linalool, nonanal, β-ionone, and dihydro-β-iononeone contributed significantly to the aroma of O. fragrans extract and absolute oil, being responsible for the floral, woody, and fruity aromas. Notably, the extract from freeze-dried O. fragrans exhibited a more intense aroma. PCA analysis indicated that freeze-drying contributed to improving the aroma quality of O. fragrans extract and absolute oil. The results of this study provide theoretical support for process optimization and quality improvement of O. fragrans extract products.

In order to investigate and evaluate the processibility of broccoli by-products (stems and leaves) and hence to provide a reference for their rational utilization, this study investigated the physicochemical properties and nutritional quality of broccoli stem and leaf powders prepared by different drying methods, namely vacuum freeze drying (FD), microwave freeze drying (MFD), heat pump drying (HPD) and hot air drying (HAD). The results showed that the color difference ΔE between MFD-treated and fresh broccoli stems was 8.52 ± 0.02, which was smaller than that between HAD-treated and fresh samples (30.27 ± 0.28), indicating that MFD had better color preservation effect. The median particle size ranges of broccoli stem and leaf powders were 31.19–52.09 and 32.30–40.47 μm, respectively. Broccoli leaf powder had lower water and oil retention capacities but higher swelling force than that broccoli stem powder. The water retention capacity of FD-dried broccoli stem powder was (11.40 ± 0.46) g/g, and the oil retention capacity of MFD-dried broccoli stem powder was (1.40 ± 0.04) g/g. FD and MFD could effectively maintain the microstructure of broccoli stems and leaves, with obvious pores. The specific energy consumption of FD and MFD for treating an equal amount of broccoli stems was 7.35 and 3.26 kW·h/kg, respectively, so MFD reduced energy consumption by 55.65% when compared with FD. MFD maintained heat-sensitive and readily oxidized nutrients well, resulting in good antioxidant activity. The 1, 1-diphenyl-2-picryl hydrazine (DPPH) scavenging capacity, 2, 2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cationic radical scavenging capacity and ferric ion reducing antioxidant power (FRAP) of MFD broccoli leaf extract at a concentration of 0.125 mg/100 mL were 70.21%, 71.11% and (0.31 ± 0.01) mmol/g, respectively. In summary, broccoli stem and leaf powders had good physicochemical properties and nutritional quality and therefore could be used as raw materials for developing functional foods. The application of drying technology enables the rational utilization of broccoli stems and leaves.

To investigate the effect of drying methods on the volatile flavor substances of Toona sinensis, the volatile components of vacuum freeze-dried, heat pump-dried, hot air-dried, and microwave vacuum-dried Toona sinensis samples were analyzed by gas chromatography-ion mobility spectrometry (GC-IMS) and gas chromatography-mass spectrometry (GC-MS) coupled with relative odor activity values, and the differences of volatile components among samples were further explored by combining the stoichiometric principal component analysis and partial least square discriminant analysis. The results showed that 78 peaks were detected and 59 compounds were identified by GC-IMS. 94 kinds of volatile compounds were identified by GC-MS, and the main volatile components were sulfides, olefins and aldehydes. The content of total volatile compounds was significantly reduced after drying. The key aroma compounds in Toona sinensis samples were identified by ROAV method, such as (E,Z)-di-1-propenyldisulfide, 2-mercapto-3,4-dimethyl-2,3-dihydrothiophene, hexanal, 2-hexenal and eugenol. The PCA and PLS-DA results showed that the samples with different drying methods were not only clearly separated from the raw samples, but also significantly different from each other. The raw samples and vacuum freeze-dried samples were grouped, and the other three dried Toona sinensis samples were grouped. According to the variable importance in projection score, a total of 10 (VIP>1) labeled volatile compounds were selected. The drying method had significant effect on the flavor characteristics of Toona sinensis, and the vacuum freeze-dried group was the closest to the raw sample, while heat pump-drying was the most suitable dehydration method for Toona sinensis, considering the practical application. This study provides some theoretical references for flavor quality control in the thermal processing process.

