Volatile Aroma Research Articles

Descriptive temporal sensory properties and volatile composition of Pinot noir wines produced with contrasting alcoholic fermentation temperatures and cap management regimes

Pinot noir is rapidly becoming a winemaking staple in the Central Coast of California. Therefore, it is important to understand how factors such as fermentation temperature and cap management affect the chemical and sensory impact of such wines. Herein, Pinot noir wines were made with three contrasting alcoholic fermentation temperature regimes (Cold, Cold/Hot, Hot) and combined factorially with two cap management regimes (with or without punch downs). The impact of these factors on colour, aroma, and the temporal retronasal aroma and mouthfeel profile was assessed by a trained sensory panel (n = 13) using descriptive analysis (DA) and time-intensity (TI), respectively. Combining a hot fermentation temperature and no punch downs led to wines with higher colour saturation and purple hue. In contrast, wines fermented at cold fermentation temperatures with no punch downs showed reduction aromas. In terms of individual main effects, wines fermented at cold temperatures had more orthonasal aroma, while wines fermented at hot temperatures had higher astringency. To understand the relationship between selected volatile aromas and perceived sensory results, a partial least square regression (PLSR) was conducted. PLSR indicated that cold fermentation temperature wines with punch downs were associated with esters, including ethyl hexanoate and ethyl heptanoate, as well as β-damascenone, which aligned with sensory results. The effect of salivary flow rate on the temporal sensory profile post-expectoration was also analysed. Low salivary flow rate panellists perceived both astringency and length significantly later and more intensely than high salivary flow rate panellists. However, the time of maximum intensity was perceived significantly later for high salivary flow rate panellists. Overall, fermentation temperature had a more significant impact on the sensory and volatile composition of Pinot noir wines than the cap management regime. However, cap management still appeared to affect sensory and volatile chemistry results through significant interactions. Therefore, the relationship between fermentation temperature and cap management was not straightforward from avolatile chemistry or sensory perspective. The importance of accounting for salivary flow rate in panellists when using time-based sensory analysis was also highlighted.

GC-MS, GC-IMS, and E-Nose Analysis of Volatile Aroma Compounds in Wet-Marinated Fermented Golden Pomfret Prepared Using Different Cooking Methods.

The cooking method is extremely important for the production of low-salt, wet-marinated, fermented golden pomfret because it strongly influences its flavor components and organoleptic quality. There are also significant differences in flavor preferences in different populations. The present study analyzed differences in the aroma characteristics of wet-marinated fermented golden pomfret after boiling, steaming, microwaving, air-frying, and baking using a combination of an electronic nose, GC-IMS, and SPME-GC-MS. Electronic nose PCA showed that the flavors of the boiled (A), steamed (B), and microwaved (C) treatment groups were similar, and the flavors of the baking (D) and air-frying (E) groups were similar. A total of 72 flavor compounds were detected in the GC-IMS analysis, and the comparative analysis of the cooked wet-marinated and fermented golden pomfret yielded a greater abundance of flavor compounds. SPME-GC-MS analysis detected 108 flavor compounds, and the results were similar for baking and air-frying. Twelve key flavor substances, including hexanal, isovaleraldehyde, and (E)-2-dodecenal, were identified by orthogonal partial least-squares discriminant analysis (OPLS-DA) and VIP analysis. These results showed that the cooking method could be a key factor in the flavor distribution of wet-marinated fermented golden pomfret, and consumers can choose the appropriate cooking method accordingly. The results can provide theoretical guidance for the more effective processing of fish products and the development of subsequent food products.

Characterisation of flavour profiles and microbial communities of fermented peppers with different fermentation years by combining flavouromics and metagenomics

The changes in flavours, volatile aromas and microbial communities of fermented peppers with different fermentation years and their relationships were investigated in this study. Results indicated a gradual increase in organic acids during fermentation, whereas free amino acids and capsaicinoids reached stability after 1 year of fermentation. Overall, the analysis detected 340 volatile compounds in fermented peppers and regarded 69 of them as differential compounds. Peppers fermented for 2 (FY2) and 4 years (FY4) possessed a greater number of differential volatiles with large odour activity values, thus endowing them with more favourable flavours. Hence, metagenomic analysis compared their microbial communities and functional annotations. Results revealed that Lactiplantibacillus plantarum and Zygosaccharomyces rouxii were the dominant bacterium and fungus, and metabolism was the main Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway in FY2. Correlation analysis demonstrated that Hyphopichia, Kazachstania and Clavispora were highly positively correlated with 12 key aroma flavours.

