Heatmap and PCA-based evaluation of bioactive compounds and volatile profiles in aronia fruits under different drying methods

True lavender (Lavandula angustifolia Mill.) is a widely used flavoring and medicinal plant, which strong aroma is mainly composed of linalool and linalyl acetate. The most valuable parts of the plant are the flowers, however leaves are also abundant in volatile constituents. One of the main factors responsible for its quality is the preservation procedure, which usually comes down to a drying process. For this reason an attempt to verify the influence of various drying methods (convective drying, vacuum-microwave drying and combined convection pre-drying with vacuum-microwave finishing drying) on the quality of true lavender leaves was carried out by determination of the volatile constituents profile by solid-phase microextraction (SPME) coupled with GC-MS technique. Total essential oil (EO) content was also verified. The study has revealed that the optimal drying method is strongly dependent on the purpose of the product. For flavoring properties convective drying at 60 °C is the most optimal method, while the best for preserving the highest amount of EO is vacuum-microwave drying at 480 W. Furthermore, SPME analysis had shown that drying may increase the value of true lavender leaves by significantly affecting the linalool to linalyl acetate to camphor ratio in the volatile profile.

The effects of five different drying conditions on kimchi powder quality were determined by comparatively analyzing their physicochemical characteristics, volatile profile, and sensory evaluations. The moisture content of the kimchi powder obtained by each method was < 10%, and the yield after drying differed among methods ranging from 9.50 to 10.38% (p < 0.05). Electronic nose and tongue analyses demonstrated significant differences (p < 0.05) between samples based on the drying temperature. The particle size distribution did not differ considerably between drying methods, except for the ground kimchi (p < 0.05). The sensory evaluation test revealed that the flavor and taste were rated the highest for the kimchi powder prepared using HADHT. Therefore, hot-air drying at a high temperature was the most effective method for kimchi powder production owing to have a good flavor and taste and the shorter drying time.

: The principal aim of the present experiment was to study the effects of different drying methods (shade drying, sun drying and oven drying at 40°C and 60°C) on essential oil compositional variation of pennyroyal (Mentha pulegium L.). Flowering tops of the plants were dried till constant weight balance via different methods. Volatile oil quantity and quality of plants were traced by Clevenger type apparatus and GC- MS, respectively. The results revealed that the drying method imposed meaningful effects on essential oil content as; shade drying (1.1 %)>oven drying at 40°C (1 %)>sun drying (0.8 %)>oven drying at 60°C (0.7 %), respectively. Volatile oil profile and their proportional percentage were also greatly affected by the drying type. Menthone (29.1-48.1 %), menthol (11.5-24.6 %), neomenthol (10.1-14.3 %), (E)-caryophyllene (3.1-8.9 %) and pulegone (4-6.9 %) were the predominant common constituents for all the drying methods with wide degree of variation. Germacrene D (4-5.1 %), menthyl acetate (1.8-8.6 %) and isopulegol (0.5-4.9 %) were the other common constituents again with the broader distribution amongst the drying methods. β-Cubebene (2.1 %) and alloocimene (1.4 %) contained the highest amount with shade drying. In contrast, piperitenone oxide (1.4-1.6 %) was exclusive of oven drying methods. Overall, considering the volatile oil major constituents, the decision on the appropriate drying method depends upon the compounds of interest.

Effect of different drying methods on color difference, microorganisms and volatile metabolites profiles of Ganpu Tea

Comparative evaluation of the volatile profiles and taste properties of roasted coffee beans as affected by drying method and detected by electronic nose, electronic tongue, and HS-SPME-GC-MS