This study aimed to understand the flavor and taste characteristics of dried Boletus edulis products prepared by different drying methods and to explored the difference in flavor among the dried products. The volatile flavor substances and non-volatile taste substances of B. edulis dried by three different drying methods including hot air drying (HAD), vacuum freeze drying (VFD) and vacuum drying (VD) were measured and analyzed. Totally 64 and 85 volatile organic compounds (VOCs) were identified by gas chromatography-ion mobility spectrometry (GC-IMS) and gas chromatography-mass spectrometry (GC-MS), respectively. The fingerprint analysis results showed large differences among the dried products, the most significant differential characteristics being found in the VD dried product. Orthogonal partial least squares-discriminate analysis (OPLS-DA) selected 17 and 22 differential characteristic markers based on the results of GC-IMS and GC-MS, respectively. Relative odor activity value (OAV) analysis showed that the key VOC was 1-octen-3-ol. The analysis of non-volatile taste substances indicated that the highest contents of both free amino acids (FAAs) and 5’-nucleotides were found in the HAD-dried product, which were 234.57 and 27.870 mg/g, respectively. Among the 16 free amino acids (FAAs), glutamic acid was the major contributor to umami taste. In summary, HAD is more conducive to the accumulation of taste substances in B. edulis, while VD results in a higher number and amount of flavor compounds. This study could provide a reference for the selection of a method for the postharvest drying of fresh B. edulis.

Abstract Drying techniques are being used more and more to extend the shelf life of industrial products. Drying could influnce the content of phenolics in food and their antioxidant activity. This study estimated the effects of different drying methods (freeze drying (FD), gradient hot air drying (GHD), and constant hot air drying (CHD)) on phenolic profiles and antioxidant activities in walnut kernels. With a maximum content of 3.61 mg g−1, GHD was found to be the most effective in preserving total phenols, while CHD and FD had maximum contents of 2.66 mg g−1 and 1.96 mg g−1, respectively. The concentration of most monomeric phenols detected in the kernels increased with temperature, particularly in the free and bound forms. Gallic acid (free form) levels in GHD2 (194.54 µg g−1) were 55.77 and 60.08 times higher, respectively, than in FD and CHD. GHD dried walnuts had higher antioxidant activity than FD and CHD dried walnuts. Furthermore, bioinformatics analysis revealed three key metabolic pathways associated with the mechanisms underlying drying changes. The GHD technique, according to these findings, is a better choice for drying walnut in order to preserve its phenolics and antioxidant activity. Graphical Abstract

Figs are renowned for their rich array of bioactive compounds, offering significant nutritional and medicinal potential. This study compared the phytochemicals, antioxidants, and antinutrients content of Ficus racemosa and Ficus hispida with Ficus carica and assessed the effects of two drying methods, oven drying (50–55 °C for 24 h) and sun drying. Total phenolic (TPC) and flavonoid content (TFC) were quantified using Folin-Ciocalteu and aluminum chloride colorimetric assays. Phytate and oxalate contents were measured as antinutrients. Results showed that Ficus racemosa pulp and seeds had the highest TPC of 90 mg GAE/g and Radical Scavenging Activity (RSA) of 90.89 % among oven-dried samples. Ficus hispida and Ficus racemosa exhibited higher TFC than Ficus carica, with Ficus hispida at 228.53 mg QE/g (sun-dried) and 132.26 mg QE/g (oven-dried). In contrast, Ficus carica had significantly lower TFC (21.14–50.33 mg QE/g). Oven-dried samples showed higher RSA, phytate, and oxalate levels than sun-dried samples. Ficus hispida and Ficus racemosa, two local fig species, showed higher phenolic and flavonoid content and better RSA than the Mediterranean Ficus carica, presenting better nutritional and medicinal potential. The local fig fruit can serve as an excellent source of beneficial bioactive compounds, minerals, and dietary fibers in Bangladesh.