Preparation of tobacco pyrolysis liquids in subcritical/supercritical ethanol and their application in the aroma enhancement of heated cigarettes.

For the aroma enhancement research of heated cigarettes, it is worth exploring whether tobacco can be pyrolyzed into pyrolysis liquids containing a large number of volatile aroma components. In this study, tobacco pyrolysis liquids were prepared in subcritical/supercritical ethanol, and their applications in the aroma enhancement of heated cigarettes were investigated. The optimal conditions of supercritical liquefaction reactions were determined by optimizing the reaction time, liquid/solid mass ratio and temperature conditions. Moreover, the effect of supercritical liquefaction conditions on volatile aroma components in tobacco pyrolysis liquids was investigated by GC-MS. The results indicated that the reaction temperature had the most significant impact on the tobacco pyrolysis reaction, and higher reaction temperature promoted the pyrolysis conversion of tobacco, resulting in enhanced tobacco conversion and a high content of volatile components in the tobacco pyrolysis liquid. The optimal reaction conditions for the preparation of tobacco pyrolysis liquid were found to be a temperature of 220°C, a liquid/solid mass ratio = 15, and a 2-h reaction time. Meanwhile, the content of ester compounds and nicotine in the tobacco pyrolysis liquid increased significantly with the increase of reaction temperature. Sub/supercritical ethanol treatment significantly destroyed the surface structure of tobacco, and the degree of tobacco depolymerization increased when temperature rised. The analysis of aroma compounds in the smoke of heated cigarettes indicated that the tobacco pyrolysis liquid could significantly increase the release of aromatic substances and has a significant aroma-enhancing effect. This article proposed and prepared tobacco pyrolysis liquid in subcritical/supercritical ethanol and explored its potential application in the aroma enhancement of heated cigarettes, offering a new route for flavor enhancement technology for this type of product.

Unraveling the Formation Mechanism of Egg's Unique Flavor via Flavoromics and Lipidomics.

Egg products after thermal treatment possess a unique flavor and are favored by consumers. In this study, the key aroma-active compounds of egg yolk products and their formation mechanism during thermal treatment were investigated. The volatile aroma compounds in egg yolks were monitored using an electronic nose, gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry-mass spectrometry (GC-O-MS), and the lipid molecular species were explored using ultra-high-performance liquid chromatography- mass spectrometry with a Q-Exactive HF-X Orbitrap (UPLC-Q-Exactive HF-X). A total of 68 volatile compounds were identified. Boiled eggs mainly derived their flavor from hexanal, 2-pentyl-furan, 2-butanone, 3-methyl-butanal and heptane. Meanwhile, fried eggs relied mainly on 14 compounds, the most important of which were 2-ethyl-3-methyl-pyrazine, 3-ethyl-2,5-dimethyl-pyrazine, 2-ethyl-3,5-dimethyl-pyrazine, nonanal and 2,3-diethyl-5-methyl-pyrazine, providing a baked and burnt sugar flavor. A total of 201 lipid molecules, belonging to 21 lipid subclasses, were identified in egg yolks, and 13 oxidized lipids were characterized using a molecular network. Phosphoethanolamines (PEs) containing polyunsaturated fatty acids were the primary flavor precursors contributing to the development of egg yolks' flavor, participating in lipid oxidation reactions and the Maillard reaction and regulating the production of aldehydes and pyrazine compounds. This study provides reference and guidance for the development of egg yolk flavor products.

Metabolomics of Red Wines Aged Traditionally, with Chips or Staves.

Traditionally and alternatively aged wines' odour activity values (OAVs) are investigated to differentiate and highlight the differences between the selected methods. An analysis of the volatile aroma compounds of wines derived from ageing in barrels, oak chips, and staves was performed using stir bar sorptive extraction chromatography-mass spectroscopy (SBSE-GC-MS). The results showed that alcohols, esters, and oak compounds were the main contributors to aroma, and their OAVs were higher in the stave samples after 3 months than in the samples from the other two systems of ageing. Furthermore, wines aged with staves have stronger fruity, spiced, and woody aromas, while samples aged in barrels present more chemistry-driven, floral, caramelly, and creamy aromas. The staves-medium plus toast (SMPT at 3 months > 225) and chips-medium plus toast (CMPT at 3 months > 170) showed the highest levels of aromatic series, suggesting that alternative systems provided more powerful aromas than traditional systems, such as barrels-medium plus toast (BMPT at 3 months > 150). A principal component analysis (PCA), orthogonal partial least squares (OPLS) analysis, and cluster analysis allowed for a clear differentiation to be made between red wines according to ageing systems and ageing times. The odour activity values fingerprint in winemaking is a feasible approach to characterise and distinguish wines. Moreover, OAVs provide important information on the effects of production methods on wine quality and aroma profile.