Physical and chemical properties of jujube powder with different powder sizes prepared by different drying methods were determined, and correlations of the properties were statistically analyzed. Air-, vacuum-, and freeze-dried (AD, VD, and FD, respectively) jujube were milled and sieved to produce powders. Powder size, morphological characteristics, color, volatile profile, moisture sorption isotherm, water solubility, rehydration, total sugar content, and polyphenol content of the powder were determined. Hunter L, a, and b, degree of browning, and volatile profile varied depending on drying methods. Moisture sorption isotherms exhibited typical Type II sigmoidal shape. Polyphenol content was highest in AD powder (2.6±0.1 mg/g). Powder size, morphology, water solubility, and total sugar content were not different by different drying methods. Correlations identified among the properties indicate rehydration of the powder could be maximized by controlling particle size and water activity of the powder. Rehydration and powder size of AD, VD, and FD powder were significantly correlated (p <0.001) (R 2= 0.92, 0.88, and 0.94, respectively). Property correlations determined could be useful in customizing properties of jujube powder and increasing commercial uses of the powder.

Acanthopanax senticosus (Rupr. and Maxim.; AS) fruit, an underutilized byproduct, possesses significant bioactive potential, yet its quality is highly influenced by drying methods. This study systematically evaluated the effects of five drying techniques, including vacuum freeze-drying (VFD), vacuum drying (VD), microwave drying (MD), hot-air drying (HD), and natural drying (ND), on the color retention, bioactive composition, volatile profile, and antioxidant activity of AS fruit. VFD preserved the highest levels of total phenolic content (TPC) and total flavonoid content (TFC), particularly chlorogenic acid, rutin, and quercitrin, leading to superior antioxidant activity. Amino acid analysis indicated that VFD retained the highest concentrations of key essential amino acids, minimizing thermal degradation. Correlation analysis revealed a strong association between TPC, TFC, and antioxidant activity, emphasizing their functional significance. Through multivariate statistical analysis, 12 volatile compounds were identified as potential biomarkers to distinguish AS fruit samples processed using different drying methods, highlighting significant metabolic differences between drying techniques. Overall, VFD emerged as the optimal method for preserving AS fruit's bioactive integrity, offering valuable insights for post-harvest processing strategies in the nutraceutical industry.

Drying Methods of Duck Blood: Changes in Volatile Components and Physicochemical Properties

Strawberries are the most popular berry fruit in the world, due to their distinctive aroma, flavor, and known health properties. Because volatile substances play a large role in strawberry flavor, even little alterations can have a big impact on how the fruit tastes. Strawberries are thought to have a complex aroma. Fresh strawberry fruits contain more than 360 volatile compounds, including esters, furans, terpenes, alcohols, aldehydes, ketones, and sulfur compounds. Despite having far lower concentrations than esters, terpenoids, furanones, and sulfur compounds, all have a considerable impact on how people perceive the aroma of strawberries. With a focus on the active aroma components and the many analytical methods used to identify them, including gas chromatography, electronic nose sensing, and proton-transfer- reaction mass spectrometry, the present review’s aim was to provide a summary of the relevant literature. Additionally, strawberry fruits are frequently dried to create a powder in order to increase their shelf life. Consequently, the impact of various drying techniques on strawberries’ volatile profile was investigated in the current review. This review can be considered a good reference for research concerning the aroma profile of strawberries. It helps to better understand the complex aroma and flavor of strawberries and provides a guide for the effects of drying processing.

Characteristic fingerprints and comparison of volatile flavor compounds in Morchella sextelata under different drying methods

Strawberry is the most consumed berry fruit worldwide due to its unique aroma and flavor. Drying fruits to produce a powder represents one of the possible conservation methods to extend their shelf-life. The aim of the present study was to compare the influence of freezing and different drying methods on the volatile profile of strawberry using the HS-SPME/GC–MS method, in addition to analysis of strawberry jam volatiles. A total of 165 compounds were identified, accounting for 85.03–96.88% of the total volatile compositions. Results and PCA showed that freezing and each drying process affected the volatile profile in a different way, and the most remarkable representative differential volatiles were ethyl hexanoate, hexyl acetate, (E)-2-hexenyl acetate, mesifurane, (E)-nerolidol, γ-decalactone, 1-hexanol, and acetoin. Shade air-dried, frozen, freeze-dried, and oven-dried 45 °C samples retained more of the fruity and sweet aromas of strawberry, representing more than 68% of the total aroma intensity according to the literature. In contrast, the microwave-drying method showed drastic loss of fruity esters. Strawberry jams demonstrated complete destruction of esters and alcohols in most jams, while terpenes were significantly increased. These findings help better understand the aroma of strawberry and provide a guide for the effects of drying, freezing, and jam processing.