Red beetroot is a unique vegetable crop with high nutritional value and various health benefits, but due to the short shelf life, it requires a suitable preservation method. The purpose of the current investigation is to study the impacts of pretreatment coating with gum Arabic and drying method (oven, microwave, and freeze‐drying) on the quality parameters and storage stability of beetroot slices. Freeze‐dried beetroot samples showed the lowest moisture content (MC) (7.59%) and the highest rehydration ratio (RR) (5.47), betalain content (48.57 mg/100 g), antioxidant activity (70.92%), and overall acceptability scores (4.48). Generally, the pretreatment coating with gum Arabic reduced the degradation of betalain and antioxidants and maintained higher sensory scores of dried beetroot samples compared to uncoated ones. The beetroot extract prepared from freeze‐dried and coated with gum Arabic samples decreased the oxidation of low‐density lipoprotein (LDL) compared to control. Freeze‐dried samples coated with gum Arabic revealed higher storage stability (after 4 weeks of storage at room temperature) in terms of betalain content and antioxidant activity with values of 43.84 mg/100 g and 67.02%, respectively, compared to uncoated ones which recorded 35.15 mg/100 g and 64.22% for betalain content and antioxidant activity, respectively. Generally, freeze‐drying and coating with gum Arabic is considered a promising treatment to maintain the quality and storage stability of dried beetroot slices. Further investigations including nutritional, technological, and economic aspects are required for the optimum application in the future. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Bacterial cellulose (BC) presents significant promise as a biomaterial, boasting unique qualities such as exceptional cellulose purity, robust mechanical strength, heightened crystalline structure, and biodegradability. Several studies have highlighted specific effects, such as the impact of dehydration/rehydration on BC tensile strength, the influence of polymer treatment methods on mechanical properties, the correlation between microorganism type, drying method, and Young's modulus value, and the relationship between culture medium composition, pH, and crystallinity. Drying methods are crucial to the structure, performance, and application of BC films. Research findings indicate that the method used for drying can influence the mechanical properties of BC films, including parameters such as tensile strength, Young's modulus, and water absorption capacity, as well as the micromorphology, crystallinity, and thermal characteristics of the material. Their versatility makes them potential biomaterials applicable in various fields, including thermal and acoustic insulation, owing to their distinct thermal and mechanical attributes. This review delves into the thermal and mechanical behavior of bacterial cellulose aerogels, which are profoundly impacted by their drying mechanism. [ABSTRACT FROM AUTHOR]

This article presents guidelines for moisture and mycological diagnosis procedures for buildings after flooding. This paper proposes a division of the diagnostic procedure according to the medium of action and collects and presents methods for drying building elements. 54 companies dealing with drying were analyzed. The task of dehumidification is to use various methods to reduce the moisture level of building partitions to the equilibrium moisture level. An analysis of dehumidification methods in terms of ease of application, duration of the dehumidification process and level of structural interference is presented. In Poland, there are no guidelines formulated in legal acts or instructions regarding the procedure for moisture diagnostics and nor drying. It was noted that in situ studies cannot always lead to determining the actual values of mass moisture and thus to creating a real model of partition drying. [ABSTRACT FROM AUTHOR]

Pleurotus citrinopileatus Singer (PCS) has attracted increasing attention as a raw material for medicine and food. Its quality is greatly affected by the accumulation of metabolites, which varies with the applied drying methods. In this study, we utilize an approach based on ultra-high-performance liquid chromatography/Q Exactive mass spectrometry (UHPLC-QE-MS) to reveal the metabolic profiles of PCS from three different drying methods (natural air-drying, NAD; hot-air-drying, HAD; vacuum freeze-drying, VFD). The results showed that lipids, amino acids and their derivatives were all important secondary metabolites produced during NAD, HAD and VFD treatments, with the key differential metabolites of PCS during drying including fifteen lipids and seven amino acids. Meanwhile, VFD was the best way for long-term preservation of dried PCS. Hot-drying methods, especially HAD, can improve the medicinal component of PCS. Furthermore, KEGG enrichment analysis highlighted 16 pathways and indicated that amino acid metabolism might be the key metabolite pathway for the PCS drying process. Our study elucidates the relationship between drying methods and metabolites or metabolic pathways of PCS to determine the mechanisms affecting the quality of PCS, and finally provides reference values for further development and application in functional food and medications. [ABSTRACT FROM AUTHOR]

