Retention Of Volatile Compounds Research Articles

Characterization of lipids and volatile compounds in boiled donkey meat by lipidomics and volatilomics.

Lipids are crucial substances for the formation and retention of volatile compounds (VOCs). The lipid and VOC profiles of boiled donkey meat were investigated by lipidomics and volatilomics. In total, 4277 lipids belonging to 39 subclasses were identified, comprising 26.93% triglycerides (TGs), 15.74% phosphatidylcholins (PCs), and 9.40% phosphatidylethanolamines. The relative percentage of TG in the meat significantly decreases (p<0.001) from 0 to 40min, after which there is no significant change, whereas PCs, sphingomyelins, and methyl phosphatidylcholines (MePCs) show the opposite trend. TG(16:1_18:1_18:2) and TG(16:0_16:1_18:2) appear to be key lipids for retaining VOCs in boiled donkey meat. Furthermore, PC(18:3e_16:0) and MePC(31:0e) were found to be potential markers for discriminating donkey meat. A total of 83 VOCs were detected, including 25.30% aldehydes, 18.07% hydrocarbons, 14.46% ketones, and 13.25% alcohols. Eleven characteristic VOCs with relative odor activity values >1 were identified as the predominant flavor compounds in boiled donkey meat, mainly hexanal and 1-octen-3-ol. Of the 258 differential lipids, 72 of them, especially polyunsaturated-fatty acid-rich lipids, are the main contributors to the formation of VOCs. Together, the key lipids for retention and formation of VOCs in donkey meat were revealed, providing a theoretical basis for VOC regulation.

Effect of Drying Methods on Chemical and Sensory Properties of Cannabis sativa Leaves.

Hemp is used as a source of fiber, oil and bioactive substances including volatile and cannabinoid-containing substances. This paper presents, for the first time, results on the evaluation of drying methods (convective, vacuum-microwave and combined convective pre-drying and vacuum-microwave finishing drying) of hemp leaves on the qualitative and quantitative changes in secondary metabolites, including essential oils, cannabinoids and sterols. A ranking and descriptive test of hemp leaves was also performed. Drying kinetics was presented using three models, including logarithmic, Midilli and modified Page. The SPME-Arrow technique was used to determine 41 volatile compounds, of which caryophyllene, β-myrcene and α-humulene were dominant in dried and fresh leaves. Regarding the essential oils obtained, 64 were identified, with caryophyllene, humulene epoxide II and limonene being the dominant ones. For preserving the highest amount of oils, the best method was the convective pre-drying followed by vacuum-microwave finishing drying (CD60-VMD) combined method, where the retention of volatile compounds was 36.08%, whereas the CD70 and 240-VMD methods resulted in the highest loss of 83%. The predominant cannabinoids in fresh hemp leaves were CBDA 6.05 and CBD 2.19 mg g-1. Drying caused no change in the cannabinoid profile of the plant material. β-Sitosterol, campesterol and lupeol were dominant in the phytosterol and triterpene fractions. No changes in either quality or quantity were observed in any of the variants found.

Changes in Functional Compounds, Volatiles, and Antioxidant Properties of Culinary Herb Coriander Leaves (Coriandrum sativum) Stored Under Red and Blue LED Light for Different Storage Times.

This study evaluated the influence of red (630–640 nm) and blue (450 nm) light-emitting diodes (LED) lights on the changes in antioxidant constituents, activity, volatile compounds, and overall acceptability of Coriander leaves (Coriandrum sativum) during post-harvest storage. Coriander leaves are harvested at commercial maturity, packed in polyethylene terephthalate punnets, and exposed for 2 h to the red LED or blue LED lights separately during storage at 5°C and 85% RH up to 9 days. Coriander leaves exposed to the white light (2 h) and continuous darkness served as controls. Samples were removed from cold storage at 3, 6, and 9 days to determine the antioxidant constituents, their activity, retention of volatile compounds, and overall acceptance. Coriander leaves exposed to red and blue LED lights for 2 h showed a commercially allowable mass loss of up to 9 days compared to the other treatments. Compared to those exposed to red LED light (2 h) and the control, leaves exposed to blue LED light for 2 h and stored for 3–9 days showed a reduction in colour change (ΔE). The β-carotene content significantly peaked at 44.55% on day 6 in coriander leaves exposed to the red LED light. However, leaves exposed to blue and red LED light showed an increase in total phenolic content by 9.34 and 6.39% on day 9, respectively. Exposure to blue LED lights increased the antioxidant activities (DPPH, ABTS, and FRAP), quercetin content, and the concentration of typical coriander aroma, 2-tridecenal, 2-dodecenal, (E), and Z-9-19 hexadecenal on day 9. Coriander leaves exposed to blue LED light (2 h) and stored up to day 9 scored a higher acceptance level by the panellists. Thus, blue light LED treatment during post-harvest storage can be recommended to retain the antioxidant property of coriander leaves.

