Search Results (1,062)

In this study, in order to verify the effects due to the addition of spirulina (Arthrospira platensis) in a food product, a wildflower honey was analyzed in terms of chemical composition, physicochemical properties and antioxidant activity before and after the addition of the spirulina. HS-SPME/GC–MS and HPLC/UV were applied to carry out the chemical analyses. The obtained results demonstrated that the volatile profile and also the sugar content were significantly influenced by the addition of spirulina, showing significant qualitative and quantitative differences compared to honey without spirulina. The increase in HMF in honey added with spirulina was significant, demonstrating that its presence could accelerate the Maillard reaction. Electrical conductivity measured by using a conductometer was also increased while the moisture content was reduced in honey enriched with spirulina. Instead, the pH value was similar between the two samples. On the other hand, honey fortification with spirulina determined a significant increase of 12.5% in the total phenolic content (TPC), and a 56.25% increase in protein content. Further, the total antioxidant capacity (TAC) was also evaluated and a significant increase was determined as a result of the addition of spirulina. In conclusion, honey enriched with A. platensis was found to be characterized by a high pool of bioactive metabolites as well as significant changes in almost all the measurements performed. Full article

Rosa roxburghii (R. roxburghii), native to the southwest provinces of China, is a fruit crop of important economic value in Guizhou Province. However, the changes in fruit quality and flavor during R. roxburghii fruit ripening have remained unknown. Here, this study investigated the changes of seven active components and volatile organic compounds (VOCs) during the ripening of the R. roxburghii fruit at five different ripening stages including 45, 65, 75, 90, and 105 days after anthesis. The results indicated that during the ripening process, the levels of total acid, vitamin C, and soluble sugar significantly increased (p < 0.05), while the levels of total flavonoids, superoxide dismutase (SOD), and soluble tannin significantly decreased (p < 0.05). Additionally, the content of total phenol exhibited a trend of first decreasing significantly and then increasing significantly (p < 0.05). A total of 145 VOCs were detected by HS-SPME-GC-MS at five mature stages, primarily consisting of aldehydes, alcohols, esters, and alkenes. As R. roxburghii matured, both the diversity and total quantity of VOCs in the fruit increased, with a notable rise in the contents of acids, ketones, and alkenes. By calculating the ROAV values of these VOCs, 53 key substances were identified, which included aromas such as fruit, citrus, green, caramel, grass, flower, sweet, soap, wood, and fat notes. The aromas of citrus, caramel, sweet, and wood were predominantly concentrated in the later stages of R. roxburghii fruit ripening. Cluster heatmap analysis revealed distinct distribution patterns of VOCs across five different maturity stages, serving as characteristic chemical fingerprints for each stage. Notably, stages IV and V were primarily characterized by a dominance of alkenes. OPLS-DA analysis categorized the ripening process of R. roxburghii fruit into three segments: the first segment encompassed the initial three stages (I, II, and III), the second segment corresponded to the fourth stage (IV), and the third segment pertained to the fifth stage (V). Following the variable importance in projection (VIP) > 1 criterion, a total of 30 key differential VOCs were identified across the five stages, predominantly comprising ester compounds, which significantly influenced the aroma profiles of R. roxburghii fruit. By integrating the VIP > 1 and ROAV > 1 criteria, 21 differential VOCs were further identified as key contributors to the aroma changes in R. roxburghii fruit during the ripening process. This study provided data on the changes in quality and aroma of R. roxburghii fruit during ripening and laid the foundation for the investigation of the mechanism of compound accumulation during ripening. Full article

The Jerez (Sherry) vinegars, including Vinagre de Jerez, Reserva, and Gran Reserva, are crafted from Sherry wines and are protected under the Denomination of Origin in Spain. The aim of this study was to (i) characterize the physicochemical properties and composition; (ii) investigate the impact of the aging process on color properties, phenolics, volatile compounds, and sensorial profiles; and (iii) find a marker for tracing the authenticity of non-aged (Apto) and aged Jerez vinegars. The phenolic components were identified through LC-MS/MS, whereas the volatile compounds were examined using the GC-MS/MS technique. As the aging progressed, a decrease was observed in the levels of flavonol and phenolic acids, with anthocyanin components being undetectable in non-aged and aged samples. In the Gran Reserva variety, 2-methylbutyl acetate, acetic acid, and ethanol emerged as the predominant volatile substances. The presence of oaklactone and ethyl butanoate components served as marker substances to authenticate the Gran Reserva. Additionally, alterations in color properties were noted, marked by a decrease in yellow content and an increase in the red component depending on aging. Furthermore, novel sensory descriptors, such as vanilla, clove, woody, and nutty notes, and winy character emerged in the samples with prolonged aging. Full article