Spirulina platensis (SP) has gained popularity over the last few years, owing to its remarkable nutritional properties and high potential across various industrial sectors. In this study, we analyzed the volatile profile of eight SP samples from the same strain subjected to different drying (oven-drying, air-drying, and spray-drying) and storing conditions ("freshly prepared" and after 12 months of storage) using HS-SPME-GC-MS. Principal component analysis (PCA) was used as a multivariate technique to discern similarities and differences among the samples. The main aim was to assess the impact of the drying technique on the aroma profile and storage life of SP samples. Air-drying leads to the less pronounced formation of by-products related to heat treatment, such as Maillard and Strecker degradation compounds, but promotes oxidative and fermentative phenomena, with the formation of organic acids and esters, especially during storage. Thermal treatment, essential for limiting degradation and fermentation during storage and extending shelf life, alters the aroma profile through the formation of volatile compounds, such as Strecker aldehydes and linear aldehydes, from amino acid and lipid degradation. High temperatures in spray-drying favor the formation of pyrazines. The findings underscore the trade-offs inherent in choosing an appropriate drying method, thereby informing decision-making processes in industrial settings aimed at optimizing both product quality and efficiency. [ABSTRACT FROM AUTHOR]

To investigate the effect of drying methods on the volatile flavor substances of Toona sinensis, the volatile components of vacuum freeze-dried, heat pump-dried, hot air-dried, and microwave vacuum-dried Toona sinensis samples were analyzed by gas chromatography-ion mobility spectrometry (GC-IMS) and gas chromatography-mass spectrometry (GC-MS) coupled with relative odor activity values, and the differences of volatile components among samples were further explored by combining the stoichiometric principal component analysis and partial least square discriminant analysis. The results showed that 78 peaks were detected and 59 compounds were identified by GC-IMS. 94 kinds of volatile compounds were identified by GC-MS, and the main volatile components were sulfides, olefins and aldehydes. The content of total volatile compounds was significantly reduced after drying. The key aroma compounds in Toona .sinensis samples were identified by ROAV method, such as (E,Z)-di-1-propenyldisulfide, 2-mercapto-3,4-dimethyl-2,3-dihydrothiophene, hexanal, 2-hexenal and eugenol. The PCA and PLS-DA results showed that the samples with different drying methods were not only clearly separated from the raw samples, but also significantly different from each other. The raw samples and vacuum freeze-dried samples were grouped, and the other three dried Toona .sinensis samples were grouped. According to the variable importance in projection score, a total of 10 (VIP>1) labeled volatile compounds were selected. The drying method had significant effect on the flavor characteristics of Toona sinensis, and the vacuum freeze-dried group was the closest to the raw sample, while heat pump-drying was the most suitable dehydration method for Toona sinensis, considering the practical application. This study provides some theoretical references for flavor quality control in the thermal processing process. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article systematically reviews the advancements in processing litchi peel (Litchi chinensis), emphasizing drying, extraction, purification methods, and the potential of bioactive compounds obtained from litchi peel. This work also highlights the impact of various drying techniques on phytochemical profiles, focusing on how methods such as hot air and freeze-drying affect the preservation of bioactive compounds. The study delves into extraction methods, detailing how different solvents and techniques influence the efficiency of extracting bioactive compounds from litchi peel. Furthermore, the purification and characterization of active compounds, showcasing the role of chromatographic techniques in isolating specific bioactive molecules, is discussed. Biological properties and mechanisms of action, such as antioxidant, antihyperglycemic, cardioprotective, hepatoprotective, anti-atherosclerotic, and anticancer activities, are reviewed, providing insight into the potential health benefits of litchi peel compounds. This review highlights the importance of optimizing and selecting accurate drying and extraction methods to maximize the therapeutic effects of litchi peel and its bioactive compounds. This review also reveals the broad pharmacological potential of the isolated compounds, underscoring the need for further research to discover their specific actions and health benefits. [ABSTRACT FROM AUTHOR]