The effects of different rootstocks on aroma components, activities and genes expression of aroma-related enzymes in oriental melon fruit.

Grafting is widely applied in the cultivation of melon. In this study, 'Qinmi No.1' (Cucumis melo L.(QG)) and 'Ribenxuesong' (Cucurbita maxima Duch. (RG)) were used as rootstocks for 'Qingxin Yangjiaocui' (Cucumis melo L.). The results showed that grafting with muskmelon rootstocks had no significant effect on fruit aroma, but grafting with pumpkin rootstocks significantly reduced the odor intensity and odor preference scores of melon fruits. Compared with the fruits from self-grafted plants (SG), four new aromatic volatiles with a sweet smell were detected, the alcohol dehydrogenase (ADH) activity was significantly decreased at 30 DAP, but unaffected at 42 DAP in QG fruits. There was no difference for alcohol acetyltransferase (AAT) activity between QG and SG fruits. The expression level of CmADH2 was significantly higher at 30 DAP and 42 DAP, but CmAAT2 was significantly lower at 42 DAP in QG fruits compared with SG fruits. In RG fruits, the main aroma compounds including butanoic acid ethyl ester, 2-methyl-2-butene-1-al, and 2-methylheptan-1-al were absent, while the volatile compounds with unpleasant odor characteristics including trans, cis-2,6-nonadien-1-ol, (E,E)-2,4-heptadienal, octanoic acid, and styrene were detected. Compared with SG fruits, 1-nonanol and 1-heptanol with green odor characteristics were significantly increased, but eucalyptol and farnesene with fruity aroma characteristics were significantly decreased in RG fruits. The ADH activity of RG fruits was significantly lower than that of SG fruits at 30 DAP and the AAT activity was significantly lower than that of SG fruits at 42 DAP. In addition, the expression levels of CmADH and CmAAT homologs in RG fruits were significantly lower than those in SG or QG fruits. These results show that grafting with pumpkin rootstocks affected the main aroma components, reduced ADH and AAT activities, and down-regulated the expression levels of CmADHs and CmAATs in the melon fruits. This study reveals the mechanism of different rootstocks on melon fruit aroma quality, and lays a theoretical foundation for the selection of rootstocks in melon production. Future studies using overexpression or CRISPR/CAS system to obtain stable transgenic lines of genes encoding key aromatic volatiles, would be promising to effectively improve the flavor quality of melon.

Characterization of Volatile Organic Compounds and Aroma Sensory Properties in Yunnan Cigar.

To characterize volatile organic compounds (VOCs) and aromatic sensory properties in Yun cigar, 27 samples from four origins were analyzed using SPME-HS-GC/MS and sensory analysis. The investigation results were analyzed using principal component analysis (PCA), Fisher linear discriminant analysis (LDA), and Pearson correlation analysis. In Yunnan cigars, the content of nicotine and neophytadiene accounted for over 90% of the total VOC content. Nicotine was significantly positively correlated with neophytadiene and phytol. The cigars from four origins were clearly classified by the PCA of VOCs. Four region discrimination functions were established through the LDA of 14 compounds, and the validation accuracy was 100%. The sensory descriptors with the highest geometric mean were woody, roasted, fresh-sweet, bean, and scorched. Acetophenone, megastigmatrienone A, and thunbergene were positively correlated with multiple aroma descriptors, while nicotine was negatively correlated with multiple aroma descriptors.

Carotenoid, Tocopherol, and Volatile Aroma Compounds in Eight Sacha Inchi Seed (Plukenetia volubilis L.) Oil Accessions.