The effect of filtrated osmotic solutions based on chokeberry juice enriched with mint extract on volatile compounds in dried apples

AbstractThe main objective of the study is to assess the effect of filtration of osmotic solution on the selective penetration during osmotic dehydration and on the retention of volatile compounds, obtained from mint extracts, in apple cylinders cv. Champion after drying using different methods. For this purpose, osmotic dehydration in filtrated and nonfiltrated concentrated chokeberry juice with the addition of mint extract was performed. Then, the process was followed by convective drying, vacuum‐microwave drying, or combined drying methods. Physical properties were determined such as open, closed, total porosity, shrinkage, and water activity. SPME and GC/MS analyses were performed to assess the changes in carvone contribution in the osmotic solutions as well as apple cylinders. Statistical analysis of variance (ANOVA) was also presented. It was found that even though, filtration did not influence osmotic dehydration kinetics, it led to significantly (p &lt;.05) higher carvone contribution in dried material than in the case of nonfiltrated solutions. Convective drying was significantly (p &lt;.05) better in preserving carvone than other drying methods such as vacuum‐microwave drying and combined drying consisting of convective predrying and vacuum‐microwave finishing drying. Drying methods also affected physical parameters like open and closed porosities. Filtration did not influence drying kinetics but resulted in better retention of carvone in dried apples, especially when convective drying was applied.Practical ApplicationsThe study might be of special interest to food processing industry, as it presents new developments (filtration of osmotic solution) in osmotic dehydration that allow to achieve higher contents of volatile compounds (carvone) in dehydrated material after drying compared to conventional osmotic dehydration. The study shows how to work with complex osmotic solutions and obtain high quality dried materials. Obtained results demonstrate that filtration of concentrated juice used as osmotic solution can be applied to affect the selective penetration during osmotic dehydration. Addition of herbal extracts to the osmotic solution can further improve the chemical composition of the dried material and lead to higher contribution of volatile compounds. Osmotic dehydration followed by convective drying results in higher retention of carvone in comparison to other drying methods. The methods presented in the manuscript might be used to create other new compositions with high volatile concentration in the biological material after drying.

Impact of different FD-related drying methods on selected quality attributes and volatile compounds of rose flavored yogurt melts

Effects of three freeze drying methods including freeze-drying (FD), infrared pulse-spouted freeze-drying (IRPSFD), and microwave pulse-spouted freeze-drying (MPSFD) on physical properties (color, odor, texture, bulk density, and rehydration time), volatile compounds, bioactive compounds (total phenolics and anthocyanins), and antioxidant capacities of rose flavored yogurt melts are evaluated and discussed. FD samples possessed the shortest rehydration time (7.30 sec) and lowest bulk density (0.117 g/cm3). The color analysis showed the MPSFD sample was darker and had higher red coloration than FD and IRPSFD samples. From the PCA and LDA results, the odor of IRPSFD sample was closer to FD sample than MPSFD sample. FD and IRPSFD showed much better retention of volatile compounds in samples than MPSFD. Moreover, IRPSFD samples contributed better product quality over MPSFD and matched to FD samples. Results indicated that IRPSFD may provide an alternative technique for freeze dried rose flavored yogurt melts and many other foods with high-quality characteristics.