Copyright of Agronomía Colombiana is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of this study was to evaluate the effects of different drying methods on bioactive compounds and to analyze their composition in Verbascum sinaiticum (V. sinaiticum) leaf extracts using UHPLC-ESI-QTOF-MS/MS. V. sinaiticum is traditionally used as an herbal medicine, yet it has undergone limited scientific investigations regarding its secondary metabolites. V. sinaiticum leaves were dried using oven dryers at 50 °C, 60 °C, and 70 °C, as well as a freeze dryer. The leaves were then extracted using 50% and 70% aqueous ethanol and 100% aqueous solutions. The results showed that the highest contents of TPC and TFC were observed when 70% aqueous ethanol was used during freeze drying, reaching 181.73 mg GAE/g dw and 78.57 mg CE/g dw, respectively. The strongest correlations were observed between the TFC and DPPH radical scavenging activity (0.9082), followed by TPC and ABTS assays (0.8933) and TPC and DPPH (0.8272). In the FTIR analysis, freeze drying exhibited a lower intensity of the phenolic -OH functional groups, contrasting with significant denaturation observed during oven drying at 70 °C. Metabolite analysis identified 29 compounds in V. sinaiticum leaves, further confirming the presence of 14 phenolic and flavonoid compounds, including kaempferol, catechin, gallic acid, and myricetin derivatives, consistent with the experimentally observed antioxidant capacity. This study highlights the impact of drying methods on the bioactive composition of V. sinaiticum and underscores its potential as a source of antioxidants for food, nutraceutical, and pharmaceutical applications. [ABSTRACT FROM AUTHOR]

Drying greatly affects the aroma of black tea. In this study, the differences in aroma of black tea under hot-air drying (HD), sun drying (SD), and pan-fired drying (PD) were investigated through quantitative descriptive analysis. Headspace solid-phase microextraction and solvent assisted flavor evaporation combined with gas chromatography–mass spectrometry and gas chromatography-olfactory were used to analyze the overall aroma profile of black tea. Aroma extract dilution analysis and odor activity values revealed that 15 aroma-active compounds led to differences in aroma, namely linalool, geraniol, phenylethyl alcohol, phenylacetaldehyde, (Z) -linalool oxide (furanoid), β-damascenone, dimethyl sulfide, methional, 2-methylbutanal, 3-methylbutanal, methyl salicylate, β-myrcene, hexanal, 1-octen-3-ol, and heptanal. Among them, geraniol, linalool, and methional significantly enhanced the floral and roasty aroma of HD, while hexanal enhanced the green aroma of SD. Finally, our results were validated through aroma recombination and addition experiments. This study provides a theoretical basis for improving the aroma of black tea.