Sacha inchi seed oil is a food matrix rich in bioactive constituents, mainly polyunsaturated fatty acids. In this study, the characteristics of color, carotenoid content, tocopherols, and volatile aroma compounds in eight sacha inchi seed (Plukenetia volubilis L.) oil accessions were evaluated. Results showed that the oil obtained from the accessions presented a lightness and chroma of 91 to 98 units and 6 to 10 units respectively, while the hue angle ranged between 93 to 97 units. The total carotenoid content in the different accessions ranged from 0.6 to 1.5 mg/kg, while γ- and δ-tocopherol ranged from 861.6 to 1142 mg/kg and 587 to 717.1 mg/kg. In addition, the total content of tocopherols varied between 1450 and 1856 mg/kg and the δ/γ ratio ranged between 0.58 and 0.70. The oils from the accessions PER000408 (861 µg/kg) and PER000411 (896 µg/kg) were those with the higher volatile concentration, especially 1-hepten-3-ol, 2-nonanol, (E)-3-hexen- 1-ol, (E)-2-hexenal, and 1-hexanol. In this study, the variability of the oil obtained from 8 accessions were observed, from which promising accessions can be selected for continuous investigations of the new sacha inchi seed genotypes.

Headspace volatiles profiles of different spring varieties and a wild relative of wheat flour.

Volatile profiling was conducted on four wheat varieties Triticum aestivum cv. Chinese Spring (CS), Highbury (High), Paragon (Para), Pavon76 (Pav76), and one wild relative Triticum timopheevii (P95). Headspace solid-phase microextraction (SPME) combined with gas chromatography-mass spectrometry (GC-MS) was used to explore differences in flavor formation mechanisms in different flours before and after starch gelatinization. Solvent retention capacity (SRC) analysis revealed subtle differences in water absorption, gluten strength, and starch characteristics across wheat flour types. Rapid Visco Analysis (RVA) of whole wheat flour demonstrated significant variations in pasting properties among wheat varieties, with P95 exhibiting higher viscosities compared to CS and High potentially influenced by starch gelatinization, protein-starch interactions, and lipid content. Aroma contributions of P95 clustered positively in PCA plots, contrasting with the four main varieties, indicative of species-level differentiation. Furthermore, the study highlighted the roles of viscosity, protein structure, lipid content, and fatty acid composition in modulating the release and perception of volatile aroma compounds during heating. This study sheds light on how the distinct characteristics of wheat flour influence aroma profiles, revealing species-level differences and the pivotal role of physiochemical properties in shaping flavor development mechanisms.

The impact of fangxian huangjiu on the fermentation quality and microbial community dynamics of cigar wrapper leaves.

Introduction: Cigar wrapper leaves (CWLs) plays a crucial role in reflecting cigar overall quality. Originating from the Qinba region of China, Fangxian Huangjiu (FHJ) is distinctive from other varieties of Huangjiu. Methods: To investigate the effects of FHJ on enhancing the aroma and quality of CWLs, as well as the consequent alterations in microbial communities, Gas Chromatography-Mass Spectrometry (GC-MS) coupled with Odor Active Value (OAV) analysis was utilized to evaluate the volatile aroma components of CWLs. Results and Discussion: The results indicated that the total amount of aroma compounds in CWLs reached 3,086.88ug/g, increasing of 270.50% and 166.31% compared to the unfermented and naturally fermented groups, respectively. Among them, β-ionone and 4,7,9-megastigmatrien-3-one from the FHJ fermentation group significantly influenced the sensory characteristics of CWLs. Metagenomic results demonstrated that FHJ fermentation enriched the abundance of both shared and unique microbial species in CWLs, while also increased the diversity of differential microbial species. Addition of FHJ effectively altered the microbial community structure of CWLs from a dominance of Staphylococcus to a prevalence of Staphylococcus, Aspergillus, Pseudomonas, and Acinetobacter. The interactions among these diverse microorganisms collectively contribute to the enhancement of the intrinsic quality of CWLs. This paper provides a theoretical basis for improving the quality of CWLs by FHJ and exploring the changes of microbial community structure and interaction between CWLs and FHJ.

The Physicochemical, Textural, Microbiological and Sensory Properties of Skimmed Buffalo Milk Yoghurt with Tragacanth Gum During Storage.