Retention of linalool and eugenol in hydrogels

SummaryTextural parameters of hydrogels prepared from hydrocolloids (guar gum or xanthan; 0.5 or 1% (w/w)) and disaccharides (sucrose and trehalose) were investigated after preparation and storage for 30 days. Volatile compounds (linalool or eugenol) were added to the hydrogels in order to investigate their behaviour in those systems and to determine whether there is correlation between textural parameters and their retention. Textural parameters that were evaluated were firmness, consistency, cohesiveness and index of viscosity. Regarding textural parameters, there was no significant difference between hydrogels prepared with 0.5% of hydrocolloids. With increase of the amount of added hydrocolloid, textural parameters increased and differences between sucrose‐ and trehalose‐containing hydrogels were observed. Hydrogels prepared with trehalose had lower values of textural parameters. Correlation between texture and retention of volatile compounds was not observed or it was very low.

Microencapsulation of cocoa liquor nanoemulsion with whey protein using spray drying to protection of volatile compounds and antioxidant capacity

The aim of this study was microencapsulated a nanoemulsion of cocoa liquor with whey protein by spray drying, and evaluate the effect of different inlet drying temperatures on the properties of microcapsules. The nanoemulsion showed a particle size of 202.13 nm, PdI of 0.424, and ζ-potential of −25.20 mV. The inlet drying temperature showed differences in physicochemical properties of microcapsules. Microcapsules presented good thermal stability and protection against the melting of cocoa liquor. Microcapsules obtained showed excellent yields of polyphenolic compounds (78–93%), and high retention of volatile compounds, especially of pyrazines. Greater microencapsulation yield of bioactive compounds and retention of volatile compounds was obtained at higher drying temperature (180 °C). Excellent stability of polyphenols content, antioxidant capacity, and volatile compounds of cocoa liquor were observed during storage of the microcapsules at different temperature conditions, indicating the feasibility of this powder for its incorporation into functional foods.

Induction of crystallization influences the retention of volatile compounds in freeze-dried marolo pulp

ABSTRACTThe effects of sucrose, maltodextrin, and ethanol as prefreezing treatments on the retention of volatile compounds in freeze-dried marolo pulp were evaluated. The volatile compounds were extracted using a solid-phase microextraction technique and investigated by gas chromatography combined with mass spectrometry. The transition temperatures, X-ray diffraction-derived microstructures, particle sizes, and scanning electron microscopy images were examined. The optimum inducer concentrations which produced typically amorphous structures were maltodextrin up to 60.0 g/L and lower ethanol and sucrose concentrations, which were optimized to achieve maximum retention of volatile substances compared with the original fruit pulp.

Cryo assisted spouted bed roasting of coffee beans

Abstract A process for roasting of coffee beans involving spouted bed roasting (SBR), followed by cryogenic cooling and grinding was developed. The temperature and time of roasting was 210 °C and 22 min. It was found that coffee subjected to SBR roasting followed by cryogenic cooling had greater impact on the retention of volatile compounds especially the furans and thiols than the conventional drum roasting (CDR). The dehydration, the zero and first order color degradation rate constants for cryo treated SBR coffee beans were found to be 0.079, 1.9 and 0.04488 respectively where as for CDR coffee beans it was 0.03942, 1.398 and 0.030 correspondingly. The sensory analysis confirmed that proposed roasting method was beneficial for the retention of volatile flavor compounds and reduction of the burning of surface, and will be very useful for coffee processing in order to produce high quality coffee beans and increase its economic value. Industrial relevance Pyrolytic reactions lead to characteristic aroma and flavor during coffee roasting. Optimizing and controlling the roasting parameters is critical for coffee quality. Coffee roasting process involving spouted bed and cryogenic cooling was developed. Proposed roasting produces high quality coffee beans leading to its improved economic importance.

Cluster ion formation during sputtering processes: a complementary investigation by ToF-SIMS and plasma ion mass spectrometry

Plasma ion mass spectrometry using a plasma process monitor (PPM) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) have been complementarily employed to investigate the sputtering and ion formation processes of Al-doped zinc oxide. By comparing the mass spectra, insights on ion formation and relative cross-sections have been obtained: positive ions as measured during magnetron sputtering by PPM are originating from the plasma while those in SIMS start at the surface leading to large differences in the mass spectra. In contrast, negative ions originating at the surface will be accelerated through the plasma sheath. They arrive at the PPM after traversing the plasma nearly collisionless as seen from the rather similar spectra. Hence, it is possible to combine the high mass resolution of ToF-SIMS to obtain insight for separating cluster ions, e.g. Znx and ZnOy, and the energy resolution of PPM to find fragmentation patterns for negative ions. While the ion formation processes during both experiments can be assumed to be similar, differences may arise due to the lower volume probed by SIMS. In the latter case, there is a chance of small target inhomogeneities being able to be enhanced and lower surface temperatures leading to less outgassing and, thus, retention of volatile compounds.