Objective: To study the content and quality characteristics of three types of apple pectin (WSP, NSP, CSP) treated by different drying methods. Methods: Apple pectin was dried by hot air drying (60, 75, 90 ℃), vacuum freeze dryingn (−50 ℃) and natural drying. The effects of different drying methods on the browning degree of apple and the pectin content, protein content, total sugar content, antioxidant capacity and pectin structure of three types of apples were studied. Results: The browning degree of apple slices was the smallest under hot air drying at 60 ℃. The content of three different types of pectin was different. The content of WSP was the most, ranging from 58.06% to 77.09%, followed by NSP, ranging from 30.57% to 54.98%, and the content of CSP was the least, ranging from 14.64% to 27.06%. Among them, the content of three types of pectin after hot air drying at 60 ℃ was the most. The total sugar content of WSP, CSP and NSP was 34.56%~6.92%, 11.02%~4.04% and 15.46%~8.75%, respectively. The total sugar content of WSP dried at 75 ℃ was the highest. The total sugar content of NSP and CSP under hot air drying at 90 ℃ was also the highest. The protein content of three different types of pectin was different. The range of WSP, NSP and CSP was 2.92%~5.73%, 1.39%~4.27% and 1.50%~5.40%, respectively. Fourier transform infrared spectroscopy analysis showed that there was little difference in the structure of apple pectin under different drying conditions. The drying method had a significant effect on the antioxidant capacity of pectin. The antioxidant capacity of WSP and NSP ranged from 91.27% to 78.54% and 8.15% to 2.14%, respectively. The antioxidant capacity of CSP was very weak. Among them, the antioxidant capacity of WSP and NSP under 90 ℃ hot air drying was the strongest, which was 91.27% and 8.15%, respectively. The antioxidant capacity of WSP and NSP under freeze drying was the weakest, which was 78.54% and 2.14%, respectively. Conclusion: After apples were treated by different drying methods, the contents and properties of three different types of pectin in apples were different. The apple pectin dried at 60 ℃ was the best, and the apple pectin content, total sugar content, protein content and antioxidant capacity were 50.69%, 15.27%, 3.61% and 31.33%, respectively. This study would provide theoretical support for the extraction process of apple pectin and the antioxidant capacity of different types of pectin, and also provide some reference value for further study on the effect of different drying methods on pectin drying.

In order to determine the optimal method for drying Apostichopus japonicus gonads, the effects of four drying methods, namely, hot air drying, cold air drying, microwave drying and vacuum freezing drying, on the lipid composition, lipid stability and fatty acid nutritional value of A. japonicus gonads were analyzed and compared. The results showed that the contents of total lipids, phospholipids, triglycerides and astaxanthin reduced to different degrees after drying treatments. The peroxide value (POV) significantly reduced, and the thiobarbituric acid reactive substances (TBARS) value significantly increased (P < 0.05). In terms of fatty acid nutritional values, the atherogenic and thrombogenic indices decreased to different degrees after drying treatments, and the hypocholesterolemic/hypercholesterolemic indices increased significantly (P < 0.05). The results of electronic nose analysis showed significant differences in odor characteristics among dried samples obtained using different drying methods. Gas chromatography-ion mobility spectrometry (GC-IMS) identified 28 volatile substances from fresh and dried samples, among which, 2,5-dimethyl pyrazine was detected only in microwave-dried samples, while pentanal and ethyl acetate were odor-active substances unique to cold air-dried samples. In conclusion, vacuum freeze drying effectively slowed down the rate of lipid oxidation, but the samples were relatively bland in odor. Hot air, cold air and microwave drying all promoted lipid oxidation, but improved the nutritional value of fatty acids and enriched the odor characteristics of the samples. The results of this study could provide a theoretical basis for the processing and utilization of A. japonicus gonads.

The physicochemical properties and antioxidant activity in vitro of selenium-enriched pea seedling powders produced by hot air drying or freeze drying were studied. The effects of different drying processes on the percentage loss of organic selenium content, color, microstructure, water distribution and antioxidant activity in vitro of pea seedling powder were investigated by chemical analysis and instrumental analyses using colorimeter, scanning electron microscopy (SEM) and low-field nuclear magnetic resonance (NMR). The results indicated that the product prepared by hot air drying at 100 ℃ had desired quality with a small percentage loss of organic selenium of 36.7% and good color. Selenium-enriched pea seedling powder consisted of blocky particles with more wrinkled surface and a larger number of fiber bundles compared with ordinary pea seedling powder. There were significant differences in water distribution between Se-enriched and non-Se-enriched pea seedling powder prepared by hot air drying. Compared with non-Se-enriched pea seedling powder, the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging capacity (half maximal inhibitory concentration IC50 = 0.61 mg/mL), hydroxyl free radical scavenging capacity (IC50 = 0.86 mg/mL), superoxide anion radical scavenging capacity (IC50 = 0.90 mg/mL) and ferric reducing power (absorbance value = 0.30) of the ethanol extract from Se-enriched pea seedling powder were significantly higher (P < 0.01). These results provide theoretical guidance and a technical reference for the development of organic selenium supplements and the industrialization of selenium-enriched foods.