In the food industry, research interest in the functional effects of natural polysaccharides from plants has increased in recent years. Tragacanth gum is used in dairy products because of its stabilising, thickening, fat-replacing and prebiotic properties. However, skimmed milk is considered a significant commercial loss in the production of buffalo clotted cream. Therefore, the aim of the present study is to investigate the potential of tragacanth gum in the production of yoghurt from buffalo milk residues with different concentrations of tragacanth gum (0.5, 1 and 1.5 g/L). Skimmed buffalo milk with different concentrations of tragacanth gum was pasteurised and, after cooling at 45 °C, a starter culture was added to each sample. All samples were fermented to a pH=4.80±0.2. The gross composition, acidity, water activity, water-holding capacity, whey separation, mass fractions of organic acids and volatile aroma compounds, counts of total aerobic mesophilic bacteria, yeasts and moulds, Lactococcus spp. and Lactobacillus spp. as well as sensory and textural properties were analysed during 15 days storage. The results showed that the use of tragacanth gum increased the dry matter mass fraction, water-holding capacity and mass fraction of proteins in the samples, while whey separation decreased as the concentration of gum increased. The addition of gum improved textural properties and hardness of the yoghurt. In terms of consistency, the sample with 1 g/L tragacanth gum was the most reliable. In the control group, the total aerobic mesophilic bacteria count was highest on the first and last day of storage. According to the results of the sensory evaluation, the sample with 0.5 g/L tragacanth gum was the most favourable. Research has shown that the use of stabilisers in varying ratios improves the quality of yoghurt made from fat-free buffalo milk, which is a by-product of industrial production. So instead of ending up as industrial waste, it is recycled and its value is increased.

How to Increase Students' Global Diversity Character: Study of the Influence of Ethno-STEM-Integrated Project Learning Model on Indonesian Tea Aroma Volatile Compounds

How to Increase Students' Global Diversity Character: Study of the Influence of Ethno-STEM-Integrated Project Learning Model on Indonesian Tea Aroma Volatile Compounds

Intercalated kaolinite with ammonium dihydrogen phosphate as an effective flame retardant to enhance the flame retardance and smoke suppression of epoxy resins

AbstractTo improve the compatibility and flame retardance of kaolinite (Kaol) in polymeric materials, ammonium dihydrogen phosphate (ADP) was intercalated into kaolinite to obtain a novel intercalated kaolinite (K‐ADP) for enhancing thermal stability, flame retardance, smoke suppression, and mechanical performance of epoxy resins (EPs). The results show that the presence of K‐ADP exerts a more positive effect on reducing the heat release and smoke generation of EPs than the same addition of Kaol. Condensed phase analysis shows that EP/K‐ADP composite generates more aromatic cross‐links in the condensed phase to reinforce the compactness and intumescence of char compared to EP/Kaol composite. Especially, 5 wt% K‐ADP confers a 43.7% reduction in peak heat release rate value and a 36.3% reduction in peak smoke production rate value to EP. Toxic gases analysis shows that K‐ADP conduces to inhibiting the release of combustible gases including isocyanates and aromatic volatiles, and generating incombustible gases including ammonia and carbon dioxide to reduce the intensity of EP combustion. The mechanical test shows that K‐ADP imparts less adverse impact on mechanical behavior to EP composites than Kaol due to the good dispersion and compatibility between K‐ADP with EP matrix.

Partial dealcoholization of a Malbec wine through pervaporation with a PDMS membrane: Effect of operation temperature on process economics, volatile aroma composition and sensory properties