Hazelnut oil cake (HOC) has the potential to be bioactive component source. Therefore, HOC was processed with a solid-state fermentation (SSF) by Aspergillus oryzae with two steps optimization: Plackett–Burman and Box–Behnken design. The variables were the initial moisture content (X₁: 30–50%), incubation temperature (X₂: 26–37 °C), and time (X₃: 3–5 days), and the response was total peptide content (TPC). The fermented HOC (FHOC) was darker with higher protein, oil, and ash but lower carbohydrate content than HOC. The FHOC had 6.1% more essential amino acid and benzaldehyde comprised 48.8% of determined volatile compounds. Fermentation provided 14 times higher TPC (462.37 mg tryptone/g) and higher phenolic content as 3.5, 48, and 7 times in aqueous, methanolic, and 80% aqueous methanolic extract in FHOC, respectively. FHOC showed higher antioxidant as ABTS⁺ (75.61 µmol Trolox/g), DPPH (14.09 µmol Trolox/g), and OH (265 mg ascorbic acid/g) radical scavenging, and α-glucosidase inhibition, whereas HOC had more angiotensin converting enzyme inhibition. HOC showed better water absorption while FHOC had better oil absorption activity. Both cakes had similar foaming and emulsifying activity; however, FHOC produced more stable foams and emulsions. SSF at lab-scale yielded more bioactive component with better functionality in FHOC. Full article

Botanical varieties of hemp differ in chemical composition, plant morphology, agronomy, and industrial suitability. Hemp is popular for cultivation for the production of cannabinoid oil, fiber production, biomass, etc. The fertilization process is one of the most important factors affecting the plant, both its condition and chemical composition. So far, research has been carried out proving that hemp is a valuable source of, among others: fatty acids, amino acids, acids, vitamins, numerous micro- and macroelements, and antioxidant compounds. In this experiment, it was decided to check the possibility of harvesting hemp panicles twice in one year. The purpose of this treatment is to use one plant to produce cannabidiol oil and grain. The main aim of the research was to determine bioactive compounds in hemp seeds and to determine whether the cultivation method affects their content and quantity. Based on the research conducted, it was observed that hemp can be grown in two directions at the same time and harvested twice because its health-promoting properties do not lose their value. It was found that regardless of whether hemp is grown solely for seeds or to obtain essential oils and then seeds, the type of fertilization does not affect the content of phenolic acids (e.g., syringic acid: 69.69–75.14 μg/100 g, vanillic acid: 1.47–1.63 μg/100 g). Based on the conducted research, it was found that essential oils can be obtained from one plant in the summer and seeds from Henola hemp cultivation in the autumn, because such a treatment does not affect the content of the discussed compounds. Full article

Phenolic compounds (PhCs) are aromatic compounds with benzene rings that have one or more hydroxyl groups. They are found or formed in the atmosphere due to various factors such as combustion processes, industrial emissions, oxidation of volatile organic compounds (VOCs), and other photochemical reactions. Due to properties such as relatively high Henry’s law constants and moderate/high water solubility, PhCs are vulnerable to reactions in atmospheric liquid phase conditions with high relative humidity, fog or cloudy conditions. PhCs can lead to the formation of secondary organic aerosols (SOAs), which can have negative effects on atmospheric conditions and human health. Changes in the optical properties of PhCs impact solar radiation absorption and scattering, potentially influencing climate. Additionally, PhCs may interact with other atmospheric constituents, potentially affecting cloud or fog formation and properties, which in turn can impact climate and precipitation patterns. Therefore, monitoring and controlling the emission of PhCs is essential. This paper discusses the transformation processes of PhCs in the atmosphere, including direct conversion of phenol, nitrate-induced and nitrite-induced reactions, hydroxylation reactions and oxidation processes involving triplet excited state organics, also providing a detailed analysis of the transformation processes. The findings lay a theoretical foundation for the future monitoring and control of atmospheric pollutants. Full article

This study aimed to explore the effects of coagulase-negative Staphylococcus inoculation on flavor generation and lipolysis-oxidation in Coppa. Acid lipase, neutral lipase, phospholipase, and lipoxygenase (LOX) activities, as well as free fatty acids, volatile compounds, and sensory evaluation, were determined during the fermentation and air-drying processes of Coppa over 40 days. Staphylococcus carnosus and Staphylococcus xylosus or a combination of both strains were selected for this study, and natural fermentation was treated as a control. The results showed that Staphylococcus inoculation significantly enhanced lipase and LOX activities, and mixed strains had a superior effect. Palmitic acid, stearic acid, linoleic acid, and oleic acid were identified as the predominant free fatty acids in Coppa, with the mixed fermentation group exhibiting the highest contents. Acids, aldehydes, alcohols, ketones, esters, and phenols were found for the volatile compounds in Coppa. These findings thus suggested a positive role of Staphylococcus inoculation in activating lipolysis-oxidation and contributing to the flavor formation of Coppa during the air-drying stage. Full article