In this study, the effect of freeze-drying, oven- and microwave-drying on the volatile profiles and sensory properties of edible locust and silkworm was studied. Fifty-five headspace volatiles were detected, including alkanes, alcohols, aldehydes, esters, and ketones, with variations in intensity depending on the insect species and drying method. Volatiles from microwave-dried locusts and silkworms were typical for the Maillard reaction, that is in accordance with the significant increase of fluorescence of advanced Maillard products (2.9 and 5.5 times higher than in raw silkworms and locusts, respectively). Comparison of fatty acid composition and Fourier transform infrared spectra revealed signs of oxidation process at different levels depending on the insect. Changes in aroma and its intensity caused by different drying methods were also detected by sensory panellists who rated the samples of oven-dried locusts (2.4) and microwave-dried silkworms (1.9) with the lowest scores. An addition 15% of dried insects to cookies decreased the diversity of the volatiles, changed their intensity and lessened the dissimilarities between cookies with differently dried insect powders. Sensory panellists determined the presence of additional ingredients by higher odour intensity and general changes in overall liking scores of the insect-based cookies. Thus, drying can modify odour and sensory characteristics of locusts and silkworms and, consequently, cookies with these insect species, that should be considered in the processing of insects and formulation of novel insect-based foods.

Impact of drying techniques on volatile aroma profiles and formation mechanisms of black soybean thua nao

Given the substantial world coffee production, tons of coffee fruit cascara rich in bioactive compounds are discarded annually. Using this by-product to produce potentially healthy and acceptable foods is a sustainable practice that aggregates value to coffee production and may help improve people’s lives. This study aimed to elaborate kombuchas from coffee cascara tea, evaluate their microbial profile, and monitor the changes in the volatile profile during fermentation, together with sensory attributes and acceptance by consumers from Rio de Janeiro (n = 113). Arabica coffee cascaras from Brazil and Nicaragua were used to make infusions, to which black tea kombucha, a Symbiotic Culture of Bacteria and Yeasts (SCOBY), and sucrose were added. Fermentation of plain black tea kombucha was also monitored for comparison. The volatile profile was analyzed after 0, 3, 6, and 9 days of fermentation via headspace solid phase microextraction GC-MS. A total of 81 compounds were identified considering all beverages, 59 in coffee cascara kombuchas and 59 in the black tea kombucha, with 37 common compounds for both. An increase mainly in acids and esters occurred during fermentation. Despite the similarity to black tea kombucha, some aldehydes, esters, alcohols, and ketones in coffee cascara kombucha were not identified in black tea kombucha. Potential impact compounds in CC were linalool, decanal, nonanal, octanal, dodecanal, ethanol, 2-ethylhexanol, ethyl acetate, ethyl butyrate, ethyl acetate, β-damascenone, γ-nonalactone, linalool oxide, phenylethyl alcohol, geranyl acetone, phenylacetaldehyde, isoamyl alcohol, acetic acid, octanoic acid, isovaleric acid, ethyl isobutyrate, ethyl hexanoate, and limonene. The mean acceptance scores for cascara kombuchas varied between 5.7 ± 0.53 and 7.4 ± 0.53 on a nine-point hedonic scale, with coffee cascara from three-day Nicaragua kombucha showing the highest score, associated with sweetness and berry, honey, woody, and herbal aromas and flavors. The present results indicate that coffee cascara is a promising by-product for elaboration of fermented beverages, exhibiting exotic and singular fingerprinting that can be explored for applications in the food industry.

Volatile fingerprinting, sensory characterization, and consumer acceptance of pure and blended arabica coffee leaf teas