In the present work, partial dealcoholization of a Malbec red wine with 14.8% v/v alcohol by pervaporation through a PDMS membrane (polydimethylsiloxane) was addressed. The influence of the process temperature on the economy of the process, the composition of volatile aroma compounds and wine sensory characteristics was deeply analyzed.To do so, partial dealcoholization experiments at lab scale were run with the pervaporation setup operated at a permeate pressure of 0.013 bar and at three different temperatures; i.e. 35, 40 and 45 °C. Two types of runs were carried out: (i) simple runs to build a conceptual model of the process and (ii) repetitions to accumulate an adequate volume of partially dealcoholized wine (10.5%v/v) to allow the sensory analysis of the following Malbec wines: the initial wine, the partially dealcoholized wines and the blends in a 70/30 ratio (13.5% v/v)).From the conceptual modeling stage the required value of the fractional pervaporation advance ηreq of 0.09 was obtained, as well as the average values of permeate overall fluxes at 35, 40 and 45 °C; i.e., 1.02, 1.38 and 1.82 kg m−2 h−1, respectively. For all variants, a permeate product with an alcohol content of 54% v/v was estimated. Experimental values agreed reasonably well with those obtained from the model simulation.The conceptual modeling of the process enabled the scaling-up of the process and the subsequent economic analysis. The best figures corresponded to the design with heat integration at 45 °C when earnings estimated from the sale of the ethanol-rich permeate to the local market was taken into account.Fresh Malbec, partially dealcoholized wines at the selected temperatures, and their corresponding blends were chemical and sensory characterized. Dealcoholized wines showed differences concerning the operating temperature on the volatile and total acidity, fructose, anthocyanins, tannins, total polymers, and CIELAB parameters, except lightness. The total and volatile acidity were affected by the temperature and showed an increase in dealcoholized and blended wines with the respective decrease of the pH. Dealcoholization favored the presence of large polymeric pigments (0.6 in initial wines and an average of 0.96 in blends), which are associated positively with color stability.Volatiles were also affected by the operating temperature, decreasing the concentration of all chemical groups in these wines. A total of thirty-two free volatile organic compounds (VOCs) including higher alcohols (HA), medium chain fatty acid ethyl esters (MCFAEE), higher alcohol acetates (HAA), medium chain fatty acids (MCFA), norisoprenoids (NI) and terpenoids (TP) were identified and quantified.Finally, sensory evaluation demonstrated that partially dealcoholized wines could not be differentiated by the operation temperature. The fullness, astringency, pungency, floral notes, bitterness, color intensity, and sweetness were significant variables that allowed differentiate between initial, partially dealcoholized, and blend wines. Despite the loss of volatile compounds, blended wines showed higher intensity of floral attributes, and in mouth were lesser astringent, bitter, and pungent than the fresh wine.From an overall perspective, pervaporation of fresh wine with a PDMS membrane at 45 °C and the adoption of a dilution ratio of 70/30 for initial wine to partially dealcoholized wine result in a promising strategy to reduce the alcohol content without affecting the sensory quality of the final red wine.

Harvest maturity stage affects watercore dissipation and postharvest quality deterioration of watercore 'Fuji' apples

Watercore 'Fuji' apples, with their special watercore shape and unique flavor and texture, are a very popular specialty fruit in the Asian markets. However, watercore disappearance and quality deterioration of apples during postharvest storage are serious problems. In this study, we compared the differences among three harvest maturity stages of apples in watercore dissipation and fruit quality deterioration. In this study, the physiochemical attributes (visual quality, watercore incidence, and firmness), flavor substances (TSS content, TA content, and TSS/TA), aroma volatiles, and cellular structure were analyzed in 'Fuji' apple fruits of low maturity (LM) at early harvest stage, medium maturity (MM) at mid harvest stage, and high maturity (HM) at late harvest stage, during a cold storage at 0 ± 1 °C for 120 d. The results showed that harvest maturity stage had a significant effect on postharvest storage quality parameters of watercore 'Fuji' apples. Specifically, L*, b*, firmness, and TA values of the flesh decreased significantly from the LM to the HM levels. However, the watercore incidence of apples significantly increased from LM to HM levels. Moreover, the parameters including L*, b*, firmenss, TA, and watercore incidence of apples with different harvest maturity stages gradually decreased as the storage time increased. In contrast, the TSS, TSS/TA, and a* values showed an increasing trend from LM to HM apples. In particular, the TSS tended to increase first and decrease after 60 d of storage. Moreover, the microstructure and cellular structure gradually deformed as the structural porosity and cell size decreased from LM to HM apples. Furthermore, the microstructure of the watercore and non-watercore sites is significantly different. Meanwhile, the content of soluble sugars and aroma volatiles increased with the advancing maturity. Non-watercore sites of apples with the same level of maturity contained higher levels of sucrose, fructose, maltose, and sorbitol than watercore sites. Furthermore, the MM apples maintained better sensory qualities during the shelf life after cold storage. Overall, the MM apples showed higher quality and were more acceptable to consumers, which suggested watercore 'Fuji' apples from mid harvest stage showed the optimal harvest-ready maturity for post-harvest long-term cold storage.