Quality changes during spouted bed drying of Pepper‐Rosmarin extract

AbstractThis study was undertaken in order to evaluate the effects of processing and feed composition variables on the retention of volatile compounds and product properties during spouted bed drying of pepper‐rosmarin extract (Lippia sidoides Cham.). The product loss on drying, LD, moisture content, Xp, water activity, Aw, concentration of bioactive markers (flavonoid, TF, polyphenol, TPF and thymol contents, TT), antioxidant activity, IC50, powder flow properties, powder morphology and crystalline state were the responses analysed. Processing conditions and feed composition significantly affected the product quality, leading to noticeable changes in the retention of bioactive substances. Results of this study show that the concentration of bioactive markers in the dried product tended to increase with the feed flow rate of the feed composition relative to the maximum dryer evaporation capacity, Ws/Wmax, and conversely with the concentration of drying carriers added to the feed composition. The dried extract showed significant antioxidant activity, although significant losses of bioactive marker compounds (TF, TPF and TT) were observed in some processing conditions.

Microencapsulation by Spray Drying: Influence of Emulsion Size on the Retention of Volatile Compounds

ABSTRACT: The influence of the mean emulsion droplet size on flavor retention during spray drying was studied. d‐Limonene, ethyl butyrate, and ethyl propionate were used as the model flavors. Gum arabic, soybean water‐soluble polysaccharides, or modified starch blended with maltodextrin, were used as the wall materials. The increasing emulsion droplet decreased the retention of flavors. The distribution curve containing larger emulsion droplets shifted toward a smaller size after atomization, indicating that the larger emulsion droplets would be changed in size during atomization and result in decreasing flavor retention. For ethyl butyrate and ethyl propionate, the retention had a maximum at the mean emulsion diameter of 1.5 to 2 and 2.5 to 3.5 μm, respectively.

The Retention of Volatile Flavors in Food

Volatile flavor compounds are often retained in the dried carbohydrates in quantities greaterthan expected on the basis of vapor pressure characteristics. In an effort to elucidate the mechanism of this phenomena, the retention of volatile compounds in the model system was studied. The systems consisted of quartic mixture of water, organic volatile, glycerol and carbohydrate. The volatile content after freeze-drying was measured gas-chromatographically by extracting the dried material with 0.5ml of absolute methanol and injecting a 1.0μl sample.The retention of volatiles was influenced by a number of factors, including the relative volatility of each volatile compound and its diffusion coefficient. Sucrose or maltose solution retained larger quantities of volatiles than the solution of polysaccharide. The volatiles retained were; 26-45% of ethyl-n-butyrate and 65-87% of alcohols in the quartic mixture. The observed volatile retentions indicated that the formations of micellar colloid and microregion for entrapping volatiles are much more important than the equilibrium of gas-liquid or diffusion consideration of the volatile.

Retention of volatile compounds in freeze‐drying slabs of malto‐dextrin

SummaryA study was made of the effect of a number of process variables on the retention of some volatile compounds during freeze‐drying of ‘model’liquid foods. As a model liquid food, aqueous solutions of malto‐dextrin were chosen. To these solutions acetone, methanol, n‐propanol and n‐pentanol were added in low concentrations.The retention of volatiles strongly increased with increasing molecular size of the volatiles but was independent of the relative volatility. For constant dissolved solids concentration and constant temperature at the sublimation front in drying slabs or granules, process conditions leading to a maximum drying rate always resulted in maximum volatile retention. Retention increased with decreasing freezing rate when solids concentration, sublimation front temperature, and drying rate were constant. Retention always increased with decreasing temperature of the sublimation front. In drying granules, retention exhibited a maximum with respect to particle diameter, and increased with decreasing layer thickness. In the dissolved solids concentration range between 5 and 20% (w/w) the retention strongly increased with increasing concentration, whereas above 20% the retention became independent of initial solids concentration.The observed effects of process variables on volatile retention can be explained qualitatively with the selective diffusivity concept.