The behavioural response of adult maize weevil, Sitophilus zeamais, to different types of semolina pasta enriched or not enriched with increasing proportions (5%, 10%, and 15%) of house cricket (Acheta domesticus) powder was investigated in olfactometer arena bioassays by using trap devices. In the five-choice behavioural bioassays, the number of S. zeamais adults attracted to 100% durum wheat semolina pasta was significantly higher than those attracted to the other pasta types enriched with A. domesticus powder. In the two-choice behavioural bioassays, the Response Index for each pasta type was positive and significant. However, although not significant, there was a progressive reduction in the Response Index as the cricket powder content increased. In similar experiments, there were no significant differences between cricket powder alone and the control in the number of attracted S. zeamais, indicating a neutral effect towards insects. These observations suggest that the lower attractiveness of pasta enriched with house cricket powder is mainly due to the masking of host food odours. Solid-phase microextraction coupled to gas chromatography–mass spectroscopy identified a total of 18 compounds in the head-space samples of the different types of pasta, highlighting differences in volatile composition. Some volatile compounds were only present in the pasta produced with cricket powder. In particular, 1-octen-3-ol and phenol were present in the samples containing 5%, 10%, or 15% cricket powder; pentanal, benzaldehyde, and dimethyl disulphide were present in samples containing 10% or 15% cricket powder; and 2,5-dimethyl-pyrazine was present in the sample containing 15% cricket powder. Further investigation with individual compounds and mixtures is needed to define the chemical basis of the differences in the insect olfactory preference observed in this study. Full article

The production of high-quality aged marc spirits includes a minimum period of six months of ageing in oak barrels. Lastly, producers are interested in alternative botanical origin wood. The present study is aimed at investigating the influence of Greek oak (Quercus trojana) and Greek chestnut (Castanea sativa) compared with French (Quercus petraia) and American oak (Quercus alba) on the chemical composition and sensorial characteristics of aged tsipouro, produced from marc from the Black Muscat variety. Gas chromatography–olfactometry–mass spectrometry (GC–O–MS) was used to identify volatile compounds of the aged tsipouro. Also, colour and polyphenol measurements were made, and an organoleptic evaluation was performed by 16 trained tasters. The findings revealed rather similar results between the tsipouro made from different wood species, especially between Greek and French oaks, and relative differentiation for that of chestnut. All the aged distillates exhibited a pleasant and rich aromatic potential, dominated by floral and fruity terpene varietal aromas as well as wood-related volatiles. Chestnut, with a high phenolic potential, gives pleasant organoleptic effects over time and can be an alternative wood for ageing spirits. This research highlights the importance of wood selection in the tsipouro ageing process and enables the use of Greek wood species in the ageing of spirits. Full article

Third-generation snacks were developed from a triad of flours made up of chestnut, spelt, and chickpea flour. Optimal snack formulations and processing parameters have been established to ensure acceptable workability of the raw dough while protecting the bioactive components of the raw materials. The parameters examined were mixing time, speed, and temperature. The properties of the snack were evaluated by analyzing the expansion ratio, hardness, moisture content, and phenolic and volatile compounds. The optimal mixing conditions that ensure maximum expansion were a temperature of 30 °C, a speed of 30 rpm, and a time of 6 min. The results showed that the proper percentage of water and sodium bicarbonate was 35% and 2%, respectively, and that the developed snacks had an alveolar and homogeneous structure. The proposed approach brings several advantages, including the preservation of bioactive compounds during the production process. Furthermore, the mild operating conditions prevented the development of unwanted or unpleasant compounds, as confirmed by the analysis of volatile compounds. Therefore, this study opens new perspectives in the food industry, satisfying the growing demand for functional products and healthy snacks. Full article

The influence of selected yeast starters (Kluyveromyces lactis L39, Kazachstania humilis AG5, Nakazawaea molendinolei IG9, Candida diddensiae IG12, and Candida adriatica L30) on the fermentation and final characteristics of natural-style Gordal and Manzanilla green table olives was investigated. In both cultivars, the addition of yeast starters had no significant influence on the evolution of physicochemical parameters or the final main metabolites compared to noninoculated olives. In the Gordal cultivar, K. lactis L39 originated the greatest enrichment of volatile compounds, whereas K. lactis L39 and C. adriatica L30 gave the best volatile profiles in the Manzanilla cultivar. In both cultivars, the β-glucosidase-positive strains N. molendinolei IG9, C. diddensiae IG12, and C. adriatica L30 produced no significant decrease in the total phenolic content at the end of fermentation. Although the yeast starters had a significant effect on the volatile contents of the fermented products, they did not have a significant influence on the main sensory characteristics perceived by a sensory panel. A significant linear relationship (R² = 0.815, p < 0.001) was found and validated between the perceived bitterness intensity and the content of total phenols in olive pulp, providing a simple and objective method for the evaluation of bitterness in table olives without the need for sensory analysis. Full article