Nitric oxide fumigation can affect the metabolism of volatile compounds derived from analyses of fatty acids and amino acids in post-harvest flat peach during cold storage

The loss of aroma volatiles can significantly reduce the economic value of postharvest flat peach during cold storage. In this study, the mechanism of NO fumigation regulating the aroma volatiles during cold storage at 1 ± 0.5 °C was investigated. The possible effects of NO on storage quality, VOCs, enzyme activity related to the fatty acid metabolism pathway, and the level of fatty acids and amino acids in fruit were analyzed. The results indicated that treatment with 10 μL L−1 NO maintained higher VC, firmness, SSC, TA, and restrained increase of MDA as well as the rotting rate. 10 μL L−1 NO treatment significantly supported a higher abundance of aldehydes before day 18 and encouraged the production of esters after day 18 of fruit under cold storage, which was associated with higher activity of ADH, AAT, HPL and LOX after day 18.10 μL L−1 NO treatment led to higher content of unsaturated acids, including OA, LA before day 18 and maintained higher content of LeA during the whole cold storage. According to these findings, 10 μL L−1 NO treatment may be a viable strategy to preserve the main aromatic volatiles and extend the shelf life of flat peaches.

Effect of Apple Cultivar and Selected Technological Treatments on the Quality of Apple Distillate.

Apple producers are looking for new markets to dispose of their harvest surpluses. One of the solutions may be the production of apple spirits by small distilleries. This study aimed to evaluate the influence of apple cultivars and technological treatments, i.e., pasteurization, depectinization, and deacidification, on the fermentation efficiency and quality of the distillates. Samples for fermentation were prepared from Polish apple cultivars (Antonówka, Delikates, Kosztela, Kronselska). The control samples were raw pulp-based samples. After fermentation, the samples were analyzed for ethanol, residual sugars, and by-product content by the HPLC technique. The distillates were tested for volatile compounds by the GC-MS method and their sensory evaluation was performed. Raw pulp-based samples, independent of the apple cultivar, showed fermentation efficiencies between (75.77 ± 4.69)% and (81.36 ± 4.69)% of the theoretical yield. Depectinization of apple pulp prior to fermentation resulted in the highest ethanol concentration and yield up to approximately 89%. All tested apple distillates were rich in volatile aroma compounds and met the requirements of the EU regulation for hydrogen cyanide content. The obtained results indicate that the tested apple cultivars can be used for the efficient production of apple spirits, providing producers with an opportunity for brand development.

The effect of freeze-drying process and arabica coffee enrichment on bioactive content, aroma volatile, and sensory characteristics of date seed coffee

This study investigated the transformative effects of incorporating Arabica coffee as a natural additive to improve the overall quality and the sensory properties of date seed coffee. Furthermore, the impact of the freeze-drying process was assessed to provide scientific proof of the marketability of this new product. The enrichment of arabica coffee in the (C + DS) sample led to a higher extractable yield, phenolic content, and consequently a higher antioxidant capacity compared to decaffeinated date seed coffee (DS). (C + DS) coffee showed a volatile profile similar to Arabica coffee (C). It is characterized by an abundance of pyrazines, ketones, and furans and a greater number of potent odorants than (DS) coffee, giving a positive note to the drink. Furthermore, the freeze-dried coffees (C-L) released the highest number of volatile compounds. The perception of coffee was investigated throughout the sensory analysis, which confirmed that evaluators accepted the coffee mixture both before and after freeze drying.

Gelatin-serum plasma film incorporated with curcumin for improvement of antioxidant and antibacterial properties for fresh pork packaging application

In this study, a novel active packaging film based on gelatin and serum plasma (GT/SM) with varying amounts of curcumin (CUR) was prepared. Curcumin, a strong antibacterial and antioxidant agent, was incorporated into the film to investigate its efficacy on physical/structural characteristics and bacterial inhibition in packaged pork. The results demonstrated significant enhancements in tensile strength (43.95–61.99 MPa), elongation at break (49.46–73.31%), swelling capacity (49.57–68.82%), solubility index (40.80–59.82%), and moisture content (13.85–16.37%). The films exhibited improved opacity (2.70–14.85 mm−1) and water vapor barrier characteristics (5.20–1.46 × 10−11 g−1 s −1 Pa−1). The antioxidant and antibacterial capacities were also increased, exhibiting enhanced preservation potential for fresh pork. Curcumin was uniformly distributed throughout the GT/SM matrix, according to scanning electron microscopy (SEM) results. Using solid-phase microextraction gas chromatography-mass spectrometry (SPME-GC-MS), over 55 volatile aroma components were identified in fresh pork loin, including ketones, acids, alcohols, hydrocarbons, aldehydes, and esters. This study offers a novel strategy for active packaging that extends the shelf life of fresh pork loins while ensuring the safety and quality of food.