While a recent characterization of non-Saccharomyces thermally inactivated yeasts (TIYs) in a wine-like solution highlighted the release of oenologically relevant compounds and different oxygen consumption rates and antioxidant activity, here the impact of TIYs derived from Saccharomycodes ludwigii (SL), Metschnikowia pulcherrima (MP), Torulaspora delbrueckii (TD), and Saccharomyces cerevisiae (SC), as the reference strain, was evaluated in white wine. Wine treatment with TIYs resulted in an increase in polysaccharide concentration compared to the untreated wine, with SL-TIY exhibiting the highest release. Additionally, all TIYs, particularly SL-TIY, improved protein stability by reducing heat-induced haze formation. The addition of TIYs also demonstrated an effect on color parameters through phenolic compound adsorption, preventing potential browning phenomena. All TIYs significantly impacted the wine’s volatile profile. Overall, it was shown that an improvement in wine quality and stability may be obtained by using TIYs in the winemaking process. Full article

Aphids pose a significant threat to global agricultural crop production, leading to widespread pesticide use and resistance. This necessitates the use of alternative substances, like plant secondary metabolites (PSMs). Plants have developed protective compounds known as alkaloids, terpenoids, phenolics, sulfur- and nitrogen-containing metabolites. These compounds exhibit promising characteristics against aphids, such as antifeedant, aphicidal, and disrupting survival fitness. This review highlights the importance and application of secondary metabolites in combating aphid populations. Different insect-resistant substances have different mechanisms for managing aphids and other pests, including defensive signaling, inhibiting growth, and attracting natural predators by releasing herbivore-induced volatiles (HIPV). The application of plant secondary metabolites as biopesticides has proven to be an effective, economical, and eco-friendly alternative to synthetic pesticide chemicals. Furthermore, this review comprehensively discusses the principle role of plant secondary metabolites, encouraging sustainable agricultural practices and emphasizing the integrated management of the aphid population. Full article

The aim of this study was to evaluate the quality of cloudy beetroot juice powders with or without a carrier obtained by spray drying using an innovative method of dehumidified air that enabled drying in low temperatures and, consequently, with a reduced carrier content. Phenolic content, betacyanin content, antioxidant activity and the content and types of aromatic compounds of the produced powders were examined. Powders obtained at a lower temperature (90 °C) without carriers were characterized by the highest share of aromatic volatile compounds, the highest content of betalains and polyphenols and the highest antioxidant activity. The addition of carriers (including the variant with added pomace as a natural type of carrier) did not indicate the protection of the active substances present in the juice. The powders obtained with carrier addition compared with those without the carrier addition were characterized by lower antioxidant activity, lower content of betalains and polyphenols and a lower amount of aromatic volatile compounds. No significant differences were found in the content of bioactive and aromatic compounds between powders obtained using different carriers (skim milk powder, Nutriose, maltodextrin and kleptose). Full article

The olive oil from the Royal cultivar has not been studied in depth, especially its relationship between analytical and sensory parameters. Currently, it is a minority cultivar, but due to its excellent organoleptic properties, it is constantly growing. The research objective is to obtain excellent-quality olive oil from the Royal cultivar at an industrial extraction plant and characterize the oil sensory and analytically. For this purpose, three important factors were set: very early olives; very low-time olive paste malaxation; and environmental temperature. The analytical parameters studied were volatile and phenolic compounds, fatty acids, photosynthetic pigments, and other quality parameters. Fourteen phenolic compounds were identified and found in significantly higher concentrations in Royal olive oil, including the oleacein compound. Moreover, volatile compounds from the LOX pathway, such as hexenal, (E)-2-hexenal, and (Z)-3-hexen-1-ol, had significantly higher concentrations, which were related to organoleptic characteristics: very fruity, not very spicy, and very low bitterness. The highest values obtained were 74.98% extraction efficiency at 30 min; 71.31 mg/kg chlorophyll content at 30 min; 156.38 mg/kg phenolic compound at 30 min; 18.98 mg/kg volatile compounds at 15 min; and better organoleptic characteristics at 15 min. The oil extraction efficiency was lower than that of other olive cultivars; nevertheless, the content of volatile compounds is higher. Full article